Citigroup (C) 10-K 23 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	CITIGROUP INC
Entity Central Index Key	831,001
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 123
Entity Common Stock, Shares Outstanding		2,570,065,748
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

CONSOLIDATED STATEMENT OF INCOM

CONSOLIDATED STATEMENT OF INCOME - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Interest revenue	[1]	$ 61,204	$ 57,615	$ 58,551
Interest expense	[1]	16,517	12,511	11,921
Net interest revenue	[1]	44,687	45,104	46,630
Commissions and fees	[1]	12,939	11,938	14,485
Principal transactions	[1]	9,168	7,585	6,008
Administration and other fiduciary fees	[1]	3,079	2,783	2,856
Realized gains on sales of investments, net	[1]	778	948	682
Other-than-temporary impairment losses on investments
Gross impairment losses	[1]	(63)	(620)	(265)
Less: Impairments recognized in AOCI	[1]	0	0	0
Net impairment losses recognized in earnings	[1]	(63)	(620)	(265)
Other revenue	[1]	861	2,137	5,958
Total non-interest revenues	[1]	26,762	24,771	29,724
Total revenues, net of interest expense	[1]	71,449	69,875	76,354
Provisions for credit losses and for benefits and claims
Provision for loan losses		7,503	6,749	7,108
Policyholder benefits and claims		109	204	731
Provision (release) for unfunded lending commitments		(161)	29	74
Total provisions for credit losses and for benefits and claims		7,451	6,982	7,913
Operating expenses
Compensation and benefits	[1]	21,181	20,970	21,769
Premises and equipment	[1]	2,453	2,542	2,878
Technology/communication	[1]	6,891	6,685	6,581
Advertising and marketing	[1]	1,608	1,632	1,547
Other operating	[1]	9,104	9,587	10,840
Total operating expenses	[1]	41,237	41,416	43,615
Income (loss) from continuing operations before income taxes		22,761	21,477	24,826
Provision for income taxes (benefits)		29,388	6,444	7,440
Income (loss) from continuing operations		(6,627)	15,033	17,386
Discontinued operations
Loss from discontinued operations		(104)	(80)	(83)
Provision (benefit) for income taxes		7	(22)	(29)
Loss from discontinued operations, net of taxes		(111)	(58)	(54)
Net income (loss) before attribution of noncontrolling interests		(6,738)	14,975	17,332
Noncontrolling interests		60	63	90
Citigroup’s net income (loss)		$ (6,798)	$ 14,912	$ 17,242
Basic earnings per share
Income (loss) from continuing operations (in dollars per share)	[2]	$ (2.94)	$ 4.74	$ 5.43
Loss from discontinued operations, net of taxes (in dollars per share)	[2]	(0.04)	(0.02)	(0.02)
Net income (loss) (in dollars per share)	[2]	$ (2.98)	$ 4.72	$ 5.41
Weighted average common shares outstanding (in shares)		2,698.5	2,888.1	3,004
Diluted earnings per share
Income (loss) from continuing operations (in dollars per share)	[2]	$ (2.94)	$ 4.74	$ 5.42
Income (loss) from discontinued operations, net of taxes (in dollars per share)	[2]	(0.04)	(0.02)	(0.02)
Net income (loss) (in dollars per share)	[2]	$ (2.98)	$ 4.72	$ 5.40
Adjusted weighted average common shares outstanding (in shares)		2,698.5	2,888.3	3,007.7
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.
[2]	Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Citigroup’s net income (loss)		$ (6,798)	$ 14,912	$ 17,242
Add: Citigroup’s other comprehensive income (loss)
Net change in unrealized gains and losses on investment securities, net of taxes		(863)	108	(964)
Net change in debt valuation adjustment (DVA), net of taxes	[1]	(569)	(337)	0
Net change in cash flow hedges, net of taxes		(138)	57	292
Benefit plans liability adjustment, net of taxes	[2]	(1,019)	(48)	43
Net change in foreign currency translation adjustment, net of taxes and hedges		(202)	(2,802)	(5,499)
Citigroup’s total other comprehensive income (loss)	[3]	(2,791)	(3,022)	(6,128)
Citigroup’s total comprehensive income (loss)		(9,589)	11,890	11,114
Add: Other comprehensive income (loss) attributable to noncontrolling interests		114	(56)	(83)
Add: Net income attributable to noncontrolling interests		60	63	90
Total comprehensive income (loss)		$ (9,415)	$ 11,897	$ 11,121
[1]	See Note 1 to the Consolidated Financial Statements.
[2]	See Note 8 to the Consolidated Financial Statements.
[3]	Includes the impact of ASU 2018-02, adopted in the fourth quarter of 2017. See Note 1 to the Consolidated Financial Statements.

CONSOLIDATED BALANCE SHEET

CONSOLIDATED BALANCE SHEET - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 23,775	$ 23,043
Deposits with banks	156,741	137,451
Federal funds sold and securities borrowed or purchased under agreements to resell (including $132,949 and $133,204 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	232,478	236,813
Brokerage receivables	38,384	28,887
Trading account assets (including $99,460 and $80,986 pledged to creditors at December 31, 2017 and December 31, 2016, respectively)	251,556	243,925
Investments:
Available for sale (including $9,493 and $8,239 pledged to creditors as of December 31, 2017 and December 31, 2016, respectively)	290,914	299,424
Held to maturity (including $435 and $843 pledged to creditors as of December 31, 2017 and December 31, 2016, respectively)	53,320	45,667
Non-marketable equity securities (including $1,206 and $1,774 at fair value as of December 31, 2017 and December 31, 2016, respectively)	8,056	8,213
Total investments	352,290	353,304
Loans:
Loans, net of unearned income	667,034	624,369
Allowance for loan losses	(12,355)	(12,060)
Total loans, net	654,679	612,309
Goodwill	22,256	21,659
Intangible assets (other than MSRs)	4,588	5,114
Mortgage servicing rights (MSRs)	558	1,564
Other assets	105,160	128,008
Total assets	1,842,465	1,792,077
Liabilities
Non-interest-bearing deposits in U.S. offices	126,880	136,698
Interest-bearing deposits in U.S. offices (including $303 and $434 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	318,613	300,972
Non-interest-bearing deposits in offices outside the U.S.	87,440	77,616
Interest-bearing deposits in offices outside the U.S. (including $1,162 and $778 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	426,889	414,120
Total deposits	959,822	929,406
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $40,638 and $33,663 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	156,277	141,821
Brokerage payables	61,342	57,152
Trading account liabilities	124,047	139,045
Short-term borrowings (including $4,627 and $2,700 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	44,452	30,701
Long-term debt (including $31,392 and $26,254 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	236,709	206,178
Other liabilities (including $15,084 and $10,796 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	58,144	61,631
Total liabilities	1,640,793	1,565,934
Stockholders’ equity
Preferred stock ($1.00 par value; authorized shares: 30 million), issued shares: 770,120 as of December 31, 2017 and December 31, 2016, at aggregate liquidation value	19,253	19,253
Common stock ($0.01 par value; authorized shares: 6 billion), issued shares: 3,099,523,273 and 3,099,482,042 as of December 31, 2017 and December 31, 2016, respectively	31	31
Additional paid-in capital	108,008	108,042
Retained earnings	138,425	146,477
Treasury stock, at cost: December 31, 2017—529,614,728 shares and December 31, 2016—327,090,192 shares	(30,309)	(16,302)
Accumulated other comprehensive income (loss)	(34,668)	(32,381)
Total Citigroup stockholders’ equity	200,740	225,120
Noncontrolling interest	932	1,023
Total equity	201,672	226,143
Total liabilities and equity	1,842,465	1,792,077
Consumer
Loans:
Loans, net of unearned income	333,656	325,063
Corporate
Loans:
Loans, net of unearned income	333,378	299,306
Consolidated VIEs
Assets
Cash and due from banks	52	142
Trading account assets (including $99,460 and $80,986 pledged to creditors at December 31, 2017 and December 31, 2016, respectively)	1,129	602
Investments:
Total investments	2,498	3,636
Loans:
Loans, net of unearned income	74,491	73,522
Allowance for loan losses	(1,930)	(1,769)
Total loans, net	72,561	71,753
Other assets	154	158
Total assets	76,394	76,291
Liabilities
Short-term borrowings (including $4,627 and $2,700 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	10,079	10,697
Long-term debt (including $31,392 and $26,254 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	30,492	23,919
Other liabilities (including $15,084 and $10,796 as of December 31, 2017 and December 31, 2016, respectively, at fair value)	611	1,275
Total liabilities	41,182	35,891
Consolidated VIEs | Consumer
Loans:
Loans, net of unearned income	54,656	53,401
Consolidated VIEs | Corporate
Loans:
Loans, net of unearned income	$ 19,835	$ 20,121

CONSOLIDATED BALANCE SHEET (Par

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal funds sold and resale agreements	$ 232,478	$ 236,813
Trading account assets, pledged to creditors	99,460	80,986
Available-for-sale securities, pledged to creditors	9,493	8,239
Held-to-maturity securities, pledged to creditors	435	843
Loans, net of unearned income	667,034	624,369
Other assets	105,160	128,008
U.S. Interest-bearing deposits, at fair value	318,613	300,972
Non U.S. Interest-bearing deposits, at fair value	426,889	414,120
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	156,277	141,821
Short-term borrowings, at fair value	44,452	30,701
Long-term debt, at fair value	236,709	206,178
Other liabilities, at fair value	$ 58,144	$ 61,631
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, authorized shares (in shares)	30,000,000	30,000,000
Preferred stock, issued shares, at aggregate liquidation value (in shares)	770,120	770,120
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	6,000,000,000	6,000,000,000
Common stock, issued shares (in shares)	3,099,523,273	3,099,482,042
Treasury stock (in shares)	529,614,728	327,090,192
Consumer
Loans, net of unearned income	$ 333,656	$ 325,063
Corporate
Loans, net of unearned income	333,378	299,306
Fair value
Federal funds sold and resale agreements	132,949	133,204
Non-marketable equity securities, pledged to creditors	1,206	1,774
Other assets	19,793	15,729
U.S. Interest-bearing deposits, at fair value	303	434
Non U.S. Interest-bearing deposits, at fair value	1,162	778
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	40,638	33,663
Short-term borrowings, at fair value	4,627	2,700
Long-term debt, at fair value	31,392	26,254
Other liabilities, at fair value	15,084	10,796
Fair value | Consumer
Loans, net of unearned income	25	29
Fair value | Corporate
Loans, net of unearned income	$ 4,349	$ 3,457

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Millions		Total	Citigroup stockholders' equity	Preferred stock at aggregate liquidation value	Citigroup common stockholders' equity	Common stock and additional paid-in capital	Retained earnings		Treasury stock, at cost		Citigroup's accumulated other comprehensive income (loss)		Noncontrolling interests
Increase (Decrease) in Stockholders' Equity
Adjusted balance, beginning of year							$ 117,852				$ (23,216)
Balance, beginning of year at Dec. 31, 2014				$ 10,468		$ 108,010	117,852		$ (2,929)		(23,216)		$ 1,511
Balance, beginning of year (in shares) at Dec. 31, 2014				419		3,082,038			58,119
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				$ 6,250
Issuance of new preferred stock (in shares)				250
Employee benefit plans						$ 357			$ 704	[1]
Employee benefit plans (in shares)						17,438			13,318	[1]
Preferred stock issuance expense						$ (23)
Other						$ (25)							(41)
Other (in shares)						6
Net income attributable to noncontrolling-interest shareholders		$ 17,332					17,242						90
Common dividends	[2]						(484)
Preferred dividends		(769)					(769)
Transactions between Citigroup and the noncontrolling-interest shareholders													(164)
Treasury stock acquired	[3]								$ (5,452)
Treasure stock acquired (in shares)	[3]								(101,402)
Dividends paid to noncontrolling-interest shareholders													(78)
Other comprehensive income (loss)		(6,128)									(6,128)	[4]	(83)
Net change in noncontrolling interests													(276)
Balance, end of year at Dec. 31, 2015		223,092	$ 221,857	$ 16,718	$ 205,139	$ 108,319	133,841		$ (7,677)		(29,344)		1,235
Balance, end of year (in shares) at Dec. 31, 2015				669	2,953,279	3,099,482			146,203
Increase (Decrease) in Stockholders' Equity
Adjusted balance, beginning of year							133,856				(29,359)
Adjustment to opening balance, net of taxes at Dec. 31, 2015	[5]						15				(15)
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				$ 2,535
Issuance of new preferred stock (in shares)				101
Employee benefit plans						$ (251)			$ 826	[1]
Employee benefit plans (in shares)	[1]								14,256
Preferred stock issuance expense						(37)
Other						42							(36)
Net income attributable to noncontrolling-interest shareholders		14,975					14,912						63
Common dividends	[2]						(1,214)
Preferred dividends		(1,077)					(1,077)
Transactions between noncontrolling-interest shareholders and the related consolidated subsidiary													(11)
Transactions between Citigroup and the noncontrolling-interest shareholders													(130)
Treasury stock acquired	[3]								$ (9,451)
Treasure stock acquired (in shares)	[3]								(195,143)
Dividends paid to noncontrolling-interest shareholders													(42)
Other comprehensive income (loss)		(3,022)									(3,022)	[4]	(56)
Net change in noncontrolling interests													(212)
Balance, end of year at Dec. 31, 2016		226,143	225,120	$ 19,253	$ 205,867	$ 108,073	146,477		$ (16,302)		(32,381)		1,023
Balance, end of year (in shares) at Dec. 31, 2016				770	2,772,392	3,099,482			327,090
Increase (Decrease) in Stockholders' Equity
Adjusted balance, beginning of year							145,817				(31,877)
Adjustment to opening balance, net of taxes at Dec. 31, 2016	[5]						(660)				504
Increase (Decrease) in Stockholders' Equity
Employee benefit plans						$ (27)			$ 531	[1]
Employee benefit plans (in shares)						41			11,651	[1]
Other						$ (7)	(90)	[6]					(72)
Net income attributable to noncontrolling-interest shareholders		(6,738)					(6,798)						60
Common dividends	[2]						(2,595)
Preferred dividends		(1,213)					(1,213)
Impact of Tax Reform related to AOCI reclassification		(3,304)					3,304	[4]
Transactions between noncontrolling-interest shareholders and the related consolidated subsidiary													(28)
Transactions between Citigroup and the noncontrolling-interest shareholders													(121)
Treasury stock acquired	[3]								$ (14,538)
Treasure stock acquired (in shares)	[3]								(214,176)
Dividends paid to noncontrolling-interest shareholders													(44)
Other comprehensive income (loss)		(2,791)									(2,791)	[4]	114
Net change in noncontrolling interests													(91)
Balance, end of year at Dec. 31, 2017		$ 201,672	$ 200,740	$ 19,253	$ 181,487	$ 108,039	$ 138,425		$ (30,309)		$ (34,668)		$ 932
Balance, end of year (in shares) at Dec. 31, 2017				770	2,569,908	3,099,523			529,615
[1]	Includes treasury stock related to (i) certain activity on employee stock option program exercises, where the employee delivers existing shares to cover the option exercise, or (ii) under Citi’s employee-restricted or deferred-stock programs, where shares are withheld to satisfy tax requirements.
[2]	Common dividends declared were $0.16 per share in the first and second quarters and $0.32 per share in the third and fourth quarters of 2017; $0.05 per share in the first and second quarters and $0.16 per share in the third and fourth quarters of 2016; and $0.01 in the first quarter and $0.05 per share in the second, third and fourth quarters of 2015.
[3]	For 2017, 2016 and 2015, primarily consists of open market purchases under Citi’s Board of Directors-approved common stock repurchase program.
[4]	Includes the impact of ASU 2018-02, which transferred those amounts from AOCI to Retained earnings. See Notes 1 and 19 to the Consolidated Financial Statements.
[5]	See Note 1 to the Consolidated Financial Statements.
[6]	Includes the impact of ASU No. 2016-09. See Note 1 to the Consolidated Financial Statements.

CONSOLIDATED STATEMENT OF CHAN7

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Statement of Stockholders' Equity [Abstract]
Common dividends declared (in dollars per share)	$ 0.32	$ 0.32	$ 0.16	$ 0.16	$ 0.16	$ 0.16	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.01

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities of continuing operations
Citigroup’s net income		$ (6,738)	$ 14,975	$ 17,332
Net income attributable to noncontrolling interests		60	63	90
Citigroup’s net income (loss)		(6,798)	14,912	17,242
Loss from discontinued operations, net of taxes		(111)	(58)	(54)
Income (loss) from continuing operations—excluding noncontrolling interests		(6,687)	14,970	17,296
Adjustments to reconcile net income to net cash provided by operating activities of continuing operations
Net gains on significant disposals	[1]	(602)	(404)	(3,210)
Depreciation and amortization		3,659	3,720	3,506
Deferred tax provision	[2]	24,877	1,459	2,794
Provision for loan losses		7,503	6,749	7,108
Realized gains from sales of investments		(778)	(948)	(682)
Net impairment losses on investments, goodwill and intangible assets		91	621	318
Change in trading account assets		(7,726)	(2,710)	46,830
Change in trading account liabilities		(14,998)	21,533	(21,524)
Change in brokerage receivables, net of brokerage payables		(5,307)	2,226	2,278
Change in loans held-for-sale (HFS)		247	6,603	(7,207)
Change in other assets		(2,489)	(6,859)	(32)
Change in other liabilities		(3,421)	(28)	(1,135)
Other, net		(2,956)	7,000	(6,603)
Total adjustments		(1,900)	38,962	22,441
Net cash provided by (used in) operating activities of continuing operations		(8,587)	53,932	39,737
Cash flows from investing activities of continuing operations
Change in deposits with banks		(19,290)	(25,311)	15,488
Change in federal funds sold and securities borrowed or purchased under agreements to resell		4,335	(17,138)	22,895
Change in loans		(58,062)	(39,761)	1,353
Proceeds from sales and securitizations of loans		8,365	18,140	9,610
Purchases of investments		(185,740)	(211,402)	(242,362)
Proceeds from sales of investments	[3]	107,368	132,183	141,470
Proceeds from maturities of investments		84,369	65,525	82,047
Proceeds from significant disposals	[1]	3,411	265	5,932
Payments due to transfers of net liabilities associated with significant disposals	[1],[4]	0	0	(18,929)
Capital expenditures on premises and equipment and capitalized software		(3,361)	(2,756)	(3,198)
Proceeds from sales of premises and equipment, subsidiaries and affiliates and repossessed assets		377	667	577
Net cash provided by (used in) investing activities of continuing operations		(58,228)	(79,588)	14,883
Cash flows from financing activities of continuing operations
Dividends paid		(3,797)	(2,287)	(1,253)
Issuance of preferred stock		0	2,498	6,227
Treasury stock acquired		(14,541)	(9,290)	(5,452)
Stock tendered for payment of withholding taxes		(405)	(316)	(428)
Change in federal funds purchased and securities loaned or sold under agreements to repurchase		14,456	(4,675)	(26,942)
Issuance of long-term debt		67,960	63,806	44,619
Payments and redemptions of long-term debt		(40,986)	(55,460)	(52,843)
Change in deposits		30,416	24,394	8,555
Change in short-term borrowings		13,751	9,622	(37,256)
Net cash provided by (used in) financing activities of continuing operations		66,854	28,292	(64,773)
Effect of exchange rate changes on cash and cash equivalents		693	(493)	(1,055)
Change in cash and due from banks		732	2,143	(11,208)
Cash and due from banks at beginning of period		23,043	20,900	32,108
Cash and due from banks at end of period		23,775	23,043	20,900
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		2,083	4,359	4,978
Cash paid during the year for interest		15,675	12,067	12,031
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS		0	0	(9,063)
Decrease in investments associated with significant disposals reclassified to HFS		0	0	(1,402)
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS		0	0	(223)
Decrease in deposits associated with banks with significant disposals reclassified to HFS		0	0	(404)
Transfers to loans HFS from loans		5,900	13,900	28,600
Transfers to OREO and other repossessed assets		113	165	276
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS		$ 0	$ 0	$ (4,673)
[1]	See Note 2 to the Consolidated Financial Statements for further information on significant disposals.
[2]	Includes the full impact of the $22.6 billion non-cash charge related to the Tax Cuts and Jobs Act (Tax Reform). See Notes 1 and 9 to the Consolidated Financial Statements for further information.
[3]	Proceeds for 2016 include approximately $3.3 billion from the sale of Citi’s investment in China Guangfa Bank.
[4]	The payments associated with significant disposals result primarily from the sale of deposit liabilities.

CONSOLIDATED STATEMENT OF CASH9

CONSOLIDATED STATEMENT OF CASH FLOWS (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Proceeds from sales of investments	$ 132,183	[1]
China Guangfa Bank
Proceeds from sales of investments	$ 3,300
[1]	Proceeds for 2016 include approximately $3.3 billion from the sale of Citi’s investment in China Guangfa Bank.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Throughout these Notes, “Citigroup,” “Citi” and the “Company” refer to Citigroup Inc. and its consolidated subsidiaries. Certain reclassifications have been made to the prior periods’ financial statements and Notes to conform to the current period’s presentation. Principles of Consolidation The Consolidated Financial Statements include the accounts of Citigroup and its subsidiaries prepared in accordance with U.S. generally accepted accounting principles (GAAP). The Company consolidates subsidiaries in which it holds, directly or indirectly, more than 50% of the voting rights or where it exercises control. Entities where the Company holds 20% to 50% of the voting rights and/or has the ability to exercise significant influence, other than investments of designated venture capital subsidiaries or investments accounted for at fair value under the fair value option, are accounted for under the equity method, and the pro rata share of their income (loss) is included in Other revenue . Income from investments in less-than- 20% -owned companies is recognized when dividends are received. As discussed in more detail in Note 21 to the Consolidated Financial Statements, Citigroup also consolidates entities deemed to be variable interest entities when Citigroup is determined to be the primary beneficiary. Gains and losses on the disposition of branches, subsidiaries, affiliates, buildings and other investments are included in Other revenue . Citibank Citibank, N.A. (Citibank) is a commercial bank and wholly owned subsidiary of Citigroup. Citibank’s principal offerings include consumer finance, mortgage lending and retail banking (including commercial banking) products and services; investment banking, cash management and trade finance; and private banking products and services. Variable Interest Entities An entity is a variable interest entity (VIE) if it meets either of the criteria outlined in Accounting Standards Codification (ASC) Topic 810, Consolidation , which are (i) the entity has equity that is insufficient to permit the entity to finance its activities without additional subordinated financial support from other parties, or (ii) the entity has equity investors that cannot make significant decisions about the entity’s operations or that do not absorb their proportionate share of the entity’s expected losses or expected returns. The Company consolidates a VIE when it has both the power to direct the activities that most significantly impact the VIE’s economic performance and a right to receive benefits or the obligation to absorb losses of the entity that could be potentially significant to the VIE (that is, Citi is the primary beneficiary). In addition to variable interests held in consolidated VIEs, the Company has variable interests in other VIEs that are not consolidated because the Company is not the primary beneficiary. All unconsolidated VIEs are monitored by the Company to assess whether any events have occurred to cause its primary beneficiary status to change. All entities not deemed to be VIEs with which the Company has involvement are evaluated for consolidation under other subtopics of ASC 810. See Note 21 to the Consolidated Financial Statements for more detailed information. Foreign Currency Translation Assets and liabilities of Citi’s foreign operations are translated from their respective functional currencies into U.S. dollars using period-end spot foreign exchange rates. The effects of those translation adjustments are reported in Accumulated other comprehensive income (loss) , a component of stockholders’ equity, net of any related hedge and tax effects, until realized upon sale or substantial liquidation of the foreign operation. Revenues and expenses of Citi’s foreign operations are translated monthly from their respective functional currencies into U.S. dollars at amounts that approximate weighted average exchange rates. For transactions that are denominated in a currency other than the functional currency, including transactions denominated in the local currencies of foreign operations that use the U.S. dollar as their functional currency, the effects of changes in exchange rates are primarily included in Principal transactions , along with the related effects of any economic hedges. Instruments used to hedge foreign currency exposures include foreign currency forward, option and swap contracts and, in certain instances, designated issues of non-U.S. dollar debt. Foreign operations in countries with highly inflationary economies designate the U.S. dollar as their functional currency, with the effects of changes in exchange rates primarily included in Other revenue . Investment Securities Investments include fixed income and equity securities. Fixed income instruments include bonds, notes and redeemable preferred stocks, as well as certain loan-backed and structured securities that are subject to prepayment risk. Equity securities include common and nonredeemable preferred stock. Investment securities are classified and accounted for as follows: • Fixed income securities classified as “held-to-maturity” are securities that the Company has both the ability and the intent to hold until maturity and are carried at amortized cost. Interest income on such securities is included in Interest revenue . • Fixed income securities and marketable equity securities classified as “available-for-sale” are carried at fair value with changes in fair value reported in Accumulated other comprehensive income (loss) , a component of stockholders’ equity, net of applicable income taxes and hedges. Realized gains and losses on sales are included in income primarily on a specific identification cost basis. Interest and dividend income on such securities is included in Interest revenue . • Certain investments in non-marketable equity securities and certain investments that would otherwise have been accounted for using the equity method are carried at fair value, since the Company has elected to apply fair value accounting. Changes in fair value of such investments are recorded in earnings. • Certain non-marketable equity securities are carried at cost. For investments in fixed income securities classified as held-to-maturity or available-for-sale, the accrual of interest income is suspended for investments that are in default or for which it is likely that future interest payments will not be made as scheduled. Investment securities are subject to evaluation for other-than-temporary impairment as described in Note 13 to the Consolidated Financial Statements. The Company uses a number of valuation techniques for investments carried at fair value, which are described in Note 24 to the Consolidated Financial Statements. Realized gains and losses on sales of investments are included in earnings. Trading Account Assets and Liabilities Trading account assets include debt and marketable equity securities, derivatives in a receivable position, residual interests in securitizations and physical commodities inventory. In addition, as described in Note 25 to the Consolidated Financial Statements, certain assets that Citigroup has elected to carry at fair value under the fair value option, such as loans and purchased guarantees, are also included in Trading account assets . Trading account liabilities include securities sold, not yet purchased (short positions) and derivatives in a net payable position, as well as certain liabilities that Citigroup has elected to carry at fair value (as described in Note 25 to the Consolidated Financial Statements). Other than physical commodities inventory, all trading account assets and liabilities are carried at fair value. Revenues generated from trading assets and trading liabilities are generally reported in Principal transactions and include realized gains and losses as well as unrealized gains and losses resulting from changes in the fair value of such instruments. Interest income on trading assets is recorded in Interest revenue reduced by interest expense on trading liabilities. Physical commodities inventory is carried at the lower of cost or market with related losses reported in Principal transactions . Realized gains and losses on sales of commodities inventory are included in Principal transactions . Investments in unallocated precious metals accounts (gold, silver, platinum and palladium) are accounted for as hybrid instruments containing a debt host contract and an embedded non-financial derivative instrument indexed to the price of the relevant precious metal. The embedded derivative instrument is separated from the debt host contract and accounted for at fair value. The debt host contract is carried at fair value under the fair value option, as described in Note 25 to the Consolidated Financial Statements. Derivatives used for trading purposes include interest rate, currency, equity, credit and commodity swap agreements, options, caps and floors, warrants, and financial and commodity futures and forward contracts. Derivative asset and liability positions are presented net by counterparty on the Consolidated Balance Sheet when a valid master netting agreement exists and the other conditions set out in ASC Topic 210-20, Balance Sheet—Offsetting , are met. See Note 22 to the Consolidated Financial Statements. The Company uses a number of techniques to determine the fair value of trading assets and liabilities, which are described in Note 24 to the Consolidated Financial Statements. Securities Borrowed and Securities Loaned Securities borrowing and lending transactions do not constitute a sale of the underlying securities for accounting purposes and are treated as collateralized financing transactions. Such transactions are recorded at the amount of proceeds advanced or received plus accrued interest. As described in Note 25 to the Consolidated Financial Statements, the Company has elected to apply fair value accounting to a number of securities borrowing and lending transactions. Fees paid or received for all securities lending and borrowing transactions are recorded in Interest expense or Interest revenue at the contractually specified rate. The Company monitors the fair value of securities borrowed or loaned on a daily basis and obtains or posts additional collateral in order to maintain contractual margin protection. As described in Note 24 to the Consolidated Financial Statements, the Company uses a discounted cash flow technique to determine the fair value of securities lending and borrowing transactions. Repurchase and Resale Agreements Securities sold under agreements to repurchase (repos) and securities purchased under agreements to resell (reverse repos) do not constitute a sale (or purchase) of the underlying securities for accounting purposes and are treated as collateralized financing transactions. As described in Note 25 to the Consolidated Financial Statements, the Company has elected to apply fair value accounting to the majority of such transactions, with changes in fair value reported in earnings. Any transactions for which fair value accounting has not been elected are recorded at the amount of cash advanced or received plus accrued interest. Irrespective of whether the Company has elected fair value accounting, interest paid or received on all repo and reverse repo transactions is recorded in Interest expense or Interest revenue at the contractually specified rate. Where the conditions of ASC 210-20-45-11, Balance Sheet—Offsetting: Repurchase and Reverse Repurchase Agreements , are met, repos and reverse repos are presented net on the Consolidated Balance Sheet. The Company’s policy is to take possession of securities purchased under reverse repurchase agreements. The Company monitors the fair value of securities subject to repurchase or resale on a daily basis and obtains or posts additional collateral in order to maintain contractual margin protection. As described in Note 24 to the Consolidated Financial Statements, the Company uses a discounted cash flow technique to determine the fair value of repo and reverse repo transactions. Loans Loans are reported at their outstanding principal balances net of any unearned income and unamortized deferred fees and costs except that credit card receivable balances also include accrued interest and fees. Loan origination fees and certain direct origination costs are generally deferred and recognized as adjustments to income over the lives of the related loans. As described in Note 25 to the Consolidated Financial Statements, Citi has elected fair value accounting for certain loans. Such loans are carried at fair value with changes in fair value reported in earnings. Interest income on such loans is recorded in Interest revenue at the contractually specified rate. Loans that are held-for-investment are classified as Loans, net of unearned income on the Consolidated Balance Sheet, and the related cash flows are included within the cash flows from investing activities category in the Consolidated Statement of Cash Flows on the line Change in loans . However, when the initial intent for holding a loan has changed from held-for-investment to HFS, the loan is reclassified to held-for-sale, but the related cash flows continue to be reported in cash flows from investing activities in the Consolidated Statement of Cash Flows on the line Proceeds from sales and securitizations of loans . Consumer Loans Consumer loans represent loans and leases managed primarily by the Global Consumer Banking (GCB) businesses and Corporate/Other . Consumer Non-accrual and Re-aging Policies As a general rule, interest accrual ceases for installment and real estate (both open- and closed-end) loans when payments are 90 days contractually past due. For credit cards and other unsecured revolving loans, however, Citi generally accrues interest until payments are 180 days past due. As a result of OCC guidance, home equity loans in regulated bank entities are classified as non-accrual if the related residential first mortgage is 90 days or more past due. Also as a result of OCC guidance, mortgage loans in regulated bank entities within 60 days of notification that the borrower has filed for bankruptcy, other than FHA-insured loans, are classified as non-accrual. Commercial market loans are placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due. Loans that have been modified to grant a concession to a borrower in financial difficulty may not be accruing interest at the time of the modification. The policy for returning such modified loans to accrual status varies by product and/or region. In most cases, a minimum number of payments (ranging from one to six ) is required, while in other cases the loan is never returned to accrual status. For regulated bank entities, such modified loans are returned to accrual status if a credit evaluation at the time of, or subsequent to, the modification indicates the borrower is able to meet the restructured terms, and the borrower is current and has demonstrated a reasonable period of sustained payment performance (minimum six months of consecutive payments). For U.S. consumer loans, generally one of the conditions to qualify for modification is that a minimum number of payments (typically ranging from one to three ) must be made. Upon modification, the loan is re-aged to current status. However, re-aging practices for certain open-ended consumer loans, such as credit cards, are governed by Federal Financial Institutions Examination Council (FFIEC) guidelines. For open-ended consumer loans subject to FFIEC guidelines, one of the conditions for the loan to be re-aged to current status is that at least three consecutive minimum monthly payments, or the equivalent amount, must be received. In addition, under FFIEC guidelines, the number of times that such a loan can be re-aged is subject to limitations (generally once in 12 months and twice in five years). Furthermore, Federal Housing Administration (FHA) and Department of Veterans Affairs (VA) loans may only be modified under those respective agencies’ guidelines, and payments are not always required in order to re-age a modified loan to current. Consumer Charge-Off Policies Citi’s charge-off policies follow the general guidelines below: • Unsecured installment loans are charged off at 120 days contractually past due. • Unsecured revolving loans and credit card loans are charged off at 180 days contractually past due. • Loans secured with non-real estate collateral are written down to the estimated value of the collateral, less costs to sell, at 120 days contractually past due. • Real estate-secured loans are written down to the estimated value of the property, less costs to sell, at 180 days contractually past due. • Real estate-secured loans are charged off no later than 180 days contractually past due if a decision has been made not to foreclose on the loans. • Unsecured loans in bankruptcy are charged off within 60 days of notification of filing by the bankruptcy court or in accordance with Citi’s charge-off policy, whichever occurs earlier. • Real estate-secured loans in bankruptcy, other than FHA-insured loans, are written down to the estimated value of the property, less costs to sell, within 60 days of notification that the borrower has filed for bankruptcy or in accordance with Citi’s charge-off policy, whichever is earlier. • Commercial market loans are written down to the extent that principal is judged to be uncollectable. Corporate Loans Corporate loans represent loans and leases managed by Institutional Clients Group (ICG) . Corporate loans are identified as impaired and placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due, except when the loan is well collateralized and in the process of collection. Any interest accrued on impaired corporate loans and leases is reversed at 90 days past due and charged against current earnings, and interest is thereafter included in earnings only to the extent actually received in cash. When there is doubt regarding the ultimate collectability of principal, all cash receipts are thereafter applied to reduce the recorded investment in the loan. Impaired corporate loans and leases are written down to the extent that principal is deemed to be uncollectable. Impaired collateral-dependent loans and leases, where repayment is expected to be provided solely by the sale of the underlying collateral and there are no other available and reliable sources of repayment, are written down to the lower of cost or collateral value. Cash-basis loans are returned to accrual status when all contractual principal and interest amounts are reasonably assured of repayment and there is a sustained period of repayment performance in accordance with the contractual terms. Loans Held-for-Sale Corporate and consumer loans that have been identified for sale are classified as loans held-for-sale and included in Other assets . The practice of Citi’s U.S. prime mortgage business has been to sell substantially all of its conforming loans. As such, U.S. prime mortgage conforming loans are classified as held-for-sale and the fair value option is elected at origination, with changes in fair value recorded in Other revenue . With the exception of those loans for which the fair value option has been elected, held-for-sale loans are accounted for at the lower of cost or market value, with any write-downs or subsequent recoveries charged to Other revenue . The related cash flows are classified in the Consolidated Statement of Cash Flows in the cash flows from operating activities category on the line Change in loans held-for-sale . Allowance for Loan Losses Allowance for loan losses represents management’s best estimate of probable losses inherent in the portfolio, including probable losses related to large individually evaluated impaired loans and troubled debt restructurings. Attribution of the allowance is made for analytical purposes only, and the entire allowance is available to absorb probable loan losses inherent in the overall portfolio. Additions to the allowance are made through the Provision for loan losses . Loan losses are deducted from the allowance and subsequent recoveries are added. Assets received in exchange for loan claims in a restructuring are initially recorded at fair value, with any gain or loss reflected as a recovery or charge-off to the provision. Consumer Loans For consumer loans, each portfolio of non-modified smaller-balance homogeneous loans is independently evaluated for impairment by product type (e.g., residential mortgage, credit card, etc.) in accordance with ASC 450, Contingencies . The allowance for loan losses attributed to these loans is established via a process that estimates the probable losses inherent in the specific portfolio. This process includes migration analysis, in which historical delinquency and credit loss experience is applied to the current aging of the portfolio, together with analyses that reflect current and anticipated economic conditions, including changes in housing prices and unemployment trends. Citi’s allowance for loan losses under ASC 450 only considers contractual principal amounts due, except for credit card loans, where estimated loss amounts related to accrued interest receivable are also included. Management also considers overall portfolio indicators, including historical credit losses, delinquent, non-performing and classified loans, trends in volumes and terms of loans, an evaluation of overall credit quality, the credit process, including lending policies and procedures, and economic, geographical, product and other environmental factors. Separate valuation allowances are determined for impaired smaller-balance homogeneous loans whose terms have been modified in a troubled debt restructuring (TDR). Long-term modification programs, and short-term (less than 12 months) modifications that provide concessions (such as interest rate reductions) to borrowers in financial difficulty, are reported as TDRs. In addition, loan modifications that involve a trial period are reported as TDRs at the start of the trial period. The allowance for loan losses for TDRs is determined in accordance with ASC 310-10-35, Receivables—Subsequent Measurement , considering all available evidence, including, as appropriate, the present value of the expected future cash flows discounted at the loan’s original contractual effective rate, the secondary market value of the loan and the fair value of collateral less disposal costs. These expected cash flows incorporate modification program default rate assumptions. The original contractual effective rate for credit card loans is the pre-modification rate, which may include interest rate increases under the original contractual agreement with the borrower. Valuation allowances for commercial market loans, which are classifiably managed consumer loans, are determined in the same manner as for corporate loans and are described in more detail in the following section. Generally, an asset-specific component is calculated under ASC 310-10-35 on an individual basis for larger-balance, non-homogeneous loans that are considered impaired, and the allowance for the remainder of the classifiably managed consumer loan portfolio is calculated under ASC 450 using a statistical methodology that may be supplemented by management adjustment. Corporate Loans In the corporate portfolios, the Allowance for loan losses includes an asset-specific component and a statistically based component. The asset-specific component is calculated under ASC 310-10-35 for larger-balance, non-homogeneous loans that are considered impaired. An asset-specific allowance is established when the discounted cash flows, collateral value (less disposal costs) or observable market price of the impaired loan are lower than its carrying value. This allowance considers the borrower’s overall financial condition, resources and payment record, the prospects for support from any financially responsible guarantors (discussed further below) and, if appropriate, the realizable value of any collateral. The asset-specific component of the allowance for smaller-balance impaired loans is calculated on a pool basis considering historical loss experience. The allowance for the remainder of the loan portfolio is determined under ASC 450 using a statistical methodology, supplemented by management judgment. The statistical analysis considers the portfolio’s size, remaining tenor and credit quality as measured by internal risk ratings assigned to individual credit facilities, which reflect probability of default and loss given default. The statistical analysis considers historical default rates and historical loss severity in the event of default, including historical average levels and historical variability. The result is an estimated range for inherent losses. The best estimate within the range is then determined by management’s quantitative and qualitative assessment of current conditions, including general economic conditions, specific industry and geographic trends and internal factors including portfolio concentrations, trends in internal credit quality indicators and current and past underwriting standards. For both the asset-specific and the statistically based components of the Allowance for loan losses , management may incorporate guarantor support. The financial wherewithal of the guarantor is evaluated, as applicable, based on net worth, cash flow statements and personal or company financial statements, which are updated and reviewed at least annually. Citi seeks performance on guarantee arrangements in the normal course of business. Seeking performance entails obtaining satisfactory cooperation from the guarantor or borrower in the specific situation. This regular cooperation is indicative of pursuit and successful enforcement of the guarantee; the exposure is reduced without the expense and burden of pursuing a legal remedy. A guarantor’s reputation and willingness to work with Citigroup is evaluated based on the historical experience with the guarantor and the knowledge of the marketplace. In the rare event that the guarantor is unwilling or unable to perform or facilitate borrower cooperation, Citi pursues a legal remedy; however, enforcing a guarantee via legal action against the guarantor is not the primary means of resolving a troubled loan situation and rarely occurs. If Citi does not pursue a legal remedy, it is because Citi does not believe that the guarantor has the financial wherewithal to perform regardless of legal action or because there are legal limitations on simultaneously pursuing guarantors and foreclosure. A guarantor’s reputation does not impact Citi’s decision or ability to seek performance under the guarantee. In cases where a guarantee is a factor in the assessment of loan losses, it is included via adjustment to the loan’s internal risk rating, which in turn is the basis for the adjustment to the statistically based component of the Allowance for loan losses . To date, it is only in rare circumstances that an impaired commercial loan or commercial real estate loan is carried at a value in excess of the appraised value due to a guarantee. When Citi’s monitoring of the loan indicates that the guarantor’s wherewithal to pay is uncertain or has deteriorated, there is either no change in the risk rating, because the guarantor’s credit support was never initially factored in, or the risk rating is adjusted to reflect that uncertainty or deterioration. Accordingly, a guarantor’s ultimate failure to perform or a lack of legal enforcement of the guarantee does not materially impact the allowance for loan losses, as there is typically no further significant adjustment of the loan’s risk rating at that time. Where Citi is not seeking performance under the guarantee contract, it provides for loan losses as if the loans were non-performing and not guaranteed. Reserve Estimates and Policies Management provides reserves for an estimate of probable losses inherent in the funded loan portfolio on the Consolidated Balance Sheet in the form of an allowance for loan losses. These reserves are established in accordance with Citigroup’s credit reserve policies, as approved by the Audit Committee of the Citigroup Board of Directors. Citi’s Chief Risk Officer and Chief Financial Officer review the adequacy of the credit loss reserves each quarter with representatives from the risk management and finance staffs for each applicable business area. Applicable business areas include those having classifiably managed portfolios, where internal credit-risk ratings are assigned (primarily ICG and GCB ) or modified consumer loans, where concessions were granted due to the borrowers’ financial difficulties. The above-mentioned representatives for these business areas present recommended reserve balances for their funded and unfunded lending portfolios along with supporting quantitative and qualitative data discussed below: Estimated probable losses for non-performing, non-homogeneous exposures within a business line’s classifiably managed portfolio and impaired smaller-balance homogeneous loans whose terms have been modified due to the borrowers’ financial difficulties, where it was determined that a concession was granted to the borrower. Consideration may be given to the following, as appropriate, when determining this estimate: (i) the present value of expected future cash flows discounted at the loan’s original effective rate, (ii) the borrower’s overall financial condition, resources and payment record and (iii) the prospects for support from financially responsible guarantors or the realizable value of any collateral. In the determination of the allowance for loan losses for TDRs, management considers a combination of historical re-default rates, the current economic environment and the nature of the modification program when forecasting expected cash flows. When impairment is measured based on the present value of expected future cash flows, the entire change in present value is recorded in Provision for loan losses . Statistically calculated losses inherent in the classifiably managed portfolio for performing and de minimis non-performing exposures. The calculation is based on (i) Citi’s internal system of credit-risk ratings, which are analogous to the risk ratings of the major rating agencies, and (ii) historical default and loss data, including rating agency information regarding default rates from 1983 to 2016 and internal data dating to the early 1970s on severity of losses in the event of default. Adjustments may be made to this data. Such adjustments include (i) statistically calculated estimates to cover the historical fluctuation of the default rates over the credit cycle, the historical variability of loss severity among defaulted loans and the degree to which there are large obligor concentrations in the global portfolio, and (ii) adjustments made for specific known items, such as current environmental factors and credit trends. In addition, representatives from each of the risk management and finance staffs that cover business areas with delinquency-managed portfolios containing smaller-balance homogeneous loans present their recommended reserve balances based on leading credit indicators, including loan delinquencies and changes in portfolio size as well as economic trends, including current and future housing prices, unemployment, length of time in foreclosure, costs to sell and GDP. This methodology is applied separately for each individual product within each geographic region in which these portfolios exist. This evaluation process is subject to numerous estimates and judgments. The frequency of default, risk ratings, loss recovery rates, the size and diversity of individual large credits and the ability of borrowers with foreign currency obligations to obtain the foreign currency necessary for orderly debt servicing, among other things, are all taken into account during this review. Changes in these estimates could have a direct impact on the credit costs in any period and could result in a change in the allowance. Allowance for Unfunded Lending Commitments A simi

DISCONTINUED OPERATIONS AND SIG

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS	DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS Summary of Discontinued Operations The Company’s discontinued operations consisted of residual activities related to the sales of the Brazil Credicard business in 2013, the Egg Banking plc Credit Card Business in 2011 and the German Retail Banking business in 2008. All discontinued operations results are recorded within Corporate/Other. The following summarizes financial information for all discontinued operations: In millions of dollars 2017 2016 2015 Total revenues, net of interest expense $ — $ — $ — Income (loss) from discontinued operations $ (104 ) $ (80 ) $ (83 ) Provision (benefit) for income taxes 7 (22 ) (29 ) Loss from discontinued operations, net of taxes $ (111 ) $ (58 ) $ (54 ) Cash flows for discontinued operations were not material for all periods presented. Significant Disposals The transactions during 2017, 2016 and 2015 described below were identified as significant disposals. The major classes of assets and liabilities derecognized from the Consolidated Balance Sheet at closing, and the income (loss) before taxes related to each business until the disposal date, are presented below. Sale of Mexico Asset Management Business On November 27, 2017, Citi entered into an agreement to sell its Mexico asset management business, which is part of Latin America GCB . The transaction is expected to result in a pretax gain on sale at closing, which is anticipated to occur during the second half of 2018, subject to regulatory approval and other customary closing conditions. The transaction will also result in derecognition of approximately $72 million of net book value, including $32 million of goodwill. Income before taxes of the business was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 164 $ 155 $ 159 Sale of Fixed Income Analytics and Index Business On August 31, 2017, Citi completed the sale of a fixed income analytics business (Yield Book) and a fixed income index business that were part of Markets and Securities Services within Institutional Clients Group (ICG). As part of the sale, Citi derecognized total assets of $112 million , including goodwill of $72 million , while the derecognized liabilities were $18 million . The transaction generated a pretax gain on sale of $580 million ( $355 million after-tax) recorded in Other Revenue in ICG during 2017. Income before taxes for the divested businesses, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 31 $ 55 $ 54 Exit of U.S. Mortgage Service Operations Citigroup executed agreements during the first quarter of 2017 to effectively exit its direct U.S. mortgage servicing operations by the end of 2018 to intensify focus on originations. The exit of the mortgage servicing operations included the sale of mortgage servicing rights and execution of a subservicing agreement for the remaining Citi-owned loans and certain other mortgage servicing rights. As part of this transaction, Citi has also transferred certain employees. This transaction, which was part of Corporate/Other , resulted in a pretax loss of $331 million ( $207 million after-tax) recorded in Other revenue during 2017. The loss on sale did not include certain other costs and charges related to the disposed operation recorded primarily in Operating expenses during 2017, resulting in a total pretax loss of $382 million . As part of the completed sale, during 2017, Citi derecognized a total of $1,162 million of servicing-related assets, including $1,046 million of mortgage servicing rights, related to approximately 750,000 Fannie Mae and Freddie Mac held loans with outstanding balances of approximately $93 billion . Excluding the loss on sale and the additional charges, income before taxes for the disposed operation was immaterial for 2017, 2016 and 2015. Sale of CitiFinancial Canada Consumer Finance Business On March 31, 2017, Citi completed the sale of CitiFinancial Canada (CitiFinancial), which was part of Corporate/Other , and included 220 retail branches and approximately 1,400 employees. As part of the sale, Citi derecognized total assets of approximately $1.9 billion , including $1.7 billion consumer loans (net of allowance), and total liabilities of approximately $1.5 billion related to intercompany borrowings, which were settled at closing of the transaction. Separately, during 2017 and prior to closing of the transaction, CitiFinancial settled $0.4 billion of debt issued through loan securitizations. The sale of CitiFinancial generated a pretax gain on sale of $350 million recorded in Other revenue ( $178 million after-tax) during 2017. Income before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 41 $ 139 $ 118 Novation of the Primerica 80% Coinsurance Agreement Effective January 1, 2016, Citi completed a novation (an arrangement that extinguishes Citi’s rights and obligations under a contract) of the Primerica 80% coinsurance agreement, which was recorded in Corporate/Other , to a third-party re-insurer. The novation resulted in revenues of $404 million recorded in Other revenue ( $263 million after-tax) during 2016. Furthermore, the novation resulted in derecognition of $1.5 billion of available-for-sale securities and cash, $0.95 billion of deferred acquisition costs and $2.7 billion of insurance liabilities. Income before taxes, excluding the revenue upon novation, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ — $ — $ 135 Sale of OneMain Financial Business On November 15, 2015, Citi sold OneMain Financial (OneMain), which was part of Corporate/Other , including 1,100 retail branches, 5,500 employees and approximately 1.3 million customer accounts. OneMain had approximately $10.2 billion of assets, including $7.8 billion of loans (net of allowance), and $1.4 billion of available-for-sale securities. OneMain also had $8.4 billion of liabilities, including $6.2 billion of long-term debt and $1.1 billion of short-term borrowings. The transaction generated a pretax gain on sale of $2.6 billion , recorded in Other revenue ($ 1.6 billion after-tax) in 2015. However, when combined with the loss on redemption of certain long-term debt supporting certain Corporate/Other assets during the fourth quarter of 2015, the resulting net after-tax gain was $0.8 billion . Income before taxes, excluding the pretax gain on sale and loss on redemption of debt, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ — $ — $ 663 Sale of Japan Cards Business On December 14, 2015, Citi sold its Japan cards business, which was part of Corporate/Other , including $1,350 million of consumer loans (net of allowance), approximately 720,000 customer accounts and 840 employees. The transaction generated a pretax gain on sale of $180 million , recorded in Other revenue ( $155 million after-tax) in 2015. Loss before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Loss before taxes $ — $ — $ (5 ) Sale of Japan Retail Banking Business On November 1, 2015, Citi sold its Japan retail banking business, which was part of Corporate/Other , including $563 million of consumer loans (net of allowance), $20 billion of deposits, approximately 725,000 customer accounts, 1,600 employees and 32 branches. The transaction generated a pretax gain on sale of $446 million , recorded in Other revenue ( $276 million after-tax) in 2015. Loss before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Loss before taxes $ — $ — $ (57 )

BUSINESS SEGMENTS

BUSINESS SEGMENTS	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
BUSINESS SEGMENTS	BUSINESS SEGMENTS Citigroup’s activities are conducted through the following business segments: Global Consumer Banking (GCB) and Institutional Clients Group (ICG) . In addition, Corporate/Other includes activities not assigned to a specific business segment as well as certain North America and international loan portfolios, other legacy assets and discontinued operations. The business segments are determined based on products and services provided or type of customers served, of which those identified as non-core are recorded in Corporate/Other and are reflective of how management currently evaluates financial information to make business decisions. GCB includes a global, full-service consumer franchise delivering a wide array of banking, including commercial banking, credit card lending and investment services through a network of local branches, offices and electronic delivery systems and is composed of three GCB businesses: North America, Latin America and Asia (including consumer banking activities in certain EMEA countries). ICG is composed of Banking and Markets and securities services and provides corporate, institutional, public sector and high-net-worth clients in 97 countries and jurisdictions with a broad range of banking and financial products and services. Corporate/Other includes certain unallocated costs of global functions, other corporate expenses and net treasury results, unallocated corporate expenses, offsets to certain line-item reclassifications and eliminations, the results of certain North America and international legacy loan portfolios, discontinued operations and unallocated taxes. The accounting policies of these reportable segments are the same as those disclosed in Note 1 to the Consolidated Financial Statements. The prior-period balances reflect reclassifications to conform the presentation for all periods to the current period’s presentation. Financial data was reclassified to reflect: • the reporting of the remaining businesses and portfolios of assets of Citi Holdings as part of Corporate/Other (prior to the first quarter of 2017, Citi Holdings was a separately reported business segment); • the re-attribution of certain treasury-related costs between Corporate/Other , GCB and ICG ; • the re-attribution of regional revenues within ICG ; and • certain other immaterial reclassifications. Citi’s consolidated results remain unchanged for all periods presented as a result of the changes and reclassifications discussed above. The following table presents certain information regarding the Company’s continuing operations by segment: Revenues, (1) Provision (benefits) (2) Income (loss) from (2)(3) Identifiable assets In millions of dollars, except identifiable assets in billions 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 Global Consumer Banking $ 32,697 $ 31,519 $ 32,251 $ 3,320 $ 2,655 $ 3,369 $ 3,893 $ 4,954 $ 6,214 $ 429 $ 412 Institutional Clients Group 35,667 33,227 33,332 7,008 4,260 4,173 9,066 9,525 9,110 1,336 1,277 Corporate/Other 3,085 5,129 10,771 19,060 (471 ) (102 ) (19,586 ) 554 2,062 77 103 Total $ 71,449 $ 69,875 $ 76,354 $ 29,388 $ 6,444 $ 7,440 $ (6,627 ) $ 15,033 $ 17,386 $ 1,842 $ 1,792 (1) Includes total revenues, net of interest expense (excluding Corporate/Other ), in North America of $33.9 billion , $32.2 billion and $32.2 billion ; in EMEA of $10.7 billion , $9.9 billion and $9.8 billion ; in Latin America of $9.4 billion , $8.9 billion and $9.7 billion ; and in Asia of $14.4 billion , $13.7 billion and $13.9 billion in 2017, 2016 and 2015, respectively. (2) Corporate/Other , GCB and ICG 2017 results include the impact of Tax Reform. See Notes 1 and 9 to the Consolidated Financial Statements. (3) Includes pretax provisions for credit losses and for benefits and claims in the GCB results of $7.6 billion , $6.4 billion and $5.5 billion ; in the ICG results of ( $15 ) million, $486 million and $962 million ; and in Corporate/Other results of ( $175 ) million, $69 million and $1.5 billion in 2017, 2016 and 2015, respectively.

INTEREST REVENUE AND EXPENSE

INTEREST REVENUE AND EXPENSE	12 Months Ended
	Dec. 31, 2017
Banking and Thrift, Interest [Abstract]
INTEREST REVENUE AND EXPENSE	INTEREST REVENUE AND EXPENSE Interest revenue and Interest expense consisted of the following: In millions of dollars 2017 2016 2015 Interest revenue Loan interest, including fees $ 41,361 $ 39,752 $ 40,510 Deposits with banks 1,635 971 727 Federal funds sold and securities borrowed or purchased under agreements to resell 3,248 2,543 2,516 Investments, including dividends 8,295 7,582 7,017 Trading account assets (1) 5,502 5,738 5,942 Other interest (2) 1,163 1,029 1,839 Total interest revenue $ 61,204 $ 57,615 $ 58,551 Interest expense Deposits (3) $ 6,586 $ 5,300 $ 5,052 Federal funds purchased and securities loaned or sold under agreements to repurchase 2,661 1,912 1,612 Trading account liabilities (1) 638 410 217 Short-term borrowings 1,059 477 523 Long-term debt 5,573 4,412 4,517 Total interest expense $ 16,517 $ 12,511 $ 11,921 Net interest revenue $ 44,687 $ 45,104 $ 46,630 Provision for loan losses 7,503 6,749 7,108 Net interest revenue after provision for loan losses $ 37,184 $ 38,355 $ 39,522 (1) Interest expense on Trading account liabilities of ICG is reported as a reduction of interest revenue from Trading account assets . (2) During 2015, interest earned related to assets of significant disposals (primarily OneMain Financial) was reclassified to Other interest. (3) Includes deposit insurance fees and charges of $1,249 million , $1,145 million and $1,118 million for 2017 , 2016 and 2015 , respectively.

COMMISSIONS AND FEES

COMMISSIONS AND FEES	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
COMMISSIONS AND FEES	COMMISSIONS AND FEES The primary components of Citi’s Commissions and fees revenue are investment banking fees, trading-related fees, fees related to trade and securities services in ICG and credit card and bank card fees. Investment banking fees are substantially composed of underwriting and advisory revenues and are recognized when Citigroup’s performance under the terms of a contractual arrangement is completed, which is typically at the closing of a transaction. Underwriting revenue is recorded in Commissions and fees , net of both reimbursable and non-reimbursable expenses, consistent with the AICPA Accounting Guide for Brokers and Dealers in Securities (codified in ASC 940-605-05-1). Expenses associated with advisory transactions are recorded in Other operating expenses, net of client reimbursements. Out-of-pocket expenses are deferred and recognized at the time the related revenue is recognized. In general, expenses incurred related to investment banking transactions that fail to close (are not consummated) are recorded gross in Other operating expenses . Trading-related fees primarily include commissions and fees from the following: executing transactions for clients on exchanges and over-the-counter markets; sales of mutual funds and other annuity products; and assisting clients in clearing transactions, providing brokerage services and other such activities. Trading-related fees are recognized when earned in Commissions and fees . Gains or losses, if any, on these transactions are included in Principal transactions (see Note 6 to the Consolidated Financial Statements). Credit card and bank card fees are primarily composed of interchange revenue and certain card fees, including annual fees, reduced by reward program costs and certain partner payments. Interchange revenue and fees are recognized when earned. Annual card fees are deferred and amortized on a straight-line basis over a 12 -month period. Reward costs are recognized when points are earned by the customers. Insurance premiums consists of premium income from insurance policies which Citi has underwritten and sold to policyholders. Insurance distribution revenue consists of commissions earned from third party insurance companies for marketing and selling insurance policies on behalf of such entities. The following table presents Commissions and fees revenue: In millions of dollars 2017 2016 2015 Investment banking $ 3,613 $ 2,847 $ 3,423 Trading-related 3,015 2,799 3,138 Trade and securities services 1,632 1,564 1,735 Credit cards and bank cards 1,510 1,324 1,786 Corporate finance (1) 713 686 493 Other consumer (2) 703 659 685 Insurance distribution revenue (3) 514 548 621 Insurance premiums (3) 122 288 1,224 Checking-related 478 467 497 Loan servicing 312 325 404 Other 327 431 479 Total commissions and fees $ 12,939 $ 11,938 $ 14,485 (1) Consists primarily of fees earned from structuring and underwriting loan syndications. (2) Primarily consists of fees for investment fund administration and management, third-party collections, commercial demand deposit accounts and certain credit card services. (3) Insurance premiums were previously separately reported on the Consolidated Statement of Income.

PRINCIPAL TRANSACTIONS

PRINCIPAL TRANSACTIONS	12 Months Ended
	Dec. 31, 2017
Principal Transactions Revenue, Net [Abstract]
PRINCIPAL TRANSACTIONS	PRINCIPAL TRANSACTIONS Citi’s Principal transactions revenue consists of realized and unrealized gains and losses from trading activities. Trading activities include revenues from fixed income, equities, credit and commodities products and foreign exchange transactions that are managed on a portfolio basis characterized by primary risk. Not included in the table below is the impact of net interest revenue related to trading activities, which is an integral part of trading activities’ profitability. For additional information regarding Principal transactions revenue, see Note 4 to the Consolidated Financial Statements for information about net interest revenue related to trading activities. Principal transactions include CVA (credit valuation adjustments on derivatives), FVA (funding valuation adjustments) on over-the-counter derivatives and, prior to 2016, DVA (debt valuation adjustments on issued liabilities for which the fair value option has been elected). These adjustments are discussed further in Note 24 to the Consolidated Financial Statements. The following table presents Principal transactions revenue: In millions of dollars 2017 2016 2015 Global Consumer Banking (1) $ 570 $ 629 $ 577 Institutional Clients Group 7,740 7,335 5,824 Corporate/Other (1) 858 (379 ) (393 ) Total Citigroup $ 9,168 $ 7,585 $ 6,008 Interest rate risks (2) $ 5,124 $ 4,115 $ 3,798 Foreign exchange risks (3) 2,488 1,726 1,532 Equity risks (4) 491 189 331 Commodity and other risks (5) 294 806 750 Credit products and risks (6) 771 749 (403 ) Total $ 9,168 $ 7,585 $ 6,008 (1) Primarily relates to foreign exchange risks. (2) Includes revenues from government securities and corporate debt, municipal securities, mortgage securities and other debt instruments. Also includes spot and forward trading of currencies and exchange-traded and over-the-counter (OTC) currency options, options on fixed income securities, interest rate swaps, currency swaps, swap options, caps and floors, financial futures, OTC options and forward contracts on fixed income securities. (3) Includes revenues from foreign exchange spot, forward, option and swap contracts, as well as foreign currency translation (FX translation) gains and losses. (4) Includes revenues from common, preferred and convertible preferred stock, convertible corporate debt, equity-linked notes and exchange-traded and OTC equity options and warrants. (5) Primarily includes revenues from crude oil, refined oil products, natural gas and other commodities trades. (6) Includes revenues from structured credit products.

INCENTIVE PLANS

INCENTIVE PLANS	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
INCENTIVE PLANS	INCENTIVE PLANS Discretionary Annual Incentive Awards Citigroup grants immediate cash bonus payments and various forms of immediate and deferred awards as part of its discretionary annual incentive award program involving a large segment of Citigroup’s employees worldwide. Most of the shares of common stock issued by Citigroup as part of its equity compensation programs are to settle the vesting of the stock components of these awards. Discretionary annual incentive awards are generally awarded in the first quarter of the year based upon the previous year’s performance. Awards valued at less than U.S. $100,000 (or the local currency equivalent) are generally paid entirely in the form of an immediate cash bonus. Pursuant to Citigroup policy and/or regulatory requirements, certain employees and officers are subject to mandatory deferrals of incentive pay and generally receive 25% to 60% of their awards in a combination of restricted or deferred stock, deferred cash stock units, or deferred cash. Discretionary annual incentive awards to many employees in the EU are subject to deferral requirements regardless of the total award value, with 50% of the immediate incentive delivered in the form of a stock payment or stock unit award subject to a restriction on sale or transfer or hold back (generally, for twelve months). Deferred annual incentive awards may be delivered in the form of one or more award types—a restricted or deferred stock award under Citi’s Capital Accumulation Program (CAP), or a deferred cash stock unit award and/or a deferred cash award under Citi’s Deferred Cash Award Plan. The applicable mix of awards may vary based on the employee’s minimum deferral requirement and the country of employment. Subject to certain exceptions (principally, for retirement-eligible employees), continuous employment within Citigroup is required to vest in CAP, deferred cash stock unit and deferred cash awards. Post employment vesting by retirement-eligible employees and participants who meet other conditions is generally conditioned upon their refraining from competition with Citigroup during the remaining vesting period, unless the employment relationship has been terminated by Citigroup under certain conditions. Generally, the deferred awards vest in equal annual installments over three - or four -year periods. Vested CAP awards are delivered in shares of common stock. Deferred cash awards are payable in cash and, except as prohibited by applicable regulatory guidance, earn a fixed notional rate of interest that is paid only if and when the underlying principal award amount vests. Deferred cash stock unit awards are payable in cash at the vesting value of the underlying stock. Generally, in the EU, vested CAP shares are subject to a restriction on sale or transfer after vesting, and vested deferred cash awards and deferred cash stock units are subject to hold back (generally, for twelve months in each case). Unvested CAP, deferred cash stock units and deferred cash awards are subject to one or more clawback provisions that apply in certain circumstances, including gross misconduct. CAP and deferred cash stock unit awards, made to certain employees, are subject to a formulaic performance-based vesting condition pursuant to which amounts otherwise scheduled to vest will be reduced based on the amount of any pretax loss in the participant’s business in the calendar year preceding the scheduled vesting date. A minimum reduction of 20% applies for the first dollar of loss for CAP and deferred cash stock unit awards. In addition, deferred cash awards are subject to a discretionary performance-based vesting condition under which an amount otherwise scheduled to vest may be reduced in the event of a “material adverse outcome” for which a participant has “significant responsibility.” These awards are also subject to an additional clawback provision pursuant to which unvested awards may be canceled if the employee engaged in misconduct or exercised materially imprudent judgment, or failed to supervise or escalate the behavior of other employees who did. Sign-on and Long-Term Retention Awards Stock awards and deferred cash awards may be made at various times during the year as sign-on awards to induce new hires to join Citi or to high-potential employees as long-term retention awards. Vesting periods and other terms and conditions pertaining to these awards tend to vary by grant. Generally, recipients must remain employed through the vesting dates to vest in the awards, except in cases of death, disability or involuntary termination other than for gross misconduct. These awards do not usually provide for post-employment vesting by retirement-eligible participants. Outstanding (Unvested) Stock Awards A summary of the status of unvested stock awards granted as discretionary annual incentive or sign-on and long-term retention awards is presented below: Unvested stock awards Shares Weighted- average grant date fair value per share Unvested at December 31, 2016 42,672,176 $ 43.24 Granted (1) 13,914,752 59.12 Canceled (1,335,297 ) 47.29 Vested (2) (18,320,591 ) 45.63 Unvested at December 31, 2017 36,931,040 $ 47.89 (1) The weighted-average fair value of the shares granted during 2016 and 2015 was $37.35 and $50.33 , respectively. (2) The weighted-average fair value of the shares vesting during 2017 was approximately $57.45 per share. Total unrecognized compensation cost related to unvested stock awards was $530 million at December 31, 2017. The cost is expected to be recognized over a weighted-average period of 1.6 years . Performance Share Units Certain executive officers were awarded a target number of performance share units (PSUs) each February from 2014 to 2017, for performance in the year prior to the award date. For grants prior to 2016, PSUs will be earned only to the extent that Citigroup attains specified performance goals relating to Citigroup’s return on assets and relative total shareholder return against peers over the three -year period beginning with the year of award. The actual dollar amounts ultimately earned could vary from zero , if performance goals are not met, to as much as 150% of target, if performance goals are meaningfully exceeded. The PSUs granted in February 2016 are earned over a three -year performance period based on Citigroup’s relative total shareholder return as compared to peers. The actual dollar amounts ultimately earned could vary from zero , if performance goals are not met, to as much as 150% of target, if performance goals are meaningfully exceeded. The PSUs granted in February 2017 are earned over a three -year performance period based half on return on tangible common equity performance in 2019, and the remaining half on cumulative earnings per share over 2017 to 2019. For the PSUs awarded in 2016 and 2017, if the total shareholder return is negative over the three -year performance period, executives may earn no more than 100% of the target PSUs, regardless of the extent to which Citi outperforms peer firms. For all award years, the value of each PSU is equal to the value of one share of Citi common stock. Dividend equivalents will be accrued and paid on the number of earned PSUs after the end of the performance period. PSUs are subject to variable accounting, pursuant to which the associated value of the award will fluctuate with changes in Citigroup’s stock price and the attainment of the specified performance goals for each award, until the award is settled solely in cash after the end of the performance period. The value of the award, subject to the performance goals, is estimated using a simulation model that incorporates multiple valuation assumptions, including the probability of achieving the specified performance goals of each award. The risk-free rate used in the model is based on the applicable U.S. Treasury yield curve. Other significant assumptions for the awards are as follows: Valuation Assumptions 2017 2016 2015 Expected volatility 25.79 % 24.37 % 27.13 % Expected dividend yield 1.30 % 0.40 % 0.08 % A summary of the performance share unit activity for 2017 is presented below: Performance Share Units Units Weighted- average grant date fair value per unit Outstanding, beginning of period 1,844,560 $ 38.22 Granted (1) 500,609 59.22 Canceled (277,546 ) 48.34 Payments (280,897 ) 48.34 Outstanding, end of period 1,786,726 $ 40.94 (1) The weighted-average grant date fair value per unit awarded in 2016 and 2015 was $27.03 and $44.07 , respectively. PSUs granted in 2015 and 2017 were equitably adjusted after the enactment of Tax Reform, as required under the terms of those awards. The adjustments were intended to reproduce the expected value of the awards immediately prior to the passage of Tax Reform. Stock Option Programs All outstanding stock options are fully vested with the related expense recognized as a charge to income in prior periods. Generally, the stock options outstanding have a six -year term, with some stock options subject to various transfer restrictions. Cash received from employee stock option exercises under this program for the year ended December 31, 2017 was approximately $14 million . Information with respect to stock option activity under Citigroup’s stock option programs is shown below: 2017 2016 2015 Options Weighted- average exercise price Intrinsic value per share Options Weighted- average exercise price Intrinsic value per share Options Weighted- average exercise price Intrinsic value per share Outstanding, beginning of period 1,527,396 $ 131.78 $ — 6,656,588 $ 67.92 $ — 26,514,119 $ 48.00 $ 6.11 Canceled — — — (25,334 ) 40.80 — (7,901 ) 40.80 — Expired — — — (2,613,909 ) 48.80 — (1,646,581 ) 40.85 — Exercised (388,583 ) 43.35 15.67 (2,489,949 ) 49.10 6.60 (18,203,048 ) 41.39 13.03 Outstanding, end of period 1,138,813 $ 161.96 $ — 1,527,396 $ 131.78 $ — 6,656,588 $ 67.92 $ — Exercisable, end of period 1,138,813 1,527,396 6,656,588 The following table summarizes information about stock options outstanding under Citigroup’s stock option programs at December 31, 2017: Options outstanding Options exercisable Range of exercise prices Number outstanding Weighted-average contractual life remaining Weighted-average exercise price Number exercisable Weighted-average exercise price $39.00—$99.99 312,309 3.0 years $ 43.56 312,309 $ 43.56 $100.00—$199.99 502,416 1.0 year 147.13 502,416 147.13 $200.00—$299.99 124,088 0.1 years 240.28 124,088 240.28 $300.00—$399.99 200,000 0.1 years 335.50 200,000 335.50 Total at December 31, 2017 1,138,813 1.3 years $ 161.96 1,138,813 $ 161.96 Other Variable Incentive Compensation Citigroup has various incentive plans globally that are used to motivate and reward performance primarily in the areas of sales, operational excellence and customer satisfaction. Participation in these plans is generally limited to employees who are not eligible for discretionary annual incentive awards. Other forms of variable compensation include monthly commissions paid to Financial Advisors and Mortgage Loan Officers. Summary Except for awards subject to variable accounting, the total expense recognized for stock awards represents the grant date fair value of such awards, which is generally recognized as a charge to income ratably over the vesting period, other than for awards to retirement-eligible employees and immediately vested awards. Whenever awards are made or are expected to be made to retirement-eligible employees, the charge to income is accelerated based on when the applicable conditions to retirement eligibility were or will be met. If the employee is retirement eligible on the grant date, or the award is vested at grant date, the entire expense is recognized in the year prior to grant. Recipients of Citigroup stock awards generally do not have any stockholder rights until shares are delivered upon vesting or exercise, or after the expiration of applicable required holding periods. Recipients of restricted or deferred stock awards and deferred cash stock unit awards, however, may, except as prohibited by applicable regulatory guidance, be entitled to receive dividends or dividend-equivalent payments during the vesting period. Recipients of restricted stock awards generally are entitled to vote the shares in their award during the vesting period. Once a stock award vests, the shares are freely transferable, unless they are subject to a restriction on sale or transfer for a specified period. All equity awards granted since April 19, 2005 have been made pursuant to stockholder-approved stock incentive plans that are administered by the Personnel and Compensation Committee of the Citigroup Board of Directors, which is composed entirely of independent non-employee directors. At December 31, 2017, approximately 39.2 million shares of Citigroup common stock were authorized and available for grant under Citigroup’s 2014 Stock Incentive Plan, the only plan from which equity awards are currently granted. The 2014 Stock Incentive Plan and predecessor plans permit the use of treasury stock or newly issued shares in connection with awards granted under the plans. Newly issued shares were distributed to settle the vesting of the majority of annual deferred stock awards from 2012 to 2015. Treasury shares were used to settle vestings in 2016 and 2017, and the first quarter of 2018, except where local laws favor newly issued shares. The use of treasury stock or newly issued shares to settle stock awards does not affect the compensation expense recorded in the Consolidated Statement of Income for equity awards. Incentive Compensation Cost The following table shows components of compensation expense, relating to certain of the above incentive compensation programs: In millions of dollars 2017 2016 2015 Charges for estimated awards to retirement-eligible employees $ 659 $ 555 $ 541 Amortization of deferred cash awards, deferred cash stock units and performance stock units 354 336 325 Immediately vested stock award expense (1) 70 73 61 Amortization of restricted and deferred stock awards (2) 474 509 461 Other variable incentive compensation 694 710 773 Total $ 2,251 $ 2,183 $ 2,161 (1) Represents expense for immediately vested stock awards that generally were stock payments in lieu of cash compensation. The expense is generally accrued as cash incentive compensation in the year prior to grant. (2) All periods include amortization expense for all unvested awards to non-retirement-eligible employees. Future Expenses Associated with Outstanding (Unvested) Awards Citi expects to record compensation expense in future periods as a result of awards granted for performance in 2017 and prior years. Because the awards contain service or other conditions that will be satisfied in the future, the expense of these already-granted awards is recognized over those future periods. The portion of these awards that is subject to variable accounting will cause the expense amount to fluctuate with changes in Citigroup’s common stock price. Citi's expected future expenses, excluding the impact of forfeitures, cancelations, clawbacks and repositioning-related accelerations that have not yet occurred, are summarized in the table below: In millions of dollars 2018 2019 2020 2021 and beyond (1) Total Awards granted in 2017 and prior: Deferred stock awards $ 276 $ 146 $ 67 $ 11 $ 500 Deferred cash awards 170 94 38 8 310 Future expense related to awards already granted $ 446 $ 240 $ 105 $ 19 $ 810 Future expense related to awards granted in 2018 (2) $ 238 $ 185 $ 148 $ 111 $ 682 Total $ 684 $ 425 $ 253 $ 130 $ 1,492 (1) Principally 2021. (2) Refers to awards granted on or about February 15, 2018, as part of Citi's discretionary annual incentive awards for services performed in 2017.

RETIREMENT BENEFITS

RETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
RETIREMENT BENEFITS	RETIREMENT BENEFITS Pension and Postretirement Plans The Company has several non-contributory defined benefit pension plans covering certain U.S. employees and has various defined benefit pension and termination indemnity plans covering employees outside the U.S. The U.S. qualified defined benefit plan was frozen effective January 1, 2008 for most employees. Accordingly, no additional compensation-based contributions have been credited to the cash balance portion of the plan for existing plan participants after 2007. However, certain employees covered under the prior final pay plan formula continue to accrue benefits. The Company also offers postretirement health care and life insurance benefits to certain eligible U.S. retired employees, as well as to certain eligible employees outside the U.S. The Company also sponsors a number of non-contributory, nonqualified pension plans. These plans, which are unfunded, provide supplemental defined pension benefits to certain U.S. employees. With the exception of certain employees covered under the prior final pay plan formula, the benefits under these plans were frozen in prior years. The plan obligations, plan assets and periodic plan expense for the Company’s most significant pension and postretirement benefit plans (Significant Plans) are measured and disclosed quarterly, instead of annually. The Significant Plans captured approximately 90% of the Company’s global pension and postretirement plan obligations as of December 31, 2017. All other plans (All Other Plans) are measured annually with a December 31 measurement date. Net (Benefit) Expense The following table summarizes the components of net (benefit) expense recognized in the Consolidated Statement of Income for the Company’s pension and postretirement plans, for Significant Plans and All Other Plans: Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 2015 Benefits earned during the year $ 3 $ 4 $ 6 $ 153 $ 154 $ 168 $ — $ — $ — $ 9 $ 10 $ 12 Interest cost on benefit obligation 533 548 581 295 282 317 26 25 33 101 94 108 Expected return on plan assets (865 ) (886 ) (893 ) (299 ) (287 ) (323 ) (6 ) (9 ) (3 ) (89 ) (86 ) (105 ) Amortization of unrecognized Prior service (benefit) cost 2 2 1 (3 ) (1 ) 2 — — — (10 ) (10 ) (11 ) Net actuarial loss 173 169 148 61 69 73 — (1 ) — 35 30 43 Curtailment loss (gain) (1) 6 13 14 — (2 ) — — — — — — (1 ) Settlement loss (1) — — — 12 6 44 — — — — — — Total net (benefit) expense $ (148 ) $ (150 ) $ (143 ) $ 219 $ 221 $ 281 $ 20 $ 15 $ 30 $ 46 $ 38 $ 46 (1) Losses and gains due to curtailment and settlement benefits relate to repositioning and divestiture actions. The estimated net actuarial loss and prior service (benefit) cost that will be amortized from Accumulated other comprehensive income (loss) into net expense in 2018 are approximately $241 million and $(2) million , respectively, for defined benefit pension plans. For postretirement plans, the estimated 2018 net actuarial loss and prior service (benefit) cost amortizations are approximately $28 million and $(9) million , respectively. Contributions The Company’s funding practice for U.S. and non-U.S. pension and postretirement plans is generally to fund to minimum funding requirements in accordance with applicable local laws and regulations. The Company may increase its contributions above the minimum required contribution, if appropriate. In addition, management has the ability to change its funding practices. For the U.S. pension plans, there were no required minimum cash contributions for 2017 or 2016. The following table summarizes the actual Company contributions for the years ended December 31, 2017 and 2016 , as well as estimated expected Company contributions for 2018. Expected contributions are subject to change, since contribution decisions are affected by various factors, such as market performance, tax considerations and regulatory requirements. Pension plans (1) Postretirement benefit plans (1) U.S. plans (2) Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2016 2018 2017 2016 2018 2017 2016 2018 2017 2016 Contributions made by the Company $ — $ 50 $ 500 $ 79 $ 90 $ 82 $ — $ 140 $ — $ 4 $ 4 $ 4 Benefits paid directly by the Company 60 55 56 49 45 44 6 36 6 6 5 5 (1) Amounts reported for 2018 are expected amounts. (2) The U.S. pension plans include benefits paid directly by the Company for the nonqualified pension plans. Funded Status and Accumulated Other Comprehensive Income The following tables summarize the funded status and amounts recognized in the Consolidated Balance Sheet for the Company’s pension and postretirement plans: Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans 2017 2016 2017 2016 2017 2016 2017 2016 Change in projected benefit obligation Projected benefit obligation at beginning of year $ 14,000 $ 13,943 $ 6,522 $ 6,534 $ 686 $ 817 $ 1,141 $ 1,291 Benefits earned during the year 3 4 153 154 — — 9 10 Interest cost on benefit obligation 533 548 295 282 26 25 101 94 Plan amendments — — 4 (28 ) — — — — Actuarial loss (gain) 536 367 127 589 43 (105 ) 19 3 Benefits paid, net of participants’ contributions and government subsidy (769 ) (780 ) (278 ) (324 ) (56 ) (51 ) (64 ) (59 ) Divestitures — — (29 ) (22 ) — — (4 ) — Settlement gain (1) — — (192 ) (38 ) — — — — Curtailment (gain) loss (1) 6 13 (3 ) (15 ) — — — (4 ) Foreign exchange impact and other (2) (269 ) (95 ) 834 (610 ) — — 59 (194 ) Projected benefit obligation at year end $ 14,040 $ 14,000 $ 7,433 $ 6,522 $ 699 $ 686 $ 1,261 $ 1,141 (1) Curtailment and settlement (gains) losses relate to repositioning and divestiture activities. (2) With respect to the U.S. Plan, de-risking activities during 2017 resulted in a reduction to plan obligations and assets. Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2017 2016 2017 2016 2017 2016 2017 2016 Change in plan assets Plan assets at fair value at beginning of year $ 12,363 $ 12,137 $ 6,149 $ 6,104 $ 129 $ 166 $ 1,015 $ 1,133 Actual return on plan assets 1,295 572 462 967 13 8 113 122 Company contributions 105 556 135 126 176 6 9 9 Divestitures — — (31 ) (5 ) — — — — Settlements — — (192 ) (38 ) — — — — Benefits paid, net of participants’ contributions and government subsidy (769 ) (779 ) (278 ) (324 ) (56 ) (51 ) (64 ) (59 ) Foreign exchange impact and other (1) (269 ) (123 ) 883 (681 ) — — 46 (190 ) Plan assets at fair value at year end $ 12,725 $ 12,363 $ 7,128 $ 6,149 $ 262 $ 129 $ 1,119 $ 1,015 Funded status of the plans Qualified plans (2) $ (565 ) $ (908 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Nonqualified plans (3) (750 ) (729 ) — — — — — — Funded status of the plans at year end $ (1,315 ) $ (1,637 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Net amount recognized Qualified plans Benefit asset $ — $ — $ 900 $ 711 $ — $ — $ 181 $ 166 Benefit liability (565 ) (908 ) (1,205 ) (1,084 ) (437 ) (557 ) (323 ) (292 ) Qualified plans $ (565 ) $ (908 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Nonqualified plans (750 ) (729 ) — — — — — — Net amount recognized on the balance sheet $ (1,315 ) $ (1,637 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Amounts recognized in Accumulated other comprehensive income (loss) Net transition obligation $ — $ — $ (1 ) $ (1 ) $ — $ — $ — $ — Prior service benefit (15 ) (17 ) 22 29 — — 92 98 Net actuarial gain (loss) (6,823 ) (6,891 ) (1,318 ) (1,302 ) 72 106 (382 ) (399 ) Net amount recognized in equity (pretax) $ (6,838 ) $ (6,908 ) $ (1,297 ) $ (1,274 ) $ 72 $ 106 $ (290 ) $ (301 ) Accumulated benefit obligation at year end $ 14,034 $ 13,994 $ 7,038 $ 6,090 $ 699 $ 686 $ 1,261 $ 1,141 (1) With respect to the U.S. Plan, de-risking activities during 2017 resulted in a reduction to plan obligations and assets. (2) The U.S. qualified pension plan is fully funded under specified Employee Retirement Income Security Act (ERISA) funding rules as of January 1, 2018 and no minimum required funding is expected for 2018. (3) The nonqualified plans of the Company are unfunded. The following table shows the change in Accumulated other comprehensive income (loss) related to the Company’s pension, postretirement and post employment plans: In millions of dollars 2017 2016 2015 Beginning of year balance, net of tax (1)(2) $ (5,164 ) $ (5,116 ) $ (5,159 ) Actuarial assumptions changes and plan experience (760 ) (854 ) 898 Net asset gain (loss) due to difference between actual and expected returns 625 400 (1,457 ) Net amortizations 229 232 236 Prior service (cost) credit (4 ) 28 (6 ) Curtailment/settlement gain (3) 17 17 57 Foreign exchange impact and other (93 ) 99 291 Impact of Tax Reform (4) (1,020 ) — — Change in deferred taxes, net (13 ) 30 24 Change, net of tax $ (1,019 ) $ (48 ) $ 43 End of year balance, net of tax (1)(2) $ (6,183 ) $ (5,164 ) $ (5,116 ) (1) See Note 19 to the Consolidated Financial Statements for further discussion of net Accumulated other comprehensive income (loss) balance. (2) Includes net-of-tax amounts for certain profit sharing plans outside the U.S. (3) Curtailment and settlement gains broadly relate to repositioning and divestiture activities. (4) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings. See Note 1 to the Consolidated Financial Statements. At December 31, 2017 and 2016, the aggregate projected benefit obligation (PBO), the aggregate accumulated benefit obligation (ABO) and the aggregate fair value of plan assets are presented for all defined benefit pension plans with a PBO in excess of plan assets and for all defined benefit pension plans with an ABO in excess of plan assets as follows: PBO exceeds fair value of plan assets ABO exceeds fair value of plan assets U.S. plans (1) Non-U.S. plans U.S. plans (1) Non-U.S. plans In millions of dollars 2017 2016 2017 2016 2017 2016 2017 2016 Projected benefit obligation $ 14,040 $ 14,000 $ 2,721 $ 2,484 $ 14,040 $ 14,000 $ 2,596 $ 2,282 Accumulated benefit obligation 14,034 13,994 2,381 2,168 14,034 13,994 2,296 2,012 Fair value of plan assets 12,725 12,363 1,516 1,399 12,725 12,363 1,407 1,224 (1) At December 31, 2017 and 2016, for both the U.S. qualified plan and nonqualified plans, the aggregate PBO and the aggregate ABO exceeded plan assets. Plan Assumptions The Company utilizes a number of assumptions to determine plan obligations and expenses. Changes in one or a combination of these assumptions will have an impact on the Company’s pension and postretirement PBO, funded status and (benefit) expense. Changes in the plans’ funded status resulting from changes in the PBO and fair value of plan assets will have a corresponding impact on Accumulated other comprehensive income (loss) . The actuarial assumptions at the respective years ended December 31 in the table below are used to measure the year-end PBO and the net periodic (benefit) expense for the subsequent year (period). Since Citi’s Significant Plans are measured on a quarterly basis, the year-end rates for those plans are used to calculate the net periodic (benefit) expense for the subsequent year’s first quarter. As a result of the quarterly measurement process, the net periodic (benefit) expense for the Significant Plans is calculated at each respective quarter end based on the preceding quarter-end rates (as shown below for the U.S. and non-U.S. pension and postretirement plans). The actuarial assumptions for All Other Plans are measured annually. Certain assumptions used in determining pension and postretirement benefit obligations and net benefit expense for the Company’s plans are shown in the following table: At year end 2017 2016 Discount rate U.S. plans Qualified pension 3.60% 4.10% Nonqualified pension 3.60 4.00 Postretirement 3.50 3.90 Non-U.S. pension plans Range 0.00 to 10.20 0.25 to 72.50 Weighted average 4.17 4.40 Non-U.S. postretirement plans Range 1.75 to 10.10 1.75 to 11.05 Weighted average 8.10 8.27 Future compensation increase rate (1) Non-U.S. pension plans Range 1.17 to 13.67 1.25 to 70.00 Weighted average 3.08 3.21 Expected return on assets U.S. plans Qualified pension 6.80 6.80 Postretirement (2) 6.80/3.00 6.80 Non-U.S. pension plans Range 0.00 to 11.50 1.00 to 11.50 Weighted average 4.52 4.55 Non-U.S. postretirement plans Range 8.00 to 9.80 8.00 to 10.30 Weighted average 8.01 8.02 (1) Not material for U.S. plans. (2) In 2017, the VEBA Trust was funded with an expected rate of return of assets of 3.00% . During the year 2017 2016 2015 Discount rate U.S. plans Qualified pension 4.10%/4.05%/ 3.80%/3.75% 4.40%/3.95%/ 3.65%/3.55% 4.00%/3.85%/ 4.45%/4.35% Nonqualified pension 4.00/3.95/ 3.75/3.65 4.35/3.90/ 3.55/3.45 3.90/3.70/ 4.30/4.25 Postretirement 3.90/3.85/ 3.60/3.55 4.20/3.75/ 3.40/3.30 3.80/3.65/ 4.20/4.10 Non-U.S. pension plans (1) Range 0.25 to 72.50 0.25 to 42.00 1.00 to 32.50 Weighted average 4.40 4.76 4.74 Non-U.S. postretirement plans (1) Range 1.75 to 11.05 2.00 to 13.20 2.25 to 12.00 Weighted average 8.27 7.90 7.50 Future compensation increase rate (2) Non-U.S. pension plans (1) Range 1.25 to 70.00 1.00 to 40.00 0.75 to 30.00 Weighted average 3.21 3.24 3.27 Expected return on assets U.S. plans Qualified pension 6.80 7.00 7.00 Postretirement 6.80 7.00 7.00 Non-U.S. pension plans (1) Range 1.00 to 11.50 1.60 to 11.50 1.30 to 11.50 Weighted average 4.55 4.95 5.08 Non-U.S. postretirement plans (1) Range 8.00 to 10.30 8.00 to 10.70 8.50 to 10.40 Weighted average 8.02 8.01 8.51 (1) Reflects rates utilized to determine the first quarter expense for Significant non-U.S. pension and postretirement plans. (2) Not material for U.S. plans. Discount Rate The discount rates for the U.S. pension and postretirement plans were selected by reference to a Citigroup-specific analysis using each plan’s specific cash flows and compared with high-quality corporate bond indices for reasonableness. The discount rates for the non-U.S. pension and postretirement plans are selected by reference to high-quality corporate bond rates in countries that have developed corporate bond markets. However, where developed corporate bond markets do not exist, the discount rates are selected by reference to local government bond rates with a premium added to reflect the additional risk for corporate bonds in certain countries. Effective December 31, 2017, the established rounding convention was to the nearest 5 bps for the top five non-U.S. countries, and 25 bps for all other countries. Expected Rate of Return The Company determines its assumptions for the expected rate of return on plan assets for its U.S. pension and postretirement plans using a “building block” approach, which focuses on ranges of anticipated rates of return for each asset class. A weighted average range of nominal rates is then determined based on target allocations to each asset class. Market performance over a number of earlier years is evaluated covering a wide range of economic conditions to determine whether there are sound reasons for projecting any past trends. The Company considers the expected rate of return to be a long-term assessment of return expectations and does not anticipate changing this assumption unless there are significant changes in investment strategy or economic conditions. This contrasts with the selection of the discount rate and certain other assumptions, which are reconsidered annually (or quarterly for the Significant Plans) in accordance with GAAP. The expected rate of return for the U.S. pension and postretirement plans was 6.80% at December 31, 2017 and 2016 and 7.00% at December 31, 2015. The expected return on assets reflects the expected annual appreciation of the plan assets and reduces the Company’s annual pension expense. The expected return on assets is deducted from the sum of service cost, interest cost and other components of pension expense to arrive at the net pension (benefit) expense. Net pension (benefit) expense for the U.S. pension plans for 2017, 2016 and 2015 reflects deductions of $865 million , $886 million and $893 million of expected returns, respectively. The following table shows the expected rates of return used in determining the Company’s pension expense compared to the actual rate of return on plan assets during 2017, 2016 and 2015 for the U.S. pension and postretirement plans: 2017 2016 2015 Expected rate of return (1) 6.80%/3.00% 7.00% 7.00% Actual rate of return (2) 10.90 4.90 (1.70) (1) In 2017, the VEBA Trust was funded for postretirement benefits with an expected rate of return of assets of 3.00% . (2) Actual rates of return are presented net of fees. For the non-U.S. pension plans, pension expense for 2017 was reduced by the expected return of $299 million , compared with the actual return of $462 million . Pension expense for 2016 and 2015 was reduced by expected returns of $287 million and $323 million , respectively. Mortality Tables At December 31, 2017, the Company maintained the Retirement Plan 2014 (RP-2014) mortality table and adopted the Mortality Projection 2017 (MP-2017) projection table for the U.S. plans. U.S. plans 2017 (1) 2016 (2) Mortality Pension RP-2014/MP-2017 RP-2014/MP-2016 Postretirement RP-2014/MP-2017 RP-2014/MP-2016 (1) The RP-2014 table is the white-collar RP-2014 table. The MP-2017 projection scale is projected from 2006, with convergence to .75% ultimate rate of annual improvement by 2033. (2) The RP-2014 table is the white-collar RP-2014 table, with a 4% increase in rates to reflect the lower life expectancy of Citi plan participants. The MP-2016 projection scale is projected from 2011, with convergence to 0.75% ultimate rate of annual improvement by 2032. Sensitivities of Certain Key Assumptions The following tables summarize the effect on pension expense of a one-percentage-point change in the discount rate: One-percentage-point increase In millions of dollars 2017 2016 2015 U.S. plans $ 29 $ 31 $ 26 Non-U.S. plans (27 ) (33 ) (32 ) One-percentage-point decrease In millions of dollars 2017 2016 2015 U.S. plans $ (44 ) $ (47 ) $ (44 ) Non-U.S. plans 41 37 44 Since the U.S. qualified pension plan was frozen, most of the prospective service cost has been eliminated and the gain/loss amortization period was changed to the life expectancy for inactive participants. As a result, pension expense for the U.S. qualified pension plan is driven more by interest costs than service costs, and an increase in the discount rate would increase pension expense, while a decrease in the discount rate would decrease pension expense. The following tables summarize the effect on pension expense of a one-percentage-point change in the expected rates of return: One-percentage-point increase In millions of dollars 2017 2016 2015 U.S. plans $ (127 ) $ (127 ) $ (128 ) Non-U.S. plans (64 ) (61 ) (63 ) One-percentage-point decrease In millions of dollars 2017 2016 2015 U.S. plans $ 127 $ 127 $ 128 Non-U.S. plans 64 61 63 Health Care Cost Trend Rate Assumed health care cost trend rates were as follows: 2017 2016 Health care cost increase rate for U.S. plans Following year 6.50% 6.50% Ultimate rate to which cost increase is assumed to decline 5.00 5.00 Year in which the ultimate rate is reached (1) 2023 2023 (1) Weighted average for plans with different following year and ultimate rates. 2017 2016 Health care cost increase rate for Non-U.S. plans (weighted average) Following year 6.87% 6.86% Ultimate rate to which cost increase is assumed to decline 6.87 6.85 Range of years in which the ultimate rate is reached 2018–2019 2017–2029 A one-percentage-point change in assumed health care cost trend rates would have the following effects: One- percentage- point increase One- percentage- point decrease In millions of dollars 2017 2016 2017 2016 U.S. plans Effect on benefits earned and interest cost for postretirement plans $ 1 $ 1 $ (1 ) $ (1 ) Effect on accumulated postretirement benefit obligation for postretirement plans 33 30 (29 ) (26 ) One-percentage- point increase One- percentage- point decrease In millions of dollars 2017 2016 2017 2016 Non-U.S. plans Effect on benefits earned and interest cost for postretirement plans $ 13 $ 12 $ (10 ) $ (10 ) Effect on accumulated postretirement benefit obligation for postretirement plans 150 144 (125 ) (118 ) Plan Assets Citigroup’s pension and postretirement plans’ asset allocations for the U.S. plans and the target allocations by asset category based on asset fair values, are as follows: Target asset allocation U.S. pension assets at December 31, U.S. postretirement assets at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities (2) 0-30% 20 % 18 % 20 % 18 % Debt securities (3) 25-72 48 47 48 47 Real estate 0-10 5 5 5 5 Private equity 0-12 3 4 3 4 Other investments 0-37 24 26 24 26 Total 100 % 100 % 100 % 100 % (1) Asset allocations for the U.S. plans are set by investment strategy, not by investment product. For example, private equities with an underlying investment in real estate are classified in the real estate asset category, not private equity. (2) Equity securities in the U.S. pension and postretirement plans do not include any Citigroup common stock at the end of 2017 and 2016. (3) In December 2017, Citi contributed $140 million to the VEBA Trust for postretirement benefits, which amount was invested solely in debt securities which are not reflected in the table above. Third-party investment managers and advisers provide their services to Citigroup’s U.S. pension and postretirement plans. Assets are rebalanced as the Company’s Pension Plan Investment Committee deems appropriate. Citigroup’s investment strategy, with respect to its assets, is to maintain a globally diversified investment portfolio across several asset classes that, when combined with Citigroup’s contributions to the plans, will maintain the plans’ ability to meet all required benefit obligations. Citigroup’s pension and postretirement plans’ weighted-average asset allocations for the non-U.S. plans and the actual ranges, and the weighted-average target allocations by asset category based on asset fair values, are as follows: Non-U.S. pension plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-63% 0-67% 0–69% 15 % 14 % Debt securities 0-100 0-99 0–100 79 79 Real estate 0-18 0-18 0–18 1 1 Other investments 0-100 0-100 0–100 5 6 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. Non-U.S. postretirement plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-37% 0-38% 0–38% 38 % 38 % Debt securities 58-100 58-100 57–100 58 58 Other investments 0-5 0-4 0–4 4 4 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. Fair Value Disclosure For information on fair value measurements, including descriptions of Levels 1, 2 and 3 of the fair value hierarchy and the valuation methodology utilized by the Company, see Notes 1 and 24 to the Consolidated Financial Statements. ASU 2015-07 removed the requirement to categorize within the fair value hierarchy investments for which fair value is measured using the NAV per share practical expedient. Certain investments may transfer between the fair value hierarchy classifications during the year due to changes in valuation methodology and pricing sources. Plan assets by detailed asset categories and the fair value hierarchy are as follows: U.S. pension and postretirement benefit plans (1) In millions of dollars Fair value measurement at December 31, 2017 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 726 $ — $ — $ 726 Non-U.S. equities 926 — — 926 Mutual funds 271 — — 271 Commingled funds — 1,184 — 1,184 Debt securities 1,381 3,080 — 4,461 Annuity contracts — — 1 1 Derivatives 11 323 — 334 Other investments — — 22 22 Total investments $ 3,315 $ 4,587 $ 23 $ 7,925 Cash and short-term investments $ 257 $ 1,004 $ — $ 1,261 Other investment liabilities (60 ) (343 ) — (403 ) Net investments at fair value $ 3,512 $ 5,248 $ 23 $ 8,783 Other investment receivables redeemed at NAV $ 16 Securities valued at NAV 4,189 Total net assets $ 12,988 (1) The investments of the U.S. pension and postretirement plans are commingled in one trust. At December 31, 2017, the allocable interests of the U.S. pension and postretirement plans were 99.0% and 1.0% , respectively. In 2017, the VEBA Trust was funded for postretirement benefits. U.S. pension and postretirement benefit plans (1) In millions of dollars Fair value measurement at December 31, 2016 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 639 $ — $ — $ 639 Non-U.S. equities 773 — — 773 Mutual funds 216 — — 216 Commingled funds — 866 — 866 Debt securities 1,297 2,845 — 4,142 Annuity contracts — — 1 1 Derivatives 8 543 — 551 Other investments — — 4 4 Total investments $ 2,933 $ 4,254 $ 5 $ 7,192 Cash and short-term investments $ 116 $ 1,239 $ — $ 1,355 Other investment liabilities (106 ) (553 ) — (659 ) Net investments at fair value $ 2,943 $ 4,940 $ 5 $ 7,888 Other investment receivables redeemed at NAV $ 100 Securities valued at NAV 4,504 Total net assets $ 12,492 (1) The investments of the U.S. pension and postretirement plans are commingled in one trust. At December 31, 2016, the allocable interests of the U.S. pension and postretirement plans were 99.0% and 1.0% , respectively. Non-U.S. pension and postretirement benefit plans In millions of dollars Fair value measurement at December 31, 2017 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 4 $ 12 $ — $ 16 Non-U.S. equities 103 122 1 226 Mutual funds 3,098 74 — 3,172 Commingled funds 24 — — 24 Debt securities 3,999 1,555 7 5,561 Real estate — 3 1 4 Annuity contracts — 1 9 10 Derivatives 1 3,102 — 3,103 Other investments 1 — 214 215 Total investments $ 7,230 $ 4,869 $ 232 $ 12,331 Cash and short-term investments $ 119 $ 3 $ — $ 122 Other investment liabilities (2 ) (4,220 ) — (4,222 ) Net investments at fair value $ 7,347 $ 652 $ 232 $ 8,231 Securities valued at NAV $ 16 Total net assets $ 8,247 Non-U.S. pension and postretirement benefit plans In millions of dollars Fair value measurement at December 31, 2016 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 4 $ 11 $ — $ 15 Non-U.S. equities 87 174 1 262 Mutual funds 2,345 406 — 2,751 Commingled funds 22 — — 22 Debt securities 3,406 1,206 7 4,619 Real estate — 3 1 4 Annuity contracts — 1 8 9 Derivatives — 43 — 43 Other investments 1 — 187 188 Total investments $ 5,865 $ 1,844 $ 204 $ 7,913 Cash and short-term investments $ 116 $ 2 $ — $ 118 Other investment liabilities (1 ) (960 ) — (961 ) Net investments at fair value $ 5,980 $ 886 $ 204 $ 7,070 Securities valued at NAV $ 92 Total net assets $ 7,162 Level 3 Rollforward The reconciliations of the beginning and ending balances during the year for Level 3 assets are as follows: In millions of dollars U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2016 Realized gains (losses) Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2017 Annuity contracts $ 1 $ — $ — $ — $ — $ 1 Other investments 4 18 — 22 Total investments $ 5 $ — $ — $ 18 $ — $ 23 In millions of dollars U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2015 Realized gains (losses) Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2016 Annuity contracts $ 25 $ — $ (3 ) $ (21 ) $ — $ 1 Other investments 149 8 (10 ) (143 ) — 4 U.S. equities — (2 ) 2 — — — Total investments $ 174 $ 6 $ (11 ) $ (164 ) $ — $ 5 In millions of dollars Non-U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2016 Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2017 Non-U.S. equities $ 1 $ — $ — $ — $ 1 Debt securities 7 — — — 7 Real estate 1 — — — 1 Annuity contracts 8 1 — — 9 Other investments 187 31 (4 ) — 214 Total investments $ 204 $ 32 $ (4 ) $ — $ 232 In millions of dollars Non-U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2015 Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2016 Non-U.S. equities $ 47 $ (3 ) $ (2 ) $ (41 ) $ 1 Debt securities 5 — 2 — 7 Real estate 1 — — — 1 Annuity contracts 8 — — — 8 Other investments 196 — (9 ) — 187 Total investments $ 257 $ (3 ) $ (9 ) $ (41 ) $ 204 Investment Strategy The Company’s global pension and postretirement funds’ investment strategy is to invest in a prudent manner for the exclusive purpose of providing benefits to participants. The investment strategies are targeted to produce a total return that, when combined with the Company’s contributions to the funds, will maintain the funds’ ability to meet all required benefit obligations. Risk is controlled through diversification of asset types and investments in domestic and international equities, fixed income securities and cash and short-term investments. The target asset allocation in most locations outside the U.S. is primarily in equity and debt securities. These allocations may vary by geographic region and country depending on the nature of applicable obligations and various other regional considerations. The wide variation in the actual range of plan asset allocations for the funded non-U.S. plans is a result of differing local statutory requirements and economic conditions. For example, in certain countries local law requires that all pension plan assets must be invested in fixed income investments, government funds or local-country securities. Significant Concentrations of Risk in Plan Assets The assets of the Company’s pension plans are diversified to limit the impact of any individual investment. The U.S. qualified pension plan is diversified across multiple asset classes, with publicly traded fixed income, hedge funds, publicly traded equity and private equity representing the most significant asset allocations. Investments in these four asset classes are further diversified across funds, managers, strategies, vintages, sectors and geographies, depending on the specific characteristics of each asset class. The pension assets for the Company’s non-U.S. Significant Plans are primarily invested in publicly traded fixed income and publicly traded equity securities. Oversight and Risk Management Practices The framework for the Company’s pension oversight process includes monitoring of retirement plans by plan fiduciaries and/or management at the global, regional or country level, as appropriate. Independent Risk Management contributes to the risk oversight and monitoring for the Company’s U.S. qualified pension plan and non-U.S. Significant Pension Plans. Although the specific components of the oversight process are tailored to the requirements of each region, country and plan, the following elements are common to the Company’s monitoring and risk management process: • periodic asset/liability management studies and strategic asset allocation reviews; • periodic monitoring of funding levels and funding ratios; • periodic monitoring of compliance with asset allocation guidelines; • periodic monitoring of asset class and/or investment manager performance against benchmarks; and • periodic risk capital analysis and stress testing. Estimated Future Benefit Payments The Company expects to pay the following estimated benefit payments in future years: Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans 2018 $ 787 $ 432 $ 61 $ 65 2019 814 398 60 70 2020 846 425 59 75 2021 864 434 58 81 2022 876 457 56 87 2023–2027 4,480 2,532 248 532 Prescription Drugs In December 2003, the Medicare Prescription Drug Improvement and Modernization Act of 2003 (Act of 2003) was enacted. The Act of 2003 established a prescription drug benefit under Medicare known as “Medicare Part D,” and a federal subsidy to spon

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Details of the Company’s income tax provision are presented below: Income Tax Provision In millions of dollars 2017 2016 2015 Current Federal $ 332 $ 1,016 $ 861 Non-U.S. 3,910 3,585 3,397 State 269 384 388 Total current income taxes $ 4,511 $ 4,985 $ 4,646 Deferred Federal $ 24,902 $ 1,280 $ 3,019 Non-U.S. (377 ) 53 (4 ) State 352 126 (221 ) Total deferred income taxes $ 24,877 $ 1,459 $ 2,794 Provision for income tax on continuing operations before non-controlling interests (1) $ 29,388 $ 6,444 $ 7,440 Provision (benefit) for income taxes on discontinued operations 7 (22 ) (29 ) Income tax expense (benefit) reported in stockholders’ equity related to: FX translation 188 (402 ) (906 ) Investment securities (149 ) 59 (498 ) Employee stock plans (4 ) 13 (35 ) Cash flow hedges (12 ) 27 176 Benefit plans 13 (30 ) (24 ) FVO DVA (250 ) (201 ) — Retained earnings (2) (295 ) — — Income taxes before non-controlling interests $ 28,886 $ 5,888 $ 6,124 (1) Includes the effect of securities transactions and other-than-temporary-impairment losses resulting in a provision (benefit) of $272 million and $(22) million in 2017, $332 million and $(217) million in 2016 and $239 million and $(93) million in 2015, respectively. (2) Reflects the tax effect of the accounting change for ASU 2017-08, “ Premium Amortization on Purchased Callable Debt Securities ”. See Note 1 to the Consolidated Financial Statements. Tax Rate The reconciliation of the federal statutory income tax rate to the Company’s effective income tax rate applicable to income from continuing operations (before non-controlling interests and the cumulative effect of accounting changes) for each of the periods indicated is as follows: 2017 2016 2015 Federal statutory rate 35.0 % 35.0 % 35.0 % State income taxes, net of federal benefit 1.1 1.8 1.7 Non-U.S. income tax rate differential (1.6 ) (3.6 ) (4.6 ) Audit settlements (1) — (0.6 ) (1.7 ) Effect of tax law changes (2) 99.7 — 0.4 Basis difference in affiliates (2.1 ) (0.1 ) — Tax advantaged investments (2.2 ) (2.4 ) (1.8 ) Other, net (0.8 ) (0.1 ) 1.0 Effective income tax rate 129.1 % 30.0 % 30.0 % (1) For 2016, primarily relates to the conclusion of an IRS audit for 2012–2013. For 2015, primarily relates to the conclusion of a New York City tax audit for 2009–2011. (2) For 2017, includes the $22,594 million charge for Tax Reform. For 2015, includes the results of tax reforms enacted in New York City and several states, which resulted in a DTA charge of approximately $101 million . As set forth in the table above, Citi’s effective tax rate for 2017 was 129.1% ( 29.8% before the effect of Tax Reform, about the same as the effective tax rate in 2016). Deferred Income Taxes Deferred income taxes at December 31 related to the following: In millions of dollars 2017 2016 Deferred tax assets Credit loss deduction $ 3,423 $ 5,146 Deferred compensation and employee benefits 1,585 3,798 Repositioning and settlement reserves 454 1,033 U.S. tax on non-U.S. earnings 2,452 10,050 Investment and loan basis differences 3,384 5,594 Cash flow hedges 233 327 Tax credit and net operating loss carry-forwards 21,575 20,793 Fixed assets and leases 1,090 1,739 Other deferred tax assets 1,988 2,714 Gross deferred tax assets $ 36,184 $ 51,194 Valuation allowance $ 9,387 $ — Deferred tax assets after valuation allowance $ 26,797 $ 51,194 Deferred tax liabilities Intangibles $ (1,247 ) $ (1,711 ) Debt issuances (294 ) (641 ) Non-U.S. withholding taxes (668 ) (739 ) Interest-related items (562 ) (765 ) Other deferred tax liabilities (1,545 ) (670 ) Gross deferred tax liabilities $ (4,316 ) $ (4,526 ) Net deferred tax assets $ 22,481 $ 46,668 Unrecognized Tax Benefits The following is a rollforward of the Company’s unrecognized tax benefits: In millions of dollars 2017 2016 2015 Total unrecognized tax benefits at January 1 $ 1,092 $ 1,235 $ 1,060 Net amount of increases for current year’s tax positions 43 34 32 Gross amount of increases for prior years’ tax positions 324 273 311 Gross amount of decreases for prior years’ tax positions (246 ) (225 ) (61 ) Amounts of decreases relating to settlements (199 ) (174 ) (45 ) Reductions due to lapse of statutes of limitation (11 ) (21 ) (22 ) Foreign exchange, acquisitions and dispositions 10 (30 ) (40 ) Total unrecognized tax benefits at December 31 $ 1,013 $ 1,092 $ 1,235 The total amounts of unrecognized tax benefits at December 31, 2017, 2016 and 2015 that, if recognized, would affect Citi’s tax expense, are $0.8 billion , $0.8 billion and $0.9 billion , respectively. The remaining uncertain tax positions have offsetting amounts in other jurisdictions or are temporary differences. Interest and penalties (not included in “unrecognized tax benefits” above) are a component of Provision for income taxes . 2017 2016 2015 In millions of dollars Pretax Net of tax Pretax Net of tax Pretax Net of tax Total interest and penalties on the Consolidated Balance Sheet at January 1 $ 260 $ 164 $ 233 $ 146 $ 269 $ 169 Total interest and penalties in the Consolidated Statement of Income 5 21 105 68 (29 ) (18 ) Total interest and penalties on the Consolidated Balance Sheet at December 31 (1) 121 101 260 164 233 146 (1) Includes $3 million for non-U.S. penalties in 2017, 2016 and 2015. Also includes $3 million for state penalties in 2017, 2016 and 2015. As of December 31, 2017, Citi is under audit by the Internal Revenue Service and other major taxing jurisdictions around the world. It is thus reasonably possible that significant changes in the gross balance of unrecognized tax benefits may occur within the next 12 months, although Citi does not expect such audits to result in amounts that would cause a significant change to its effective tax rate. The following are the major tax jurisdictions in which the Company and its affiliates operate and the earliest tax year subject to examination: Jurisdiction Tax year United States 2014 Mexico 2011 New York State and City 2009 United Kingdom 2014 India 2014 Singapore 2011 Hong Kong 2011 Ireland 2013 Non-U.S. Earnings Non-U.S. pretax earnings approximated $13.7 billion in 2017 (of which a $0.1 billion loss was recorded in Discontinued operations ), $11.6 billion in 2016 and $11.3 billion in 2015. As a U.S. corporation, Citigroup and its U.S. subsidiaries are currently subject to U.S. taxation on all non-U.S. pretax earnings of a non-U.S. branch. Starting in 2018, there will be a separate foreign tax credit (FTC) basket for branches. Also starting in 2018, dividends from a non-U.S. subsidiary or affiliate are effectively exempt from U.S. taxation. The Company provides income taxes on the book over tax basis differences of non-U.S. subsidiaries except to the extent that such differences are indefinitely reinvested outside the U.S. At December 31, 2017, $14.1 billion of basis differences of non-U.S. subsidiaries was indefinitely invested. At the existing tax rates, additional taxes (net of U.S. FTCs) of $3.5 billion would have to be provided if such basis differences were realized. These amounts are significantly less than the corresponding amounts at December 31, 2016 due to the deemed repatriation of unremitted earnings of non-U.S. subsidiaries under the provisions of Tax Reform. Income taxes are not provided for the Company’s “savings bank base year bad debt reserves” that arose before 1988, because under current U.S. tax rules, such taxes will become payable only to the extent that such amounts are distributed in excess of limits prescribed by federal law. At December 31, 2017, the amount of the base year reserves totaled approximately $358 million (subject to a tax of $75 million ). Deferred Tax Assets As of December 31, 2017, Citi had a valuation allowance of $9.4 billion , composed of valuation allowances of $5.7 billion on its FTC carry-forwards, $2.2 billion on its U.S. residual DTA related to its non-U.S. branches, $1.4 billion on local non-U.S. DTAs and $0.1 billion on state net operating loss carry-forwards. The valuation allowance against FTCs results from the impact of the lower tax rate and the new separate FTC basket for non-U.S. branches, as well as diminished ability under Tax Reform to generate income from sources outside the U.S. to support FTC utilization. The absolute amount of Citi’s post-Tax Reform-related valuation allowances may change in future years. First, the separate FTC basket for non-U.S. branches will result in additional DTAs (for FTCs) requiring a valuation allowance, given that the local tax rate for these branches exceeds on average the U.S. tax rate of 21%. Second, in Citi’s general basket for FTCs, changes in the forecasted amount of income in U.S. locations derived from sources outside the U.S. could alter the amount of valuation allowance that is needed against such FTCs. As of December 31, 2016, Citi had no valuation allowance on its DTAs. The following table summarizes Citi’s DTAs: In billions of dollars Jurisdiction/component (1) DTAs balance December 31, 2017 DTAs balance December 31, 2016 U.S. federal (2) Net operating losses (NOLs) (3) $ 2.3 $ 3.5 Foreign tax credits (FTCs) 7.6 14.2 General business credits (GBCs) 1.4 0.9 Future tax deductions and credits 4.8 21.9 Total U.S. federal $ 16.1 $ 40.5 State and local New York NOLs $ 2.3 $ 2.2 Other state NOLs 0.2 0.2 Future tax deductions 1.3 1.7 Total state and local $ 3.8 $ 4.1 Non-U.S. NOLs $ 0.6 $ 0.6 Future tax deductions 2.0 1.5 Total non-U.S. $ 2.6 $ 2.1 Total $ 22.5 $ 46.7 (1) All amounts are net of valuation allowances. (2) Included in the net U.S. federal DTAs of $16.1 billion as of December 31, 2017 were deferred tax liabilities of $2.4 billion that will reverse in the relevant carry-forward period and may be used to support the DTAs. (3) Consists of non-consolidated tax return NOL carry-forwards that are eventually expected to be utilized in Citigroup’s consolidated tax return. The following table summarizes the amounts of tax carry-forwards and their expiration dates: In billions of dollars Year of expiration December 31, 2017 December 31, 2016 U.S. tax return foreign tax credit carry-forwards (1) 2018 $ 0.4 $ 2.7 2019 1.3 1.3 2020 3.2 3.1 2021 2.0 1.9 2022 3.4 3.3 2023 (2) 0.4 0.5 2025 (2) 1.4 1.4 2027 (2) 1.2 — Total U.S. tax return foreign tax credit carry-forwards $ 13.3 $ 14.2 U.S. tax return general business credit carry-forwards 2032 $ 0.2 $ — 2033 0.3 0.3 2034 0.2 0.2 2035 0.2 0.2 2036 0.2 0.2 2037 0.3 — Total U.S. tax return general business credit carry-forwards $ 1.4 $ 0.9 U.S. subsidiary separate federal NOL carry-forwards 2027 $ 0.2 $ 0.2 2028 0.1 0.1 2030 0.3 0.3 2032 0.1 — 2033 1.6 1.7 2034 2.3 2.3 2035 3.3 3.2 2036 2.1 2.2 2037 1.0 — Total U.S. subsidiary separate federal NOL carry-forwards (3) $ 11.0 $ 10.0 New York State NOL carry-forwards (3) 2034 $ 13.6 $ 13.0 New York City NOL carry-forwards (3) 2034 $ 13.1 $ 12.2 Non-U.S. NOL carry-forwards (1) Various $ 2.0 $ 2.1 (1) Before valuation allowance. (2) The $3.0 billion in FTC carry-forwards that expire in 2023, 2025 and 2027 are in a non-consolidated tax return entity but are eventually expected to be utilized (net of valuation allowances) in Citigroup’s consolidated tax return. (3) Pretax. The time remaining for utilization of the FTC component has shortened, given the passage of time. Although realization is not assured, Citi believes that the realization of the recognized net DTAs of $22.5 billion at December 31, 2017 is more-likely-than-not based upon expectations as to future taxable income in the jurisdictions in which the DTAs arise and available tax planning strategies (as defined in ASC 740, Income Taxes ) that would be implemented, if necessary, to prevent a carry-forward from expiring. Citi believes the U.S. federal and New York state and city NOL carry-forward period of 20 years provides enough time to fully utilize the DTAs pertaining to the existing NOL carry-forwards. This is due to Citi’s forecast of sufficient U.S. taxable income and the fact that New York state and city continue to tax Citi’s non-U.S. income. With respect to the FTCs component of the DTAs, the carry-forward period is 10 years. Utilization of FTCs in any year is restricted to 21% of foreign source taxable income in that year. However, overall domestic losses that Citi has incurred of approximately $52 billion as of December 31, 2017 are allowed to be reclassified as foreign source income to the extent of 50 %– 100% of domestic source income produced in subsequent years. Such resulting foreign source income would cover the FTC carry-forwards after valuation allowance. As noted in the tables above, Citi’s FTC carry-forwards were $7.6 billion ( $13.3 billion before valuation allowance) as of December 31, 2017, compared to $14.2 billion as of December 31, 2016. This decrease represented $6.6 billion of the $24.2 billion decrease in Citi’s overall DTAs during 2017. Citi believes that it will generate sufficient U.S. taxable income within the 10-year carry-forward period to be able to utilize the net FTCs after the valuation allowance, in addition to any FTCs produced in the tax return for such period, which must be used prior to any carry-forward utilization.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table reconciles the income and share data used in the basic and diluted earnings per share (EPS) computations: In millions, except per-share amounts 2017 2016 2015 Income (loss) from continuing operations before attribution of noncontrolling interests $ (6,627 ) $ 15,033 $ 17,386 Less: Noncontrolling interests from continuing operations 60 63 90 Net income (loss) from continuing operations (for EPS purposes) $ (6,687 ) $ 14,970 $ 17,296 Income (loss) from discontinued operations, net of taxes (111 ) (58 ) (54 ) Citigroup's net income (loss) $ (6,798 ) $ 14,912 $ 17,242 Less: Preferred dividends (1) 1,213 1,077 769 Net income (loss) available to common shareholders $ (8,011 ) $ 13,835 $ 16,473 Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS 37 195 224 Net income (loss) allocated to common shareholders for basic EPS $ (8,048 ) $ 13,640 $ 16,249 Add: Interest expense, net of tax, and dividends on convertible securities and adjustment of undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to diluted EPS — — — Net income (loss) allocated to common shareholders for diluted EPS $ (8,048 ) $ 13,640 $ 16,249 Weighted-average common shares outstanding applicable to basic EPS 2,698.5 2,888.1 3,004.0 Effect of dilutive securities (2) Options (3) — 0.1 3.6 Other employee plans non-dividend eligible — 0.1 0.1 Adjusted weighted-average common shares outstanding applicable to diluted EPS (4) 2,698.5 2,888.3 3,007.7 Basic earnings per share (5) Income (loss) from continuing operations $ (2.94 ) $ 4.74 $ 5.43 Discontinued operations (0.04 ) (0.02 ) (0.02 ) Net income (loss) $ (2.98 ) $ 4.72 $ 5.41 Diluted earnings per share (5) Income (loss) from continuing operations $ (2.94 ) $ 4.74 $ 5.42 Discontinued operations (0.04 ) (0.02 ) (0.02 ) Net income (loss) $ (2.98 ) $ 4.72 $ 5.40 (1) See Note 20 to the Consolidated Financial Statements for the potential future impact of preferred stock dividends. (2) Warrants issued to the U.S. Treasury as part of the Troubled Asset Relief Program (TARP) and the loss-sharing agreement (all of which were subsequently sold to the public in January 2011), with exercise prices of $178.50 and $104.96 per share for approximately 21.0 million and 25.5 million shares of Citigroup common stock, respectively. Both warrants were not included in the computation of earnings per share in 2017 , 2016 and 2015 because they were anti-dilutive. (3) During 2017 , 2016 and 2015 , weighted-average options to purchase 0.8 million , 4.2 million and 0.9 million shares of common stock, respectively, were outstanding but not included in the computation of earnings per share because the weighted-average exercise prices of $204.80 , $98.01 and $199.16 per share, respectively, were anti-dilutive. (4) Due to rounding, common shares outstanding applicable to basic EPS and the effect of dilutive securities may not sum to common shares outstanding applicable to diluted EPS. (5) Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.

FEDERAL FUNDS, SECURITIES BORRO

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS	12 Months Ended
	Dec. 31, 2017
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS	FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS Federal funds sold and securities borrowed or purchased under agreements to resell , at their respective carrying values, consisted of the following: December 31 December 31 In millions of dollars 2017 2016 Federal funds sold $ — $ — Securities purchased under agreements to resell 130,984 131,473 Deposits paid for securities borrowed 101,494 105,340 Total (1) $ 232,478 $ 236,813 Federal funds purchased and securities loaned or sold under agreements to repurchase , at their respective carrying values, consisted of the following: December 31 December 31 In millions of dollars 2017 2016 Federal funds purchased $ 326 $ 178 Securities sold under agreements to repurchase 142,646 125,685 Deposits received for securities loaned 13,305 15,958 Total (1) $ 156,277 $ 141,821 (1) The above tables do not include securities-for-securities lending transactions of $14.0 billion and $9.3 billion at December 31, 2017 and December 31, 2016, respectively, where the Company acts as lender and receives securities that can be sold or pledged as collateral. In these transactions, the Company recognizes the securities received at fair value within Other assets and the obligation to return those securities as a liability within Brokerage payables . The resale and repurchase agreements represent collateralized financing transactions. Citi executes these transactions primarily through its broker-dealer subsidiaries to facilitate customer matched-book activity and to efficiently fund a portion of Citi’s trading inventory. Transactions executed by Citi’s bank subsidiaries primarily facilitate customer financing activity. To maintain reliable funding under a wide range of market conditions, including under periods of stress, Citi manages these activities by taking into consideration the quality of the underlying collateral, and stipulating financing tenor. Citi manages the risks in its collateralized financing transactions by conducting daily stress tests to account for changes in capacity, tenors, haircut, collateral profile and client actions. Additionally, Citi maintains counterparty diversification by establishing concentration triggers and assessing counterparty reliability and stability under stress. It is the Company’s policy to take possession of the underlying collateral, monitor its market value relative to the amounts due under the agreements and, when necessary, require prompt transfer of additional collateral in order to maintain contractual margin protection. For resale and repurchase agreements, when necessary, the company posts additional collateral in order to maintain contractual margin protection. Collateral typically consists of government and government-agency securities, corporate and municipal bonds, equities and mortgage-backed and other asset-backed securities. The resale and repurchase agreements are generally documented under industry standard agreements that allow the prompt close-out of all transactions (including the liquidation of securities held) and the offsetting of obligations to return cash or securities by the non-defaulting party, following a payment default or other type of default under the relevant master agreement. Events of default generally include (i) failure to deliver cash or securities as required under the transaction, (ii) failure to provide or return cash or securities as used for margining purposes, (iii) breach of representation, (iv) cross-default to another transaction entered into among the parties, or, in some cases, their affiliates, and (v) a repudiation of obligations under the agreement. The counterparty that receives the securities in these transactions is generally unrestricted in its use of the securities, with the exception of transactions executed on a tri-party basis, where the collateral is maintained by a custodian and operational limitations may restrict its use of the securities. A substantial portion of the resale and repurchase agreements is recorded at fair value, as described in Notes 24 and 25 to the Consolidated Financial Statements. The remaining portion is carried at the amount of cash initially advanced or received, plus accrued interest, as specified in the respective agreements. The securities borrowing and lending agreements also represent collateralized financing transactions similar to the resale and repurchase agreements. Collateral typically consists of government and government-agency securities and corporate debt and equity securities. Similar to the resale and repurchase agreements, securities borrowing and lending agreements are generally documented under industry standard agreements that allow the prompt close-out of all transactions (including the liquidation of securities held) and the offsetting of obligations to return cash or securities by the non-defaulting party, following a payment default or other default by the other party under the relevant master agreement. Events of default and rights to use securities under the securities borrowing and lending agreements are similar to the resale and repurchase agreements referenced above. A substantial portion of securities borrowing and lending agreements is recorded at the amount of cash advanced or received. The remaining portion is recorded at fair value as the Company elected the fair value option for certain securities borrowed and loaned portfolios, as described in Note 25 to the Consolidated Financial Statements. With respect to securities loaned, the Company receives cash collateral in an amount generally in excess of the market value of the securities loaned. The Company monitors the market value of securities borrowed and securities loaned on a daily basis and obtains or posts additional collateral in order to maintain contractual margin protection. The enforceability of offsetting rights incorporated in the master netting agreements for resale and repurchase agreements and securities borrowing and lending agreements is evidenced to the extent that a supportive legal opinion has been obtained from counsel of recognized standing that provides the requisite level of certainty regarding the enforceability of these agreements. Also, the exercise of rights by the non-defaulting party to terminate and closeout transactions on a net basis under these agreements will not be stayed or avoided under applicable law upon an event of default including bankruptcy, insolvency or similar proceeding. A legal opinion may not have been sought or obtained for certain jurisdictions where local law is silent or sufficiently ambiguous to determine the enforceability of offsetting rights or where adverse case law or conflicting regulation may cast doubt on the enforceability of such rights. In some jurisdictions and for some counterparty types, the insolvency law for a particular counterparty type may be nonexistent or unclear as overlapping regimes may exist. For example, this may be the case for certain sovereigns, municipalities, central banks and U.S. pension plans. The following tables present the gross and net resale and repurchase agreements and securities borrowing and lending agreements and the related offsetting amount permitted under ASC 210-20-45. The tables also include amounts related to financial instruments that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default occurred and a legal opinion supporting enforceability of the offsetting rights has been obtained. Remaining exposures continue to be secured by financial collateral, but the Company may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right. As of December 31, 2017 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 204,460 $ 73,476 $ 130,984 $ 103,022 $ 27,962 Deposits paid for securities borrowed 101,494 — 101,494 22,271 79,223 Total $ 305,954 $ 73,476 $ 232,478 $ 125,293 $ 107,185 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 216,122 $ 73,476 $ 142,646 $ 73,716 $ 68,930 Deposits received for securities loaned 13,305 — 13,305 4,079 9,226 Total $ 229,427 $ 73,476 $ 155,951 $ 77,795 $ 78,156 As of December 31, 2016 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 176,284 $ 44,811 $ 131,473 $ 102,874 $ 28,599 Deposits paid for securities borrowed 105,340 — 105,340 16,200 89,140 Total $ 281,624 $ 44,811 $ 236,813 $ 119,074 $ 117,739 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 170,496 $ 44,811 $ 125,685 $ 63,517 $ 62,168 Deposits received for securities loaned 15,958 — 15,958 3,529 12,429 Total $ 186,454 $ 44,811 $ 141,643 $ 67,046 $ 74,597 (1) Includes financial instruments subject to enforceable master netting agreements that are permitted to be offset under ASC 210-20-45. (2) The total of this column for each period excludes federal funds sold/purchased. See tables above. (3) Includes financial instruments subject to enforceable master netting agreements that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default has occurred and a legal opinion supporting enforceability of the offsetting right has been obtained. (4) Remaining exposures continue to be secured by financial collateral, but Citi may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right. The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by remaining contractual maturity: As of December 31, 2017 In millions of dollars Open and overnight Up to 30 days 31–90 days Greater than 90 days Total Securities sold under agreements to repurchase $ 82,073 $ 68,372 $ 33,846 $ 31,831 $ 216,122 Deposits received for securities loaned 9,946 266 1,912 1,181 13,305 Total $ 92,019 $ 68,638 $ 35,758 $ 33,012 $ 229,427 As of December 31, 2016 In millions of dollars Open and overnight Up to 30 days 31–90 days Greater than 90 days Total Securities sold under agreements to repurchase $ 79,740 $ 50,399 $ 19,396 $ 20,961 $ 170,496 Deposits received for securities loaned 10,813 2,169 2,044 932 15,958 Total $ 90,553 $ 52,568 $ 21,440 $ 21,893 $ 186,454 The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by class of underlying collateral: As of December 31, 2017 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 58,774 $ — $ 58,774 State and municipal securities 1,605 — 1,605 Foreign government securities 89,576 105 89,681 Corporate bonds 20,194 657 20,851 Equity securities 20,724 11,907 32,631 Mortgage-backed securities 17,791 — 17,791 Asset-backed securities 5,479 — 5,479 Other 1,979 636 2,615 Total $ 216,122 $ 13,305 $ 229,427 As of December 31, 2016 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 66,263 $ — $ 66,263 State and municipal securities 334 — 334 Foreign government securities 52,988 1,390 54,378 Corporate bonds 17,164 630 17,794 Equity securities 12,206 13,913 26,119 Mortgage-backed securities 11,421 — 11,421 Asset-backed securities 5,428 — 5,428 Other 4,692 25 4,717 Total $ 170,496 $ 15,958 $ 186,454

BROKERAGE RECEIVABLES AND BROKE

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES	12 Months Ended
	Dec. 31, 2017
Brokers and Dealers [Abstract]
BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES	BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES Citi has receivables and payables for financial instruments sold to and purchased from brokers, dealers and customers, which arise in the ordinary course of business. Citi is exposed to risk of loss from the inability of brokers, dealers or customers to pay for purchases or to deliver the financial instruments sold, in which case Citi would have to sell or purchase the financial instruments at prevailing market prices. Credit risk is reduced to the extent that an exchange or clearing organization acts as a counterparty to the transaction and replaces the broker, dealer or customer in question. Citi seeks to protect itself from the risks associated with customer activities by requiring customers to maintain margin collateral in compliance with regulatory and internal guidelines. Margin levels are monitored daily, and customers deposit additional collateral as required. Where customers cannot meet collateral requirements, Citi may liquidate sufficient underlying financial instruments to bring the customer into compliance with the required margin level. Exposure to credit risk is impacted by market volatility, which may impair the ability of clients to satisfy their obligations to Citi. Credit limits are established and closely monitored for customers and for brokers and dealers engaged in forwards, futures and other transactions deemed to be credit sensitive. Brokerage receivables and Brokerage payables consisted of the following: December 31, In millions of dollars 2017 2016 Receivables from customers $ 19,215 $ 10,374 Receivables from brokers, dealers and clearing organizations 19,169 18,513 Total brokerage receivables (1) $ 38,384 $ 28,887 Payables to customers $ 38,741 $ 37,237 Payables to brokers, dealers and clearing organizations 22,601 19,915 Total brokerage payables (1) $ 61,342 $ 57,152 (1) Includes brokerage receivables and payables recorded by Citi broker-dealer entities that are accounted for in accordance with the AICPA Accounting Guide for Brokers and Dealers in Securities as codified in ASC 940-320.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS Overview The following table presents Citi’s investments by category: December 31, In millions of dollars 2017 2016 Securities available-for-sale (AFS) $ 290,914 $ 299,424 Debt securities held-to-maturity (HTM) (1) 53,320 45,667 Non-marketable equity securities carried at fair value (2) 1,206 1,774 Non-marketable equity securities carried at cost (3) 6,850 6,439 Total investments $ 352,290 $ 353,304 (1) Carried at adjusted amortized cost basis, net of any credit-related impairment. (2) Unrealized gains and losses for non-marketable equity securities carried at fair value are recognized in earnings. (3) Primarily consists of shares issued by the Federal Reserve Bank, Federal Home Loan Banks, and various clearing houses of which Citigroup is a member. The following table presents interest and dividend income on investments: In millions of dollars 2017 2016 2015 Taxable interest $ 7,538 $ 6,858 $ 6,433 Interest exempt from U.S. federal income tax 535 549 196 Dividend income 222 175 388 Total interest and dividend income $ 8,295 $ 7,582 $ 7,017 The following table presents realized gains and losses on the sale of investments, which excludes losses from other-than-temporary impairment (OTTI): In millions of dollars 2017 2016 2015 Gross realized investment gains $ 1,039 $ 1,460 $ 1,124 Gross realized investment losses (261 ) (512 ) (442 ) Net realized gains on sale of investments $ 778 $ 948 $ 682 The Company has sold certain debt securities that were classified as HTM. These sales were in response to significant deterioration in the creditworthiness of the issuers or securities or because the Company has collected a substantial portion (at least 85% ) of the principal outstanding at acquisition of the security. In addition, certain other securities were reclassified to AFS investments in response to significant credit deterioration. Because the Company generally intends to sell these reclassified securities, Citi recorded OTTI on the securities. The following table sets forth, for the periods indicated, the carrying value of HTM securities sold and reclassified to AFS, as well as the related gain (loss) or the OTTI losses recorded on these securities. In millions of dollars 2017 2016 2015 Carrying value of HTM securities sold $ 81 $ 49 $ 392 Net realized gain (loss) on sale of HTM securities 13 14 10 Carrying value of securities reclassified to AFS 74 150 243 OTTI losses on securities reclassified to AFS — (6 ) (15 ) Securities Available-for-Sale The amortized cost and fair value of AFS securities were as follows: 2017 2016 In millions of dollars Amortized cost Gross unrealized gains Gross unrealized losses Fair value Amortized cost Gross unrealized gains Gross unrealized losses Fair value Debt securities AFS Mortgage-backed securities (1) U.S. government-sponsored agency guaranteed $ 42,116 $ 125 $ 500 $ 41,741 $ 38,663 $ 248 $ 506 $ 38,405 Prime 11 6 — 17 2 — — 2 Alt-A 26 90 — 116 43 7 — 50 Non-U.S. residential 2,744 13 6 2,751 3,852 13 7 3,858 Commercial 334 — 2 332 357 2 1 358 Total mortgage-backed securities $ 45,231 $ 234 $ 508 $ 44,957 $ 42,917 $ 270 $ 514 $ 42,673 U.S. Treasury and federal agency securities U.S. Treasury $ 108,344 $ 77 $ 971 $ 107,450 $ 113,606 $ 629 $ 452 $ 113,783 Agency obligations 10,813 7 124 10,696 9,952 21 85 9,888 Total U.S. Treasury and federal agency securities $ 119,157 $ 84 $ 1,095 $ 118,146 $ 123,558 $ 650 $ 537 $ 123,671 State and municipal (2) $ 8,870 $ 140 $ 245 $ 8,765 $ 10,797 $ 80 $ 757 $ 10,120 Foreign government 100,615 508 590 100,533 98,112 590 554 98,148 Corporate 14,144 51 86 14,109 17,195 105 176 17,124 Asset-backed securities (1) 3,906 14 2 3,918 6,810 6 22 6,794 Other debt securities 297 — — 297 503 — — 503 Total debt securities AFS $ 292,220 $ 1,031 $ 2,526 $ 290,725 $ 299,892 $ 1,701 $ 2,560 $ 299,033 Marketable equity securities AFS $ 186 $ 4 $ 1 $ 189 $ 377 $ 20 $ 6 $ 391 Total securities AFS $ 292,406 $ 1,035 $ 2,527 $ 290,914 $ 300,269 $ 1,721 $ 2,566 $ 299,424 (1) The Company invests in mortgage-backed and asset-backed securities. These securitizations are generally considered VIEs. The Company’s maximum exposure to loss from these VIEs is equal to the carrying amount of the securities, which is reflected in the table above. For mortgage-backed and asset-backed securitizations in which the Company has other involvement, see Note 21 to the Consolidated Financial Statements. (2) In the second quarter of 2017, Citi early adopted ASU 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of purchase premiums and cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. At December 31, 2017 , the amortized cost of approximately 4,600 investments in equity and fixed income securities exceeded their fair value by $2,527 million . Of the $2,527 million , the gross unrealized losses on equity securities were $1 million . Of the remainder, $ 1,854 million represented unrealized losses on fixed income investments that have been in a gross-unrealized-loss position for less than a year and, of these, 99% were rated investment grade; and $ 672 million represented unrealized losses on fixed income investments that have been in a gross-unrealized-loss position for a year or more and, of these, 94% were rated investment grade. Of the $ 672 million mentioned above, $234 million represent state and municipal securities. The following table shows the fair value of AFS securities that have been in an unrealized loss position: Less than 12 months 12 months or longer Total In millions of dollars Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses December 31, 2017 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 30,994 $ 438 $ 2,206 $ 62 $ 33,200 $ 500 Prime — — — — — — Non-U.S. residential 753 6 — — 753 6 Commercial 150 1 57 1 207 2 Total mortgage-backed securities $ 31,897 $ 445 $ 2,263 $ 63 $ 34,160 $ 508 U.S. Treasury and federal agency securities U.S. Treasury $ 79,050 $ 856 $ 7,404 $ 115 $ 86,454 $ 971 Agency obligations 8,857 110 1,163 14 10,020 124 Total U.S. Treasury and federal agency securities $ 87,907 $ 966 $ 8,567 $ 129 $ 96,474 $ 1,095 State and municipal $ 1,009 $ 11 $ 1,155 $ 234 $ 2,164 $ 245 Foreign government 53,206 356 9,051 234 62,257 590 Corporate 6,737 74 859 12 7,596 86 Asset-backed securities 449 1 25 1 474 2 Other debt securities — — — — — — Marketable equity securities AFS 11 1 — — 11 1 Total securities AFS $ 181,216 $ 1,854 $ 21,920 $ 673 $ 203,136 $ 2,527 December 31, 2016 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 23,534 $ 436 $ 2,236 $ 70 $ 25,770 $ 506 Prime 1 — — — 1 — Non-U.S. residential 486 — 1,276 7 1,762 7 Commercial 75 1 58 — 133 1 Total mortgage-backed securities $ 24,096 $ 437 $ 3,570 $ 77 $ 27,666 $ 514 U.S. Treasury and federal agency securities U.S. Treasury $ 44,342 $ 445 $ 1,335 $ 7 $ 45,677 $ 452 Agency obligations 6,552 83 250 2 6,802 85 Total U.S. Treasury and federal agency securities $ 50,894 $ 528 $ 1,585 $ 9 $ 52,479 $ 537 State and municipal $ 1,616 $ 55 $ 3,116 $ 702 $ 4,732 $ 757 Foreign government 38,226 243 8,973 311 47,199 554 Corporate 7,011 129 1,877 47 8,888 176 Asset-backed securities 411 — 3,213 22 3,624 22 Other debt securities 5 — — — 5 — Marketable equity securities AFS 19 2 24 4 43 6 Total securities AFS $ 122,278 $ 1,394 $ 22,358 $ 1,172 $ 144,636 $ 2,566 The following table presents the amortized cost and fair value of AFS debt securities by contractual maturity dates: December 31, 2017 2016 In millions of dollars Amortized cost Fair value Amortized cost Fair value Mortgage-backed securities (1) Due within 1 year $ 45 $ 45 $ 132 $ 132 After 1 but within 5 years 1,306 1,304 736 738 After 5 but within 10 years 1,376 1,369 2,279 2,265 After 10 years (2) 42,504 42,239 39,770 39,538 Total $ 45,231 $ 44,957 $ 42,917 $ 42,673 U.S. Treasury and federal agency securities Due within 1 year $ 4,913 $ 4,907 $ 4,945 $ 4,945 After 1 but within 5 years 111,236 110,238 101,369 101,323 After 5 but within 10 years 3,008 3,001 17,153 17,314 After 10 years (2) — — 91 89 Total $ 119,157 $ 118,146 $ 123,558 $ 123,671 State and municipal Due within 1 year $ 1,792 $ 1,792 $ 2,093 $ 2,092 After 1 but within 5 years 2,579 2,576 2,668 2,662 After 5 but within 10 years 514 528 335 334 After 10 years (2) 3,985 3,869 5,701 5,032 Total $ 8,870 $ 8,765 $ 10,797 $ 10,120 Foreign government Due within 1 year $ 32,130 $ 32,100 $ 32,540 $ 32,547 After 1 but within 5 years 53,034 53,165 51,008 50,881 After 5 but within 10 years 12,949 12,680 12,388 12,440 After 10 years (2) 2,502 2,588 2,176 2,280 Total $ 100,615 $ 100,533 $ 98,112 $ 98,148 All other (3) Due within 1 year $ 3,998 $ 3,991 $ 2,629 $ 2,628 After 1 but within 5 years 9,047 9,027 12,339 12,334 After 5 but within 10 years 3,415 3,431 6,566 6,528 After 10 years (2) 1,887 1,875 2,974 2,931 Total $ 18,347 $ 18,324 $ 24,508 $ 24,421 Total debt securities AFS $ 292,220 $ 290,725 $ 299,892 $ 299,033 (1) Includes mortgage-backed securities of U.S. government-sponsored agencies. (2) Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment rights. (3) Includes corporate, asset-backed and other debt securities. Debt Securities Held-to-Maturity The carrying value and fair value of debt securities HTM were as follows: In millions of dollars Adjusted amortized cost basis (1) Net unrealized gains (losses) recognized in AOCI Carrying value (2) Gross unrealized gains Gross unrealized (losses) Fair value December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 23,854 $ 26 $ 23,880 $ 40 $ (157 ) $ 23,763 Prime — — — — — — Alt-A 206 (65 ) 141 57 — 198 Non-U.S. residential 1,887 (46 ) 1,841 65 — 1,906 Commercial 237 — 237 — — 237 Total mortgage-backed securities $ 26,184 $ (85 ) $ 26,099 $ 162 $ (157 ) $ 26,104 State and municipal (4) $ 8,925 $ (28 ) $ 8,897 $ 378 $ (73 ) $ 9,202 Foreign government 740 — 740 — (18 ) 722 Asset-backed securities (3) 17,588 (4 ) 17,584 162 (22 ) 17,724 Total debt securities held-to-maturity $ 53,437 $ (117 ) $ 53,320 $ 702 $ (270 ) $ 53,752 December 31, 2016 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 22,462 $ 33 $ 22,495 $ 47 $ (186 ) $ 22,356 Prime 31 (7 ) 24 10 (1 ) 33 Alt-A 314 (27 ) 287 69 (1 ) 355 Non-U.S. residential 1,871 (47 ) 1,824 49 — 1,873 Commercial 14 — 14 — — 14 Total mortgage-backed securities $ 24,692 $ (48 ) $ 24,644 $ 175 $ (188 ) $ 24,631 State and municipal $ 9,025 $ (442 ) $ 8,583 $ 129 $ (238 ) $ 8,474 Foreign government 1,339 — 1,339 — (26 ) 1,313 Asset-backed securities (3) 11,107 (6 ) 11,101 41 (5 ) 11,137 Total debt securities held-to-maturity (5) $ 46,163 $ (496 ) $ 45,667 $ 345 $ (457 ) $ 45,555 (1) For securities transferred to HTM from Trading account assets , adjusted amortized cost basis is defined as the fair value of the securities at the date of transfer plus any accretion income and less any impairments recognized in earnings subsequent to transfer. For securities transferred to HTM from AFS, adjusted amortized cost basis is defined as the original purchase cost, adjusted for the cumulative accretion or amortization of any purchase discount or premium, plus or minus any cumulative fair value hedge adjustments, net of accretion or amortization, and less any other-than-temporary impairment recognized in earnings. (2) HTM securities are carried on the Consolidated Balance Sheet at adjusted amortized cost basis, plus or minus any unamortized unrealized gains and losses and fair value hedge adjustments recognized in AOCI prior to reclassifying the securities from AFS to HTM. Changes in the values of these securities are not reported in the financial statements, except for the amortization of any difference between the carrying value at the transfer date and par value of the securities, and the recognition of any non-credit fair value adjustments in AOCI in connection with the recognition of any credit impairment in earnings related to securities the Company continues to intend to hold until maturity. (3) The Company invests in mortgage-backed and asset-backed securities. These securitizations are generally considered VIEs. The Company’s maximum exposure to loss from these VIEs is equal to the carrying amount of the securities, which is reflected in the table above. For mortgage-backed and asset-backed securitizations in which the Company has other involvement, see Note 21 to the Consolidated Financial Statements. (4) In the second quarter of 2017, Citi early adopted ASU 2017-08. Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of purchase premiums and cumulative fair value hedge adjustments that would have been recorded under the ASU on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. (5) During the fourth quarter of 2016, securities with a total fair value of approximately $5.8 billion were transferred from AFS to HTM, composed of $5 billion of U.S. government agency mortgage-backed securities and $830 million of municipal securities. The transfer reflects the Company’s intent to hold these securities to maturity or to issuer call, in part, in order to reduce the impact of price volatility on AOCI and certain capital measures under Basel III. While these securities were transferred to HTM at fair value as of the transfer date, no subsequent changes in value may be recorded, other than in connection with the recognition of any subsequent other-than-temporary impairment and the amortization of differences between the carrying values at the transfer date and the par values of each security as an adjustment of yield. Any net unrealized holding losses within AOCI related to the respective securities at the date of transfer, inclusive of any cumulative fair value hedge adjustments, will be amortized as an adjustment of yield in a manner consistent with the amortization of any premium or discount. The Company has the positive intent and ability to hold these securities to maturity or, where applicable, the exercise of any issuer call options, absent any unforeseen significant changes in circumstances, including deterioration in credit or changes in regulatory capital requirements. The net unrealized losses classified in AOCI for HTM securities primarily relate to debt securities previously classified as AFS that were transferred to HTM, and include any cumulative fair value hedge adjustments. The net unrealized loss amount also includes any non-credit-related changes in fair value of HTM securities that have suffered credit impairment recorded in earnings. The AOCI balance related to HTM securities is amortized as an adjustment of yield, in a manner consistent with the accretion of any difference between the carrying value at the transfer date and par value of the same debt securities. The table below shows the fair value of debt securities HTM that have been in an unrecognized loss position: Less than 12 months 12 months or longer Total In millions of dollars Fair Gross Fair Gross Fair Gross December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities $ 46 $ — $ 15,096 $ 157 $ 15,142 $ 157 State and municipal 353 5 835 68 1,188 73 Foreign government 723 18 — — 723 18 Asset-backed securities 71 3 134 19 205 22 Total debt securities held-to-maturity $ 1,193 $ 26 $ 16,065 $ 244 $ 17,258 $ 270 December 31, 2016 Debt securities held-to-maturity Mortgage-backed securities $ 17 $ — $ 17,176 $ 188 $ 17,193 $ 188 State and municipal 2,200 58 1,210 180 3,410 238 Foreign government 1,313 26 — — 1,313 26 Asset-backed securities 2 — 2,503 5 2,505 5 Total debt securities held-to-maturity $ 3,532 $ 84 $ 20,889 $ 373 $ 24,421 $ 457 Note: Excluded from the gross unrecognized losses presented in the above table are $(117) million and $(496) million of net unrealized losses recorded in AOCI as of December 31, 2017 and December 31, 2016 , respectively, primarily related to the difference between the amortized cost and carrying value of HTM securities that were reclassified from AFS. Substantially all of these net unrecognized losses relate to securities that have been in a loss position for 12 months or longer at December 31, 2017 and December 31, 2016 . The following table presents the carrying value and fair value of HTM debt securities by contractual maturity dates: December 31, 2017 2016 In millions of dollars Carrying value Fair value Carrying value Fair value Mortgage-backed securities Due within 1 year $ — $ — $ — $ — After 1 but within 5 years 720 720 760 766 After 5 but within 10 years 148 149 54 55 After 10 years (1) 25,231 25,235 23,830 23,810 Total $ 26,099 $ 26,104 $ 24,644 $ 24,631 State and municipal Due within 1 year $ 407 $ 425 $ 406 $ 406 After 1 but within 5 years 259 270 112 110 After 5 but within 10 years 512 524 363 367 After 10 years (1) 7,719 7,983 7,702 7,591 Total $ 8,897 $ 9,202 $ 8,583 $ 8,474 Foreign government Due within 1 year $ 381 $ 381 $ 824 $ 818 After 1 but within 5 years 359 341 515 495 After 5 but within 10 years — — — — After 10 years (1) — — — — Total $ 740 $ 722 $ 1,339 $ 1,313 All other (2) Due within 1 year $ — $ — $ — $ — After 1 but within 5 years — — — — After 5 but within 10 years 1,669 1,680 513 514 After 10 years (1) 15,915 16,044 10,588 10,623 Total $ 17,584 $ 17,724 $ 11,101 $ 11,137 Total debt securities held-to-maturity $ 53,320 $ 53,752 $ 45,667 $ 45,555 (1) Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment rights. (2) Includes corporate and asset-backed securities. Evaluating Investments for Other-Than-Temporary Impairment (OTTI) Overview The Company conducts periodic reviews of all securities with unrealized losses to evaluate whether the impairment is other-than-temporary. An unrealized loss exists when the current fair value of an individual security is less than its adjusted amortized cost basis. Unrealized losses that are determined to be temporary in nature are recorded, net of tax, in AOCI for AFS securities. Losses related to HTM securities generally are not recorded, as these investments are carried at adjusted amortized cost basis. However, for HTM securities with credit-related losses, the credit loss is recognized in earnings as OTTI and any difference between the cost basis adjusted for the OTTI and fair value is recognized in AOCI and amortized as an adjustment of yield over the remaining contractual life of the security. Regardless of the classification of the securities as AFS or HTM, the Company assesses each position with an unrealized loss for OTTI. Factors considered in determining whether a loss is temporary include: • the length of time and the extent to which fair value has been below cost; • the severity of the impairment; • the cause of the impairment and the financial condition and near-term prospects of the issuer; • activity in the market of the issuer that may indicate adverse credit conditions; and • the Company’s ability and intent to hold the investment for a period of time sufficient to allow for recovery of the amortized cost basis. The Company’s review for impairment generally entails: • identification and evaluation of impaired investments; • analysis of individual investments that have fair values less than the amortized cost, including consideration of the length of time the investment has been in an unrealized loss position and the expected recovery period; • consideration of evidential matter, including an evaluation of factors or triggers that could cause individual investments to qualify as having other-than-temporary impairment and those that would not support other-than-temporary impairment; and • documentation of the results of these analyses, as required under business policies. Debt Securities The entire difference between the adjusted amortized cost basis and fair value is recognized in earnings as OTTI for impaired debt securities that the Company has an intent to sell or for which the Company believes it will more-likely-than-not be required to sell prior to recovery of the adjusted amortized cost basis. However, for those securities that the Company does not intend to sell and is not likely to be required to sell, only the credit-related impairment is recognized in earnings and any non-credit-related impairment is recorded in AOCI. For debt securities, credit impairment exists where the present value of cash flows management expects to receive is not sufficient to recover the entire amortized cost basis of a security. Equity Securities For equity securities, management considers the various factors described above, including its intent and ability to hold the equity security for a period of time sufficient for recovery or whether it is more-likely-than-not that the Company will be required to sell the security prior to recovery of its cost basis. Where management lacks that intent or ability, the security’s decline in fair value is deemed to be other-than-temporary and is recorded in earnings. AFS equity securities deemed to be other-than-temporarily impaired are written down to fair value, with the full difference between fair value and cost recognized in earnings. Management also assesses equity method investments that have fair values that are less than their respective carrying values for OTTI. Fair value is measured as price multiplied by quantity if the investee has publicly listed securities. If the investee is not publicly listed, other methods are used (see Note 24 to the Consolidated Financial Statements). For impaired equity method investments that Citi plans to sell prior to recovery of value or would likely be required to sell with no expectation that the fair value will recover prior to the expected sale date, the full impairment is recognized in earnings as OTTI regardless of severity and duration. The measurement of the OTTI does not include partial projected recoveries subsequent to the balance sheet date. For impaired equity method investments that management does not plan to sell and is not likely to be required to sell prior to recovery of value, the evaluation of whether an impairment is other-than-temporary is based on (i) whether and when an equity method investment will recover in value and (ii) whether the investor has the intent and ability to hold that investment for a period of time sufficient to recover the value. The determination of whether the impairment is considered other-than-temporary considers the following indicators, regardless of the time and extent of impairment: • the cause of the impairment and the financial condition and near-term prospects of the issuer, including any specific events that may influence the operations of the issuer; • the intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value; and • the length of time and extent to which fair value has been less than the carrying value. The sections below describe the Company’s process for identifying credit-related impairments for security types that have the most significant unrealized losses as of December 31, 2017 . Mortgage-Backed Securities For U.S. mortgage-backed securities, credit impairment is assessed using a cash flow model that estimates the principal and interest cash flows on the underlying mortgages using the security-specific collateral and transaction structure. The model distributes the estimated cash flows to the various tranches of securities, considering the transaction structure and any subordination and credit enhancements that exist in that structure. The cash flow model incorporates actual cash flows on the mortgage-backed securities through the current period and then estimates the remaining cash flows using a number of assumptions, including default rates, prepayment rates, recovery rates (on foreclosed properties) and loss severity rates (on non-agency mortgage-backed securities). Management develops specific assumptions using market data, internal estimates and estimates published by rating agencies and other third-party sources. Default rates are projected by considering current underlying mortgage loan performance, generally assuming the default of (i) 10% of current loans, (ii) 25% of 30 – 59 day delinquent loans, (iii) 70% of 60 – 90 day delinquent loans and (iv) 100% of 91 + day delinquent loans. These estimates are extrapolated along a default timing curve to estimate the total lifetime pool default rate. Other assumptions contemplate the actual collateral attributes, including geographic concentrations, rating actions and current market prices. Cash flow projections are developed using different stress test scenarios. Management evaluates the results of those stress tests (including the severity of any cash shortfall indicated and the likelihood of the stress scenarios actually occurring based on the underlying pool’s characteristics and performance) to assess whether management expects to recover the amortized cost basis of the security. If cash flow projections indicate that the Company does not expect to recover its amortized cost basis, the Company recognizes the estimated credit loss in earnings. State and Municipal Securities The process for identifying credit impairments in Citigroup’s AFS and HTM state and municipal bonds is primarily based on a credit analysis that incorporates third-party credit ratings. Citigroup monitors the bond issuers and any insurers providing default protection in the form of financial guarantee insurance. The average external credit rating, ignoring any insurance, is Aa3/AA-. In the event of an external rating downgrade or other indicator of credit impairment (i.e., based on instrument-specific estimates of cash flows or probability of issuer default), the subject bond is specifically reviewed for adverse changes in the amount or timing of expected contractual principal and interest payments. For state and municipal bonds with unrealized losses that Citigroup plans to sell or would be more-likely-than-not required to sell (for AFS only) or that will be subject to an issuer call deemed probable of exercise prior to the expected recovery of its amortized cost basis (for AFS and HTM), the full impairment is recognized in earnings as OTTI. Recognition and Measurement of OTTI The following tables present total OTTI recognized in earnings: OTTI on Investments and Other Assets Year ended In millions of dollars AFS (1) HTM Other assets Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 2 $ — $ — $ 2 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 2 $ — $ — $ 2 Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise 59 2 — 61 Total impairment losses recognized in earnings $ 61 $ 2 $ — $ 63 (1) Includes OTTI on non-marketable equity securities. OTTI on Investments and Other Assets Year ended In millions of dollars AFS (1)(2) HTM Other (3) Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 3 $ 1 $ — $ 4 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 3 $ 1 $ — $ 4 Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise 246 38 332 616 Total impairment losses recognized in earnings $ 249 $ 39 $ 332 $ 620 (1) Includes OTTI on non-marketable equity securities. (2) Includes a $160 million impairment related to AFS securities affected by changes in the Venezuela exchange rate during the year ended December 31, 2016. (3) The impairment charge is related to the carrying value of an equity investment, which was sold in 2016. OTTI on Investments and Other Assets Year ended December 31, 2015 In millions of dollars AFS (1) HTM Other Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 33 $ 1 $ — $ 34 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 33 $ 1 $ — $ 34 Impairment losses recognized in earnings for securities that the Company intends to sell or more-likely-than-not will be required to sell before recovery 182 43 6 231 Total impairment losses recognized in earnings $ 215 $ 44 $ 6 $ 265 (1) Includes OTTI on non-marketable equity securities. The following are 12-month rollforwards of the credit-related impairments recognized in earnings for AFS and HTM debt securities held that the Company does not intend to sell nor likely will be required to sell: Cumulative OTTI credit losses recognized in earnings on securities still held In millions of dollars Dec. 31, 2016 balance Credit Credit Reductions due to (1) Dec. 31, 2017 balance AFS debt securities Mortgage-backed securities (1)(2) $ — $ — $ — $ 38 $ 38 State and municipal 4 — — — 4 Foreign government securities — — — — — Corporate 5 — — (1 ) 4 All other debt securities 22 — 2 (22 ) 2 Total OTTI credit losses recognized for AFS debt securities $ 31 $ — $ 2 $ 15 $ 48 HTM debt securities Mortgage-backed securities (1)(3) $ 101 $ — $ — $ (47 ) $ 54 State and municipal 3 — — — 3 Total OTTI credit losses recognized for HTM debt securities $ 104 $ — $ — $ (47 ) $ 57 (1) Includes $38 million in cumulative OTTI reclassified from HTM to AFS due to the transfer of the related securities from HTM to AFS. (2) Primarily consists of Prime securities. (3) Primarily consists of Alt-A securities. Cumulative OTTI credit losses recognized in earnings on securities still held In millions of dollars Dec. 31, 2015 balance Credit Credit Reductions due to Dec. 31, 2016 balance AFS debt securities Mortgage-backed securities $ — $ 1 $ — $ (1 ) $ — State and municipal 12 — — (8 ) 4 Foreign government securities 5 — — (5 ) — Corporate 9 1 1 (6 ) 5 All other debt securities 47 — — (25 ) 22 Total OTTI credit losses recognized for AFS debt securities $ 73 $ 2 $ 1 $ (45 ) $ 31 HTM debt securities Mortgage-backed securities (1) $ 132 $ — $ — $ (31 ) $ 101 State and municipal 4 1 — (2 ) 3 Total OTTI credit losses recognized for HTM debt securities $ 136 $ 1 $ — $ (33 ) $ 104 (1) Primarily consists of Alt-A securities. Investments in Alternative Investment Funds That Calculate Net Asset Value The Company holds investments in certain alternative investment funds that calculate net asset value (NAV) or its equivalent, including hedge funds, private equity funds, funds of funds and real estate funds, as provided by third-party asset managers. Investments in such funds are generally classified as non-marketable equity securities carried at fair value. The fair values of these investments are estimated using the NAV of the Company’s ownership interest in the funds. Some of these investments are in “covered funds” for purposes of the Volcker Rule, which prohibits certain proprietary investment activities and limits the ownership of, and relationships with, covered funds. On April 21, 2017, Citi’s request for extension of the permitted holding period under the Volcker Rule for certain of its investments in illiquid funds was approved. This allows the Company to hold such investments until the earlier of 5 years from the July 21, 2017 (expiration date of the general conformance period), or the date such investments mature or are otherwise conformed with the Volcker Rule. Fair value Unfunded Redemption frequency (

LOANS

LOANS	12 Months Ended
	Dec. 31, 2017
Loans and Leases Receivable Disclosure [Abstract]
LOANS	LOANS Citigroup loans are reported in two categories—consumer and corporate. These categories are classified primarily according to the segment and subsegment that manage the loans. Consumer Loans Consumer loans represent loans and leases managed primarily by GCB and Corporate/Other. The following table provides Citi’s consumer loans by loan type: December 31, In millions of dollars 2017 2016 In U.S. offices Mortgage and real estate (1) $ 65,467 $ 72,957 Installment, revolving credit and other 3,398 3,395 Cards 139,006 132,654 Commercial and industrial 7,840 7,159 $ 215,711 $ 216,165 In offices outside the U.S. Mortgage and real estate (1) $ 44,081 $ 42,803 Installment, revolving credit and other 26,556 24,887 Cards 26,257 23,783 Commercial and industrial 20,238 16,568 Lease financing 76 81 $ 117,208 $ 108,122 Total consumer loans $ 332,919 $ 324,287 Net unearned income $ 737 $ 776 Consumer loans, net of unearned income $ 333,656 $ 325,063 (1) Loans secured primarily by real estate. Citigroup has established a risk management process to monitor, evaluate and manage the principal risks associated with its consumer loan portfolio. Credit quality indicators that are actively monitored include delinquency status, consumer credit scores (FICO) and loan to value (LTV) ratios, each as discussed in more detail below. Included in the loan table above are lending products whose terms may give rise to greater credit issues. Credit cards with below-market introductory interest rates and interest-only loans are examples of such products. These products are closely managed using credit techniques that are intended to mitigate their higher inherent risk. During the years ended December 31, 2017 and 2016 , the Company sold and/or reclassified to held-for-sale, $4.9 billion and $9.7 billion , respectively, of consumer loans. Delinquency Status Delinquency status is monitored and considered a key indicator of credit quality of consumer loans. Principally, the U.S. residential first mortgage loans use the Mortgage Bankers Association (MBA) method of reporting delinquencies, which considers a loan delinquent if a monthly payment has not been received by the end of the day immediately preceding the loan’s next due date. All other loans use a method of reporting delinquencies that considers a loan delinquent if a monthly payment has not been received by the close of business on the loan’s next due date. As a general policy, residential first mortgages, home equity loans and installment loans are classified as non-accrual when loan payments are 90 days contractually past due. Credit cards and unsecured revolving loans generally accrue interest until payments are 180 days past due. Home equity loans in regulated bank entities are classified as non-accrual if the related residential first mortgage is 90 days or more past due. Mortgage loans, other than Federal Housing Administration (FHA)-insured loans, are classified as non-accrual within 60 days of notification that the borrower has filed for bankruptcy. Commercial market loans are placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due. The policy for re-aging modified U.S. consumer loans to current status varies by product. Generally, one of the conditions to qualify for these modifications is that a minimum number of payments (typically ranging from one to three ) be made. Upon modification, the loan is re-aged to current status. However, re-aging practices for certain open-ended consumer loans, such as credit cards, are governed by Federal Financial Institutions Examination Council (FFIEC) guidelines. For open-ended consumer loans subject to FFIEC guidelines, one of the conditions for a loan to be re-aged to current status is that at least three consecutive minimum monthly payments, or the equivalent amount, must be received. In addition, under FFIEC guidelines, the number of times that such a loan can be re-aged is subject to limitations (generally once in 12 months and twice in five years). Furthermore, FHA and Department of Veterans Affairs (VA) loans are modified under those respective agencies’ guidelines and payments are not always required in order to re-age a modified loan to current. Consumer Loan Delinquency and Non-Accrual Details at December 31, 2017 In millions of dollars Total current (1)(2) 30–89 days past due (3) ≥ 90 days past due (3) Past due government guaranteed (4) Total loans (2) Total non-accrual 90 days past due and accruing In North America offices Residential first mortgages (5) $ 47,366 $ 505 $ 280 $ 1,225 $ 49,376 $ 665 $ 941 Home equity loans (6)(7) 14,268 207 352 — 14,827 750 — Credit cards 136,588 1,528 1,613 — 139,729 — 1,596 Installment and other 3,395 45 16 — 3,456 22 1 Commercial market loans 9,395 51 65 — 9,511 213 15 Total $ 211,012 $ 2,336 $ 2,326 $ 1,225 $ 216,899 $ 1,650 $ 2,553 In offices outside North America Residential first mortgages (5) $ 37,062 $ 209 $ 148 $ — $ 37,419 $ 400 $ — Credit cards 24,934 427 366 — 25,727 323 259 Installment and other 25,634 275 123 — 26,032 157 — Commercial market loans 27,449 57 72 — 27,578 160 — Total $ 115,079 $ 968 $ 709 $ — $ 116,756 $ 1,040 $ 259 Total GCB and Corporate/Other— consumer $ 326,091 $ 3,304 $ 3,035 $ 1,225 $ 333,655 $ 2,690 $ 2,812 Other (8) 1 — — — 1 — — Total Citigroup $ 326,092 $ 3,304 $ 3,035 $ 1,225 $ 333,656 $ 2,690 $ 2,812 (1) Loans less than 30 days past due are presented as current. (2) Includes $25 million of residential first mortgages recorded at fair value. (3) Excludes loans guaranteed by U.S. government-sponsored entities. (4) Consists of residential first mortgages that are guaranteed by U.S. government-sponsored entities that are 30–89 days past due of $0.2 billion and 90 days or more past due of $1.0 billion . (5) Includes approximately $0.1 billion of residential first mortgage loans in process of foreclosure. (6) Includes approximately $0.1 billion of home equity loans in process of foreclosure. (7) Fixed-rate home equity loans and loans extended under home equity lines of credit, which are typically in junior lien positions. (8) Represents loans classified as consumer loans on the Consolidated Balance Sheet that are not included in GCB or Corporate/Other consumer credit metrics. Consumer Loan Delinquency and Non-Accrual Details at December 31, 2016 In millions of dollars Total current (1)(2) 30–89 days past due (3) ≥ 90 days past due (3) Past due government guaranteed (4) Total loans (2) Total non-accrual 90 days past due and accruing In North America offices Residential first mortgages (5) $ 50,766 $ 522 $ 371 $ 1,474 $ 53,133 $ 848 $ 1,227 Home equity loans (6)(7) 18,767 249 438 — 19,454 914 — Credit cards 130,327 1,465 1,509 — 133,301 — 1,509 Installment and other 4,486 106 38 — 4,630 70 2 Commercial market loans 8,876 23 74 — 8,973 328 14 Total $ 213,222 $ 2,365 $ 2,430 $ 1,474 $ 219,491 $ 2,160 $ 2,752 In offices outside North America Residential first mortgages (5) $ 35,862 $ 206 $ 135 $ — $ 36,203 $ 360 $ — Credit cards 22,363 368 324 — 23,055 258 239 Installment and other 22,683 264 126 — 23,073 163 — Commercial market loans 23,054 72 112 — 23,238 217 — Total $ 103,962 $ 910 $ 697 $ — $ 105,569 $ 998 $ 239 Total GCB and Corporate/Other— consumer $ 317,184 $ 3,275 $ 3,127 $ 1,474 $ 325,060 $ 3,158 $ 2,991 Other (9) 3 — — — 3 — — Total Citigroup $ 317,187 $ 3,275 $ 3,127 $ 1,474 $ 325,063 $ 3,158 $ 2,991 (1) Loans less than 30 days past due are presented as current. (2) Includes $29 million of residential first mortgages recorded at fair value. (3) Excludes loans guaranteed by U.S. government-sponsored entities. (4) Consists of residential first mortgages that are guaranteed by U.S. government-sponsored entities that are 30–89 days past due of $0.2 billion and 90 days or more past due of $1.3 billion . (5) Includes approximately $0.1 billion of residential first mortgage loans in process of foreclosure. (6) Includes approximately $0.1 billion of home equity loans in process of foreclosure. (7) Fixed-rate home equity loans and loans extended under home equity lines of credit, which are typically in junior lien positions. (8) Represents loans classified as consumer loans on the Consolidated Balance Sheet that are not included in the Corporate/Other consumer credit metrics. Consumer Credit Scores (FICO) In the U.S., independent credit agencies rate an individual’s risk for assuming debt based on the individual’s credit history and assign every consumer a “FICO” (Fair Isaac Corporation) credit score. These scores are continually updated by the agencies based upon an individual’s credit actions (e.g., taking out a loan or missed or late payments). The following tables provide details on the FICO scores for Citi’s U.S. consumer loan portfolio based on end-of-period receivables (commercial market loans are excluded from the table since they are business based and FICO scores are not a primary driver in their credit evaluation). FICO scores are updated monthly for substantially all of the portfolio or, otherwise, on a quarterly basis for the remaining portfolio. FICO score distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than 620 ≥ 620 but less than 660 Equal to or Residential first mortgages $ 2,100 $ 1,932 $ 42,265 Home equity loans 1,379 1,081 11,976 Credit cards 9,079 11,651 115,577 Installment and other 276 250 2,485 Total $ 12,834 $ 14,914 $ 172,303 FICO score distribution in U.S. portfolio (1)(2) December 31, 2016 In millions of dollars Less than 620 ≥ 620 but less than 660 Equal to or greater than 660 Residential first mortgages $ 2,744 $ 2,422 $ 44,279 Home equity loans 1,750 1,418 14,743 Credit cards 8,310 11,320 110,522 Installment and other 284 271 2,601 Total $ 13,088 $ 15,431 $ 172,145 (1) Excludes loans guaranteed by U.S. government entities, loans subject to long-term standby commitments (LTSCs) with U.S. government-sponsored entities and loans recorded at fair value. (2) Excludes balances where FICO was not available. Such amounts are not material. Loan to Value (LTV) Ratios LTV ratios (loan balance divided by appraised value) are calculated at origination and updated by applying market price data. The following tables provide details on the LTV ratios for Citi’s U.S. consumer mortgage portfolios. LTV ratios are updated monthly using the most recent Core Logic Home Price Index data available for substantially all of the portfolio applied at the Metropolitan Statistical Area level, if available, or the state level if not. The remainder of the portfolio is updated in a similar manner using the Federal Housing Finance Agency indices. LTV distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 43,626 $ 2,578 $ 247 Home equity loans 11,403 2,147 800 Total $ 55,029 $ 4,725 $ 1,047 LTV distribution in U.S. portfolio (1)(2) December 31, 2016 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 45,849 $ 3,467 $ 324 Home equity loans 12,869 3,653 1,305 Total $ 58,718 $ 7,120 $ 1,629 (1) Excludes loans guaranteed by U.S. government entities, loans subject to LTSCs with U.S. government-sponsored entities and loans recorded at fair value. (2) Excludes balances where LTV was not available. Such amounts are not material. Impaired Consumer Loans A loan is considered impaired when Citi believes it is probable that all amounts due according to the original contractual terms of the loan will not be collected. Impaired consumer loans include non-accrual commercial market loans, as well as smaller-balance homogeneous loans whose terms have been modified due to the borrower’s financial difficulties and where Citi has granted a concession to the borrower. These modifications may include interest rate reductions and/or principal forgiveness. Impaired consumer loans exclude smaller-balance homogeneous loans that have not been modified and are carried on a non-accrual basis. The following tables present information about impaired consumer loans and interest income recognized on impaired consumer loans: At and for the year ended December 31, 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income recognized (5) Mortgage and real estate Residential first mortgages $ 2,877 $ 3,121 $ 278 $ 3,155 $ 119 Home equity loans 1,151 1,590 216 1,181 28 Credit cards 1,787 1,819 614 1,803 150 Installment and other Individual installment and other 431 460 175 415 25 Commercial market loans 334 541 51 429 20 Total $ 6,580 $ 7,531 $ 1,334 $ 6,983 $ 342 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount and direct write-downs and includes accrued interest only on credit card loans. (2) $607 million of residential first mortgages, $370 million of home equity loans and $10 million of commercial market loans do not have a specific allowance. (3) Included in the Allowance for loan losses . (4) Average carrying value represents the average recorded investment ending balance for the last four quarters and does not include the related specific allowance. (5) Includes amounts recognized on both an accrual and cash basis. At and for the year ended December 31, 2016 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income (5)(6) Mortgage and real estate Residential first mortgages $ 3,786 $ 4,157 $ 540 $ 4,632 $ 170 Home equity loans 1,298 1,824 189 1,326 35 Credit cards 1,747 1,781 566 1,831 158 Installment and other Individual installment and other 455 481 215 475 27 Commercial market loans 513 744 98 538 12 Total $ 7,799 $ 8,987 $ 1,608 $ 8,802 $ 402 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount and direct write-downs and includes accrued interest only on credit card loans. (2) $740 million of residential first mortgages, $406 million of home equity loans and $97 million of commercial market loans do not have a specific allowance. (3) Included in the Allowance for loan losses . (4) Average carrying value represents the average recorded investment ending balance for the last four quarters and does not include the related specific allowance. (5) Includes amounts recognized on both an accrual and cash basis. (6) Interest income recognized for the year ended December 31, 2015 was $ 728 million . Consumer Troubled Debt Restructurings At and for the year ended December 31, 2017 In millions of dollars except number of loans modified Number of loans modified Post- modification recorded investment (1)(2) Deferred principal (3) Contingent principal forgiveness (4) Principal forgiveness (5) Average interest rate reduction North America Residential first mortgages 4,063 $ 580 $ 6 $ — $ 2 1 % Home equity loans 2,807 247 16 — 1 1 Credit cards 230,042 880 — — — 17 Installment and other revolving 1,088 8 — — — 5 Commercial banking (6) 112 117 — — — — Total (8) 238,112 $ 1,832 $ 22 $ — $ 3 International Residential first mortgages 4,477 $ 123 $ — $ — $ — — % Credit cards 115,941 399 — — 7 11 Installment and other revolving 44,880 254 — — 11 9 Commercial banking (6) 370 50 — — — — Total (8) 165,668 $ 826 $ — $ — $ 18 At and for the year ended December 31, 2016 In millions of dollars except number of loans modified Number of loans modified Post- modification recorded investment (1)(7) Deferred principal (3) Contingent principal forgiveness (4) Principal forgiveness (5) Average interest rate reduction North America Residential first mortgages 5,023 $ 726 $ 6 $ — $ 3 1 % Home equity loans 4,100 200 6 — 1 2 Credit cards 196,004 762 — — — 17 Installment and other revolving 5,649 47 — — — 14 Commercial banking (6) 132 91 — — — — Total (8) 210,908 $ 1,826 $ 12 $ — $ 4 International Residential first mortgages 2,722 $ 80 $ — $ — $ — — % Credit cards 137,466 385 — — 9 12 Installment and other revolving 60,094 276 — — 7 7 Commercial banking (6) 162 109 — — — — Total (8) 200,444 $ 850 $ — $ — $ 16 (1) Post-modification balances include past due amounts that are capitalized at the modification date. (2) Post-modification balances in North America include $ 53 million of residential first mortgages and $ 21 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the year ended December 31, 2017 . These amounts include $ 36 million of residential first mortgages and $ 18 million of home equity loans that were newly classified as TDRs during 2017, based on previously received OCC guidance. (3) Represents portion of contractual loan principal that is non-interest bearing, but still due from the borrower. Such deferred principal is charged off at the time of permanent modification to the extent that the related loan balance exceeds the underlying collateral value. (4) Represents portion of contractual loan principal that is non-interest bearing and, depending upon borrower performance, eligible for forgiveness. (5) Represents portion of contractual loan principal that was forgiven at the time of permanent modification. (6) Commercial banking loans are generally borrower-specific modifications and incorporate changes in the amount and/or timing of principal and/or interest. (7) Post-modification balances in North America include $ 74 million of residential first mortgages and $ 22 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the year ended December 31, 2016 . These amounts include $ 48 million of residential first mortgages and $ 20 million of home equity loans that were newly classified as TDRs during 2016, based on previously received OCC guidance. (8) The above tables reflect activity for loans outstanding as of the end of the reporting period that were considered TDRs. The following table presents consumer TDRs that defaulted, for which the payment default occurred within one year of a permanent modification. Default is defined as 60 days past due, except for classifiably managed commercial banking loans, where default is defined as 90 days past due. In millions of dollars 2017 2016 North America Residential first mortgages $ 253 $ 229 Home equity loans 46 25 Credit cards 221 188 Installment and other revolving 2 9 Commercial banking 2 15 Total $ 524 $ 466 International Residential first mortgages $ 11 $ 11 Credit cards 185 148 Installment and other revolving 96 90 Commercial banking 1 37 Total $ 293 $ 286 Corporate Loans Corporate loans represent loans and leases managed by ICG . The following table presents information by corporate loan type: In millions of dollars December 31, December 31, In U.S. offices Commercial and industrial $ 51,319 $ 49,586 Financial institutions 39,128 35,517 Mortgage and real estate (1) 44,683 38,691 Installment, revolving credit and other 33,181 34,501 Lease financing 1,470 1,518 $ 169,781 $ 159,813 In offices outside the U.S. Commercial and industrial $ 93,750 $ 81,882 Financial institutions 35,273 26,886 Mortgage and real estate (1) 7,309 5,363 Installment, revolving credit and other 22,638 19,965 Lease financing 190 251 Governments and official institutions 5,200 5,850 $ 164,360 $ 140,197 Total corporate loans $ 334,141 $ 300,010 Net unearned income $ (763 ) $ (704 ) Corporate loans, net of unearned income $ 333,378 $ 299,306 (1) Loans secured primarily by real estate. The Company sold and/or reclassified to held-for-sale $1.0 billion and $4.2 billion of corporate loans during the years ended December 31, 2017 and 2016 , respectively. The Company did not have significant purchases of corporate loans classified as held-for-investment for the years ended December 31, 2017 or 2016 . Delinquency Status Citi generally does not manage corporate loans on a delinquency basis. Corporate loans are identified as impaired and placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due, except when the loan is well collateralized and in the process of collection. Any interest accrued on impaired corporate loans and leases is reversed at 90 days and charged against current earnings, and interest is thereafter included in earnings only to the extent actually received in cash. When there is doubt regarding the ultimate collectability of principal, all cash receipts are thereafter applied to reduce the recorded investment in the loan. While corporate loans are generally managed based on their internally assigned risk rating (see further discussion below), the following tables present delinquency information by corporate loan type. Corporate Loan Delinquency and Non-Accrual Details at December 31, 2017 In millions of dollars 30–89 days past due and accruing (1) ≥ 90 days past due and accruing (1) Total past due and accruing Total non-accrual (2) Total current (3) Total loans (4) Commercial and industrial $ 249 $ 13 $ 262 $ 1,506 $ 139,554 $ 141,322 Financial institutions 93 15 108 92 73,557 73,757 Mortgage and real estate 147 59 206 195 51,563 51,964 Leases 68 8 76 46 1,533 1,655 Other 70 13 83 103 60,145 60,331 Loans at fair value 4,349 Total $ 627 $ 108 $ 735 $ 1,942 $ 326,352 $ 333,378 Corporate Loan Delinquency and Non-Accrual Details at December 31, 2016 In millions of dollars 30–89 days past due and accruing (1) ≥ 90 days past due and accruing (1) Total past due and accruing Total non-accrual (2) Total current (3) Total loans (4) Commercial and industrial $ 143 $ 52 $ 195 $ 1,909 $ 127,012 $ 129,116 Financial institutions 119 2 121 185 61,254 61,560 Mortgage and real estate 148 137 285 139 43,607 44,031 Leases 27 8 35 56 1,678 1,769 Other 349 12 361 132 58,880 59,373 Loans at fair value 3,457 Total $ 786 $ 211 $ 997 $ 2,421 $ 292,431 $ 299,306 (1) Corporate loans that are 90 days past due are generally classified as non-accrual. Corporate loans are considered past due when principal or interest is contractually due but unpaid. (2) Non-accrual loans generally include those loans that are ≥ 90 days past due or those loans for which Citi believes, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful. (3) Loans less than 30 days past due are presented as current. (4) Total loans include loans at fair value, which are not included in the various delinquency columns. Citigroup has a risk management process to monitor, evaluate and manage the principal risks associated with its corporate loan portfolio. As part of its risk management process, Citi assigns numeric risk ratings to its corporate loan facilities based on quantitative and qualitative assessments of the obligor and facility. These risk ratings are reviewed at least annually or more often if material events related to the obligor or facility warrant. Factors considered in assigning the risk ratings include financial condition of the obligor, qualitative assessment of management and strategy, amount and sources of repayment, amount and type of collateral and guarantee arrangements, amount and type of any contingencies associated with the obligor and the obligor’s industry and geography. The obligor risk ratings are defined by ranges of default probabilities. The facility risk ratings are defined by ranges of loss norms, which are the product of the probability of default and the loss given default. The investment grade rating categories are similar to the category BBB-/Baa3 and above as defined by S&P and Moody’s. Loans classified according to the bank regulatory definitions as special mention, substandard and doubtful will have risk ratings within the non-investment grade categories. Corporate Loans Credit Quality Indicators Recorded investment in loans (1) In millions of dollars December 31, 2017 December 31, Investment grade (2) Commercial and industrial $ 101,313 $ 87,201 Financial institutions 60,404 50,597 Mortgage and real estate 23,213 18,718 Leases 1,090 1,303 Other 56,306 52,828 Total investment grade $ 242,326 $ 210,647 Non-investment grade (2) Accrual Commercial and industrial $ 38,503 $ 39,874 Financial institutions 13,261 10,873 Mortgage and real estate 2,881 1,821 Leases 518 410 Other 3,924 6,450 Non-accrual Commercial and industrial 1,506 1,909 Financial institutions 92 185 Mortgage and real estate 195 139 Leases 46 56 Other 103 132 Total non-investment grade $ 61,029 $ 61,849 Private bank loans managed on a delinquency basis (2) $ 25,674 $ 23,353 Loans at fair value 4,349 3,457 Corporate loans, net of unearned income $ 333,378 $ 299,306 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount, less any direct write-downs. (2) Held-for-investment loans are accounted for on an amortized cost basis. Impaired collateral-dependent loans and leases, where repayment is expected to be provided solely by the sale of the underlying collateral and there are no other available and reliable sources of repayment, are written down to the lower of cost or collateral value, less cost to sell. Cash-basis loans are returned to an accrual status when all contractual principal and interest amounts are reasonably assured of repayment and there is a sustained period of repayment performance, generally six months , in accordance with the contractual terms of the loan. The following tables present non-accrual loan information by corporate loan type and interest income recognized on non-accrual corporate loans: Non-Accrual Corporate Loans At and for the year ended December 31, 2017 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Interest income recognized (3) Non-accrual corporate loans Commercial and industrial $ 1,506 $ 1,775 $ 368 $ 1,547 $ 23 Financial institutions 92 102 41 212 1 Mortgage and real estate 195 324 11 183 10 Lease financing 46 46 4 59 — Other 103 212 2 108 1 Total non-accrual corporate loans $ 1,942 $ 2,459 $ 426 $ 2,109 $ 35 At and for the year ended December 31, 2016 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Interest income recognized (3) Non-accrual corporate loans Commercial and industrial $ 1,909 $ 2,259 $ 362 $ 1,919 $ 25 Financial institutions 185 192 16 183 3 Mortgage and real estate 139 250 10 174 6 Lease financing 56 56 4 44 — Other 132 197 — 87 6 Total non-accrual corporate loans $ 2,421 $ 2,954 $ 392 $ 2,407 $ 40 December 31, 2017 December 31, 2016 In millions of dollars Recorded investment (1) Related specific allowance Recorded investment (1) Related specific allowance Non-accrual corporate loans with valuation allowances Commercial and industrial $ 1,017 $ 368 $ 1,343 $ 362 Financial institutions 88 41 45 16 Mortgage and real estate 51 11 41 10 Lease financing 46 4 55 4 Other 13 2 1 — Total non-accrual corporate loans with specific allowance $ 1,215 $ 426 $ 1,485 $ 392 Non-accrual corporate loans without specific allowance Commercial and industrial $ 489 $ 566 Financial institutions 4 140 Mortgage and real estate 144 98 Lease financing — 1 Other 90 131 Total non-accrual corporate loans without specific allowance $ 727 N/A $ 936 N/A (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount, less any direct write-downs. (2) Average carrying value represents the average recorded investment balance and does not include related specific allowance. (3) Interest income recognized for the year ended December 31, 2015 was $11 million . N/A Not applicable Corporate Troubled Debt Restructurings The following table presents corporate TDR activity at and for the year ended December 31, 2017 : In millions of dollars Carrying Value TDRs involving changes in the amount and/or timing of principal payments (1) TDRs involving changes in the amount and/or timing of interest payments (2) TDRs involving changes in the amount and/or timing of both principal and interest payments Commercial and industrial $ 509 $ 131 $ 7 $ 371 Financial institutions 15 — — 15 Mortgage and real estate 36 — — 36 Total $ 560 $ 131 $ 7 $ 422 The following table presents corporate TDR activity at and for the year ended December 31, 2016 : In millions of dollars Carrying Value TDRs involving changes in the amount and/or timing of principal payments (1) TDRs involving changes in the amount and/or timing of interest payments (2) TDRs involving changes in the amount and/or timing of both principal and interest payments Commercial and industrial $ 338 $ 176 $ 34 $ 128 Financial institutions 10 10 — — Mortgage and real estate 15 6 — 9 Other 142 — 142 — Total $ 505 $ 192 $ 176 $ 137 (1) TDRs involving changes in the amount or timing of principal payments may involve principal forgiveness or deferral of periodic and/or final principal payments. Because forgiveness of principal is rare for corporate loans, modifications typically have little to no impact on the loans’ projected cash flows and thus little to no impact on the allowance established for the loans. Charge-offs for amounts deemed uncollectable may be recorded at the time of the restructuring or may have already been recorded in prior periods such that no charge-off is required at the time of the modification. (2) TDRs involving changes in the amount or timing of interest payments may involve a below-market interest rate. The following table presents total corporate loans modified in a TDR as well as those TDRs that defaulted and for which the payment default occurred within one year of a permanent modification. Default is defined as 60 days past due, except for classifiably managed commercial banking loans, where default is defined as 90 days past due. In millions of dollars TDR balances at December 31, 2017 TDR loans in payment default during the year ended December 31, 2017 TDR balances at December 31, 2016 TDR loans in payment default during the year ended December 31, 2016 Commercial and industrial $ 617 $ 72 $ 408 $ 7 Financial institutions 48 — 9 — Mortgage and real estate 101 — 87 8 Lease financing 7 — — — Other 45 — 228 — Total (1) $ 818 $ 72 $ 732 $ 15 (1) The above tables reflect activity for loans outstanding as of the end of the reporting period that were considered TDRs.

ALLOWANCE FOR CREDIT LOSSES

ALLOWANCE FOR CREDIT LOSSES	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
ALLOWANCE FOR CREDIT LOSSES	ALLOWANCE FOR CREDIT LOSSES In millions of dollars 2017 2016 2015 Allowance for loan losses at beginning of period $ 12,060 $ 12,626 $ 15,994 Gross credit losses (8,673 ) (8,222 ) (9,041 ) Gross recoveries (1) 1,597 1,661 1,739 Net credit losses (NCLs) $ (7,076 ) $ (6,561 ) $ (7,302 ) NCLs $ 7,076 $ 6,561 $ 7,302 Net reserve builds (releases) 544 340 139 Net specific reserve releases (117 ) (152 ) (333 ) Total provision for loan losses $ 7,503 $ 6,749 $ 7,108 Other, net (see table below) (132 ) (754 ) (3,174 ) Allowance for loan losses at end of period $ 12,355 $ 12,060 $ 12,626 Allowance for credit losses on unfunded lending commitments at beginning of period $ 1,418 $ 1,402 $ 1,063 Provision (release) for unfunded lending commitments (161 ) 29 74 Other, net (2) 1 (13 ) 265 Allowance for credit losses on unfunded lending commitments at end of period (3) $ 1,258 $ 1,418 $ 1,402 Total allowance for loans, leases and unfunded lending commitments $ 13,613 $ 13,478 $ 14,028 (1) Recoveries have been reduced by certain collection costs that are incurred only if collection efforts are successful. (2) 2015 includes a reclassification of $271 million of Allowance for loan losses to Allowance for unfunded lending commitments, included in Other, net. This reclassification reflects the re-attribution of $271 million in Allowances for credit losses between the funded and unfunded portions of the corporate credit portfolios and does not reflect a change in the underlying credit performance of these portfolios. (3) Represents additional credit loss reserves for unfunded lending commitments and letters of credit recorded in Other liabilities on the Consolidated Balance Sheet. Other, net details: In millions of dollars 2017 2016 2015 Sales or transfers of various consumer loan portfolios to held-for-sale Transfer of real estate loan portfolios $ (106 ) $ (106 ) $ (1,462 ) Transfer of other loan portfolios (155 ) (468 ) (948 ) Sales or transfers of various consumer loan portfolios to held-for-sale $ (261 ) $ (574 ) $ (2,410 ) FX translation, consumer 115 (199 ) (474 ) Other 14 19 (290 ) Other, net $ (132 ) $ (754 ) $ (3,174 ) Allowance for Credit Losses and Investment in Loans at December 31, 2017 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,702 $ 9,358 $ 12,060 Charge-offs (491 ) (8,182 ) (8,673 ) Recoveries 112 1,485 1,597 Replenishment of net charge-offs 379 6,697 7,076 Net reserve builds (releases) (267 ) 811 544 Net specific reserve builds (releases) 28 (145 ) (117 ) Other 23 (155 ) (132 ) Ending balance $ 2,486 $ 9,869 $ 12,355 Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,060 $ 8,531 $ 10,591 Individually evaluated in accordance with ASC 310-10-35 426 1,334 1,760 Purchased credit-impaired in accordance with ASC 310-30 — 4 4 Total allowance for loan losses $ 2,486 $ 9,869 $ 12,355 Loans, net of unearned income Collectively evaluated for impairment in accordance with ASC 450 $ 327,142 $ 326,884 $ 654,026 Individually evaluated for impairment in accordance with ASC 310-10-35 1,887 6,580 8,467 Purchased credit-impaired in accordance with ASC 310-30 — 167 167 Held at fair value 4,349 25 4,374 Total loans, net of unearned income $ 333,378 $ 333,656 $ 667,034 Allowance for Credit Losses and Investment in Loans at December 31, 2016 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,791 $ 9,835 $ 12,626 Charge-offs (580 ) (7,642 ) (8,222 ) Recoveries 67 1,594 1,661 Replenishment of net charge-offs 513 6,048 6,561 Net reserve builds (releases) (85 ) 425 340 Net specific reserve builds (releases) — (152 ) (152 ) Other (4 ) (750 ) (754 ) Ending balance $ 2,702 $ 9,358 $ 12,060 Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,310 $ 7,744 $ 10,054 Individually evaluated in accordance with ASC 310-10-35 392 1,608 2,000 Purchased credit-impaired in accordance with ASC 310-30 — 6 6 Total allowance for loan losses $ 2,702 $ 9,358 $ 12,060 Loans, net of unearned income Collectively evaluated for impairment in accordance with ASC 450 $ 293,218 $ 317,048 $ 610,266 Individually evaluated for impairment in accordance with ASC 310-10-35 2,631 7,799 10,430 Purchased credit-impaired in accordance with ASC 310-30 — 187 187 Held at fair value 3,457 29 3,486 Total loans, net of unearned income $ 299,306 $ 325,063 $ 624,369 Allowance for Credit Losses at December 31, 2015 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,447 $ 13,547 $ 15,994 Charge-offs (349 ) (8,692 ) (9,041 ) Recoveries 105 1,634 1,739 Replenishment of net charge-offs 244 7,058 7,302 Net reserve builds (releases) 550 (411 ) 139 Net specific reserve builds (releases) 86 (419 ) (333 ) Other (292 ) (2,882 ) (3,174 ) Ending balance $ 2,791 $ 9,835 $ 12,626

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Goodwill The changes in Goodwill were as follows: In millions of dollars Balance at December 31, 2014 $ 23,592 Foreign exchange translation and other $ (1,000 ) Divestitures (1) (212 ) Impairment of goodwill (2) (31 ) Balance at December 31, 2015 $ 22,349 Foreign exchange translation and other $ (613 ) Divestitures (3) (77 ) Balance at December 31, 2016 $ 21,659 Foreign exchange translation and other $ 729 Divestitures (4) (104 ) Impairment of goodwill (5) (28 ) Balance at December 31, 2017 $ 22,256 The changes in Goodwill by segment were as follows: In millions of dollars Global Consumer Banking Institutional Clients Group Corporate/Other (6) Total Balance at December 31, 2015 (7) $ 12,704 $ 9,545 $ 100 $ 22,349 Foreign exchange translation and other $ (174 ) $ (447 ) $ 8 $ (613 ) Divestitures (3) — (13 ) (64 ) (77 ) Balance at December 31, 2016 $ 12,530 $ 9,085 $ 44 $ 21,659 Foreign exchange translation and other $ 286 $ 443 $ — $ 729 Divestitures (4) (32 ) (72 ) — (104 ) Impairment of goodwill (5) — — (28 ) (28 ) Balance at December 31, 2017 $ 12,784 $ 9,456 $ 16 $ 22,256 (1) Primarily related to the sales of the Latin America Retirement Services and Japan cards businesses completed in 2015, and agreements to sell certain businesses in Citi Holdings as of December 31, 2015. See Note 2 to the Consolidated Financial Statements. (2) Goodwill impairment related to reporting units subsequently sold, including Citi Holdings— Consumer Finance South Korea of $16 million and Citi Holdings— Consumer Latin America of $15 million . (3) Primarily related to the sale of the private equity services business completed in 2016 and agreements to sell Argentina and Brazil consumer operations as of December 31, 2016. (4) Primarily related to the sale of a fixed income analytics business and a fixed income index business completed in 2017 and an agreement to sell a Mexico asset management business as of December 31, 2017. See Note 2 to the Consolidated Financial Statements. (5) Goodwill impairment related to the mortgage servicing business upon transfer from North America GCB to Corporate/Other effective January 1, 2017. (6) All Citi Holdings reporting units are presented in Corporate/Other. See Note 3 to the Consolidated Financial Statements. (7) December 31, 2015 has been restated to reflect intersegment goodwill allocations that resulted from the reorganizations in 2016 and on January 1, 2017 including transfers of GCB businesses to ICG and to Corporate/Other . See Note 3 to the Consolidated Financial Statements. Goodwill impairment testing is performed at the level below each business segment (referred to as a reporting unit). The Company performed its annual goodwill impairment test as of July 1, 2017. The fair values of the Company’s reporting units exceeded their carrying values by approximately 32% to 168% and no reporting unit is at risk of impairment, except for Citi Holdings— Consumer Latin America . Interim impairment tests were performed for Citi Holdings— Consumer Latin America , which is reported as part of Corporate/Other , for all other quarters in 2017. While there is no indication of impairment, each interim impairment test showed that the fair value of Citi Holdings— Consumer Latin America reporting unit, which has $16 million of goodwill, only marginally exceeded its carrying value. The fair value as a percentage of allocated book value as of December 31, 2017 was 111% . Subsequently, on January 31, 2018, Citi executed a definitive agreement to sell the reporting unit and allocated the entire goodwill to the sale, which is expected to result in a pre-tax gain upon closing. Further, effective January 1, 2017, the mortgage servicing business in North America GCB was reorganized and is now reported as part of Corporate/Other . Goodwill was allocated to the transferred business based on its relative fair value to the legacy North America GCB reporting unit. An interim test was performed under both the legacy and current reporting unit structures, which resulted in full impairment of the $28 million of allocated goodwill upon transfer to Citi Holdings —REL , recorded in Operating expenses in 2017. Intangible Assets The components of intangible assets were as follows: December 31, 2017 December 31, 2016 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,375 $ 3,836 $ 1,539 $ 8,215 $ 6,549 $ 1,666 Credit card contract related intangibles 5,045 2,456 2,589 5,149 2,177 2,972 Core deposit intangibles 639 628 11 801 771 30 Other customer relationships 459 272 187 474 272 202 Present value of future profits 32 28 4 31 27 4 Indefinite-lived intangible assets 244 — 244 210 — 210 Other 100 86 14 504 474 30 Intangible assets (excluding MSRs) $ 11,894 $ 7,306 $ 4,588 $ 15,384 $ 10,270 $ 5,114 Mortgage servicing rights (MSRs) (1) 558 — 558 1,564 — 1,564 Total intangible assets $ 12,452 $ 7,306 $ 5,146 $ 16,948 $ 10,270 $ 6,678 (1) In January 2017, Citi signed agreements to effectively exit its U.S. mortgage servicing operations by the end of 2018 and intensify its focus on loan originations. For additional information on these transactions, see Note 2 to the Consolidated Financial Statements. Intangible assets amortization expense was $603 million , $595 million and $625 million for 2017, 2016 and 2015, respectively. Intangible assets amortization expense is estimated to be $503 million in 2018, $479 million in 2019, $332 million in 2020, $314 million in 2021 and $866 million in 2022. The changes in intangible assets were as follows: Net carrying Net carrying amount at In millions of dollars December 31, 2016 Acquisitions/ divestitures Amortization Impairments FX translation and other December 31, Purchased credit card relationships $ 1,666 $ 20 $ (149 ) $ — $ 2 $ 1,539 Credit card contract-related intangibles (1) 2,972 9 (393 ) — 1 2,589 Core deposit intangibles 30 — (20 ) — 1 11 Other customer relationships 202 — (24 ) — 9 187 Present value of future profits 4 — — — — 4 Indefinite-lived intangible assets 210 — — — 34 244 Other 30 (14 ) (17 ) — 15 14 Intangible assets (excluding MSRs) $ 5,114 $ 15 $ (603 ) $ — $ 62 $ 4,588 Mortgage servicing rights (MSRs) (2) 1,564 558 Total intangible assets $ 6,678 $ 5,146 (1) Primarily reflects contract-related intangibles associated with the American Airlines, The Home Depot, Costco, Sears and AT&T credit card program agreements, which represent 97% of the aggregate net carrying amount as of December 31, 2017. (2) For additional information on Citi’s MSRs, including the rollforward from 2016 to 2017, see Note 21 to the Consolidated Financial Statements.

DEBT

DEBT	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
DEBT	DEBT Short-Term Borrowings December 31, 2017 2016 In millions of dollars Balance Weighted average coupon Balance Weighted average coupon Commercial paper $ 9,940 1.28 % $ 9,989 0.79 % Other borrowings (1) 34,512 1.62 20,712 1.39 Total $ 44,452 $ 30,701 (1) Includes borrowings from the Federal Home Loan Banks and other market participants. At December 31, 2017 and December 31, 2016 , collateralized short-term advances from the Federal Home Loan Banks were $23.8 billion and $12.0 billion , respectively. Borrowings under bank lines of credit may be at interest rates based on LIBOR, CD rates, the prime rate or bids submitted by the banks. Citigroup pays commitment fees for its lines of credit. Some of Citigroup’s non-bank subsidiaries have credit facilities with Citigroup’s subsidiary depository institutions, including Citibank. Borrowings under these facilities are secured in accordance with Section 23A of the Federal Reserve Act. Citigroup Global Markets Holdings Inc. (CGMHI) has borrowing agreements consisting of facilities that CGMHI has been advised are available, but where no contractual lending obligation exists. These arrangements are reviewed on an ongoing basis to ensure flexibility in meeting CGMHI’s short-term requirements. Long-Term Debt Balances at December 31, In millions of dollars Weighted average coupon Maturities 2017 2016 Citigroup Inc. (1) Senior debt 4.15 % 2018-2098 $ 123,488 $ 118,881 Subordinated debt (2) 4.48 2018-2046 26,963 26,758 Trust preferred securities 6.90 2036-2067 1,712 1,694 Bank (3) Senior debt 2.06 2018-2049 65,856 49,454 Broker-dealer (4) Senior debt 3.44 2018-2057 18,666 9,387 Subordinated debt (2) 5.37 2021-2037 24 4 Total 3.57 % $ 236,709 $ 206,178 Senior debt $ 208,010 $ 177,722 Subordinated debt (2) 26,987 26,762 Trust preferred securities 1,712 1,694 Total $ 236,709 $ 206,178 (1) Represents the parent holding company. (2) Includes notes that are subordinated within certain countries, regions or subsidiaries. (3) Represents Citibank entities as well as other bank entities. At December 31, 2017 and December 31, 2016 , collateralized long-term advances from the Federal Home Loan Banks were $19.3 billion and $21.6 billion , respectively. (4) Represents broker-dealer and other non-bank subsidiaries that are consolidated into Citigroup Inc., the parent holding company. The Company issues both fixed- and variable-rate debt in a range of currencies. It uses derivative contracts, primarily interest rate swaps, to effectively convert a portion of its fixed-rate debt to variable-rate debt. The maturity structure of the derivatives generally corresponds to the maturity structure of the debt being hedged. In addition, the Company uses other derivative contracts to manage the foreign exchange impact of certain debt issuances. At December 31, 2017 , the Company’s overall weighted average interest rate for long-term debt was 3.57% on a contractual basis and 2.70% including the effects of derivative contracts. Aggregate annual maturities of long-term debt obligations (based on final maturity dates) including trust preferred securities are as follows: In millions of dollars 2018 2019 2020 2021 2022 Thereafter Total Citigroup Inc. $ 20,050 $ 16,656 $ 9,565 $ 15,499 $ 9,627 $ 80,766 $ 152,163 Bank 29,270 17,245 10,302 4,077 1,471 3,491 65,856 Broker-dealer 4,158 2,388 3,321 1,443 1,266 6,114 18,690 Total $ 53,478 $ 36,289 $ 23,188 $ 21,019 $ 12,364 $ 90,371 $ 236,709 The following table summarizes the Company’s outstanding trust preferred securities at December 31, 2017 : Junior subordinated debentures owned by trust Trust Issuance date Securities issued Liquidation value (1) Coupon rate (2) Common shares issued to parent Amount Maturity Redeemable by issuer beginning In millions of dollars, except share amounts Citigroup Capital III Dec. 1996 194,053 $ 194 7.625 % 6,003 $ 200 Dec. 1, 2036 Not redeemable Citigroup Capital XIII Sept. 2010 89,840,000 2,246 3 mo LIBOR + 637 bps 1,000 2,246 Oct. 30, 2040 Oct. 30, 2015 Citigroup Capital XVIII June 2007 99,901 135 3 mo LIBOR + 88.75 bps 50 135 June 28, 2067 June 28, 2017 Total obligated $ 2,575 $ 2,581 Note: Distributions on the trust preferred securities and interest on the subordinated debentures are payable semiannually for Citigroup Capital III and Citigroup Capital XVIII and quarterly for Citigroup Capital XIII. (1) Represents the notional value received by investors from the trusts at the time of issuance. (2) In each case, the coupon rate on the subordinated debentures is the same as that on the trust preferred securities.

REGULATORY CAPITAL

REGULATORY CAPITAL	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
REGULATORY CAPITAL	REGULATORY CAPITAL Citigroup is subject to risk-based capital and leverage standards issued by the Federal Reserve Board, which constitute the U.S. Basel III rules. Citi’s U.S.-insured depository institution subsidiaries, including Citibank, are subject to similar standards issued by their respective primary federal bank regulatory agencies. These standards are used to evaluate capital adequacy and include the required minimums shown in the following table. The regulatory agencies are required by law to take specific, prompt corrective actions with respect to institutions that do not meet minimum capital standards. The following table sets forth for Citigroup and Citibank the regulatory capital tiers, total risk-weighted assets, quarterly adjusted average total assets, Total Leverage Exposure, risk-based capital ratios and leverage ratios in accordance with current regulatory standards (reflecting Basel III Transition Arrangements): In millions of dollars, except ratios Stated minimum Citigroup Citibank Well- capitalized minimum December 31, 2017 Well- capitalized minimum December 31, 2017 Common Equity Tier 1 Capital $ 147,891 $ 124,733 Tier 1 Capital 164,841 126,303 Total Capital (Tier 1 Capital + Tier 2 Capital) (1) 190,331 139,351 Total risk-weighted assets (2) 1,138,167 1,014,242 Quarterly adjusted average total assets (3) 1,869,206 1,401,615 Total Leverage Exposure (4) 2,433,371 1,901,069 Common Equity Tier 1 Capital ratio (5) 4.5 % N/A 12.99 % 6.5 % 12.30 % Tier 1 Capital ratio (5) 6.0 6.0 % 14.48 8.0 12.45 Total Capital ratio (5) 8.0 10.0 16.77 10.0 14.60 Tier 1 Leverage ratio 4.0 N/A 8.82 5.0 9.01 Supplementary Leverage ratio (6) N/A N/A 6.77 N/A 6.64 (1) Reflected in the table above is Citigroup’s and Citibank’s Total Capital as derived under the Basel III Advanced Approaches framework. At December 31, 2017 , Citigroup’s and Citibank’s Total Capital as derived under the Basel III Standardized Approach was $202 billion and $150 billion , respectively. (2) Reflected in the table above are Citigroup’s and Citibank’s total risk-weighted assets as derived under the Basel III Standardized Approach. At December 31, 2017, Citigroup’s and Citibank’s total risk-weighted assets as derived under the Basel III Advanced Approaches were $1,135 billion and $955 billion , respectively. (3) Tier 1 Leverage ratio denominator. (4) Supplementary Leverage ratio denominator. (5) As of December 31, 2017 , Citigroup’s and Citibank’s reportable Common Equity Tier 1 Capital and Tier 1 Capital ratios were the lower derived under the Basel III Standardized Approach, whereas the reportable Total Capital ratios were the lower derived under the Basel III Advanced Approaches framework. (6) Commencing on January 1, 2018, Citigroup and Citibank will be required to maintain a stated minimum Supplementary Leverage ratio of 3% , and Citibank will be required to maintain a Supplementary Leverage ratio of 6% to be considered “well capitalized.” N/A Not applicable As indicated in the table above, Citigroup and Citibank were “well capitalized” under the current federal bank regulatory agency definitions as of December 31, 2017 . Banking Subsidiaries—Constraints on Dividends There are various legal limitations on the ability of Citigroup’s subsidiary depository institutions to extend credit, pay dividends, or otherwise supply funds to Citigroup and its non-bank subsidiaries. The approval of the Office of the Comptroller of the Currency is required if total dividends declared in any calendar year were to exceed amounts specified by the applicable agency’s regulations. In determining the dividends, each subsidiary depository institution must also consider its effect on applicable risk-based capital and leverage ratio requirements, as well as policy statements of the federal bank regulatory agencies that indicate that banking organizations should generally pay dividends out of current operating earnings. Citigroup received $7.5 billion and $13.8 billion in dividends from Citibank during 2017 and 2016 , respectively.

CHANGES IN ACCUMULATED OTHER CO

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI)	12 Months Ended
	Dec. 31, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI)	CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) Changes in each component of Citigroup’s Accumulated other comprehensive income (loss) : In millions of dollars Net Debt valuation adjustment (DVA) (1) Cash flow hedges (2) Benefit plans (3) Foreign (4) Accumulated Balance, December 31, 2014 $ 57 $ — $ (909 ) $ (5,159 ) $ (17,205 ) $ (23,216 ) Other comprehensive income before reclassifications (695 ) — 83 (143 ) (5,465 ) (6,220 ) Increase (decrease) due to amounts reclassified from AOCI (269 ) — 209 186 (34 ) 92 Change, net of taxes $ (964 ) $ — $ 292 $ 43 $ (5,499 ) $ (6,128 ) Balance, December 31, 2015 $ (907 ) $ — $ (617 ) $ (5,116 ) $ (22,704 ) $ (29,344 ) Adjustment to opening balance, net of taxes (1) $ — $ (15 ) $ — $ — $ — $ (15 ) Adjusted balance, beginning of period $ (907 ) $ (15 ) $ (617 ) $ (5,116 ) $ (22,704 ) $ (29,359 ) Other comprehensive income before reclassifications $ 530 $ (335 ) $ (88 ) $ (208 ) $ (2,802 ) $ (2,903 ) Increase (decrease) due to amounts reclassified from AOCI (422 ) (2 ) 145 160 — (119 ) Change, net of taxes $ 108 $ (337 ) $ 57 $ (48 ) $ (2,802 ) $ (3,022 ) Balance, December 31, 2016 $ (799 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ (32,381 ) Adjustment to opening balance, net of taxes (5) $ 504 $ — $ — $ — $ — $ 504 Adjusted balance, beginning of period $ (295 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ (31,877 ) Impact of Tax Reform (6) (223 ) (139 ) (113 ) (1,020 ) (1,809 ) (3,304 ) Other comprehensive income before reclassifications (186 ) (426 ) (111 ) (158 ) 1,607 726 Increase (decrease) due to amounts reclassified from AOCI (454 ) (4 ) 86 159 — (213 ) Change, net of taxes $ (863 ) $ (569 ) $ (138 ) $ (1,019 ) $ (202 ) $ (2,791 ) Balance at December 31, 2017 $ (1,158 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ (34,668 ) (1) Beginning in the first quarter of 2016, changes in DVA are reflected as a component of AOCI, pursuant to the adoption of only the provisions of ASU 2016-01 relating to the presentation of DVA on fair value option liabilities. See Note 1 to the Consolidated Financial Statements for further information regarding this change. (2) Primarily driven by Citi’s pay fixed/receive floating interest rate swap programs that hedge the floating rates on liabilities. (3) Primarily reflects adjustments based on the quarterly actuarial valuations of Citi’s significant pension and postretirement plans, annual actuarial valuations of all other plans and amortization of amounts previously recognized in Other comprehensive income. (4) Primarily reflects the movements in (by order of impact) the Euro, Mexican peso, Polish zloty and Korean won against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2017 . Primarily reflects the movements in (by order of impact) the Mexican peso, Euro, British pound and Indian rupee against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2016 . Primarily reflects the movements in (by order of impact) the Mexican peso, Brazilian real, Korean won and Euro against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2015 . (5) In the second quarter of 2017, Citi early adopted ASU No. 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. (6) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings . See Note 1 to the Consolidated Financial Statements. The pretax and after-tax changes in each component of Accumulated other comprehensive income (loss) are as follows: In millions of dollars Pretax Tax Effect Adoption of ASU 2018-02 (1) After-tax Balance, December 31, 2014 $ (31,060 ) $ 7,844 $ — $ (23,216 ) Change in net unrealized gains (losses) on investment securities (1,462 ) 498 — (964 ) Cash flow hedges 468 (176 ) — 292 Benefit plans 19 24 — 43 Foreign currency translation adjustment (6,405 ) 906 — (5,499 ) Change $ (7,380 ) $ 1,252 $ — $ (6,128 ) Balance, December 31, 2015 $ (38,440 ) $ 9,096 $ — $ (29,344 ) Adjustment to opening balance (2) (26 ) 11 — (15 ) Adjusted balance, beginning of period $ (38,466 ) $ 9,107 $ — $ (29,359 ) Change in net unrealized gains (losses) on investment securities 167 (59 ) — 108 Debt valuation adjustment (DVA) (538 ) 201 — (337 ) Cash flow hedges 84 (27 ) — 57 Benefit plans (78 ) 30 — (48 ) Foreign currency translation adjustment (3,204 ) 402 — (2,802 ) Change $ (3,569 ) $ 547 $ — $ (3,022 ) Balance, December 31, 2016 $ (42,035 ) $ 9,654 $ — $ (32,381 ) Adjustment to opening balance (3) 803 (299 ) — 504 Adjusted balance, beginning of period $ (41,232 ) $ 9,355 $ — $ (31,877 ) Change in net unrealized gains (losses) on investment securities (1,088 ) 448 (223 ) (863 ) Debt valuation adjustment (DVA) (680 ) 250 (139 ) (569 ) Cash flow hedges (37 ) 12 (113 ) (138 ) Benefit plans 14 (13 ) (1,020 ) (1,019 ) Foreign currency translation adjustment 1,795 (188 ) (1,809 ) (202 ) Change $ 4 $ 509 $ (3,304 ) $ (2,791 ) Balance, December 31, 2017 $ (41,228 ) $ 9,864 $ (3,304 ) $ (34,668 ) (1) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings . See Note 1 to the Consolidated Financial Statements. (2) Represents the $(15) million adjustment related to the initial adoption of ASU 2016-01. See Note 1 to the Consolidated Financial Statements. (3) In the second quarter of 2017, Citi early adopted ASU 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. The Company recognized pretax gain (loss) related to amounts in AOCI reclassified in the Consolidated Statement of Income as follows: Increase (decrease) in AOCI due to amounts reclassified to Consolidated Statement of Income Year ended December 31, In millions of dollars 2017 2016 2015 Realized (gains) losses on sales of investments $ (778 ) $ (948 ) $ (682 ) OTTI gross impairment losses 63 288 265 Subtotal, pretax $ (715 ) $ (660 ) $ (417 ) Tax effect 261 238 148 Net realized (gains) losses on investment securities, after-tax (1) $ (454 ) $ (422 ) $ (269 ) Realized DVA (gains) losses on fair value option liabilities $ (7 ) $ (3 ) $ — Subtotal, pretax $ (7 ) $ (3 ) $ — Tax effect 3 1 — Net realized debt valuation adjustment, after-tax $ (4 ) $ (2 ) $ — Interest rate contracts $ 126 $ 140 $ 186 Foreign exchange contracts 10 93 146 Subtotal, pretax $ 136 $ 233 $ 332 Tax effect (50 ) (88 ) (123 ) Amortization of cash flow hedges, after-tax (2) $ 86 $ 145 $ 209 Amortization of unrecognized Prior service cost (benefit) $ (42 ) $ (40 ) $ (40 ) Net actuarial loss 271 272 276 Curtailment/settlement impact (3) 17 18 57 Subtotal, pretax $ 246 $ 250 $ 293 Tax effect (87 ) (90 ) (107 ) Amortization of benefit plans, after-tax (3) $ 159 $ 160 $ 186 Foreign currency translation adjustment $ — $ — $ (53 ) Tax effect — — 19 Foreign currency translation adjustment $ — $ — $ (34 ) Total amounts reclassified out of AOCI, pretax $ (340 ) $ (180 ) $ 155 Total tax effect 127 61 (63 ) Total amounts reclassified out of AOCI, after-tax $ (213 ) $ (119 ) $ 92 (1) The pretax amount is reclassified to Realized gains (losses) on sales of investments, net and Gross impairment losses in the Consolidated Statement of Income. See Note 13 to the Consolidated Financial Statements for additional details. (2) See Note 22 to the Consolidated Financial Statements for additional details. (3) See Note 8 to the Consolidated Financial Statements for additional details.

PREFERRED STOCK

PREFERRED STOCK	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
PREFERRED STOCK	PREFERRED STOCK The following table summarizes the Company’s preferred stock outstanding: Redemption Carrying value in millions of dollars Issuance date Redeemable by issuer beginning Dividend Number December 31, December 31, Series AA (1) January 25, 2008 February 15, 2018 8.125 % $ 25 3,870,330 $ 97 $ 97 Series E (2) April 28, 2008 April 30, 2018 8.400 1,000 121,254 121 121 Series A (3) October 29, 2012 January 30, 2023 5.950 1,000 1,500,000 1,500 1,500 Series B (4) December 13, 2012 February 15, 2023 5.900 1,000 750,000 750 750 Series C (5) March 26, 2013 April 22, 2018 5.800 25 23,000,000 575 575 Series D (6) April 30, 2013 May 15, 2023 5.350 1,000 1,250,000 1,250 1,250 Series J (7) September 19, 2013 September 30, 2023 7.125 25 38,000,000 950 950 Series K (8) October 31, 2013 November 15, 2023 6.875 25 59,800,000 1,495 1,495 Series L (9) February 12, 2014 February 12, 2019 6.875 25 19,200,000 480 480 Series M (10) April 30, 2014 May 15, 2024 6.300 1,000 1,750,000 1,750 1,750 Series N (11) October 29, 2014 November 15, 2019 5.800 1,000 1,500,000 1,500 1,500 Series O (12) March 20, 2015 March 27, 2020 5.875 1,000 1,500,000 1,500 1,500 Series P (13) April 24, 2015 May 15, 2025 5.950 1,000 2,000,000 2,000 2,000 Series Q (14) August 12, 2015 August 15, 2020 5.950 1,000 1,250,000 1,250 1,250 Series R (15) November 13, 2015 November 15, 2020 6.125 1,000 1,500,000 1,500 1,500 Series S (16) February 2, 2016 February 12, 2021 6.300 25 41,400,000 1,035 1,035 Series T (17) April 25, 2016 August 15, 2026 6.250 1,000 1,500,000 1,500 1,500 $ 19,253 $ 19,253 (1) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 15, May 15, August 15 and November 15, in each case when, as and if declared by the Citi Board of Directors. (2) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on April 30 and October 30 at a fixed rate until April 30, 2018, thereafter payable quarterly on January 30, April 30, July 30 and October 30 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (3) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on January 30 and July 30 at a fixed rate until January 30, 2023, thereafter payable quarterly on January 30, April 30, July 30 and October 30 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (4) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until February 15, 2023, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (5) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on January 22, April 22, July 22 and October 22 when, as and if declared by the Citi Board of Directors. (6) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until May 15, 2023, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (7) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on March 30, June 30, September 30 and December 30 at a fixed rate until September 30, 2023, thereafter payable quarterly on the same dates at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (8) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 15, May 15, August 15 and November 15 at a fixed rate until November 15, 2023, thereafter payable quarterly on the same dates at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (9) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 12, May 12, August 12 and November 12 at a fixed rate, in each case when, as and if declared by the Citi Board of Directors. (10) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until May 15, 2024, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (11) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, November 15, 2019, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (12) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on March 27 and September 27 at a fixed rate until, but excluding, March 27, 2020, and thereafter payable quarterly on March 27, June 27, September 27 and December 27 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (13) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, May 15, 2025, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (14) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until, but excluding, August 15, 2020, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (15) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, November 15, 2020, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (16) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 12, May 12, August 12 and November 12 at a fixed rate, in each case when, as and if declared by the Citi Board of Directors. (17) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until August 15, 2026, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. During 2017 , Citi distributed $1,213 million in dividends on its outstanding preferred stock. Based on its preferred stock outstanding as of December 31, 2017 and the planned redemption of Series AA on February 15, 2018, Citi estimates it will distribute preferred dividends of approximately $ 1,179 million during 2018, assuming such dividends are declared by the Citi Board of Directors.

SECURITIZATIONS AND VARIABLE IN

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2017
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES	SECURITIZATIONS AND VARIABLE INTEREST ENTITIES Uses of Special Purpose Entities A special purpose entity (SPE) is an entity designed to fulfill a specific limited need of the company that organized it. The principal uses of SPEs by Citi are to obtain liquidity and favorable capital treatment by securitizing certain financial assets, to assist clients in securitizing their financial assets and to create investment products for clients. SPEs may be organized in various legal forms, including trusts, partnerships or corporations. In a securitization, through the SPE’s issuance of debt and equity instruments, certificates, commercial paper or other notes of indebtedness, the company transferring assets to the SPE converts all (or a portion) of those assets into cash before they would have been realized in the normal course of business. These issuances are recorded on the balance sheet of the SPE, which may or may not be consolidated onto the balance sheet of the company that organized the SPE. Investors usually have recourse only to the assets in the SPE, but may also benefit from other credit enhancements, such as a collateral account, a line of credit or a liquidity facility, such as a liquidity put option or asset purchase agreement. Because of these enhancements, the SPE issuances typically obtain a more favorable credit rating than the transferor could obtain for its own debt issuances. This results in less expensive financing costs than unsecured debt. The SPE may also enter into derivative contracts in order to convert the yield or currency of the underlying assets to match the needs of the SPE investors or to limit or change the credit risk of the SPE. Citigroup may be the provider of certain credit enhancements as well as the counterparty to any related derivative contracts. Most of Citigroup’s SPEs are variable interest entities (VIEs), as described below. Variable Interest Entities VIEs are entities that have either a total equity investment that is insufficient to permit the entity to finance its activities without additional subordinated financial support or whose equity investors lack the characteristics of a controlling financial interest (i.e., ability to make significant decisions through voting rights or similar rights and a right to receive the expected residual returns of the entity or an obligation to absorb the expected losses of the entity). Investors that finance the VIE through debt or equity interests or other counterparties providing other forms of support, such as guarantees, certain fee arrangements or certain types of derivative contracts, are variable interest holders in the entity. The variable interest holder, if any, that has a controlling financial interest in a VIE is deemed to be the primary beneficiary and must consolidate the VIE. Citigroup would be deemed to have a controlling financial interest and be the primary beneficiary if it has both of the following characteristics: • power to direct the activities of the VIE that most significantly impact the entity’s economic performance; and • an obligation to absorb losses of the entity that could potentially be significant to the VIE, or a right to receive benefits from the entity that could potentially be significant to the VIE. The Company must evaluate each VIE to understand the purpose and design of the entity, the role the Company had in the entity’s design and its involvement in the VIE’s ongoing activities. The Company then must evaluate which activities most significantly impact the economic performance of the VIE and who has the power to direct such activities. For those VIEs where the Company determines that it has the power to direct the activities that most significantly impact the VIE’s economic performance, the Company must then evaluate its economic interests, if any, and determine whether it could absorb losses or receive benefits that could potentially be significant to the VIE. When evaluating whether the Company has an obligation to absorb losses that could potentially be significant, it considers the maximum exposure to such loss without consideration of probability. Such obligations could be in various forms, including, but not limited to, debt and equity investments, guarantees, liquidity agreements and certain derivative contracts. In various other transactions, the Company may (i) act as a derivative counterparty (for example, interest rate swap, cross-currency swap or purchaser of credit protection under a credit default swap or total return swap where the Company pays the total return on certain assets to the SPE), (ii) act as underwriter or placement agent, (iii) provide administrative, trustee or other services or (iv) make a market in debt securities or other instruments issued by VIEs. The Company generally considers such involvement, by itself, not to be variable interests and thus not an indicator of power or potentially significant benefits or losses. Citigroup’s involvement with consolidated and unconsolidated VIEs with which the Company holds significant variable interests or has continuing involvement through servicing a majority of the assets in a VIE is presented below: As of December 31, 2017 Maximum exposure to loss in significant unconsolidated VIEs (1) Funded exposures (2) Unfunded exposures In millions of dollars Total involvement with SPE assets Consolidated VIE/SPE assets Significant unconsolidated VIE assets (3) Debt investments Equity investments Funding commitments Guarantees and derivatives Total Credit card securitizations $ 50,795 $ 50,795 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored (5) 116,610 — 116,610 2,647 — — 74 2,721 Non-agency-sponsored 22,251 2,035 20,216 330 — — 1 331 Citi-administered asset-backed commercial paper conduits (ABCP) 19,282 19,282 — — — — — — Collateralized loan obligations (CLOs) 20,588 — 20,588 5,956 — — 9 5,965 Asset-based financing 60,472 633 59,839 19,478 583 5,878 — 25,939 Municipal securities tender option bond trusts (TOBs) 6,925 2,166 4,759 138 — 3,035 — 3,173 Municipal investments 19,119 7 19,112 2,709 3,640 2,344 — 8,693 Client intermediation 958 824 134 32 — — 9 41 Investment funds 1,892 616 1,276 14 7 13 — 34 Other 677 36 641 27 9 34 47 117 Total $ 319,569 $ 76,394 $ 243,175 $ 31,331 $ 4,239 $ 11,304 $ 140 $ 47,014 As of December 31, 2016 Maximum exposure to loss in significant unconsolidated VIEs (1) Funded exposures (2) Unfunded exposures In millions of dollars Total involvement with SPE assets Consolidated VIE/SPE assets Significant unconsolidated VIE assets (3) Debt investments Equity investments Funding commitments Guarantees and derivatives Total Credit card securitizations $ 50,171 $ 50,171 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored 214,458 — 214,458 3,852 — — 78 3,930 Non-agency-sponsored 15,965 1,092 14,873 312 35 — 1 348 Citi-administered asset-backed commercial paper conduits (ABCP) 19,693 19,693 — — — — — — Collateralized loan obligations (CLOs) 18,886 — 18,886 5,128 — — 62 5,190 Asset-based financing 53,168 733 52,435 16,553 475 4,915 — 21,943 Municipal securities tender option bond trusts (TOBs) 7,070 2,843 4,227 40 — 2,842 — 2,882 Municipal investments 17,679 14 17,665 2,441 3,578 2,580 — 8,599 Client intermediation 515 371 144 49 — — 3 52 Investment funds 2,788 767 2,021 32 120 27 3 182 Other 1,429 607 822 116 11 58 43 228 Total $ 401,822 $ 76,291 $ 325,531 $ 28,523 $ 4,219 $ 10,422 $ 190 $ 43,354 (1) The definition of maximum exposure to loss is included in the text that follows this table. (2) Included on Citigroup’s December 31, 2017 and 2016 Consolidated Balance Sheet. (3) A significant unconsolidated VIE is an entity in which the Company has any variable interest or continuing involvement considered to be significant, regardless of the likelihood of loss. (4) Citigroup mortgage securitizations also include agency and non-agency (private-label) re-securitization activities. These SPEs are not consolidated. See “Re-securitizations” below for further discussion. (5) See Note 2 to the Consolidated Financial Statements for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs. The previous tables do not include the following: • certain venture capital investments made by some of the Company’s private equity subsidiaries, as the Company accounts for these investments in accordance with the Investment Company Audit Guide (codified in ASC Topic 946); • certain investment funds for which the Company provides investment management services and personal estate trusts for which the Company provides administrative, trustee and/or investment management services; • certain VIEs structured by third parties in which the Company holds securities in inventory, as these investments are made on arm’s-length terms; • certain positions in mortgage-backed and asset-backed securities held by the Company, which are classified as Trading account assets or Investments , in which the Company has no other involvement with the related securitization entity deemed to be significant (for more information on these positions, see Notes 13 and 24 to the Consolidated Financial Statements); • certain representations and warranties exposures in legacy ICG -sponsored mortgage-backed and asset-backed securitizations, in which the Company has no variable interest or continuing involvement as servicer. The outstanding balance of mortgage loans securitized during 2005 to 2008 in which the Company has no variable interest or continuing involvement as servicer was approximately $9 billion and $10 billion at December 31, 2017 and 2016 , respectively; • certain representations and warranties exposures in Citigroup residential mortgage securitizations, in which the original mortgage loan balances are no longer outstanding; and • VIEs such as trust preferred securities trusts used in connection with the Company’s funding activities. The Company does not have a variable interest in these trusts. The asset balances for consolidated VIEs represent the carrying amounts of the assets consolidated by the Company. The carrying amount may represent the amortized cost or the current fair value of the assets depending on the legal form of the asset (e.g., loan or security) and the Company’s standard accounting policies for the asset type and line of business. The asset balances for unconsolidated VIEs in which the Company has significant involvement represent the most current information available to the Company. In most cases, the asset balances represent an amortized cost basis without regard to impairments, unless fair value information is readily available to the Company. The maximum funded exposure represents the balance sheet carrying amount of the Company’s investment in the VIE. It reflects the initial amount of cash invested in the VIE adjusted for any accrued interest and cash principal payments received. The carrying amount may also be adjusted for increases or declines in fair value or any impairment in value recognized in earnings. The maximum exposure of unfunded positions represents the remaining undrawn committed amount, including liquidity and credit facilities provided by the Company or the notional amount of a derivative instrument considered to be a variable interest. In certain transactions, the Company has entered into derivative instruments or other arrangements that are not considered variable interests in the VIE (e.g., interest rate swaps, cross-currency swaps or where the Company is the purchaser of credit protection under a credit default swap or total return swap where the Company pays the total return on certain assets to the SPE). Receivables under such arrangements are not included in the maximum exposure amounts. Funding Commitments for Significant Unconsolidated VIEs—Liquidity Facilities and Loan Commitments The following table presents the notional amount of liquidity facilities and loan commitments that are classified as funding commitments in the VIE tables above: December 31, 2017 December 31, 2016 In millions of dollars Liquidity facilities Loan/equity commitments Liquidity facilities Loan/equity commitments Asset-based financing $ — $ 5,878 $ 5 $ 4,910 Municipal securities tender option bond trusts (TOBs) 3,035 — 2,842 — Municipal investments — 2,344 — 2,580 Investment funds — 13 — 27 Other — 34 — 58 Total funding commitments $ 3,035 $ 8,269 $ 2,847 $ 7,575 Consolidated VIEs The Company engages in on-balance sheet securitizations, which are securitizations that do not qualify for sales treatment; thus, the assets remain on the Citi’s Consolidated Balance Sheet, and any proceeds received are recognized as secured liabilities. The consolidated VIEs represent hundreds of separate entities with which the Company is involved. In general, the third-party investors in the obligations of consolidated VIEs have legal recourse only to the assets of the respective VIEs and do not have such recourse to the Company, except where Citi has provided a guarantee to the investors or is the counterparty to certain derivative transactions involving the VIE. Thus, Citigroup’s maximum legal exposure to loss related to consolidated VIEs is significantly less than the carrying value of the consolidated VIE assets due to outstanding third-party financing. Intercompany assets and liabilities are excluded from Citi’s Consolidated Balance Sheet. All VIE assets are restricted from being sold or pledged as collateral. The cash flows from these assets are the only source used to pay down the associated liabilities, which are non-recourse to Citi’s general assets. See the Consolidated Balance Sheet for more information about these Consolidated VIE assets and liabilities. Significant Interests in Unconsolidated VIEs—Balance Sheet Classification The following table presents the carrying amounts and classification of significant variable interests in unconsolidated VIEs: In billions of dollars December 31, 2017 December 31, 2016 Cash $ — $ 0.1 Trading account assets 8.5 8.0 Investments 4.4 4.4 Total loans, net of allowance 22.2 18.8 Other 0.5 1.5 Total assets $ 35.6 $ 32.8 Credit Card Securitizations The Company securitizes credit card receivables through trusts established to purchase the receivables. Citigroup transfers receivables into the trusts on a non-recourse basis. Credit card securitizations are revolving securitizations; as customers pay their credit card balances, the cash proceeds are used to purchase new receivables and replenish the receivables in the trust. Substantially all of Citigroup’s credit card securitization activity is through two trusts—Citibank Credit Card Master Trust (Master Trust) and Citibank Omni Master Trust (Omni Trust), with the substantial majority through the Master Trust. These trusts are consolidated entities because, as servicer, Citigroup has the power to direct the activities that most significantly impact the economic performance of the trusts. Citigroup holds a seller’s interest and certain securities issued by the trusts, which could result in exposure to potentially significant losses or benefits from the trusts. Accordingly, the transferred credit card receivables remain on Citi’s Consolidated Balance Sheet with no gain or loss recognized. The debt issued by the trusts to third parties is included on Citi’s Consolidated Balance Sheet. Citi utilizes securitizations as one of the sources of funding for its business in North America . The following table reflects amounts related to the Company’s securitized credit card receivables: In billions of dollars December 31, 2017 December 31, 2016 Ownership interests in principal amount of trust credit card receivables Sold to investors via trust-issued securities $ 28.8 $ 22.7 Retained by Citigroup as trust-issued securities 7.6 7.4 Retained by Citigroup via non-certificated interests 14.4 20.6 Total $ 50.8 $ 50.7 The following table summarizes selected cash flow information related to Citigroup’s credit card securitizations: In billions of dollars 2017 2016 2015 Proceeds from new securitizations $ 11.1 $ 3.3 $ — Pay down of maturing notes (5.0 ) (10.3 ) (7.4 ) Managed Loans After securitization of credit card receivables, the Company continues to maintain credit card customer account relationships and provides servicing for receivables transferred to the trusts. As a result, the Company considers the securitized credit card receivables to be part of the business it manages. As Citigroup consolidates the credit card trusts, all managed securitized card receivables are on-balance sheet. Funding, Liquidity Facilities and Subordinated Interests As noted above, Citigroup securitizes credit card receivables through two securitization trusts—Master Trust and Omni Trust. The liabilities of the trusts are included on the Consolidated Balance Sheet, excluding those retained by Citigroup. The Master Trust issues fixed- and floating-rate term notes. Some of the term notes may be issued to multi-seller commercial paper conduits. The weighted average maturity of the term notes issued by the Master Trust was 2.6 years as of December 31, 2017 and 2016 . Master Trust Liabilities (at Par Value) In billions of dollars Dec. 31, 2017 Dec. 31, 2016 Term notes issued to third parties $ 27.8 $ 21.7 Term notes retained by Citigroup affiliates 5.7 5.5 Total Master Trust liabilities $ 33.5 $ 27.2 The Omni Trust issues fixed- and floating-rate term notes, some of which are purchased by multi-seller commercial paper conduits. The weighted average maturity of the third-party term notes issued by the Omni Trust was 1.9 years as of December 31, 2017 and 2016 . Omni Trust Liabilities (at Par Value) In billions of dollars Dec. 31, 2017 Dec. 31, 2016 Term notes issued to third parties $ 1.0 $ 1.0 Term notes retained by Citigroup affiliates 1.9 1.9 Total Omni Trust liabilities $ 2.9 $ 2.9 Mortgage Securitizations Citigroup provides a wide range of mortgage loan products to a diverse customer base. Once originated, the Company often securitizes these loans through the use of VIEs. These VIEs are funded through the issuance of trust certificates backed solely by the transferred assets. These certificates have the same life as the transferred assets. In addition to providing a source of liquidity and less expensive funding, securitizing these assets also reduces Citi’s credit exposure to the borrowers. These mortgage loan securitizations are primarily non-recourse, thereby effectively transferring the risk of future credit losses to the purchasers of the securities issued by the trust. However, Citi’s U.S. consumer mortgage business generally retains the servicing rights and in certain instances retains investment securities, interest-only strips and residual interests in future cash flows from the trusts and also provides servicing for a limited number of ICG securitizations. The Company securitizes mortgage loans generally through either a government-sponsored agency, such as Ginnie Mae, Fannie Mae or Freddie Mac (U.S. agency-sponsored mortgages), or private-label (non-agency-sponsored mortgages) securitization. Citi is not the primary beneficiary of its U.S. agency-sponsored mortgage securitizations because Citigroup does not have the power to direct the activities of the VIE that most significantly impact the entity’s economic performance. Therefore, Citi does not consolidate these U.S. agency-sponsored mortgage securitizations. Substantially all of the consumer loans sold or securitized through non-consolidated trusts by Citigroup are U.S. prime residential mortgage loans. Retained interests in non-consolidated mortgage securitization trusts are classified as Trading account assets , except for MSRs, which are included in Mortgage servicing rights on Citigroup’s Consolidated Balance Sheet. Citigroup does not consolidate certain non-agency-sponsored mortgage securitizations because Citi is either not the servicer with the power to direct the significant activities of the entity or Citi is the servicer, but the servicing relationship is deemed to be a fiduciary relationship; therefore, Citi is not deemed to be the primary beneficiary of the entity. In certain instances, the Company has (i) the power to direct the activities and (ii) the obligation to either absorb losses or the right to receive benefits that could be potentially significant to its non-agency-sponsored mortgage securitizations and, therefore, is the primary beneficiary and, thus, consolidates the VIE. The following table summarizes selected cash flow information related to Citigroup mortgage securitizations: 2017 2016 2015 In billions of dollars U.S. agency- Non-agency- U.S. agency- Non-agency- U.S. agency- Non-agency- Proceeds from new securitizations (1) $ 33.9 $ 7.9 $ 41.3 $ 11.8 $ 35.0 $ 12.1 Contractual servicing fees received 0.2 — 0.4 — 0.5 — Cash flows received on retained interests and other net cash flows — — 0.1 — 0.1 — (1) The proceeds from new securitizations in 2016 and 2015 include $0.5 billion and $0.7 billion , respectively, related to personal loan securitizations. Agency and non-agency securitization gains for the year ended December 31, 2017 were $73 million and $77 million , respectively. Agency and non-agency securitization gains for the year ended December 31, 2016 were $105 million and $107 million , respectively, and $149 million and $41 million , respectively, for the year ended December 31, 2015 . Key assumptions used in measuring the fair value of retained interests at the date of sale or securitization of mortgage receivables were as follows: December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 1.8% to 19.9% — — Weighted average discount rate 8.6 % — — Constant prepayment rate 3.8% to 31.6% — — Weighted average constant prepayment rate 9.4 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 2.5 to 20.7 years — — December 31, 2016 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 0.8% to 13.7% — — Weighted average discount rate 9.9 % — — Constant prepayment rate 3.8% to 30.9% — — Weighted average constant prepayment rate 11.1 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 0.5 to 17.5 years — — (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. (2) Anticipated net credit losses represent estimated loss severity associated with defaulted mortgage loans underlying the mortgage securitizations disclosed above. Anticipated net credit losses, in this instance, do not represent total credit losses incurred to date, nor do they represent credit losses expected on retained interests in mortgage securitizations. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees. The interests retained by Citi range from highly rated and/or senior in the capital structure to unrated and/or residual interests. The key assumptions used to value retained interests, and the sensitivity of the fair value to adverse changes of 10% and 20% in each of the key assumptions, are set forth in the tables below. The negative effect of each change is calculated independently, holding all other assumptions constant. Because the key assumptions may not be independent, the net effect of simultaneous adverse changes in the key assumptions may be less than the sum of the individual effects shown below. December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 1.8% to 84.2% 5.8% to 100.0% 2.8% to 35.1% Weighted average discount rate 7.1 % 5.8 % 9.0 % Constant prepayment rate 6.9% to 27.8% 8.9% to 15.5% 8.6% to 13.1% Weighted average constant prepayment rate 11.6 % 8.9 % 10.6 % Anticipated net credit losses (2) NM 0.4% to 46.9% 35.1% to 52.1% Weighted average anticipated net credit losses NM 46.9 % 44.9 % Weighted average life 0.1 to 27.8 years 4.8 to 5.3 years 0.2 to 18.6 years December 31, 2016 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 0.7% to 28.2% 0.0% to 8.1% 5.1% to 26.4% Weighted average discount rate 9.0 % 2.1 % 13.1 % Constant prepayment rate 6.8% to 22.8% 4.2% to 14.7% 0.5% to 37.5% Weighted average constant prepayment rate 10.2 % 11.0 % 10.8 % Anticipated net credit losses (2) NM 0.5% to 85.6% 8.0% to 63.7% Weighted average anticipated net credit losses NM 31.4 % 48.3 % Weighted average life 0.2 to 28.8 years 5.0 to 8.5 years 1.2 to 12.1 years (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. (2) Anticipated net credit losses represent estimated loss severity associated with defaulted mortgage loans underlying the mortgage securitizations disclosed above. Anticipated net credit losses, in this instance, do not represent total credit losses incurred to date, nor do they represent credit losses expected on retained interests in mortgage securitizations. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees. December 31, 2017 Non-agency-sponsored mortgages In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests (1) $ 1,634 $ 214 $ 139 Discount rates Adverse change of 10% $ (44 ) $ (2 ) $ (3 ) Adverse change of 20% (85 ) (4 ) (5 ) Constant prepayment rate Adverse change of 10% (41 ) (1 ) (1 ) Adverse change of 20% (84 ) (1 ) (2 ) Anticipated net credit losses Adverse change of 10% NM (3 ) — Adverse change of 20% NM (7 ) — December 31, 2016 Non-agency-sponsored mortgages In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests (1) $ 2,258 $ 26 $ 161 Discount rates Adverse change of 10% $ (71 ) $ (7 ) $ (8 ) Adverse change of 20% (138 ) (14 ) (16 ) Constant prepayment rate Adverse change of 10% (80 ) (2 ) (4 ) Adverse change of 20% (160 ) (3 ) (8 ) Anticipated net credit losses Adverse change of 10% NM (7 ) (1 ) Adverse change of 20% NM (14 ) (2 ) (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees. Mortgage Servicing Rights In connection with the securitization of mortgage loans, Citi’s U.S. consumer mortgage business generally retains the servicing rights, which entitle the Company to a future stream of cash flows based on the outstanding principal balances of the loans and the contractual servicing fee. Failure to service the loans in accordance with contractual requirements may lead to a termination of the servicing rights and the loss of future servicing fees. These transactions create an intangible asset referred to as mortgage servicing rights (MSRs), which are recorded at fair value on Citi’s Consolidated Balance Sheet. The fair value of Citi’s capitalized MSRs was $558 million and $1.6 billion at December 31, 2017 and 2016 , respectively. The MSRs correspond to principal loan balances of $66 billion and $168 billion as of December 31, 2017 and 2016 , respectively. The following table summarizes the changes in capitalized MSRs: In millions of dollars 2017 2016 Balance, beginning of year $ 1,564 $ 1,781 Originations 96 152 Changes in fair value of MSRs due to changes in inputs and assumptions 65 (36 ) Other changes (1) (110 ) (313 ) Sale of MSRs (2) (1,057 ) (20 ) Balance, as of December 31 $ 558 $ 1,564 (1) Represents changes due to customer payments and passage of time. (2) See Note 2 to the Consolidated Financial Statements for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs. 2016 amount includes sales of credit-challenged MSRs for which Citi paid the new servicer. The fair value of the MSRs is primarily affected by changes in prepayments of mortgages that result from shifts in mortgage interest rates. Specifically, higher interest rates tend to lead to declining prepayments, which causes the fair value of the MSRs to increase. In managing this risk, Citigroup economically hedges a significant portion of the value of its MSRs through the use of interest rate derivative contracts, forward purchase and sale commitments of mortgage-backed securities and purchased securities all classified as Trading account assets . The Company receives fees during the course of servicing previously securitized mortgages. The amounts of these fees were as follows: In millions of dollars 2017 2016 2015 Servicing fees $ 276 $ 484 $ 552 Late fees 10 14 16 Ancillary fees 13 17 31 Total MSR fees $ 299 $ 515 $ 599 In the Consolidated Statement of Income these fees are primarily classified as Commissions and fees, and changes in MSR fair values are classified as Other revenue . Citi signed agreements during the first quarter of 2017 to effectively exit its direct U.S. mortgage servicing operations by the end of 2018 to intensify focus on originations. The exit of the mortgage servicing operations included the sale of mortgage servicing rights and execution of a subservicing agreement for the remaining Citi-owned loans and certain other mortgage servicing rights. As part of this transaction, Citi is also transferring certain employees. See Note 2 to the Consolidated Financial Statements for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs. Re-securitizations Citigroup engages in re-securitization transactions in which debt securities are transferred to a VIE in exchange for new beneficial interests. Citi did not transfer non-agency (private-label) securities to re-securitization entities during the years ended December 31, 2017 and 2016 . These securities are backed by either residential or commercial mortgages and are often structured on behalf of clients. As of December 31, 2017 , the fair value of Citi-retained interests in private-label re-securitization transactions structured by Citi totaled approximately $79 million (all related to re-securitization transactions executed prior to 2016 ), which has been recorded in Trading account assets . Of this amount, substantially all was related to subordinated beneficial interests. As of December 31, 2016 , the fair value of Citi-retained interests in private-label re-securitization transactions structured by Citi totaled approximately $126 million (all related to re-securitization transactions executed prior to 2016 ). Of this amount, substantially all was related to subordinated beneficial interests. The original par value of private-label re-securitization transactions in which Citi holds a retained interest as of December 31, 2017 and 2016 was approximately $887 million and $1.3 billion , respectively. The Company also re-securitizes U.S. government-agency guaranteed mortgage-backed (agency) securities. During the years ended December 31, 2017 and 2016 , Citi transferred agency securities with a fair value of approximately $26.6 billion and $26.5 billion , respectively, to re-securitization entities. As of December 31, 2017 , the fair value of Citi-retained interests in agency re-securitization transactions structured by Citi totaled approximately $2.1 billion (including $854 million related to re-securitization transactions executed in 2017 ) compared to $2.3 billion as of December 31, 2016 (including $741 million related to re-securitization transactions executed in 2016 ), which is recorded in Trading account assets . The original fair value of agency re-securitization transactions in which Citi holds a retained interest as of December 31, 2017 and 2016 was approximately $68.3 billion and $71.8 billion , respectively. As of December 31, 2017 and 2016 , the Company did not consolidate any private-label or agency re-securitization entities. Citi-Administered Asset-Backed Commercial Paper Conduits The Company is active in the asset-backed commercial paper conduit business as administrator of several multi-seller commercial paper conduits and also as a service provider to single-seller and other commercial paper conduits sponsored by third parties. Citi’s multi-seller commercial paper conduits are designed to provide the Company’s clients access to low-cost funding in the commercial paper markets. The conduits purchas

DERIVATIVES ACTIVITIES

DERIVATIVES ACTIVITIES	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES ACTIVITIES	DERIVATIVES ACTIVITIES In the ordinary course of business, Citigroup enters into various types of derivative transactions, which include: • Futures and forward contracts , which are commitments to buy or sell at a future date a financial instrument, commodity or currency at a contracted price and may be settled in cash or through delivery of an item readily convertible to cash. • Swap contracts , which are commitments to settle in cash at a future date or dates that may range from a few days to a number of years, based on differentials between specified indices or financial instruments, as applied to a notional principal amount. • Option contracts , which give the purchaser, for a premium, the right, but not the obligation, to buy or sell within a specified time a financial instrument, commodity or currency at a contracted price that may also be settled in cash, based on differentials between specified indices or prices. Swaps, forwards and some option contracts are over-the-counter (OTC) derivatives that are bilaterally negotiated with counterparties and settled with those counterparties, except for swap contracts that are novated and "cleared" through central counterparties (CCPs). Futures contracts and other option contracts are standardized contracts that are traded on an exchange with a CCP as the counterparty from the inception of the transaction. Citigroup enters into derivative contracts relating to interest rate, foreign currency, commodity and other market/credit risks for the following reasons: • Trading Purposes : Citigroup trades derivatives as an active market maker. Citigroup offers its customers derivatives in connection with their risk management actions to transfer, modify or reduce their interest rate, foreign exchange and other market/credit risks or for their own trading purposes. Citigroup also manages its derivative risk positions through offsetting trade activities, controls focused on price verification and daily reporting of positions to senior managers. • Hedging : Citigroup uses derivatives in connection with its own risk management activities to hedge certain risks or reposition the risk profile of the Company. Hedging may be accomplished by applying hedge accounting in accordance with ASC 815, Derivatives and Hedging , or by an economic hedge. For example, Citigroup issues fixed-rate long-term debt and then enters into a receive-fixed, pay-variable-rate interest rate swap with the same tenor and notional amount to synthetically convert the interest payments to a net variable-rate basis. This strategy is the most common form of an interest rate hedge, as it minimizes net interest cost in certain yield curve environments. Derivatives are also used to manage market risks inherent in specific groups of on-balance sheet assets and liabilities, including AFS securities, commodities and borrowings, as well as other interest-sensitive assets and liabilities. In addition, foreign exchange contracts are used to hedge non-U.S.-dollar-denominated debt, foreign currency-denominated AFS securities and net investment exposures. Derivatives may expose Citigroup to market, credit or liquidity risks in excess of the amounts recorded on the Consolidated Balance Sheet. Market risk on a derivative product is the exposure created by potential fluctuations in interest rates, market prices, foreign exchange rates and other factors and is a function of the type of product, the volume of transactions, the tenor and terms of the agreement and the underlying volatility. Credit risk is the exposure to loss in the event of nonperformance by the other party to satisfy a derivative liability where the value of any collateral held by Citi is not adequate to cover such losses. The recognition in earnings of unrealized gains on derivative transactions is subject to management’s assessment of the probability of counterparty default. Liquidity risk is the potential exposure that arises when the size of a derivative position may affect the ability to monetize the position in a reasonable period of time and at a reasonable cost in periods of high volatility and financial stress. Derivative transactions are customarily documented under industry standard master netting agreements, which provide that following an event of default, the non-defaulting party may promptly terminate all transactions between the parties and determine the net amount due to be paid to, or by, the defaulting party. Events of default include (i) failure to make a payment on a derivatives transaction that remains uncured following applicable notice and grace periods, (ii) breach of agreement that remains uncured after applicable notice and grace periods, (iii) breach of a representation, (iv) cross default, either to third-party debt or to other derivative transactions entered into between the parties, or, in some cases, their affiliates, (v) the occurrence of a merger or consolidation which results in a party’s becoming a materially weaker credit and (vi) the cessation or repudiation of any applicable guarantee or other credit support document. Obligations under master netting agreements are often secured by collateral posted under an industry standard credit support annex to the master netting agreement. An event of default may also occur under a credit support annex if a party fails to make a collateral delivery that remains uncured following applicable notice and grace periods. The netting and collateral rights incorporated in the master netting agreements are considered to be legally enforceable if a supportive legal opinion has been obtained from counsel of recognized standing that provides (i) the requisite level of certainty regarding enforceability, and (ii) that the exercise of rights by the non-defaulting party to terminate and close-out transactions on a net basis under these agreements will not be stayed or avoided under applicable law upon an event of default, including bankruptcy, insolvency or similar proceeding. A legal opinion may not be sought for certain jurisdictions where local law is silent or unclear as to the enforceability of such rights or where adverse case law or conflicting regulation may cast doubt on the enforceability of such rights. In some jurisdictions and for some counterparty types, the insolvency law may not provide the requisite level of certainty. For example, this may be the case for certain sovereigns, municipalities, central banks and U.S. pension plans. Exposure to credit risk on derivatives is affected by market volatility, which may impair the ability of counterparties to satisfy their obligations to the Company. Credit limits are established and closely monitored for customers engaged in derivatives transactions. Citi considers the level of legal certainty regarding enforceability of its offsetting rights under master netting agreements and credit support annexes to be an important factor in its risk management process. Specifically, Citi generally transacts much lower volumes of derivatives under master netting agreements where Citi does not have the requisite level of legal certainty regarding enforceability, because such derivatives consume greater amounts of single counterparty credit limits than those executed under enforceable master netting agreements. Cash collateral and security collateral in the form of G10 government debt securities are often posted by a party to a master netting agreement to secure the net open exposure of the other party; the receiving party is free to commingle/rehypothecate such collateral in the ordinary course of its business. Nonstandard collateral such as corporate bonds, municipal bonds, U.S. agency securities and/or MBS may also be pledged as collateral for derivative transactions. Security collateral posted to open and maintain a master netting agreement with a counterparty, in the form of cash and/or securities, may from time to time be segregated in an account at a third-party custodian pursuant to a tri-party account control agreement. Information pertaining to Citigroup’s derivative activities, based on notional amounts, is presented in the table below. Derivative notional amounts are reference amounts from which contractual payments are derived and do not represent a complete and accurate measure of Citi’s exposure to derivative transactions. Rather, Citi’s derivative exposure arises primarily from market fluctuations (i.e., market risk), counterparty failure (i.e., credit risk) and/or periods of high volatility or financial stress (i.e., liquidity risk), as well as any market valuation adjustments that may be required on the transactions. Moreover, notional amounts do not reflect the netting of offsetting trades. For example, if Citi enters into a receive-fixed interest rate swap with $100 million notional, and offsets this risk with an identical but opposite pay-fixed position with a different counterparty, $200 million in derivative notionals is reported, although these offsetting positions may result in de minimis overall market risk. Aggregate derivative notional amounts can fluctuate from period to period in the normal course of business based on Citi’s market share, levels of client activity and other factors. Derivative Notionals Hedging instruments under (1)(2) Other derivative instruments Trading derivatives Management hedges (3) In millions of dollars December 31, December 31, December 31, December 31, December 31, December 31, Interest rate contracts Swaps $ 189,779 $ 151,331 $ 18,718,224 $ 19,145,250 $ 35,995 $ 47,324 Futures and forwards — 97 6,447,886 6,864,276 12,653 30,834 Written options — — 3,513,759 2,921,070 2,372 4,759 Purchased options — — 3,230,915 2,768,528 3,110 7,320 Total interest rate contract notionals $ 189,779 $ 151,428 $ 31,910,784 $ 31,699,124 $ 54,130 $ 90,237 Foreign exchange contracts Swaps $ 37,162 $ 19,042 $ 5,538,231 $ 5,492,145 $ 38,126 $ 22,676 Futures, forwards and spot 33,103 56,964 3,080,361 3,251,132 17,339 3,419 Written options 3,951 — 1,127,728 1,194,325 — — Purchased options 6,427 — 1,148,686 1,215,961 — — Total foreign exchange contract notionals $ 80,643 $ 76,006 $ 10,895,006 $ 11,153,563 $ 55,465 $ 26,095 Equity contracts Swaps $ — $ — $ 215,834 $ 192,366 $ — $ — Futures and forwards — — 72,616 37,557 — — Written options — — 389,961 304,579 — — Purchased options — — 328,154 266,070 — — Total equity contract notionals $ — $ — $ 1,006,565 $ 800,572 $ — $ — Commodity and other contracts Swaps $ — $ — $ 82,039 $ 70,774 $ — $ — Futures and forwards 23 182 153,248 142,530 — — Written options — — 62,045 74,627 — — Purchased options — — 60,526 69,629 — — Total commodity and other contract notionals $ 23 $ 182 $ 357,858 $ 357,560 $ — $ — Credit derivatives (4) Protection sold $ — $ — $ 735,142 $ 859,420 $ — $ — Protection purchased — — 766,565 883,003 11,148 19,470 Total credit derivatives $ — $ — $ 1,501,707 $ 1,742,423 $ 11,148 $ 19,470 Total derivative notionals $ 270,445 $ 227,616 $ 45,671,920 $ 45,753,242 $ 120,743 $ 135,802 (1) The notional amounts presented in this table do not include hedge accounting relationships under ASC 815 where Citigroup is hedging the foreign currency risk of a net investment in a foreign operation by issuing a foreign currency-denominated debt instrument. The notional amount of such debt was $63 million and $1,825 million at December 31, 2017 and December 31, 2016 , respectively. (2) Derivatives in hedge accounting relationships accounted for under ASC Topic 815 are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities on the Consolidated Balance Sheet. (3) Management hedges represent derivative instruments used to mitigate certain economic risks, but for which hedge accounting is not applied. These derivatives are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities on the Consolidated Balance Sheet. (4) Credit derivatives are arrangements designed to allow one party (protection buyer) to transfer the credit risk of a “reference asset” to another party (protection seller). These arrangements allow a protection seller to assume the credit risk associated with the reference asset without directly purchasing that asset. The Company enters into credit derivative positions for purposes such as risk management, yield enhancement, reduction of credit concentrations and diversification of overall risk. The following tables present the gross and net fair values of the Company’s derivative transactions and the related offsetting amounts as of December 31, 2017 and December 31, 2016 . Gross positive fair values are offset against gross negative fair values by counterparty pursuant to enforceable master netting agreements. Under ASC 815-10-45, payables and receivables in respect of cash collateral received from or paid to a given counterparty pursuant to a credit support annex are included in the offsetting amount if a legal opinion supporting the enforceability of netting and collateral rights has been obtained. GAAP does not permit similar offsetting for security collateral. In addition, the table for December 31, 2017 reflects rule changes adopted by clearing organizations that require or allow entities to elect to treat derivative assets, liabilities and the related variation margin as settlement of the related derivative fair values for legal and accounting purposes, as opposed to presenting gross derivative assets and liabilities that are subject to collateral, whereby the counterparties would record a related collateral payable or receivable. As a result, the table for December 31, 2017 reflects a reduction of approximately $100 billion of derivative assets and derivative liabilities that previously would have been reported on a gross basis, but are now settled and not subject to collateral. The table for December 31, 2016 presents derivative assets and liabilities as gross amounts subject to variation margin collateral that were netted under enforceable master netting agreements. Therefore, the net presentation of the affected items on the consolidated balance sheet is consistent for all periods. The tables also present amounts that are not permitted to be offset, such as security collateral or cash collateral posted at third-party custodians, but which would be eligible for offsetting to the extent an event of default occurred and a legal opinion supporting enforceability of the netting and collateral rights has been obtained. Derivative Mark-to-Market (MTM) Receivables/Payables In millions of dollars at December 31, 2017 Derivatives classified (1)(2)(3) Derivatives classified (2)(3) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Assets Liabilities Over-the-counter $ 644 $ 121 $ 1,325 $ 13 Cleared 71 24 39 68 Interest rate contracts $ 715 $ 145 $ 1,364 $ 81 Over-the-counter $ 885 $ 1,064 $ 258 $ 86 Foreign exchange contracts $ 885 $ 1,064 $ 258 $ 86 Total derivative instruments designated as ASC 815 hedges $ 1,600 $ 1,209 $ 1,622 $ 167 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 195,648 $ 173,921 $ 29 $ 16 Cleared 7,051 10,268 78 113 Exchange traded 102 95 — — Interest rate contracts $ 202,801 $ 184,284 $ 107 $ 129 Over-the-counter $ 118,611 $ 116,962 $ 481 $ 511 Cleared 1,690 2,028 — — Exchange traded 34 121 — — Foreign exchange contracts $ 120,335 $ 119,111 $ 481 $ 511 Over-the-counter $ 17,221 $ 21,201 $ — $ — Cleared 21 25 — — Exchange traded 9,736 10,147 — — Equity contracts $ 26,978 $ 31,373 $ — $ — Over-the-counter $ 13,499 $ 16,362 $ — $ — Exchange traded 604 665 — — Commodity and other contracts $ 14,103 $ 17,027 $ — $ — Over-the-counter $ 12,954 $ 12,895 $ 18 $ 63 Cleared 7,530 8,327 32 248 Credit derivatives $ 20,484 $ 21,222 $ 50 $ 311 Total derivatives instruments not designated as ASC 815 hedges $ 384,701 $ 373,017 $ 638 $ 951 Total derivatives $ 386,301 $ 374,226 $ 2,260 $ 1,118 Cash collateral paid/received (4)(5) $ 7,541 $ 14,296 $ — $ 12 Less: Netting agreements (6) (306,401 ) (306,401 ) — — Less: Netting cash collateral received/paid (7) (37,506 ) (35,659 ) (1,026 ) (7 ) Net receivables/payables included on the Consolidated Balance Sheet (8) $ 49,935 $ 46,462 $ 1,234 $ 1,123 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (872 ) $ (121 ) $ — $ — Less: Non-cash collateral received/paid (12,453 ) (6,929 ) (286 ) — Total net receivables/payables (8) $ 36,610 $ 39,412 $ 948 $ 1,123 (1) The trading derivatives fair values are presented in Note 24 to the Consolidated Financial Statements. (2) Derivative mark-to-market receivables/payables related to management hedges are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities . (3) Over-the-counter (OTC) derivatives are derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. Cleared derivatives include derivatives executed bilaterally with a counterparty in the OTC market, but then novated to a central clearing house, whereby the central clearing house becomes the counterparty to both of the original counterparties. Exchange traded derivatives include derivatives executed directly on an organized exchange that provides pre-trade price transparency. (4) For the trading account assets/liabilities, reflects the net amount of the $43,200 million and $51,801 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $35,659 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $37,506 million was used to offset trading derivative assets. (5) For cash collateral paid with respect to non-trading derivative assets, reflects the net amount of $7 million of gross cash collateral paid, of which $7 million is netted against non-trading derivative positions within Other liabilities . For cash collateral received with respect to non-trading derivative liabilities, reflects the net amount of $1,038 million of gross cash collateral received, of which $1,026 million is netted against OTC non-trading derivative positions within Other assets . (6) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $283 billion , $14 billion and $9 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange traded derivatives, respectively. (7) Represents the netting of cash collateral paid and received by counterparty under enforceable credit support agreements. Substantially all cash collateral received and paid is netted against OTC derivative assets and liabilities, respectively. (8) The net receivables/payables include approximately $6 billion of derivative asset and $8 billion of derivative liability fair values not subject to enforceable master netting agreements, respectively. In millions of dollars at December 31, 2016 Derivatives classified in Trading (1)(2)(3) Derivatives classified in Other assets/liabilities (2)(3) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Assets Liabilities Over-the-counter $ 716 $ 171 $ 1,927 $ 22 Cleared 3,530 2,154 47 82 Interest rate contracts $ 4,246 $ 2,325 $ 1,974 $ 104 Over-the-counter $ 2,494 $ 393 $ 747 $ 645 Foreign exchange contracts $ 2,494 $ 393 $ 747 $ 645 Total derivative instruments designated as ASC 815 hedges $ 6,740 $ 2,718 $ 2,721 $ 749 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 244,072 $ 221,534 $ 225 $ 5 Cleared 120,920 130,855 240 349 Exchange traded 87 47 — — Interest rate contracts $ 365,079 $ 352,436 $ 465 $ 354 Over-the-counter $ 182,659 $ 186,867 $ — $ 60 Cleared 482 470 — — Exchange traded 27 31 — — Foreign exchange contracts $ 183,168 $ 187,368 $ — $ 60 Over-the-counter $ 15,625 $ 19,119 $ — $ — Cleared 1 21 — — Exchange traded 8,484 7,376 — — Equity contracts $ 24,110 $ 26,516 $ — $ — Over-the-counter $ 13,046 $ 14,234 $ — $ — Exchange traded 719 798 — — Commodity and other contracts $ 13,765 $ 15,032 $ — $ — Over-the-counter $ 19,033 $ 19,563 $ 159 $ 78 Cleared 5,582 5,874 47 310 Credit derivatives $ 24,615 $ 25,437 $ 206 $ 388 Total derivatives instruments not designated as ASC 815 hedges $ 610,737 $ 606,789 $ 671 $ 802 Total derivatives $ 617,477 $ 609,507 $ 3,392 $ 1,551 Cash collateral paid/received (4)(5) $ 11,188 $ 15,731 $ 8 $ 1 Less: Netting agreements (6) (519,000 ) (519,000 ) — — Less: Netting cash collateral received/paid (7) (45,912 ) (49,811 ) (1,345 ) (53 ) Net receivables/payables included on the Consolidated Balance Sheet (8) $ 63,753 $ 56,427 $ 2,055 $ 1,499 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (819 ) $ (19 ) $ — $ — Less: Non-cash collateral received/paid (11,767 ) (5,883 ) (530 ) — Total net receivables/payables (8) $ 51,167 $ 50,525 $ 1,525 $ 1,499 (1) The trading derivatives fair values are presented in Note 24 to the Consolidated Financial Statements. (2) Derivative mark-to-market receivables/payables related to management hedges are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities . (3) Over-the-counter (OTC) derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. Cleared derivatives include derivatives executed bilaterally with a counterparty in the OTC market, but then novated to a central clearing house, whereby the central clearing house becomes the counterparty to both of the original counterparties. Exchange traded derivatives include derivatives executed directly on an organized exchange that provides pre-trade price transparency. (4) For the trading account assets/liabilities, reflects the net amount of the $60,999 million and $61,643 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $49,811 million was used to offset derivative liabilities and, of the gross cash collateral received, $45,912 million was used to offset derivative assets. (5) For cash collateral paid with respect to non-trading derivative assets, reflects the net amount of $61 million of the gross cash collateral paid, of which $53 million is netted against non-trading derivative positions within Other liabilities . For cash collateral received with respect to non-trading derivative liabilities, reflects the net amount of $1,346 million of gross cash collateral received of which $1,345 million is netted against non-trading derivative positions within Other assets . (6) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $383 billion , $128 billion and $8 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange traded derivatives, respectively. (7) Represents the netting of cash collateral paid and received by counterparty under enforceable credit support agreements. Substantially all cash collateral received and paid is netted against OTC derivative assets and liabilities, respectively. (8) The net receivables/payables include approximately $7 billion of derivative asset and $9 billion of liability fair values not subject to enforceable master netting agreements, respectively. For the years ended December 31, 2017 , 2016 and 2015, the amounts recognized in Principal transactions in the Consolidated Statement of Income related to derivatives not designated in a qualifying hedging relationship, as well as the underlying non-derivative instruments, are presented in Note 6 to the Consolidated Financial Statements. Citigroup presents this disclosure by business classification, showing derivative gains and losses related to its trading activities together with gains and losses related to non-derivative instruments within the same trading portfolios, as this represents the way these portfolios are risk managed. The amounts recognized in Other revenue in the Consolidated Statement of Income related to derivatives not designated in a qualifying hedging relationship are shown below. The table below does not include any offsetting gains/losses on the economically hedged items to the extent such amounts are also recorded in Other revenue . Gains (losses) included in Other revenue In millions of dollars 2017 2016 2015 Interest rate contracts $ (54 ) $ (81 ) $ 117 Foreign exchange 244 12 (39 ) Credit derivatives (494 ) (1,009 ) 476 Total $ (304 ) $ (1,078 ) $ 554 Accounting for Derivative Hedging Citigroup accounts for its hedging activities in accordance with ASC 815, Derivatives and Hedging . As a general rule, hedge accounting is permitted where the Company is exposed to a particular risk, such as interest rate or foreign exchange risk, that causes changes in the fair value of an asset or liability or variability in the expected future cash flows of an existing asset, liability or a forecasted transaction that may affect earnings. Derivative contracts hedging the risks associated with changes in fair value are referred to as fair value hedges, while contracts hedging the variability of expected future cash flows are cash flow hedges. Hedges that utilize derivatives or debt instruments to manage the foreign exchange risk associated with equity investments in non-U.S.-dollar-functional-currency foreign subsidiaries (net investment in a foreign operation) are net investment hedges. To qualify as an accounting hedge under the hedge accounting rules (versus an economic hedge where hedge accounting is not applied), a hedging relationship must be highly effective in offsetting the risk designated as being hedged. The hedge relationship must be formally documented at inception, detailing the particular risk management objective and strategy for the hedge. This includes the item and risk(s) being hedged, the hedging instrument being used and how effectiveness will be assessed. The effectiveness of these hedging relationships is evaluated at hedge inception and on an ongoing basis both on a retrospective and prospective basis, typically using quantitative measures of correlation, with hedge ineffectiveness measured and recorded in current earnings. Hedge effectiveness assessment methodologies are performed in a similar manner for similar hedges, and are used consistently throughout the hedging relationships. The assessment of effectiveness may exclude changes in the value of the hedged item that are unrelated to the risks being hedged and the changes in fair value of the derivative associated with time value. These excluded items are recognized in current earnings for the hedging derivative, while changes in the value of a hedged item that are not related to the hedged risk are not recorded. Discontinued Hedge Accounting A hedging instrument must be highly effective in accomplishing the hedge objective of offsetting either changes in the fair value or cash flows of the hedged item for the risk being hedged. Management may voluntarily de-designate an accounting hedge at any time, but if a hedge relationship is not highly effective, it no longer qualifies for hedge accounting and must be de-designated. Subsequent changes in the fair value of the derivative are recognized in Other revenue or Principal transactions , similar to trading derivatives, with no offset recorded related to the hedged item. For fair value hedges, any changes in the fair value of the hedged item remain as part of the basis of the asset or liability and are ultimately realized as an element of the yield on the item. For cash flow hedges, changes in fair value of the end-user derivative remain in Accumulated other comprehensive income (loss) (AOCI) and are included in the earnings of future periods when the forecasted hedged cash flows impact earnings. However, if it becomes probable that some or all of the hedged forecasted transactions will not occur, any amounts that remain in AOCI related to these transactions must be immediately reflected in Other revenue . The foregoing criteria are applied on a decentralized basis, consistent with the level at which market risk is managed, but are subject to various limits and controls. The underlying asset, liability or forecasted transaction may be an individual item or a portfolio of similar items. Fair Value Hedges Hedging of Benchmark Interest Rate Risk Citigroup’s fair value hedges are primarily hedges of fixed-rate long-term debt or assets, such as available-for-sale securities. Citigroup hedges exposure to changes in the fair value of outstanding fixed-rate issued debt. These hedges are designated as fair value hedges of the benchmark interest rate risk associated with the currency of the hedged liability. The fixed cash flows of the hedged items are typically converted to benchmark variable-rate cash flows by entering into receive-fixed, pay-variable interest rate swaps. By designating an interest rate swap contract as a hedging instrument and electing to apply ASC 815 fair value hedge accounting, the carrying value of the debt is adjusted to reflect the impact of changes in the benchmark interest rate, with such changes in value recorded in Other revenue . The related interest rate swap is recorded on the balance sheet at fair value, with changes in fair value also reflected in Other revenue . These amounts are expected to, and generally do, offset. Any net amount, representing hedge ineffectiveness, is automatically reflected in current earnings. These fair value hedge relationships use either regression or dollar-offset ratio analysis to assess whether the hedging relationships are highly effective at inception and on an ongoing basis. Citigroup also hedges its exposure to changes in the fair value of fixed-rate available for sale debt securities due to changes in benchmark interest rates. The hedging instruments are typically receive-variable, pay-fixed interest rate swaps. These fair value hedging relationships use either regression or dollar-offset ratio analysis to assess whether the hedging relationships are highly effective at inception and on an ongoing basis. Hedging of Foreign Exchange Risk Citigroup hedges the change in fair value attributable to foreign exchange rate movements in available-for-sale securities that are denominated in currencies other than the functional currency of the entity holding the securities, which may be within or outside the U.S. The hedging instrument may be a cross currency swap or a forward foreign exchange contract. When a forward foreign exchange contract is used as the hedging instrument, the portion of the change in the fair value of the hedged available-for-sale security attributable to foreign exchange risk (i.e., spot rates) is reported in earnings, and not AOCI, which offsets the change in the fair value of the forward contract that is also reflected in earnings. Citigroup considers the premium associated with forward contracts (i.e., the differential between spot and contractual forward rates) as the cost of hedging; this amount is excluded from the assessment of hedge effectiveness and reflected directly in earnings over the life of the hedge. Hedging of Commodity Price Risk Citigroup hedges the change in fair value attributable to spot price movements in physical commodities inventory. The hedging instrument is a futures contract to sell the underlying commodity. In this hedge, the change in the value of the hedged inventory is reflected in earnings, which offsets the change in the fair value of the futures contract that is also reflected in earnings. Although the change in the fair value of the hedging instrument recorded in earnings includes changes in forward rates, Citigroup excludes the differential between the spot and the contractual forward rates under the futures contract from the assessment of hedge effectiveness. Since the assessment is based on changes in fair value attributable to change in spot prices on both the physical commodity and the futures contract, the amount of hedge ineffectiveness is not significant. The following table summarizes the gains (losses) on the Company’s fair value hedges: Gains (losses) on fair value hedges (1) Year ended December 31, In millions of dollars 2017 2016 2015 Gain (loss) on the derivatives in designated and qualifying fair value hedges Inte

CONCENTRATIONS OF CREDIT RISK

CONCENTRATIONS OF CREDIT RISK	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
CONCENTRATIONS OF CREDIT RISK	CONCENTRATIONS OF CREDIT RISK Concentrations of credit risk exist when changes in economic, industry or geographic factors similarly affect groups of counterparties whose aggregate credit exposure is material in relation to Citigroup’s total credit exposure. Although Citigroup’s portfolio of financial instruments is broadly diversified along industry, product and geographic lines, material transactions are completed with other financial institutions, particularly in the securities trading, derivatives and foreign exchange businesses. In connection with the Company’s efforts to maintain a diversified portfolio, the Company limits its exposure to any one geographic region, country or individual creditor and monitors this exposure on a continuous basis. At December 31, 2017 , Citigroup’s most significant concentration of credit risk was with the U.S. government and its agencies. The Company’s exposure, which primarily results from trading assets and investments issued by the U.S. government and its agencies, amounted to $227.8 billion and $228.5 billion at December 31, 2017 and 2016 , respectively. The German and Japanese governments and their agencies, which are rated investment grade by both Moody’s and S&P, were the next largest exposures. The Company’s exposure to Germany amounted to $38.3 billion and $26.7 billion at December 31, 2017 and 2016 , respectively, and was composed of investment securities, loans and trading assets. The Company’s exposure to Japan amounted to $25.8 billion and $27.3 billion at December 31, 2017 and 2016 , respectively, and was composed of investment securities, loans and trading assets. The Company’s exposure to states and municipalities amounted to $30.6 billion and $30.7 billion at December 31, 2017 and 2016 , respectively, and was composed of trading assets, investment securities, derivatives and lending activities.

FAIR VALUE MEASUREMENT

FAIR VALUE MEASUREMENT	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENT	FAIR VALUE MEASUREMENT ASC 820-10, Fair Value Measurement , defines fair value, establishes a consistent framework for measuring fair value and requires disclosures about fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Among other things, the standard requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Under ASC 820-10, the probability of default of a counterparty is factored into the valuation of derivative and other positions as well as the impact of Citigroup’s own credit risk on derivatives and other liabilities measured at fair value. Fair Value Hierarchy ASC 820-10 specifies a hierarchy of inputs based on whether the inputs are observable or unobservable. Observable inputs are developed using market data and reflect market participant assumptions, while unobservable inputs reflect the Company’s market assumptions. These two types of inputs have created the following fair value hierarchy: • Level 1: Quoted prices for identical instruments in active markets. • Level 2: Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. • Level 3: Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable . As required under the fair value hierarchy, the Company considers relevant and observable market inputs in its valuations where possible. The frequency of transactions, the size of the bid-ask spread and the amount of adjustment necessary when comparing similar transactions are all factors in determining the liquidity of markets and the relevance of observed prices in those markets. The Company’s policy with respect to transfers between levels of the fair value hierarchy is to recognize transfers into and out of each level as of the end of the reporting period. Determination of Fair Value For assets and liabilities carried at fair value, the Company measures fair value using the procedures set out below, irrespective of whether the assets and liabilities are measured at fair value as a result of an election or whether they are required to be measured at fair value. When available, the Company uses quoted market prices to determine fair value and classifies such items as Level 1. In some cases where a market price is available, the Company will make use of acceptable practical expedients (such as matrix pricing) to calculate fair value, in which case the items are classified as Level 2. The Company may also apply a price-based methodology, which utilizes, where available, quoted prices or other market information obtained from recent trading activity in positions with the same or similar characteristics to the position being valued. The market activity and the amount of the bid-ask spread are among the factors considered in determining the liquidity of markets and the observability of prices from those markets. If relevant and observable prices are available, those valuations may be classified as Level 2. When less liquidity exists for a security or loan, a quoted price is stale, a significant adjustment to the price of a similar security is necessary to reflect differences in the terms of the actual security or loan being valued, or prices from independent sources are insufficient to corroborate the valuation, the “price” inputs are considered unobservable and the fair value measurements are classified as Level 3. If quoted market prices are not available, fair value is based upon internally developed valuation techniques that use, where possible, current market-based parameters, such as interest rates, currency rates and option volatilities. Items valued using such internally generated valuation techniques are classified according to the lowest level input or value driver that is significant to the valuation. Thus, an item may be classified as Level 3 even though there may be some significant inputs that are readily observable. Fair value estimates from internal valuation techniques are verified, where possible, to prices obtained from independent vendors or brokers. Vendors’ and brokers’ valuations may be based on a variety of inputs ranging from observed prices to proprietary valuation models. The following section describes the valuation methodologies used by the Company to measure various financial instruments at fair value, including an indication of the level in the fair value hierarchy in which each instrument is generally classified. Where appropriate, the description includes details of the valuation models, the key inputs to those models and any significant assumptions. Market Valuation Adjustments Generally, the unit of account for a financial instrument is the individual financial instrument. The Company applies market valuation adjustments that are consistent with the unit of account, which does not include adjustment due to the size of the Company’s position, except as follows. ASC 820-10 permits an exception, through an accounting policy election, to measure the fair value of a portfolio of financial assets and financial liabilities on the basis of the net open risk position when certain criteria are met. Citi has elected to measure certain portfolios of financial instruments, such as derivatives, that meet those criteria on the basis of the net open risk position. The Company applies market valuation adjustments, including adjustments to account for the size of the net open risk position, consistent with market participant assumptions and in accordance with the unit of account. Liquidity adjustments are applied to items in Level 2 or Level 3 of the fair value hierarchy in an effort to ensure that the fair value reflects the price at which the net open risk position could be liquidated. The liquidity adjustment is based on the bid/offer spread for an instrument. When Citi has elected to measure certain portfolios of financial investments, such as derivatives, on the basis of the net open risk position, the liquidity adjustment may be adjusted to take into account the size of the position. Credit valuation adjustments (CVA) and funding valuation adjustments (FVA) are applied to over-the-counter (OTC) derivative instruments in which the base valuation generally discounts expected cash flows using the relevant base interest rate curve for the currency of the derivative (e.g., LIBOR for uncollateralized U.S.-dollar derivatives). As not all counterparties have the same credit risk as that implied by the relevant base curve, a CVA is necessary to incorporate the market view of both counterparty credit risk and Citi’s own credit risk in the valuation. FVA reflects a market funding risk premium inherent in the uncollateralized portion of derivative portfolios and in collateralized derivatives where the terms of the agreement do not permit the reuse of the collateral received. Citi’s CVA and FVA methodology consists of two steps: • First, the exposure profile for each counterparty is determined using the terms of all individual derivative positions and a Monte Carlo simulation or other quantitative analysis to generate a series of expected cash flows at future points in time. The calculation of this exposure profile considers the effect of credit risk mitigants and sources of funding, including pledged cash or other collateral and any legal right of offset that exists with a counterparty through arrangements such as netting agreements. Individual derivative contracts that are subject to an enforceable master netting agreement with a counterparty are aggregated as a netting set for this purpose, since it is those aggregate net cash flows that are subject to nonperformance risk. This process identifies specific, point-in-time future cash flows that are subject to nonperformance risk and unsecured funding, rather than using the current recognized net asset or liability as a basis to measure the CVA and FVA. • Second, for CVA, market-based views of default probabilities derived from observed credit spreads in the credit default swap (CDS) market are applied to the expected future cash flows determined in step one. Citi’s own-credit CVA is determined using Citi-specific CDS spreads for the relevant tenor. Generally, counterparty CVA is determined using CDS spread indices for each credit rating and tenor. For certain identified netting sets where individual analysis is practicable (e.g., exposures to counterparties with liquid CDSs), counterparty-specific CDS spreads are used. For FVA, a term structure of future liquidity spreads is applied to the expected future funding requirement. The CVA and FVA are designed to incorporate a market view of the credit and funding risk, respectively, inherent in the derivative portfolio. However, most unsecured derivative instruments are negotiated bilateral contracts and are not commonly transferred to third parties. Derivative instruments are normally settled contractually or, if terminated early, are terminated at a value negotiated bilaterally between the counterparties. Thus, the CVA and FVA may not be realized upon a settlement or termination in the normal course of business. In addition, all or a portion of these adjustments may be reversed or otherwise adjusted in future periods in the event of changes in the credit or funding risk associated with the derivative instruments. The table below summarizes the CVA and FVA applied to the fair value of derivative instruments at December 31, 2017 and 2016: Credit and funding valuation adjustments contra-liability (contra-asset) In millions of dollars December 31, December 31, Counterparty CVA $ (970 ) $ (1,488 ) Asset FVA (447 ) (536 ) Citigroup (own-credit) CVA 287 459 Liability FVA 47 62 Total CVA—derivative instruments (1) $ (1,083 ) $ (1,503 ) (1) FVA is included with CVA for presentation purposes. The table below summarizes pretax gains (losses) related to changes in CVA on derivative instruments, net of hedges, FVA on derivatives and debt valuation adjustments (DVA) on Citi’s own fair value option (FVO) liabilities for the years indicated: Credit/funding/debt valuation adjustments gain (loss) In millions of dollars 2017 2016 2015 Counterparty CVA $ 276 $ 157 $ (115 ) Asset FVA 90 47 (66 ) Own-credit CVA (153 ) 17 (28 ) Liability FVA (15 ) (44 ) 97 Total CVA—derivative instruments $ 198 $ 177 $ (112 ) DVA related to own FVO liabilities (1) $ (680 ) $ (538 ) $ 367 Total CVA and DVA (2) $ (482 ) $ (361 ) $ 255 (1) Effective January 1, 2016, Citigroup early adopted on a prospective basis only the provisions of ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , related to the presentation of DVA on fair value option liabilities. Accordingly, beginning in the first quarter of 2016, the portion of the change in fair value of these liabilities related to changes in Citigroup’s own credit spreads (DVA) is reflected as a component of AOCI; previously these amounts were recognized in Citigroup’s revenues and net income. DVA amounts in AOCI will be recognized in revenue and net income if realized upon the settlement of the related liability. (2) FVA is included with CVA for presentation purposes. Valuation Process for Fair Value Measurements Price verification procedures and related internal control procedures are governed by the Citigroup Pricing and Price Verification Policy and Standards , which is jointly owned by Finance and Risk Management. For fair value measurements of substantially all assets and liabilities held by the Company, individual business units are responsible for valuing the trading account assets and liabilities, and Product Control within Finance performs independent price verification procedures to evaluate those fair value measurements. Product Control is independent of the individual business units and reports to the Global Head of Product Control. It has authority over the valuation of financial assets and liabilities. Fair value measurements of assets and liabilities are determined using various techniques, including, but not limited to, discounted cash flows and internal models, such as option and correlation models. Based on the observability of inputs used, Product Control classifies the inventory as Level 1, Level 2 or Level 3 of the fair value hierarchy. When a position involves one or more significant inputs that are not directly observable, price verification procedures are performed that may include reviewing relevant historical data, analyzing profit and loss, valuing each component of a structured trade individually and benchmarking, among others. Reports of inventory that is classified within Level 3 of the fair value hierarchy are distributed to senior management in Finance, Risk and the business. This inventory is also discussed in Risk Committees and in monthly meetings with senior trading management. As deemed necessary, reports may go to the Audit Committee of the Board of Directors or to the full Board of Directors. Whenever an adjustment is needed to bring the price of an asset or liability to its exit price, Product Control reports it to management along with other price verification results. In addition, the pricing models used in measuring fair value are governed by an independent control framework. Although the models are developed and tested by the individual business units, they are independently validated by the Model Validation Group within Risk Management and reviewed by Finance with respect to their impact on the price verification procedures. The purpose of this independent control framework is to assess model risk arising from models’ theoretical soundness, calibration techniques where needed and the appropriateness of the model for a specific product in a defined market. To ensure their continued applicability, models are independently reviewed annually. In addition, Risk Management approves and maintains a list of products permitted to be valued under each approved model for a given business. Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase No quoted prices exist for these instruments, so fair value is determined using a discounted cash flow technique. Cash flows are estimated based on the terms of the contract, taking into account any embedded derivative or other features. These cash flows are discounted using interest rates appropriate to the maturity of the instrument as well as the nature of the underlying collateral. Generally, when such instruments are recorded at fair value, they are classified within Level 2 of the fair value hierarchy, as the inputs used in the valuation are readily observable. However, certain long-dated positions are classified within Level 3 of the fair value hierarchy. Trading Account Assets and Liabilities—Trading Securities and Trading Loans When available, the Company uses quoted market prices in active markets to determine the fair value of trading securities; such items are classified as Level 1 of the fair value hierarchy. Examples include government securities and exchange-traded equity securities. For bonds and secondary market loans traded over the counter, the Company generally determines fair value utilizing valuation techniques, including discounted cash flows, price-based and internal models, such as Black-Scholes and Monte Carlo simulation. Fair value estimates from these internal valuation techniques are verified, where possible, to prices obtained from independent sources, including third-party vendors. Vendors compile prices from various sources and may apply matrix pricing for similar bonds or loans where no price is observable. A price-based methodology utilizes, where available, quoted prices or other market information obtained from recent trading activity of assets with similar characteristics to the bond or loan being valued. The yields used in discounted cash flow models are derived from the same price information. Trading securities and loans priced using such methods are generally classified as Level 2. However, when less liquidity exists for a security or loan, a quoted price is stale, a significant adjustment to the price of a similar security or loan is necessary to reflect differences in the terms of the actual security or loan being valued, or prices from independent sources are insufficient to corroborate valuation, a loan or security is generally classified as Level 3. The price input used in a price-based methodology may be zero for a security, such as a subprime CDO, that is not receiving any principal or interest and is currently written down to zero. When the Company’s principal market for a portfolio of loans is the securitization market, the Company uses the securitization price to determine the fair value of the portfolio. The securitization price is determined from the assumed proceeds of a hypothetical securitization in the current market, adjusted for transformation costs (i.e., direct costs other than transaction costs) and securitization uncertainties such as market conditions and liquidity. As a result of the severe reduction in the level of activity in certain securitization markets since the second half of 2007, observable securitization prices for certain directly comparable portfolios of loans have not been readily available. Therefore, such portfolios of loans are generally classified as Level 3 of the fair value hierarchy. However, for other loan securitization markets, such as commercial real estate loans, price verification of the hypothetical securitizations has been possible, since these markets have remained active. Accordingly, this loan portfolio is classified as Level 2 of the fair value hierarchy. For most of the lending and structured direct subprime exposures, fair value is determined utilizing observable transactions where available, other market data for similar assets in markets that are not active and other internal valuation techniques. The valuation of certain asset-backed security (ABS) CDO positions utilizes prices based on the underlying assets of the ABS CDO. Trading Account Assets and Liabilities—Derivatives Exchange-traded derivatives, measured at fair value using quoted (i.e., exchange) prices in active markets, where available, are classified as Level 1 of the fair value hierarchy. Derivatives without a quoted price in an active market and derivatives executed over the counter are valued using internal valuation techniques. These derivative instruments are classified as either Level 2 or Level 3 depending upon the observability of the significant inputs to the model. The valuation techniques and inputs depend on the type of derivative and the nature of the underlying instrument. The principal techniques used to value these instruments are discounted cash flows and internal models, including Black-Scholes and Monte Carlo simulation. The key inputs depend upon the type of derivative and the nature of the underlying instrument and include interest rate yield curves, foreign exchange rates, volatilities and correlation. The Company uses overnight indexed swap (OIS) curves as fair value measurement inputs for the valuation of certain collateralized derivatives. Citi uses the relevant benchmark curve for the currency of the derivative (e.g., the London Interbank Offered Rate for U.S.-dollar derivatives) as the discount rate for uncollateralized derivatives. As referenced above, during the third quarter of 2016 , Citi incorporated FVA into the fair value measurements due to what it believes to be an industry migration toward incorporating the market’s view of funding risk premium in OTC derivatives. The charge incurred in connection with the implementation of FVA was reflected in Principal transactions as a change in accounting estimate. Citi’s FVA methodology leverages the existing CVA methodology to estimate a funding exposure profile. The calculation of this exposure profile considers collateral agreements where the terms do not permit the Company to reuse the collateral received, including where counterparties post collateral to third-party custodians. Investments The investments category includes available-for-sale debt and marketable equity securities whose fair values are generally determined by utilizing similar procedures described for trading securities above or, in some cases, using vendor pricing as the primary source. Also included in investments are nonpublic investments in private equity and real estate entities. Determining the fair value of nonpublic securities involves a significant degree of management judgment, as no quoted prices exist and such securities are generally thinly traded. In addition, there may be transfer restrictions on private equity securities. The Company’s process for determining the fair value of such securities utilizes commonly accepted valuation techniques, including comparables analysis. In determining the fair value of nonpublic securities, the Company also considers events such as a proposed sale of the investee company, initial public offerings, equity issuances or other observable transactions. Private equity securities are generally classified as Level 3 of the fair value hierarchy. In addition, the Company holds investments in certain alternative investment funds that calculate NAV per share, including hedge funds, private equity funds and real estate funds. Investments in funds are generally classified as non-marketable equity securities carried at fair value. The fair values of these investments are estimated using the NAV per share of the Company’s ownership interest in the funds where it is not probable that the investment will be realized at a price other than the NAV. Consistent with the provisions of ASU 2015-07 these investments have not been categorized within the fair value hierarchy and are not included in the tables below. See Note 13 to the Consolidated Financial Statements for additional information. Short-Term Borrowings and Long-Term Debt Where fair value accounting has been elected, the fair value of non-structured liabilities is determined by utilizing internal models using the appropriate discount rate for the applicable maturity. Such instruments are generally classified as Level 2 of the fair value hierarchy when all significant inputs are readily observable. The Company determines the fair value of hybrid financial instruments, including structured liabilities, using the appropriate derivative valuation methodology (described above in “Trading Account Assets and Liabilities—Derivatives”) given the nature of the embedded risk profile. Such instruments are classified as Level 2 or Level 3 depending on the observability of significant inputs to the model. Items Measured at Fair Value on a Recurring Basis The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis at December 31, 2017 and December 31, 2016 . The Company may hedge positions that have been classified in the Level 3 category with other financial instruments (hedging instruments) that may be classified as Level 3, but also with financial instruments classified as Level 1 or Level 2 of the fair value hierarchy. The effects of these hedges are presented gross in the following tables: Fair Value Levels In millions of dollars at December 31, 2017 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ — $ 188,571 $ 16 $ 188,587 $ (55,638 ) $ 132,949 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,801 163 22,964 — 22,964 Residential — 649 164 813 — 813 Commercial — 1,309 57 1,366 — 1,366 Total trading mortgage-backed securities $ — $ 24,759 $ 384 $ 25,143 $ — $ 25,143 U.S. Treasury and federal agency securities $ 17,524 $ 3,613 $ — $ 21,137 $ — $ 21,137 State and municipal — 4,426 274 4,700 — 4,700 Foreign government 39,347 20,843 16 60,206 — 60,206 Corporate 301 15,129 275 15,705 — 15,705 Equity securities 53,305 6,794 120 60,219 — 60,219 Asset-backed securities — 1,198 1,590 2,788 — 2,788 Other trading assets (3) 3 11,105 615 11,723 — 11,723 Total trading non-derivative assets $ 110,480 $ 87,867 $ 3,274 $ 201,621 $ — $ 201,621 Trading derivatives Interest rate contracts $ 145 $ 201,663 $ 1,708 $ 203,516 Foreign exchange contracts 19 120,624 577 121,220 Equity contracts 2,364 24,170 444 26,978 Commodity contracts 282 13,252 569 14,103 Credit derivatives — 19,574 910 20,484 Total trading derivatives $ 2,810 $ 379,283 $ 4,208 $ 386,301 Cash collateral paid (4) $ 7,541 Netting agreements $ (306,401 ) Netting of cash collateral received (37,506 ) Total trading derivatives $ 2,810 $ 379,283 $ 4,208 $ 393,842 $ (343,907 ) $ 49,935 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 41,717 $ 24 $ 41,741 $ — $ 41,741 Residential — 2,884 — 2,884 — 2,884 Commercial — 329 3 332 — 332 Total investment mortgage-backed securities $ — $ 44,930 $ 27 $ 44,957 $ — $ 44,957 U.S. Treasury and federal agency securities $ 106,964 $ 11,182 $ — $ 118,146 $ — $ 118,146 State and municipal — 8,028 737 8,765 — 8,765 Foreign government 56,456 43,985 92 100,533 — 100,533 Corporate 1,911 12,127 71 14,109 — 14,109 Equity securities 176 11 2 189 — 189 Asset-backed securities — 3,091 827 3,918 — 3,918 Other debt securities — 297 — 297 — 297 Non-marketable equity securities (5) — 121 681 802 — 802 Total investments $ 165,507 $ 123,772 $ 2,437 $ 291,716 $ — $ 291,716 Table continues on the next page, including footnotes. In millions of dollars at December 31, 2017 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Loans $ — $ 3,824 $ 550 $ 4,374 $ — $ 4,374 Mortgage servicing rights — — 558 558 — 558 Non-trading derivatives and other financial assets measured on a recurring basis, gross $ 13,903 $ 6,900 $ 16 $ 20,819 Cash collateral paid (6) — Netting of cash collateral received $ (1,026 ) Non-trading derivatives and other financial assets measured on a recurring basis $ 13,903 $ 6,900 $ 16 $ 20,819 $ (1,026 ) $ 19,793 Total assets $ 292,700 $ 790,217 $ 11,059 $ 1,101,517 $ (400,571 ) $ 700,946 Total as a percentage of gross assets (7) 26.8 % 72.2 % 1.0 % Liabilities Interest-bearing deposits $ — $ 1,179 $ 286 $ 1,465 $ — $ 1,465 Federal funds purchased and securities loaned or sold under agreements to repurchase — 95,550 726 96,276 (55,638 ) 40,638 Trading account liabilities Securities sold, not yet purchased 65,843 10,306 22 76,171 — 76,171 Other trading liabilities — 1,409 5 1,414 — 1,414 Total trading liabilities $ 65,843 $ 11,715 $ 27 $ 77,585 $ — $ 77,585 Trading derivatives Interest rate contracts $ 137 $ 182,162 $ 2,130 $ 184,429 Foreign exchange contracts 9 119,719 447 120,175 Equity contracts 2,430 26,472 2,471 31,373 Commodity contracts 115 14,482 2,430 17,027 Credit derivatives — 19,513 1,709 21,222 Total trading derivatives $ 2,691 $ 362,348 $ 9,187 $ 374,226 Cash collateral received (8) $ 14,296 Netting agreements $ (306,401 ) Netting of cash collateral paid (35,659 ) Total trading derivatives $ 2,691 $ 362,348 $ 9,187 $ 388,522 $ (342,060 ) $ 46,462 Short-term borrowings $ — $ 4,609 $ 18 $ 4,627 $ — $ 4,627 Long-term debt — 18,310 13,082 31,392 — 31,392 Non-trading derivatives and other financial liabilities measured on a recurring basis, gross $ 13,903 $ 1,168 $ 8 $ 15,079 Cash collateral received (9) 12 Netting of cash collateral paid $ (7 ) Total non-trading derivatives and other financial liabilities measured on a recurring basis $ 13,903 $ 1,168 $ 8 $ 15,091 $ (7 ) $ 15,084 Total liabilities $ 82,437 $ 494,879 $ 23,334 $ 614,958 $ (397,705 ) $ 217,253 Total as a percentage of gross liabilities (7) 13.7 % 82.4 % 3.9 % (1) In 2017, the Company transferred assets of approximately $4.8 billion from Level 1 to Level 2, primarily related to foreign government securities and equity securities not traded in active markets. In 2017, the Company transferred assets of approximately $4.0 billion from Level 2 to Level 1, primarily related to foreign government bonds and equity securities traded with sufficient frequency to constitute a liquid market. In 2017, the Company transferred liabilities of approximately $0.4 billion from Level 1 to Level 2. In 2017, the Company transferred liabilities of approximately $0.3 billion from Level 2 to Level 1. (2) Represents netting of (i) the amounts due under securities purchased under agreements to resell and the amounts owed under securities sold under agreements to repurchase and (ii) derivative exposures covered by a qualifying master netting agreement and cash collateral offsetting. (3) Includes positions related to investments in unallocated precious metals, as discussed in Note 25 to the Consolidated Financial Statements. Also includes physical commodities accounted for at the lower of cost or fair value and unfunded credit products. (4) Reflects the net amount of $43,200 million of gross cash collateral paid, of which $35,659 million was used to offset trading derivative liabilities. (5) Amounts exclude $0.4 billion of investments measured at Net Asset Value (NAV) in accordance with ASU No. 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). (6) Reflects the net amount of $7 million of gross cash collateral paid, all of which was used to offset non-trading derivative liabilities. (7) Because the amount of the cash collateral paid/received has not been allocated to the Level 1, 2 and 3 subtotals, these percentages are calculated based on total assets and liabilities measured at fair value on a recurring basis, excluding the cash collateral paid/received on derivatives. (8) Reflects the net amount of $51,802 million of gross cash collateral received, of which $37,506 million was used to offset trading derivative assets. (9) Reflects the net amount of $1,038 million of gross cash collateral received, of which $1,026 million was used to offset non-trading derivatives. Fair Value Levels In millions of dollars at December 31, 2016 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ — $ 172,394 $ 1,496 $ 173,890 $ (40,686 ) $ 133,204 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,718 176 22,894 — 22,894 Residential — 291 399 690 — 690 Commercial — 1,000 206 1,206 — 1,206 Total trading mortgage-backed securities $ — $ 24,009 $ 781 $ 24,790 $ — $ 24,790 U.S. Treasury and federal agency securities $ 16,368 $ 4,811 $ 1 $ 21,180 $ — $ 21,180 State and municipal — 3,780 296 4,076 — 4,076 Foreign government 32,164 17,492 40 49,696 — 49,696 Corporate 424 14,199 324 14,947 — 14,947 Equity securities 45,056 5,260 127 50,443 — 50,443 Asset-backed securities — 892 1,868 2,760 — 2,760 Other trading assets (3) — 9,466 2,814 12,280 — 12,280 Total trading non-derivative assets $ 94,012 $ 79,909 $ 6,251 $ 180,172 $ — $ 180,172 Trading derivatives Interest rate contracts $ 105 $ 366,995 $ 2,225 $ 369,325 Foreign exchange contracts 53 184,776 833 185,662 Equity contracts 2,306 21,209 595 24,110 Commodity contracts 261 12,999 505 13,765 Credit derivatives — 23,021 1,594 24,615 Total trading derivatives $ 2,725 $ 609,000 $ 5,752 $ 617,477 Cash collateral paid (4) $ 11,188 Netting agreements $ (519,000 ) Netting of cash collateral received (45,912 ) Total trading derivatives $ 2,725 $ 609,000 $ 5,752 $ 628,665 $ (564,912 ) $ 63,753 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 38,304 $ 101 $ 38,405 $ — $ 38,405 Residential — 3,860 50 3,910 — 3,910 Commercial — 358 — 358 — 358 Total investment mortgage-backed securities $ — $ 42,522 $ 151 $ 42,673 $ — $ 42,673 U.S. Treasury and federal agency securities $ 112,916 $ 10,753 $ 2 $ 123,671 $ — $ 123,671 State and municipal — 8,909 1,211 10,120 — 10,120 Foreign government 54,028 43,934 186 98,148 — 98,148 Corporate 3,215 13,598 311 17,124 — 17,124 Equity securities 336 46 9 391 — 391 Asset-backed securities — 6,134 660 6,794 — 6,794 Other debt securities — 503 — 503 — 503 Non-marketable equi

FAIR VALUE ELECTIONS

FAIR VALUE ELECTIONS	12 Months Ended
	Dec. 31, 2017
Fair Value, Option, Aggregate Differences [Abstract]
FAIR VALUE ELECTIONS	FAIR VALUE ELECTIONS The Company may elect to report most financial instruments and certain other items at fair value on an instrument-by-instrument basis with changes in fair value reported in earnings, other than DVA (see below). The election is made upon the initial recognition of an eligible financial asset, financial liability or firm commitment or when certain specified reconsideration events occur. The fair value election may not be revoked once an election is made. The changes in fair value are recorded in current earnings, other than DVA, which from January 1, 2016 is reported in AOCI. Additional discussion regarding the applicable areas in which fair value elections were made is presented in Note 24 to the Consolidated Financial Statements. The Company has elected fair value accounting for its mortgage servicing rights. See Note 21 to the Consolidated Financial Statements for further discussions regarding the accounting and reporting of MSRs. The following table presents the changes in fair value of those items for which the fair value option has been elected: Changes in fair value gains (losses) for the years ended December 31, In millions of dollars 2017 2016 Assets Federal funds sold and securities borrowed or purchased under agreements to resell selected portfolios of securities purchased under agreements to resell and securities borrowed $ (133 ) $ (89 ) Trading account assets 1,622 404 Investments (3 ) (25 ) Loans Certain corporate loans (537 ) 40 Certain consumer loans 3 — Total loans $ (534 ) $ 40 Other assets MSRs $ 65 $ (36 ) Certain mortgage loans held for sale (1) 142 284 Other assets — 376 Total other assets $ 207 $ 624 Total assets $ 1,159 $ 954 Liabilities Interest-bearing deposits $ (69 ) $ (50 ) Federal funds purchased and securities loaned or sold under agreements to repurchase selected portfolios of securities sold under agreements to repurchase and securities loaned 223 45 Trading account liabilities 70 105 Short-term borrowings (116 ) (61 ) Long-term debt (1,491 ) (935 ) Total liabilities $ (1,383 ) $ (896 ) (1) Includes gains (losses) associated with interest rate lock-commitments for those loans that have been originated and elected under the fair value option. Own Debt Valuation Adjustments (DVA) Own debt valuation adjustments are recognized on Citi’s liabilities for which the fair value option has been elected using Citi’s credit spreads observed in the bond market. Effective January 1, 2016, changes in fair value of fair value option liabilities related to changes in Citigroup’s own credit spreads (DVA) are reflected as a component of AOCI; previously these amounts were recognized in Citigroup’s Revenues and Net income along with all other changes in fair value. See Note 1 to the Consolidated Financial Statements for additional information. Among other variables, the fair value of liabilities for which the fair value option has been elected (other than non-recourse and similar liabilities) is impacted by the narrowing or widening of the Company’s credit spreads. The estimated change in the fair value of these liabilities due to such changes in the Company’s own credit spread (or instrument-specific credit risk) were losses of $ 680 million and $ 538 million for the years ended December 31, 2017 and 2016 , respectively. Changes in fair value resulting from changes in instrument-specific credit risk were estimated by incorporating the Company’s current credit spreads observable in the bond market into the relevant valuation technique used to value each liability as described above. The Fair Value Option for Financial Assets and Financial Liabilities Selected Portfolios of Securities Purchased Under Agreements to Resell, Securities Borrowed, Securities Sold Under Agreements to Repurchase, Securities Loaned and Certain Non-Collateralized Short-Term Borrowings The Company elected the fair value option for certain portfolios of fixed income securities purchased under agreements to resell and fixed income securities sold under agreements to repurchase, securities borrowed, securities loaned and certain non-collateralized short-term borrowings held primarily by broker-dealer entities in the United States, United Kingdom and Japan. In each case, the election was made because the related interest-rate risk is managed on a portfolio basis, primarily with offsetting derivative instruments that are accounted for at fair value through earnings. Changes in fair value for transactions in these portfolios are recorded in Principal transactions . The related interest revenue and interest expense are measured based on the contractual rates specified in the transactions and are reported as Interest revenue and expense in the Consolidated Statement of Income. Certain Loans and Other Credit Products Citigroup has also elected the fair value option for certain other originated and purchased loans, including certain unfunded loan products, such as guarantees and letters of credit, executed by Citigroup’s lending and trading businesses. None of these credit products are highly leveraged financing commitments. Significant groups of transactions include loans and unfunded loan products that are expected to be either sold or securitized in the near term, or transactions where the economic risks are hedged with derivative instruments, such as purchased credit default swaps or total return swaps where the Company pays the total return on the underlying loans to a third party. Citigroup has elected the fair value option to mitigate accounting mismatches in cases where hedge accounting is complex and to achieve operational simplifications. Fair value was not elected for most lending transactions across the Company. The following table provides information about certain credit products carried at fair value: December 31, 2017 December 31, 2016 In millions of dollars Trading assets Loans Trading assets Loans Carrying amount reported on the Consolidated Balance Sheet $ 8,851 $ 4,374 $ 9,824 $ 3,486 Aggregate unpaid principal balance in excess of fair value 623 682 758 18 Balance of non-accrual loans or loans more than 90 days past due — 1 — 1 Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due — 1 — 1 In addition to the amounts reported above, $ 508 million and $ 1,828 million of unfunded commitments related to certain credit products selected for fair value accounting were outstanding as of December 31, 2017 and 2016 , respectively. Changes in the fair value of funded and unfunded credit products are classified in Principal transactions in Citi’s Consolidated Statement of Income. Related interest revenue is measured based on the contractual interest rates and reported as Interest revenue on Trading account assets or loan interest depending on the balance sheet classifications of the credit products. The changes in fair value for the years ended December 31, 2017 and 2016 due to instrument-specific credit risk totaled to gains of $ 10 million and $ 76 million , respectively. Certain Investments in Unallocated Precious Metals Citigroup invests in unallocated precious metals accounts (gold, silver, platinum and palladium) as part of its commodity and foreign currency trading activities or to economically hedge certain exposures from issuing structured liabilities. Under ASC 815, the investment is bifurcated into a debt host contract and a commodity forward derivative instrument. Citigroup elects the fair value option for the debt host contract, and reports the debt host contract within Trading account assets on the Company’s Consolidated Balance Sheet. The total carrying amount of debt host contracts across unallocated precious metals accounts was approximately $ 0.9 billion and $ 0.6 billion at December 31, 2017 and 2016 , respectively. The amounts are expected to fluctuate based on trading activity in future periods. As part of its commodity and foreign currency trading activities, Citi trades unallocated precious metals investments and executes forward purchase and forward sale derivative contracts with trading counterparties. When Citi sells an unallocated precious metals investment, Citi’s receivable from its depository bank is repaid and Citi derecognizes its investment in the unallocated precious metal. The forward purchase or sale contract with the trading counterparty indexed to unallocated precious metals is accounted for as a derivative, at fair value through earnings. As of December 31, 2017 , there were approximately $ 10.3 billion and $ 9.3 billion notional amounts of such forward purchase and forward sale derivative contracts outstanding, respectively. Certain Investments in Private Equity and Real Estate Ventures and Certain Equity Method and Other Investments Citigroup invests in private equity and real estate ventures for the purpose of earning investment returns and for capital appreciation. The Company has elected the fair value option for certain of these ventures, because such investments are considered similar to many private equity or hedge fund activities in Citi’s investment companies, which are reported at fair value. The fair value option brings consistency in the accounting and evaluation of these investments. All investments (debt and equity) in such private equity and real estate entities are accounted for at fair value. These investments are classified as Investments on Citigroup’s Consolidated Balance Sheet. Changes in the fair values of these investments are classified in Other revenue in the Company’s Consolidated Statement of Income. Citigroup also elects the fair value option for certain non-marketable equity securities whose risk is managed with derivative instruments that are accounted for at fair value through earnings. These securities are classified as Trading account assets on Citigroup’s Consolidated Balance Sheet. Changes in the fair value of these securities and the related derivative instruments are recorded in Principal transactions . Certain Mortgage Loans Held-for-Sale (HFS) Citigroup has elected the fair value option for certain purchased and originated prime fixed-rate and conforming adjustable-rate first mortgage loans HFS. These loans are intended for sale or securitization and are hedged with derivative instruments. The Company has elected the fair value option to mitigate accounting mismatches in cases where hedge accounting is complex and to achieve operational simplifications. The following table provides information about certain mortgage loans HFS carried at fair value: In millions of dollars December 31, December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 426 $ 915 Aggregate fair value in excess of (less than) unpaid principal balance 14 8 Balance of non-accrual loans or loans more than 90 days past due — — Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due — — The changes in the fair values of these mortgage loans are reported in Other revenue in the Company’s Consolidated Statement of Income. There was no net change in fair value during the years ended December 31, 2017 and 2016 due to instrument-specific credit risk. Related interest income continues to be measured based on the contractual interest rates and reported as Interest revenue in the Consolidated Statement of Income. Certain Structured Liabilities The Company has elected the fair value option for certain structured liabilities whose performance is linked to structured interest rates, inflation, currency, equity, referenced credit or commodity risks. The Company elected the fair value option, because these exposures are considered to be trading-related positions and, therefore, are managed on a fair value basis. These positions will continue to be classified as debt, deposits or derivatives ( Trading account liabilities ) on the Company’s Consolidated Balance Sheet according to their legal form. The following table provides information about the carrying value of structured notes, disaggregated by type of embedded derivative instrument: In billions of dollars December 31, 2017 December 31, 2016 Interest rate linked $ 13.9 $ 10.6 Foreign exchange linked 0.3 0.2 Equity linked 13.0 12.3 Commodity linked 0.2 0.3 Credit linked 1.9 0.9 Total $ 29.3 $ 24.3 Prior to 2016, the total change in the fair value of these structured liabilities was reported in Principal transactions in the Company’s Consolidated Statement of Income. Beginning in the first quarter of 2016, the portion of the changes in fair value attributable to changes in Citigroup’s own credit spreads (DVA) are reflected as a component of AOCI while all other changes in fair value will continue to be reported in Principal transactions . Changes in the fair value of these structured liabilities include accrued interest, which is also included in the change in fair value reported in Principal transactions . Certain Non-Structured Liabilities The Company has elected the fair value option for certain non-structured liabilities with fixed and floating interest rates. The Company has elected the fair value option where the interest-rate risk of such liabilities may be economically hedged with derivative contracts or the proceeds are used to purchase financial assets that will also be accounted for at fair value through earnings. The elections have been made to mitigate accounting mismatches and to achieve operational simplifications. These positions are reported in Short-term borrowings and Long-term debt on the Company’s Consolidated Balance Sheet. Prior to 2016, the total change in the fair value of these non-structured liabilities was reported in Principal transactions in the Company’s Consolidated Statement of Income. Beginning in the first quarter of 2016, the portion of the changes in fair value attributable to changes in Citigroup’s own credit spreads (DVA) is reflected as a component of AOCI while all other changes in fair value will continue to be reported in Principal transactions . Interest expense on non-structured liabilities is measured based on the contractual interest rates and reported as Interest expense in the Consolidated Statement of Income. The following table provides information about long-term debt carried at fair value: In millions of dollars December 31, 2017 December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 31,392 $ 26,254 Aggregate unpaid principal balance in excess of (less than) fair value (579 ) (128 ) The following table provides information about short-term borrowings carried at fair value: In millions of dollars December 31, 2017 December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 4,627 $ 2,700 Aggregate unpaid principal balance in excess of (less than) fair value 74 (61 )

PLEDGED ASSETS, COLLATERAL, GUA

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS	12 Months Ended
	Dec. 31, 2017
Pledged Assets, Collateral, Guarantees and Commitments [Abstract]
PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS	PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS Pledged Assets In connection with Citi’s financing and trading activities, Citi has pledged assets to collateralize its obligations under repurchase agreements, secured financing agreements, secured liabilities of consolidated VIEs and other borrowings. The approximate carrying values of the significant components of pledged assets recognized on Citi’s Consolidated Balance Sheet included: In millions of dollars 2017 2016 Investment securities $ 138,807 $ 161,914 Loans 229,552 231,833 Trading account assets 102,892 84,371 Total $ 471,251 $ 478,118 In addition, included in Cash and due from banks and Deposits with banks at December 31, 2017 and 2016 were $7.4 billion and $6.8 billion , respectively, of cash segregated under federal and other brokerage regulations or deposited with clearing organizations. Collateral At December 31, 2017 and 2016 , the approximate fair value of collateral received by Citi that may be resold or repledged, excluding the impact of allowable netting, was $457.5 billion and $378.1 billion , respectively. This collateral was received in connection with resale agreements, securities borrowings and loans, derivative transactions and margined broker loans. At December 31, 2017 and 2016 , a substantial portion of the collateral received by Citi had been sold or repledged in connection with repurchase agreements, securities sold, not yet purchased, securities borrowings and loans, pledges to clearing organizations, segregation requirements under securities laws and regulations, derivative transactions and bank loans. In addition, at December 31, 2017 and 2016 , Citi had pledged $362 billion and $388 billion , respectively, of collateral that may not be sold or repledged by the secured parties. Lease Commitments Rental expense (principally for offices, branches and computer equipment) was $1.1 billion , $1.1 billion and $1.3 billion for the years ended December 31, 2017 , 2016 and 2015 , respectively. Future minimum annual rentals under non-cancelable leases, net of sublease income, are as follows: In millions of dollars 2018 $ 968 2019 837 2020 676 2021 568 2022 469 Thereafter 2,593 Total $ 6,111 Guarantees Citi provides a variety of guarantees and indemnifications to its customers to enhance their credit standing and enable them to complete a wide variety of business transactions. For certain contracts meeting the definition of a guarantee, the guarantor must recognize, at inception, a liability for the fair value of the obligation undertaken in issuing the guarantee. In addition, the guarantor must disclose the maximum potential amount of future payments that the guarantor could be required to make under the guarantee, if there were a total default by the guaranteed parties. The determination of the maximum potential future payments is based on the notional amount of the guarantees without consideration of possible recoveries under recourse provisions or from collateral held or pledged. As such, Citi believes such amounts bear no relationship to the anticipated losses, if any, on these guarantees. The following tables present information about Citi’s guarantees: Maximum potential amount of future payments In billions of dollars at December 31, 2017 except carrying value in millions Expire within 1 year Expire after 1 year Total amount outstanding Carrying value (in millions of dollars) Financial standby letters of credit $ 27.9 $ 65.9 $ 93.8 $ 93 Performance guarantees 7.2 4.1 11.3 20 Derivative instruments considered to be guarantees 11.0 84.9 95.9 423 Loans sold with recourse — 0.2 0.2 9 Securities lending indemnifications (1) 103.7 — 103.7 — Credit card merchant processing (1)(2) 85.5 — 85.5 — Credit card arrangements with partners 0.3 1.1 1.4 205 Custody indemnifications and other — 36.0 36.0 59 Total $ 235.6 $ 192.2 $ 427.8 $ 809 Maximum potential amount of future payments In billions of dollars at December 31, 2016 except carrying value in millions Expire within Expire after Total amount Carrying value ( in millions of dollars) Financial standby letters of credit $ 26.0 $ 67.1 $ 93.1 $ 141 Performance guarantees 7.5 3.6 11.1 19 Derivative instruments considered to be guarantees 7.2 80.0 87.2 747 Loans sold with recourse — 0.2 0.2 12 Securities lending indemnifications (1) 80.3 — 80.3 — Credit card merchant processing (1)(2) 86.4 — 86.4 — Credit card arrangements with partners — 1.5 1.5 206 Custody indemnifications and other — 45.4 45.4 58 Total $ 207.4 $ 197.8 $ 405.2 $ 1,183 (1) The carrying values of securities lending indemnifications and credit card merchant processing were not material for either period presented, as the probability of potential liabilities arising from these guarantees is minimal. (2) At December 31, 2017 and 2016, this maximum potential exposure was estimated to be $86 billion and $86 billion , respectively. However, Citi believes that the maximum exposure is not representative of the actual potential loss exposure based on its historical experience. This contingent liability is unlikely to arise, as most products and services are delivered when purchased and amounts are refunded when items are returned to merchants. Financial Standby Letters of Credit Citi issues standby letters of credit, which substitute its own credit for that of the borrower. If a letter of credit is drawn down, the borrower is obligated to repay Citi. Standby letters of credit protect a third party from defaults on contractual obligations. Financial standby letters of credit include (i) guarantees of payment of insurance premiums and reinsurance risks that support industrial revenue bond underwriting, (ii) settlement of payment obligations to clearing houses, including futures and over-the-counter derivatives clearing (see further discussion below), (iii) support options and purchases of securities in lieu of escrow deposit accounts and (iv) letters of credit that backstop loans, credit facilities, promissory notes and trade acceptances. Performance Guarantees Performance guarantees and letters of credit are issued to guarantee a customer’s tender bid on a construction or systems-installation project or to guarantee completion of such projects in accordance with contract terms. They are also issued to support a customer’s obligation to supply specified products, commodities or maintenance or warranty services to a third party. Derivative Instruments Considered to Be Guarantees Derivatives are financial instruments whose cash flows are based on a notional amount and an underlying instrument, reference credit or index, where there is little or no initial investment, and whose terms require or permit net settlement. For a discussion of Citi’s derivatives activities, see Note 22 to the Consolidated Financial Statements. Derivative instruments considered to be guarantees include only those instruments that require Citi to make payments to the counterparty based on changes in an underlying instrument that is related to an asset, a liability or an equity security held by the guaranteed party. More specifically, derivative instruments considered to be guarantees include certain over-the-counter written put options where the counterparty is not a bank, hedge fund or broker-dealer (such counterparties are considered to be dealers in these markets and may, therefore, not hold the underlying instruments). Credit derivatives sold by Citi are excluded from the tables above as they are disclosed separately in Note 22 to the Consolidated Financial Statements. In instances where Citi’s maximum potential future payment is unlimited, the notional amount of the contract is disclosed. Loans Sold with Recourse Loans sold with recourse represent Citi’s obligations to reimburse the buyers for loan losses under certain circumstances. Recourse refers to the clause in a sales agreement under which a seller/lender will fully reimburse the buyer/investor for any losses resulting from the purchased loans. This may be accomplished by the seller taking back any loans that become delinquent. In addition to the amounts shown in the tables above, Citi has recorded a repurchase reserve for its potential repurchases or make-whole liability regarding residential mortgage representation and warranty claims related to its whole loan sales to the U.S. government-sponsored enterprises (GSEs) and, to a lesser extent, private investors. The repurchase reserve was approximately $66 million and $107 million at December 31, 2017 and 2016 , respectively, and these amounts are included in Other liabilities on the Consolidated Balance Sheet. Securities Lending Indemnifications Owners of securities frequently lend those securities for a fee to other parties who may sell them short or deliver them to another party to satisfy some other obligation. Banks may administer such securities lending programs for their clients. Securities lending indemnifications are issued by the bank to guarantee that a securities lending customer will be made whole in the event that the security borrower does not return the security subject to the lending agreement and collateral held is insufficient to cover the market value of the security. Credit Card Merchant Processing Credit card merchant processing guarantees represent the Company’s indirect obligations in connection with (i) providing transaction processing services to various merchants with respect to its private-label cards and (ii) potential liability for bank card transaction processing services. The nature of the liability in either case arises as a result of a billing dispute between a merchant and a cardholder that is ultimately resolved in the cardholder’s favor. The merchant is liable to refund the amount to the cardholder. In general, if the credit card processing company is unable to collect this amount from the merchant, the credit card processing company bears the loss for the amount of the credit or refund paid to the cardholder. With regard to (i) above, Citi has the primary contingent liability with respect to its portfolio of private-label merchants. The risk of loss is mitigated as the cash flows between Citi and the merchant are settled on a net basis, and Citi has the right to offset any payments with cash flows otherwise due to the merchant. To further mitigate this risk, Citi may delay settlement, require a merchant to make an escrow deposit, include event triggers to provide Citi with more financial and operational control in the event of the financial deterioration of the merchant or require various credit enhancements (including letters of credit and bank guarantees). In the unlikely event that a private-label merchant is unable to deliver products, services or a refund to its private-label cardholders, Citi is contingently liable to credit or refund cardholders. With regard to (ii) above, Citi has a potential liability for bank card transactions where Citi provides the transaction processing services as well as those where a third party provides the services and Citi acts as a secondary guarantor, should that processor fail to perform. Citi’s maximum potential contingent liability related to both bank card and private-label merchant processing services is estimated to be the total volume of credit card transactions that meet the requirements to be valid charge-back transactions at any given time. At December 31, 2017 and 2016 , this maximum potential exposure was estimated to be $86 billion and $86 billion , respectively. However, Citi believes that the maximum exposure is not representative of the actual potential loss exposure based on its historical experience. This contingent liability is unlikely to arise, as most products and services are delivered when purchased and amounts are refunded when items are returned to merchants. Citi assesses the probability and amount of its contingent liability related to merchant processing based on the financial strength of the primary guarantor, the extent and nature of unresolved charge-backs and its historical loss experience. At December 31, 2017 and 2016 , the losses incurred and the carrying amounts of Citi’s contingent obligations related to merchant processing activities were immaterial. Credit Card Arrangements with Partners Citi, in certain of its credit card partner arrangements, provides guarantees to the partner regarding the volume of certain customer originations during the term of the agreement. To the extent that such origination targets are not met, the guarantees serve to compensate the partner for certain payments that otherwise would have been generated in connection with such originations. Custody Indemnifications Custody indemnifications are issued to guarantee that custody clients will be made whole in the event that a third-party subcustodian or depository institution fails to safeguard clients’ assets. Other Guarantees and Indemnifications Credit Card Protection Programs Citi, through its credit card businesses, provides various cardholder protection programs on several of its card products, including programs that provide insurance coverage for rental cars, coverage for certain losses associated with purchased products, price protection for certain purchases and protection for lost luggage. These guarantees are not included in the table, since the total outstanding amount of the guarantees and Citi’s maximum exposure to loss cannot be quantified. The protection is limited to certain types of purchases and losses, and it is not possible to quantify the purchases that would qualify for these benefits at any given time. Citi assesses the probability and amount of its potential liability related to these programs based on the extent and nature of its historical loss experience. At December 31, 2017 and 2016, the actual and estimated losses incurred and the carrying value of Citi’s obligations related to these programs were immaterial. Other Representation and Warranty Indemnifications In the normal course of business, Citi provides standard representations and warranties to counterparties in contracts in connection with numerous transactions and also provides indemnifications, including indemnifications that protect the counterparties to the contracts in the event that additional taxes are owed, due either to a change in the tax law or an adverse interpretation of the tax law. Counterparties to these transactions provide Citi with comparable indemnifications. While such representations, warranties and indemnifications are essential components of many contractual relationships, they do not represent the underlying business purpose for the transactions. The indemnification clauses are often standard contractual terms related to Citi’s own performance under the terms of a contract and are entered into in the normal course of business based on an assessment that the risk of loss is remote. Often these clauses are intended to ensure that terms of a contract are met at inception. No compensation is received for these standard representations and warranties, and it is not possible to determine their fair value because they rarely, if ever, result in a payment. In many cases, there are no stated or notional amounts included in the indemnification clauses, and the contingencies potentially triggering the obligation to indemnify have not occurred and are not expected to occur. As a result, these indemnifications are not included in the tables above. Value-Transfer Networks Citi is a member of, or shareholder in, hundreds of value-transfer networks (VTNs) (payment, clearing and settlement systems as well as exchanges) around the world. As a condition of membership, many of these VTNs require that members stand ready to pay a pro rata share of the losses incurred by the organization due to another member’s default on its obligations. Citi’s potential obligations may be limited to its membership interests in the VTNs, contributions to the VTN’s funds, or, in limited cases, the obligation may be unlimited. The maximum exposure cannot be estimated as this would require an assessment of future claims that have not yet occurred. Citi believes the risk of loss is remote given historical experience with the VTNs. Accordingly, Citi’s participation in VTNs is not reported in the guarantees tables above, and there are no amounts reflected on the Consolidated Balance Sheet as of December 31, 2017 or 2016 for potential obligations that could arise from Citi’s involvement with VTN associations. Long-Term Care Insurance Indemnification In 2000, Travelers Life & Annuity (Travelers), then a subsidiary of Citi, entered into a reinsurance agreement to transfer the risks and rewards of its long-term care (LTC) business to GE Life (now Genworth Financial Inc., or Genworth), then a subsidiary of the General Electric Company (GE). As part of this transaction, the reinsurance obligations were provided by two regulated insurance subsidiaries of GE Life, which funded two collateral trusts with securities. Presently, as discussed below, the trusts are referred to as the Genworth Trusts. As part of GE’s spin-off of Genworth in 2004, GE retained the risks and rewards associated with the 2000 Travelers reinsurance agreement by providing a reinsurance contract to Genworth through its Union Fidelity Life Insurance Company (UFLIC) subsidiary that covers the Travelers LTC policies. In addition, GE provided a capital maintenance agreement in favor of UFLIC which is designed to assure that UFLIC will have the funds to pay its reinsurance obligations. As a result of these reinsurance agreements and the spin-off of Genworth, Genworth has reinsurance protection from UFLIC (supported by GE) and has reinsurance obligations in connection with the Travelers LTC policies. As noted below, the Genworth reinsurance obligations now benefit Brighthouse Financial, Inc. (Brighthouse). While neither Brighthouse nor Citi are direct beneficiaries of the capital maintenance agreement between GE and UFLIC, Brighthouse and Citi benefit indirectly from the existence of the capital maintenance agreement, which helps assure that UFLIC will continue to have funds necessary to pay its reinsurance obligations to Genworth. In connection with Citi’s 2005 sale of Travelers to MetLife Inc. (MetLife), Citi provided an indemnification to MetLife for losses (including policyholder claims) relating to the LTC business for the entire term of the Travelers LTC policies, which, as noted above, are reinsured by subsidiaries of Genworth. In 2017, MetLife spun off its retail insurance business to Brighthouse. As a result, the Travelers LTC policies now reside with Brighthouse. The original reinsurance agreement between Travelers (now Brighthouse) and Genworth remains in place and Brighthouse is the sole beneficiary of the Genworth Trusts. The fair value of the Genworth Trusts is approximately $7.5 billion as of December 31, 2017, compared to $7.0 billion at December 31, 2016. The Genworth Trusts are designed to provide collateral to Brighthouse in an amount equal to the statutory liabilities of Brighthouse in respect of the Travelers LTC policies. The assets in the Genworth Trusts are evaluated and adjusted periodically to ensure that the fair value of the assets continues to provide collateral in an amount equal to these estimated statutory liabilities, as the liabilities change over time. If both (i) Genworth fails to perform under the original Travelers/GE Life reinsurance agreement for any reason, including insolvency or the failure of UFLIC to perform in a timely manner, and (ii) the assets of the two Genworth Trusts are insufficient or unavailable, then Citi, through its LTC reinsurance indemnification, must reimburse Brighthouse for any losses incurred in connection with the LTC policies. Since both events would have to occur before Citi would become responsible for any payment to Brighthouse pursuant to its indemnification obligation, and the likelihood of such events occurring is currently not probable, there is no liability reflected on the Consolidated Balance Sheet as of December 31, 2017 and 2016 related to this indemnification. Citi continues to closely monitor its potential exposure under this indemnification obligation. Separately, Genworth announced that it had agreed to be purchased by China Oceanwide Holdings Co., Ltd, subject to a series of conditions and regulatory approvals. Citi is monitoring these developments. Futures and Over-the-Counter Derivatives Clearing Citi provides clearing services on central clearing parties (CCPs) for clients that need to clear exchange traded and over-the-counter (OTC) derivatives contracts. Based on all relevant facts and circumstances, Citi has concluded that it acts as an agent for accounting purposes in its role as clearing member for these client transactions. As such, Citi does not reflect the underlying exchange traded or OTC derivatives contracts in its Consolidated Financial Statements. See Note 22 for a discussion of Citi’s derivatives activities that are reflected in its Consolidated Financial Statements. As a clearing member, Citi collects and remits cash and securities collateral (margin) between its clients and the respective CCP. In certain circumstances, Citi collects a higher amount of cash (or securities) from its clients than it needs to remit to the CCPs. This excess cash is then held at depository institutions such as banks or carry brokers. There are two types of margin: initial and variation. Where Citi obtains benefits from or controls cash initial margin (e.g., retains an interest spread), cash initial margin collected from clients and remitted to the CCP or depository institutions is reflected within Brokerage payables (payables to customers) and Brokerage receivables (receivables from brokers, dealers and clearing organizations) or Cash and due from banks , respectively. However, for exchange traded and OTC-cleared derivatives contracts where Citi does not obtain benefits from or control the client cash balances, the client cash initial margin collected from clients and remitted to the CCP or depository institutions is not reflected on Citi’s Consolidated Balance Sheet. These conditions are met when Citi has contractually agreed with the client that (i) Citi will pass through to the client all interest paid by the CCP or depository institutions on the cash initial margin, (ii) Citi will not utilize its right as a clearing member to transform cash margin into other assets, (iii) Citi does not guarantee and is not liable to the client for the performance of the CCP or the depository institution and (iv) the client cash balances are legally isolated from Citi’s bankruptcy estate. The total amount of cash initial margin collected and remitted in this manner was approximately $10.7 billion and $9.4 billion as of December 31, 2017 and 2016 , respectively. Variation margin due from clients to the respective CCP, or from the CCP to clients, reflects changes in the value of the client’s derivative contracts for each trading day. As a clearing member, Citi is exposed to the risk of non-performance by clients (e.g., failure of a client to post variation margin to the CCP for negative changes in the value of the client’s derivative contracts). In the event of non-performance by a client, Citi would move to close out the client’s positions. The CCP would typically utilize initial margin posted by the client and held by the CCP, with any remaining shortfalls required to be paid by Citi as clearing member. Citi generally holds incremental cash or securities margin posted by the client, which would typically be expected to be sufficient to mitigate Citi’s credit risk in the event that the client fails to perform. As required by ASC 860-30-25-5, securities collateral posted by clients is not recognized on Citi’s Consolidated Balance Sheet. Carrying Value—Guarantees and Indemnifications At December 31, 2017 and 2016 , the total carrying amounts of the liabilities related to the guarantees and indemnifications included in the tables above amounted to approximately $0.8 billion and $ 1.2 billion , respectively. The carrying value of financial and performance guarantees is included in Other liabilities. For loans sold with recourse, the carrying value of the liability is included in Other liabilities . Collateral Cash collateral available to Citi to reimburse losses realized under these guarantees and indemnifications amounted to $46 billion and $48 billion at December 31, 2017 and 2016 , respectively. Securities and other marketable assets held as collateral amounted to $70 billion and $41 billion at December 31, 2017 and 2016 , respectively. The majority of collateral is held to reimburse losses realized under securities lending indemnifications. Additionally, letters of credit in favor of Citi held as collateral amounted to $3.7 billion and $5.4 billion at December 31, 2017 and 2016 , respectively. Other property may also be available to Citi to cover losses under certain guarantees and indemnifications; however, the value of such property has not been determined. Performance Risk Citi evaluates the performance risk of its guarantees based on the assigned referenced counterparty internal or external ratings. Where external ratings are used, investment-grade ratings are considered to be Baa/BBB and above, while anything below is considered non-investment grade. Citi’s internal ratings are in line with the related external rating system. On certain underlying referenced assets or entities, ratings are not available. Such referenced assets are included in the “not rated” category. The maximum potential amount of the future payments related to the outstanding guarantees is determined to be the notional amount of these contracts, which is the par amount of the assets guaranteed. Presented in the tables below are the maximum potential amounts of future payments that are classified based upon internal and external credit ratings. As previously mentioned, the determination of the maximum potential future payments is based on the notional amount of the guarantees without consideration of possible recoveries under recourse provisions or from collateral held or pledged. As such, Citi believes such amounts bear no relationship to the anticipated losses, if any, on these guarantees. Maximum potential amount of future payments In billions of dollars at December 31, 2017 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 68.1 $ 10.9 $ 14.8 $ 93.8 Performance guarantees 7.9 2.4 1.0 11.3 Derivative instruments deemed to be guarantees — — 95.9 95.9 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 103.7 103.7 Credit card merchant processing — — 85.5 85.5 Credit card arrangements with partners — — 1.4 1.4 Custody indemnifications and other 23.7 12.3 — 36.0 Total $ 99.7 $ 25.6 $ 302.5 $ 427.8 Maximum potential amount of future payments In billions of dollars at December 31, 2016 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 66.8 $ 13.4 $ 12.9 $ 93.1 Performance guarantees 6.3 4.0 0.8 11.1 Derivative instruments deemed to be guarantees — — 87.2 87.2 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 80.3 80.3 Credit card merchant processing — — 86.4 86.4 Credit card arrangements with partners — — 1.5 1.5 Custody indemnifications and other 33.3 12.1 — 45.4 Total $ 106.4 $ 29.5 $ 269.3 $ 405.2 Credit Commitments and Lines of Credit The table below summarizes Citigroup’s credit commitments: In millions of dollars U.S. Outside of U.S. December 31, December 31, 2016 Commercial and similar letters of credit $ 904 $ 4,096 $ 5,000 $ 5,736 One- to four-family residential mortgages 988 1,686 2,674 2,838 Revolving open-end loans secured by one- to four-family residential properties 10,825 1,498 12,323 13,405 Commercial real estate, construction and land development 9,594 1,557 11,151 10,781 Credit card lines 578,634 99,666 678,300 664,335 Commercial and other consumer loan commitments 171,383 101,272 272,655 259,934 Other commitments and contingencies 2,182 889 3,071 3,202 Total $ 774,510 $ 210,664 $ 985,174 $ 960,231 The majority of unused commitments are contingent upon customers maintaining specific credit standards. Commercial commitments generally have floating interest rates and fixed expiration dates and may require payment of fees. Such fees (net of certain direct costs) are deferred and, upon exercise of the commitment, amortized over the life of the loan or, if exercise is deemed remote, amortized over the commitment period. Commercial and Similar Letters of Credit A commercial letter of credit is an instrument by which Citigroup substitutes its credit for that of a customer to enable the customer to finance the purchase of goods or to incur other commitments. Citigroup issues a letter on behalf of its client to a supplier and agrees to pay the supplier upon presentation of documentary evidence that the supplier has performed in accordance with the terms of the letter of credit. When a letter of credit is drawn, the customer is then required to reimburse Citigroup. One- to Four-Family Residential Mortgages A one- to four-family residential mortgage commitment is a written confirmation from Citigroup to a seller of a property that the bank will advance the specified sums enabling the buyer to complete the purchase. Revolving Open-End Loans Secured by One- to Four-Family Residential Properties Revolving open-end loans secured by one- to four-family residential properties are essentially home equity lines of credit. A home equity line of credit is a loan secured by a primary residence or second home to the extent of the excess of fair market value over the debt outstanding for the first mortgage. Commercial Real Estate, Construction and Land Development Commercial real estate, construction and land development include unused portions of commitments to extend credit for the purpose of financing commercial and multifamily residential properties as well as land development projects. Both secured-by-real-estate and unsecured commitments are included in this line, as well as undistributed loan proceeds, where there is an obligation to advance for construction progress payments. However, this line only includes those extensions of credit that, once funded, will be classified as Total loans, net on the Consolidated Balance Sheet. Credit Card Lines Citigroup provides credit to customers by issuing credit cards. The credit card lines are cancelable by providing notice to the cardholder or without such notice as permitted by local law. Commercial and Other Consumer Loan Commitments Commercial and other consumer loan commitments include overdraft and liquidity facilities as well as commercial commitments to make or purchase loans, purchase third-party receivables, provide note issuance or revolving underwriting facilities and invest in the form of equity. Other Commitments and Contingencies Other commitments and contingencies include committed or unsettled regular-way reverse repurchase agreements and all other transactions related to commitments and contingencies not reported on the lines above. Unsettled Reverse Repurchase and Securities Lending Agreements and Unsettled Repurchase and Securities Borrowing Agreements In addition, in the normal course of business, Citigroup enters into reverse repurchase and securities borrowing agreements, as well as repurchase and securities lending agreements, which settle at a future date. At December 31, 2017, and December 31, 2016, Citigroup had $35.0 billion and $43.1 billion unsettled reverse repurchase and securities borrowing agreements, and $19.1 billion and $14.9 billion unsettled repurchase and securities lending agreements. For a further discussion of securities purchased under agreements to resell and securities borrowed, and securities sold under agreements to repurchase and securities loaned, including the Company’s policy for offsetting repurchase and reverse repurchase agreements, see Note 11 to the Consolidated Financial Statements.

CONTINGENCIES

CONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Accounting and Disclosure Framework ASC 450 governs the disclosure and recognition of loss contingencies, including potential losses from litigation and regulatory matters. ASC 450 defines a “loss contingency” as “an existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an entity that will ultimately be resolved when one or more future events occur or fail to occur.” It imposes different requirements for the recognition and disclosure of loss contingencies based on the likelihood of occurrence of the contingent future event or events. It distinguishes among degrees of likelihood using the following three terms: “probable,” meaning that “the future event or events are likely to occur”; “remote,” meaning that “the chance of the future event or events occurring is slight”; and “reasonably possible,” meaning that “the chance of the future event or events occurring is more than remote but less than likely.” These three terms are used below as defined in ASC 450. Accruals . ASC 450 requires accrual for a loss contingency when it is “probable that one or more future events will occur confirming the fact of loss” and “the amount of the loss can be reasonably estimated.” In accordance with ASC 450, Citigroup establishes accruals for contingencies, including the litigation and regulatory matters disclosed herein, when Citigroup believes it is probable that a loss has been incurred and the amount of the loss can be reasonably estimated. When the reasonable estimate of the loss is within a range of amounts, the minimum amount of the range is accrued, unless some higher amount within the range is a better estimate than any other amount within the range. Once established, accruals are adjusted from time to time, as appropriate, in light of additional information. The amount of loss ultimately incurred in relation to those matters may be substantially higher or lower than the amounts accrued for those matters. Disclosure . ASC 450 requires disclosure of a loss contingency if “there is at least a reasonable possibility that a loss or an additional loss may have been incurred” and there is no accrual for the loss because the conditions described above are not met or an exposure to loss exists in excess of the amount accrued. In accordance with ASC 450, if Citigroup has not accrued for a matter because Citigroup believes that a loss is reasonably possible but not probable, or that a loss is probable but not reasonably estimable, and the reasonably possible loss is material, it discloses the loss contingency. In addition, Citigroup discloses matters for which it has accrued if it believes a reasonably possible exposure to material loss exists in excess of the amount accrued. In accordance with ASC 450, Citigroup’s disclosure includes an estimate of the reasonably possible loss or range of loss for those matters as to which an estimate can be made. ASC 450 does not require disclosure of an estimate of the reasonably possible loss or range of loss where an estimate cannot be made. Neither accrual nor disclosure is required for losses that are deemed remote. Litigation and Regulatory Contingencies Overview. In addition to the matters described below, in the ordinary course of business, Citigroup, its affiliates and subsidiaries, and current and former officers, directors and employees (for purposes of this section, sometimes collectively referred to as Citigroup and Related Parties) routinely are named as defendants in, or as parties to, various legal actions and proceedings. Certain of these actions and proceedings assert claims or seek relief in connection with alleged violations of consumer protection, fair lending, securities, banking, antifraud, antitrust, anti-money laundering, employment and other statutory and common laws. Certain of these actual or threatened legal actions and proceedings include claims for substantial or indeterminate compensatory or punitive damages, or for injunctive relief, and in some instances seek recovery on a class-wide basis. In the ordinary course of business, Citigroup and Related Parties also are subject to governmental and regulatory examinations, information-gathering requests, investigations and proceedings (both formal and informal), certain of which may result in adverse judgments, settlements, fines, penalties, restitution, disgorgement, injunctions or other relief. In addition, certain affiliates and subsidiaries of Citigroup are banks, registered broker-dealers, futures commission merchants, investment advisers or other regulated entities and, in those capacities, are subject to regulation by various U.S., state and foreign securities, banking, commodity futures, consumer protection and other regulators. In connection with formal and informal inquiries by these regulators, Citigroup and such affiliates and subsidiaries receive numerous requests, subpoenas and orders seeking documents, testimony and other information in connection with various aspects of their regulated activities. From time to time Citigroup and Related Parties also receive grand jury subpoenas and other requests for information or assistance, formal or informal, from federal or state law enforcement agencies including, among others, various United States Attorneys’ Offices, the Asset Forfeiture and Money Laundering Section and other divisions of the Department of Justice, the Financial Crimes Enforcement Network of the United States Department of the Treasury, and the Federal Bureau of Investigation relating to Citigroup and its customers. Because of the global scope of Citigroup’s operations, and its presence in countries around the world, Citigroup and Related Parties are subject to litigation and governmental and regulatory examinations, information-gathering requests, investigations and proceedings (both formal and informal) in multiple jurisdictions with legal and regulatory regimes that may differ substantially, and present substantially different risks, from those Citigroup and Related Parties are subject to in the United States. In some instances, Citigroup and Related Parties may be involved in proceedings involving the same subject matter in multiple jurisdictions, which may result in overlapping, cumulative or inconsistent outcomes. Citigroup seeks to resolve all litigation and regulatory matters in the manner management believes is in the best interests of Citigroup and its shareholders, and contests liability, allegations of wrongdoing and, where applicable, the amount of damages or scope of any penalties or other relief sought as appropriate in each pending matter. Inherent Uncertainty of the Matters Disclosed. Certain of the matters disclosed below involve claims for substantial or indeterminate damages. The claims asserted in these matters typically are broad, often spanning a multi-year period and sometimes a wide range of business activities, and the plaintiffs’ or claimants’ alleged damages frequently are not quantified or factually supported in the complaint or statement of claim. Other matters relate to regulatory investigations or proceedings, as to which there may be no objective basis for quantifying the range of potential fine, penalty or other remedy. As a result, Citigroup is often unable to estimate the loss in such matters, even if it believes that a loss is probable or reasonably possible, until developments in the case or investigation have yielded additional information sufficient to support a quantitative assessment of the range of reasonably possible loss. Such developments may include, among other things, discovery from adverse parties or third parties, rulings by the court on key issues, analysis by retained experts and engagement in settlement negotiations. Depending on a range of factors, such as the complexity of the facts, the novelty of the legal theories, the pace of discovery, the court’s scheduling order, the timing of court decisions and the adverse party’s willingness to negotiate in good faith toward a resolution, it may be months or years after the filing of a case or commencement of an investigation before an estimate of the range of reasonably possible loss can be made. Matters as to Which an Estimate Can Be Made . For some of the matters disclosed below, Citigroup is currently able to estimate a reasonably possible loss or range of loss in excess of amounts accrued (if any). For some of the matters included within this estimation, an accrual has been made because a loss is believed to be both probable and reasonably estimable, but an exposure to loss exists in excess of the amount accrued. In these cases, the estimate reflects the reasonably possible range of loss in excess of the accrued amount. For other matters included within this estimation, no accrual has been made because a loss, although estimable, is believed to be reasonably possible, but not probable; in these cases, the estimate reflects the reasonably possible loss or range of loss. As of December 31, 2017, Citigroup estimates that the reasonably possible unaccrued loss for these matters ranges up to approximately $1.0 billion in the aggregate. These estimates are based on currently available information. As available information changes, the matters for which Citigroup is able to estimate will change, and the estimates themselves will change. In addition, while many estimates presented in financial statements and other financial disclosures involve significant judgment and may be subject to significant uncertainty, estimates of the range of reasonably possible loss arising from litigation and regulatory proceedings are subject to particular uncertainties. For example, at the time of making an estimate, (i) Citigroup may have only preliminary, incomplete, or inaccurate information about the facts underlying the claim, (ii) its assumptions about the future rulings of the court or other tribunal on significant issues, or the behavior and incentives of adverse parties or regulators, may prove to be wrong and (iii) the outcomes it is attempting to predict are often not amenable to the use of statistical or other quantitative analytical tools. In addition, from time to time an outcome may occur that Citigroup had not accounted for in its estimate because it had deemed such an outcome to be remote. For all of these reasons, the amount of loss in excess of accruals ultimately incurred for the matters as to which an estimate has been made could be substantially higher or lower than the range of loss included in the estimate. Matters as to Which an Estimate Cannot Be Made . For other matters disclosed below, Citigroup is not currently able to estimate the reasonably possible loss or range of loss. Many of these matters remain in very preliminary stages (even in some cases where a substantial period of time has passed since the commencement of the matter), with few or no substantive legal decisions by the court or tribunal defining the scope of the claims, the class (if any) or the potentially available damages, and fact discovery is still in progress or has not yet begun. In many of these matters, Citigroup has not yet answered the complaint or statement of claim or asserted its defenses, nor has it engaged in any negotiations with the adverse party (whether a regulator or a private party). For all these reasons, Citigroup cannot at this time estimate the reasonably possible loss or range of loss, if any, for these matters. Opinion of Management as to Eventual Outcome. Subject to the foregoing, it is the opinion of Citigroup’s management, based on current knowledge and after taking into account its current legal accruals, that the eventual outcome of all matters described in this Note would not be likely to have a material adverse effect on the consolidated financial condition of Citigroup. Nonetheless, given the substantial or indeterminate amounts sought in certain of these matters, and the inherent unpredictability of such matters, an adverse outcome in certain of these matters could, from time to time, have a material adverse effect on Citigroup’s consolidated results of operations or cash flows in particular quarterly or annual periods. CARD Act Matter Citi identified certain methodological issues in connection with determining annual percentage rates (APRs) for certain cardholders under the rate re-evaluation provisions of the Credit Card Accountability Responsibility and Disclosure Act (CARD Act) and Regulation Z. Citi self-reported the issues to its regulators and will be providing remediation to affected customers. Citi is cooperating fully with the regulatory reviews. Credit Crisis-Related Litigation and Other Matters Citigroup and Related Parties were named as defendants in numerous legal actions and other proceedings asserting claims for damages and related relief for losses arising from the global financial credit crisis that began in 2007. Citigroup also received subpoenas and requests for information from various regulatory agencies and other government authorities concerning certain businesses impacted by the credit crisis. The vast majority of these matters have been resolved as of December 31, 2017. Mortgage-Related Litigation and Other Matters Mortgage-Backed Securities and CDO Investor Actions: Beginning in July 2010, Citigroup and Related Parties were named as defendants in complaints filed by purchasers of MBS and CDOs sold or underwritten by Citigroup. The complaints generally assert that defendants made material misrepresentations and omissions about the credit quality of the assets underlying the securities or the manner in which those assets were selected, and typically assert claims under Section 11 of the Securities Act of 1933, state blue sky laws, and/or common-law misrepresentation-based causes of action. All but one of these matters have been resolved through settlement or otherwise. As of December 31, 2017, the aggregate original purchase amount of the purchases covered by the remaining tolling (extension) agreement with an investor threatening litigation is approximately $500 million . Mortgage-Backed Securities Repurchase Claims : Various parties to MBS securitizations and other interested parties have asserted that certain Citigroup affiliates breached representations and warranties made in connection with mortgage loans sold into securitization trusts (private-label securitizations). Typically, these claims are based on allegations that securitized mortgages were not underwritten in accordance with the applicable underwriting standards. Citigroup also has received inquiries, demands for loan files, and requests to toll the applicable statutes of limitation for representation and warranty claims, relating to its private-label securitizations. These inquiries, demands and requests have been made by trustees of securitization trusts and others. To date, trustees have filed six actions against Citigroup seeking to enforce certain of these contractual repurchase claims that were excluded from the April 7, 2014 settlement in connection with four private-label securitizations. Citigroup has reached an agreement with the trustees to resolve all six of these actions. Additional information concerning these actions is publicly available in court filings under the docket numbers 13 Civ. 2843 (S.D.N.Y.) (Daniels, J.), 13 Civ. 6989 (S.D.N.Y.) (Daniels, J.), 653816/2013 (N.Y. Sup. Ct.) (Kornreich, J.), 653919/2014 (N.Y. Sup. Ct.), 653929/2014 (N.Y. Sup. Ct.), and 653930/2014 (N.Y. Sup. Ct.). Mortgage-Backed Securities Trustee Actions : On November 24, 2014, a group of investors in 27 RMBS trusts for which Citibank served or currently serves as trustee filed an action in the United States District Court for the Southern District of New York, captioned FIXED INCOME SHARES: SERIES M ET AL. v. CITIBANK N.A., alleging claims that Citibank failed to pursue contractual remedies against securitization sponsors and servicers. On September 8, 2015, the United States District Court for the Southern District of New York dismissed all claims as to 24 of the 27 trusts and allowed certain of the claims to proceed as to the other three trusts. On September 7, 2016, plaintiffs filed a stipulation of voluntary dismissal of their claims with respect to two of the three remaining trusts, leaving one trust at issue. On September 30, 2016, plaintiffs moved to certify a class action, and on April 7, 2017, Citibank moved for summary judgment on all remaining claims. Both motions are pending. Additional information concerning this action is publicly available in court filings under the docket number 14-cv-9373 (S.D.N.Y.) (Furman, J.). On November 24, 2015, largely the same group of investors filed an action in the New York State Supreme Court, captioned FIXED INCOME SHARES: SERIES M, ET AL. v. CITIBANK N.A., related to the 24 trusts dismissed from the federal court action and one additional trust, asserting claims similar to the action filed in federal court. On June 22, 2016, the court dismissed plaintiffs’ complaint. Plaintiffs filed an amended complaint on August 5, 2016. On June 27, 2017, the court granted in part and denied in part Citibank’s motion to dismiss the amended complaint. Citibank appealed as to the sustained claims, and on January 16, 2018, the New York Appellate Division, First Department, dismissed all of the remaining claims except the claim for breach of contract related to purported discovery of alleged underwriter breaches of representations and warranties. Additional information concerning this action is publicly available in court filings under the docket number 653891/2015 (N.Y. Sup. Ct.) (Ramos, J.). On August 19, 2015, the Federal Deposit Insurance Corporation (FDIC), as receiver for a financial institution, filed a civil action against Citibank in the United States District Court for the Southern District of New York, captioned FEDERAL DEPOSIT INSURANCE CORPORATION AS RECEIVER FOR GUARANTY BANK v. CITIBANK N.A. The complaint concerns one RMBS trust for which Citibank formerly served as trustee, and alleges that Citibank failed to pursue contractual remedies against the sponsor and servicers of that trust. On September 30, 2016, the court granted Citibank’s motion to dismiss on the grounds that the FDIC lacked standing to pursue its claims. On October 14, 2016, the FDIC filed a motion for reconsideration or relief from judgment from the court’s dismissal order. On July 10, 2017, the court denied the motion for reconsideration but granted the FDIC leave to file an amended complaint. The FDIC filed an amended complaint on December 8, 2017. Additional information concerning this action is publicly available in court filings under the docket number 15-cv-6574 (S.D.N.Y.) (Carter, J.). Lehman Brothers Bankruptcy Proceedings On February 8, 2012, Citibank and certain Citigroup affiliates were named as defendants in an adversary proceeding asserting objections to certain proofs of claim totaling approximately $2.6 billion filed by Citibank and those affiliates, and claims under federal bankruptcy and state law to recover $2 billion deposited by Lehman Brothers Holdings Inc. (LBHI) with Citibank against which Citibank asserted a right of setoff. A global settlement between the parties was approved by the bankruptcy court on October 13, 2017. As part of the global settlement, Citibank retained $350 million from LBHI’s deposit at Citibank and returned to LBHI and its affiliates the remaining deposited funds, and LBHI withdrew its remaining objections to the bankruptcy claims filed by Citibank and its affiliates. This action was dismissed by stipulation on November 3, 2017. Additional information concerning this action is publicly available in court filings under the docket numbers 12-01044 and 08-13555 (Bankr. S.D.N.Y.) (Chapman, J.). Tribune Company Bankruptcy Certain Citigroup affiliates have been named as defendants in adversary proceedings related to the Chapter 11 cases of Tribune Company (Tribune) filed in the United States Bankruptcy Court for the District of Delaware, asserting claims arising out of the approximately $11 billion leveraged buyout of Tribune in 2007. On August 2, 2013, the Litigation Trustee, as successor plaintiff to the Official Committee of Unsecured Creditors, filed a fifth amended complaint in the adversary proceeding KIRSCHNER v. FITZSIMONS, ET AL. The complaint seeks to avoid and recover as actual fraudulent transfers the transfers of Tribune stock that occurred as a part of the leveraged buyout. Several Citigroup affiliates are named as “Shareholder Defendants” and are alleged to have tendered Tribune stock to Tribune as a part of the buyout. Several Citigroup affiliates are named as defendants in certain actions brought by Tribune noteholders, which seek to recover the transfers of Tribune stock that occurred as a part of the leveraged buyout, as state-law constructive fraudulent conveyances. The noteholders’ claims were previously dismissed and the United States Court of Appeals for the Second Circuit affirmed the dismissal on appeal. The noteholders’ petition to the United States Supreme Court for a writ of certiorari is pending. In the FITZSIMONS action, on February 1, 2017, the Litigation Trustee requested leave to file an interlocutory appeal of Judge Sullivan’s order dismissing the actual fraudulent transfer claim against the shareholder defendants, including several Citigroup affiliates. On February 23, 2017, Judge Sullivan entered an order stating that an interlocutory appeal will be certified after the remaining motions to dismiss are resolved. Those motions remain pending. Additional information concerning these actions is publicly available in court filings under the docket numbers 08-13141 (Bankr. D. Del.) (Carey, J.), 11 MD 02296 (S.D.N.Y.) (Sullivan, J.), 12 MC 2296 (S.D.N.Y.) (Sullivan, J.), 13-3992, 13-3875, 13-4196 (2d Cir.) and 16-317 (U.S.). Credit Default Swaps Matters Antitrust and Other Litigation : On June 8, 2017, a complaint was filed in the United States District Court for the Southern District of New York against numerous credit default swap (CDS) market participants, including Citigroup, Citibank, Citigroup Global Markets Inc. (CGMI), and Citigroup Global Markets Ltd. (CGML), under the caption TERA GROUP, INC., ET AL. v. CITIGROUP INC., ET AL. The complaint alleges that defendants colluded to prevent plaintiffs’ electronic CDS trading platform, TeraExchange, from entering the market, resulting in lost profits to plaintiffs. The complaint asserts federal and state antitrust claims, and claims for unjust enrichment and tortious interference with business relations. Plaintiffs seek a finding of joint and several liability, treble damages, attorneys’ fees, interest, and injunctive relief. On September 11, 2017, defendants, including Citigroup, Citibank, CGMI, and CGML, filed motions to dismiss all claims. Additional information concerning this action is publicly available in court filings under the docket number 17-cv-04302 (S.D.N.Y.) (Sullivan, J.). Depositary Receipts Conversion Litigation Citibank was sued by a purported class of persons or entities who, from January 2000 to the present, are or were holders of depositary receipts for which Citibank served as the depositary bank and converted, or caused to be converted, foreign-currency dividends or other distributions into U.S. dollars. On August 15, 2016, the court dismissed certain claims against Citibank as well as all claims against two of its affiliates, leaving one claim against Citibank. Plaintiffs assert that Citibank breached its deposit agreements by charging a spread for the conversions of dividends and other distributions. On June 30, 2017, plaintiffs moved for certification of a damages class consisting of persons or entities who, from January 1, 2006 to the present, were holders of 35 depositary receipts for which Citibank served as the depositary bank and converted, or caused to be converted, foreign currency dividends or other distributions into U.S. dollars. Plaintiffs also moved to certify an injunctive class of persons or entities who currently hold the same 35 depositary receipts. Citibank has opposed certification. Additional information concerning this action is publicly available in court filings under the docket number 15 Civ. 9185 (S.D.N.Y.) (McMahon, C.). Foreign Exchange Matters Regulatory Actions : Government and regulatory agencies in the U.S. and in other jurisdictions are conducting investigations or making inquiries regarding Citigroup’s foreign exchange business. Citigroup is fully cooperating with these and related investigations and inquiries. Antitrust and Other Litigation : Numerous foreign exchange dealers, including Citigroup, Citicorp, CGMI, and Citibank, are named as defendants in putative class actions that are proceeding on a consolidated basis in the United States District Court for the Southern District of New York under the caption IN RE FOREIGN EXCHANGE BENCHMARK RATES ANTITRUST LITIGATION. Plaintiffs allege that they suffered losses as a result of defendants’ alleged manipulation of, and collusion with respect to, the foreign exchange market. Plaintiffs allege violations of the Commodity Exchange Act, the Sherman Act, and/or the Clayton Act, and seek compensatory damages, treble damages, and declaratory and injunctive relief. On December 15, 2015, the court entered an order preliminarily approving a proposed settlement between the Citi defendants and classes of plaintiffs who traded foreign exchange instruments in the spot market and on exchanges. The proposed settlement provides for the Citi defendants to receive a release in exchange for a payment of approximately $400 million . On January 12, 2018, plaintiffs moved for final approval of the settlements with the Citi defendants and several other defendants in that case. Additional information concerning this action is available in court filings under the consolidated lead docket number 13 Civ. 7789 (S.D.N.Y.) (Schofield, J.). On May 21, 2015, an action captioned NYPL v. JPMORGAN CHASE & CO., ET AL. was brought in the United States District Court for the Northern District of California against Citigroup, as well as numerous other foreign exchange dealers for possible consolidation with IN RE FOREIGN EXCHANGE BENCHMARK RATES ANTITRUST LITIGATION. On August 10, 2017, plaintiffs filed a third amended class action complaint in the United States District Court for the Southern District of New York naming Citibank, Citigroup, and Citicorp as defendants. Plaintiffs seek to represent a putative class of “consumers and businesses in the United States who directly purchased supracompetitive foreign currency at Benchmark exchange rates” from defendants. Plaintiffs allege claims under federal and California antitrust and consumer protection laws, and are seeking compensatory damages, treble damages, and declaratory and injunctive relief. On October 16, 2017, defendants completed briefing on their renewed motion to dismiss or to certify the court’s ruling for interlocutory appeal. Additional information concerning this action is publicly available in court filings under the docket numbers 15 Civ. 2290 (N.D. Cal.) (Chhabria, J.) and 15 Civ. 9300 (S.D.N.Y.) (Schofield, J.). On June 3, 2015, an action captioned ALLEN v. BANK OF AMERICA CORPORATION, ET AL. was brought in the United States District Court for the Southern District of New York against Citigroup and Citibank, as well as numerous other foreign exchange dealers. Plaintiffs seek to represent a putative class of participants, beneficiaries, and named fiduciaries of qualified Employee Retirement Income Security Act (ERISA) plans for whom a defendant provided foreign exchange transactional services or authorized or permitted foreign exchange transactional services involving a plan’s assets in connection with its exercise of authority or control regarding an ERISA plan. Plaintiffs allege violations of ERISA, and seek compensatory damages, restitution, disgorgement, and declaratory and injunctive relief. On September 20, 2016, plaintiffs and settling defendants in IN RE FOREIGN EXCHANGE BENCHMARK RATES ANTITRUST LITIGATION filed a joint stipulation dismissing plaintiffs’ claims with prejudice. The case is currently on appeal to the United States Court of Appeals for the Second Circuit, where briefing and argument are complete. Additional information concerning this action is publicly available in court filings under the docket numbers 13 Civ. 7789 (S.D.N.Y.) (Schofield, J.), 15 Civ. 4285 (S.D.N.Y.) (Schofield, J.), 16-3327 (2d Cir.), and 16-3571 (2d Cir.). On June 30, 2017, plaintiffs filed a consolidated amended complaint on behalf of purported classes of indirect purchasers of foreign exchange instruments sold by the defendants, naming various financial institutions, including Citigroup, Citibank, Citicorp and CGMI as defendants, captioned CONTANT ET AL. v. BANK OF AMERICA CORPORATION ET AL. Plaintiffs allege that defendants engaged in a conspiracy to fix currency prices in violation of the Sherman Act and various state antitrust laws, and seek unspecified money damages (including treble damages), as well as equitable and injunctive relief. Additional information concerning these actions is publicly available in court filings under the docket numbers 16 Civ. 7512 (S.D.N.Y.) (Schofield, J.), 17 Civ. 4392 (S.D.N.Y.) (Schofield, J.), and 17 Civ. 3139 (S.D.N.Y.) (Schofield, J.). Interbank Offered Rates-Related Litigation and Other Matters Regulatory Actions : A consortium of state attorneys general is conducting an investigation regarding submissions made by panel banks to bodies that publish various interbank offered rates and other benchmark rates. As a member of a number of such panels, Citigroup has received requests for information and documents. Citigroup is cooperating with the investigation and is responding to the requests. Antitrust and Other Litigation : Citigroup and Citibank, along with other U.S. Dollar (USD) LIBOR panel banks, are defendants in a multi-district litigation (MDL) proceeding before the United States District Court for the Southern District of New York captioned IN RE LIBOR-BASED FINANCIAL INSTRUMENTS ANTITRUST LITIGATION (the LIBOR MDL). On July 27, 2017, Citigroup and Citibank executed a settlement with one class (investors who transacted in Eurodollar futures or options on exchanges), pursuant to which the Citi defendants agreed to pay $33.4 million . On October 6, 2017, Citigroup and Citibank agreed to pay $130 million pursuant to its settlement with the largest plaintiffs’ class (investors who purchased over-the-counter (OTC) derivatives from USD LIBOR panel banks) in IN RE LIBOR-BASED FINANCIAL INSTRUMENTS ANTITRUST LITIGATION. On January 10, 2018, Citigroup and Citibank executed a settlement agreement with another class (lending institutions with interests in loans tied to USD LIBOR) pursuant to which the Citi defendants will pay $23 million . Additional information concerning these actions and related actions and appeals is publicly available in court filings under the docket numbers 11 MD 2262 (S.D.N.Y.) (Buchwald, J.) and 17-1569 (2d Cir.). On August 13, 2015, plaintiffs in the class action SULLIVAN v. BARCLAYS PLC, ET AL., pending in the United States District Court for the Southern District of New York, filed a fourth amended complaint naming Citigroup and Citibank as defendants. Plaintiffs claim to have suffered losses as a result of purported EURIBOR manipulation and assert claims under the Commodity Exchange Act, the Sherman Act and the federal civil Racketeer Influenced and Corrupt Organizations (RICO) Act and for unjust enrichment. On February 21, 2017, the court granted in part and denied in part defendants’ motion to dismiss. Additional information concerning this action is publicly available in court filings under the docket number 13 Civ. 2811 (S.D.N.Y.) (Castel, J.). On July 1, 2016, a putative class action captioned FRONTPOINT ASIAN EVENT DRIVEN FUND, LTD. ET AL v. CITIBANK, N.A. ET AL. was filed in the United States District Court for the Southern District of New York against Citibank, Citigroup and various other banks. Plaintiffs assert claims for violation of the Sherman Act, Clayton Act and RICO Act, as well as state law claims for alleged manipulation of the Singapore Interbank Offered Rate and Singapore Swap Offer Rate. On August 18, 2017, the court granted in part the defendants’ motion to dismiss, dismissing all claims against foreign bank defendants, antitrust claims asserted by one of the two named plaintiffs, and all RICO, implied covenant, and unjust enrich

CONDENSED CONSOLIDATING FINANCI

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
CONDENSED CONSOLIDATING FINANCIAL STATEMENTS	CONDENSED CONSOLIDATING FINANCIAL STATEMENTS Citigroup amended its Registration Statement on Form S-3 on file with the SEC (File No. 33-192302) to add its wholly owned subsidiary, Citigroup Global Markets Holdings Inc. (CGMHI), as a co-registrant. Any securities issued by CGMHI under the Form S-3 will be fully and unconditionally guaranteed by Citigroup. The following are the Condensed Consolidating Statements of Income and Comprehensive Income for the years ended December 31, 2017, 2016 and 2015, Condensed Consolidating Balance Sheet as of December 31, 2017 and 2016 and Condensed Consolidating Statement of Cash Flows for the years ended December 31, 2017, 2016 and 2015 for Citigroup Inc., the parent holding company (Citigroup parent company), CGMHI, other Citigroup subsidiaries and eliminations and total consolidating adjustments. “Other Citigroup subsidiaries and eliminations” includes all other subsidiaries of Citigroup, intercompany eliminations and income (loss) from discontinued operations. “Consolidating adjustments” includes Citigroup parent company elimination of distributed and undistributed income of subsidiaries and investment in subsidiaries. These Condensed Consolidating Financial Statements have been prepared and presented in accordance with SEC Regulation S-X Rule 3-10, “Financial Statements of Guarantors and Issuers of Guaranteed Securities Registered or Being Registered.” These Condensed Consolidating Financial Statements schedules are presented for purposes of additional analysis, but should be considered in relation to the Consolidated Financial Statements of Citigroup taken as a whole. Condensed Consolidating Statements of Income and Comprehensive Income Year ended December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 22,499 $ — $ — $ (22,499 ) $ — Interest revenue 1 5,274 55,929 — 61,204 Interest revenue—intercompany 3,972 1,178 (5,150 ) — — Interest expense 4,766 2,340 9,411 — 16,517 Interest expense—intercompany 829 2,297 (3,126 ) — — Net interest revenue $ (1,622 ) $ 1,815 $ 44,494 $ — $ 44,687 Commissions and fees $ — $ 5,139 $ 7,800 $ — $ 12,939 Commissions and fees—intercompany (2 ) 182 (180 ) — — Principal transactions 1,654 1,019 6,495 — 9,168 Principal transactions—intercompany 934 1,200 (2,134 ) — — Other income (2,581 ) 855 6,381 — 4,655 Other income—intercompany 5 158 (163 ) — — Total non-interest revenues $ 10 $ 8,553 $ 18,199 $ — $ 26,762 Total revenues, net of interest expense $ 20,887 $ 10,368 $ 62,693 $ (22,499 ) $ 71,449 Provisions for credit losses and for benefits and claims $ — $ — $ 7,451 $ — $ 7,451 Operating expenses Compensation and benefits $ (107 ) $ 4,403 $ 16,885 $ — $ 21,181 Compensation and benefits—intercompany 120 — (120 ) — — Other operating (318 ) 1,776 18,598 — 20,056 Other operating—intercompany (35 ) 2,219 (2,184 ) — — Total operating expenses $ (340 ) $ 8,398 $ 33,179 $ — $ 41,237 Equity in undistributed income of subsidiaries $ (18,847 ) $ — $ — $ 18,847 $ — Income (loss) from continuing operations before income taxes $ 2,380 $ 1,970 $ 22,063 $ (3,652 ) $ 22,761 Provision (benefit) for income taxes $ 9,178 $ 873 $ 19,337 $ — $ 29,388 Income (loss) from continuing operations $ (6,798 ) $ 1,097 $ 2,726 $ (3,652 ) $ (6,627 ) Loss from discontinued operations, net of taxes — — (111 ) — (111 ) Net income (loss) before attribution of noncontrolling interests $ (6,798 ) $ 1,097 $ 2,615 $ (3,652 ) $ (6,738 ) Noncontrolling interests — (1 ) 61 — 60 Net income (loss) $ (6,798 ) $ 1,098 $ 2,554 $ (3,652 ) $ (6,798 ) Comprehensive income Add: Other comprehensive income (loss) $ (2,791 ) $ (117 ) $ (5,969 ) $ 6,086 $ (2,791 ) Total Citigroup comprehensive income (loss) $ (9,589 ) $ 981 $ (3,415 ) $ 2,434 $ (9,589 ) Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ 114 $ — $ 114 Add: Net income attributable to noncontrolling interests — (1 ) 61 — 60 Total comprehensive income (loss) $ (9,589 ) $ 980 $ (3,240 ) $ 2,434 $ (9,415 ) Condensed Consolidating Statements of Income and Comprehensive Income Year ended December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 15,570 $ — $ — $ (15,570 ) $ — Interest revenue 7 4,586 53,022 — 57,615 Interest revenue—intercompany 3,008 545 (3,553 ) — — Interest expense 4,419 1,418 6,674 — 12,511 Interest expense—intercompany 209 1,659 (1,868 ) — — Net interest revenue $ (1,613 ) $ 2,054 $ 44,663 $ — $ 45,104 Commissions and fees $ — $ 4,340 $ 7,598 $ — $ 11,938 Commissions and fees—intercompany (20 ) 246 (226 ) — — Principal transactions (1,025 ) 5,576 3,034 — 7,585 Principal transactions—intercompany 24 (2,842 ) 2,818 — — Other income 2,599 183 2,466 — 5,248 Other income—intercompany (2,095 ) 305 1,790 — — Total non-interest revenues $ (517 ) $ 7,808 $ 17,480 $ — $ 24,771 Total revenues, net of interest expense $ 13,440 $ 9,862 $ 62,143 $ (15,570 ) $ 69,875 Provisions for credit losses and for benefits and claims $ — $ — $ 6,982 $ — $ 6,982 Operating expenses Compensation and benefits $ 22 $ 4,719 $ 16,229 $ — $ 20,970 Compensation and benefits—intercompany 36 — (36 ) — — Other operating 482 1,634 18,330 — 20,446 Other operating—intercompany 217 1,333 (1,550 ) — — Total operating expenses $ 757 $ 7,686 $ 32,973 $ — $ 41,416 Equity in undistributed income of subsidiaries $ 871 $ — $ — $ (871 ) $ — Income (loss) from continuing operations before income taxes $ 13,554 $ 2,176 $ 22,188 $ (16,441 ) $ 21,477 Provision (benefit) for income taxes $ (1,358 ) $ 746 $ 7,056 $ — $ 6,444 Income (loss) from continuing operations $ 14,912 $ 1,430 $ 15,132 $ (16,441 ) $ 15,033 Loss from discontinued operations, net of taxes — — (58 ) — (58 ) Net income (loss) before attribution of noncontrolling interests $ 14,912 $ 1,430 $ 15,074 $ (16,441 ) $ 14,975 Noncontrolling interests — (13 ) 76 — 63 Net income (loss) $ 14,912 $ 1,443 $ 14,998 $ (16,441 ) $ 14,912 Comprehensive income Add: Other comprehensive income (loss) $ (3,022 ) $ (26 ) $ 2,364 $ (2,338 ) $ (3,022 ) Total Citigroup comprehensive income (loss) $ 11,890 $ 1,417 $ 17,362 $ (18,779 ) $ 11,890 Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ (56 ) $ — $ (56 ) Add: Net income attributable to noncontrolling interests — (13 ) 76 — 63 Total comprehensive income (loss) $ 11,890 $ 1,404 $ 17,382 $ (18,779 ) $ 11,897 Condensed Consolidating Statements of Income and Comprehensive Income Year ended December 31, 2015 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 13,500 $ — $ — $ (13,500 ) $ — Interest revenue 9 4,389 54,153 — 58,551 Interest revenue—intercompany 2,880 272 (3,152 ) — — Interest expense 4,563 988 6,370 — 11,921 Interest expense—intercompany (475 ) 1,304 (829 ) — — Net interest revenue $ (1,199 ) $ 2,369 $ 45,460 $ — $ 46,630 Commissions and fees $ — $ 4,872 $ 9,613 $ — $ 14,485 Commissions and fees—intercompany — 210 (210 ) — — Principal transactions 1,012 5,532 (536 ) — 6,008 Principal transactions—intercompany (1,733 ) (3,875 ) 5,608 — — Other income 3,294 403 5,534 — 9,231 Other income—intercompany (3,054 ) 1,088 1,966 — — Total non-interest revenues $ (481 ) $ 8,230 $ 21,975 $ — $ 29,724 Total revenues, net of interest expense $ 11,820 $ 10,599 $ 67,435 $ (13,500 ) $ 76,354 Provisions for credit losses and for benefits and claims $ — $ — $ 7,913 $ — $ 7,913 Operating expenses Compensation and benefits $ (58 ) $ 5,003 $ 16,824 $ — $ 21,769 Compensation and benefits—intercompany 59 — (59 ) — — Other operating 271 1,940 19,635 — 21,846 Other operating—intercompany 247 1,173 (1,420 ) — — Total operating expenses $ 519 $ 8,116 $ 34,980 $ — $ 43,615 Equity in undistributed income of subsidiaries $ 4,601 $ — $ — $ (4,601 ) $ — Income (loss) from continuing operations before income taxes $ 15,902 $ 2,483 $ 24,542 $ (18,101 ) $ 24,826 Provision (benefit) for income taxes $ (1,340 ) $ 537 $ 8,243 $ — $ 7,440 Income (loss) from continuing operations $ 17,242 $ 1,946 $ 16,299 $ (18,101 ) $ 17,386 Loss from discontinued operations, net of taxes — — (54 ) — (54 ) Net income (loss) before attribution of noncontrolling interests $ 17,242 $ 1,946 $ 16,245 $ (18,101 ) $ 17,332 Noncontrolling interests — 9 81 — 90 Net income (loss) $ 17,242 $ 1,937 $ 16,164 $ (18,101 ) $ 17,242 Comprehensive income Add: Other comprehensive income (loss) $ (6,128 ) $ (125 ) $ 1,017 $ (892 ) $ (6,128 ) Total Citigroup comprehensive income (loss) $ 11,114 $ 1,812 $ 17,181 $ (18,993 ) $ 11,114 Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ (83 ) $ — $ (83 ) Add: Net income attributable to noncontrolling interests — 9 81 — 90 Total comprehensive income (loss) $ 11,114 $ 1,821 $ 17,179 $ (18,993 ) $ 11,121 Condensed Consolidating Balance Sheet December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ — $ 378 $ 23,397 $ — $ 23,775 Cash and due from banks—intercompany 13 3,750 (3,763 ) — — Federal funds sold and resale agreements — 182,685 49,793 — 232,478 Federal funds sold and resale agreements—intercompany — 16,091 (16,091 ) — — Trading account assets — 139,462 112,094 — 251,556 Trading account assets—intercompany 38 2,711 (2,749 ) — — Investments 27 181 352,082 — 352,290 Loans, net of unearned income — 900 666,134 — 667,034 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,355 ) — (12,355 ) Total loans, net $ — $ 900 $ 653,779 $ — $ 654,679 Advances to subsidiaries $ 139,722 $ — $ (139,722 ) $ — $ — Investments in subsidiaries 210,537 — — (210,537 ) — Other assets (1) 10,844 61,647 255,196 — 327,687 Other assets—intercompany 14,428 48,832 (63,260 ) — — Total assets $ 375,609 $ 456,637 $ 1,220,756 $ (210,537 ) $ 1,842,465 Liabilities and equity Deposits $ — $ — $ 959,822 $ — $ 959,822 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 134,888 21,389 — 156,277 Federal funds purchased and securities loaned or sold—intercompany — 18,597 (18,597 ) — — Trading account liabilities — 80,801 43,246 — 124,047 Trading account liabilities—intercompany 15 2,182 (2,197 ) — — Short-term borrowings 251 3,568 40,633 — 44,452 Short-term borrowings—intercompany — 32,871 (32,871 ) — — Long-term debt 152,163 18,048 66,498 — 236,709 Long-term debt—intercompany — 60,765 (60,765 ) — — Advances from subsidiaries 19,136 — (19,136 ) — — Other liabilities 2,673 62,113 54,700 — 119,486 Other liabilities—intercompany 631 9,753 (10,384 ) — — Stockholders’ equity 200,740 33,051 178,418 (210,537 ) 201,672 Total liabilities and equity $ 375,609 $ 456,637 $ 1,220,756 $ (210,537 ) $ 1,842,465 (1) Other assets for Citigroup parent company at December 31, 2017 included $ 29.7 billion of placements to Citibank and its branches, of which $ 18.9 billion had a remaining term of less than 30 days. Condensed Consolidating Balance Sheet December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ — $ 870 $ 22,173 $ — $ 23,043 Cash and due from banks—intercompany 142 3,820 (3,962 ) — — Federal funds sold and resale agreements — 196,236 40,577 — 236,813 Federal funds sold and resale agreements—intercompany — 12,270 (12,270 ) — — Trading account assets 6 121,484 122,435 — 243,925 Trading account assets—intercompany 1,173 907 (2,080 ) — — Investments 173 335 352,796 — 353,304 Loans, net of unearned income — 575 623,794 — 624,369 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,060 ) — (12,060 ) Total loans, net $ — $ 575 $ 611,734 $ — $ 612,309 Advances to subsidiaries $ 143,154 $ — $ (143,154 ) $ — $ — Investments in subsidiaries 226,279 — — (226,279 ) — Other assets (1) 23,734 46,095 252,854 — 322,683 Other assets—intercompany 27,845 38,207 (66,052 ) — — Total assets $ 422,506 $ 420,799 $ 1,175,051 $ (226,279 ) $ 1,792,077 Liabilities and equity Deposits $ — $ — $ 929,406 $ — $ 929,406 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 122,320 19,501 — 141,821 Federal funds purchased and securities loaned or sold—intercompany — 25,417 (25,417 ) — — Trading account liabilities — 87,714 51,331 — 139,045 Trading account liabilities—intercompany 1,006 868 (1,874 ) — — Short-term borrowings — 1,356 29,345 — 30,701 Short-term borrowings—intercompany — 35,596 (35,596 ) — — Long-term debt 147,333 8,128 50,717 — 206,178 Long-term debt—intercompany — 41,287 (41,287 ) — — Advances from subsidiaries 41,258 — (41,258 ) — — Other liabilities 3,466 57,430 57,887 — 118,783 Other liabilities—intercompany 4,323 7,894 (12,217 ) — — Stockholders’ equity 225,120 32,789 194,513 (226,279 ) 226,143 Total liabilities and equity $ 422,506 $ 420,799 $ 1,175,051 $ (226,279 ) $ 1,792,077 (1) Other assets for Citigroup parent company at December 31, 2016 included $20.7 billion of placements to Citibank and its branches, of which $6.8 billion had a remaining term of less than 30 days. Condensed Consolidating Statement of Cash Flows Year ended December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by (used in) operating activities of continuing operations $ 34,940 $ (33,359 ) $ (10,168 ) $ — $ (8,587 ) Cash flows from investing activities of continuing operations Purchases of investments $ — $ (1 ) $ (185,739 ) $ — $ (185,740 ) Proceeds from sales of investments 132 — 107,236 — 107,368 Proceeds from maturities of investments — — 84,369 — 84,369 Change in deposits with banks — 11,861 (31,151 ) — (19,290 ) Change in loans — — (58,062 ) — (58,062 ) Proceeds from sales and securitizations of loans — — 8,365 — 8,365 Proceeds from significant disposals — — 3,411 — 3,411 Change in federal funds sold and resales — 9,730 (5,395 ) — 4,335 Changes in investments and advances—intercompany (899 ) (2,790 ) 3,689 — — Other investing activities — (24 ) (2,960 ) — (2,984 ) Net cash provided by (used in) investing activities of continuing operations $ (767 ) $ 18,776 $ (76,237 ) $ — $ (58,228 ) Cash flows from financing activities of continuing operations Dividends paid $ (3,797 ) $ — $ — $ — $ (3,797 ) Treasury stock acquired (14,541 ) — — — (14,541 ) Proceeds (repayments) from issuance of long-term debt, net 6,544 4,909 15,521 — 26,974 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (2,031 ) 2,031 — — Change in deposits — — 30,416 — 30,416 Change in federal funds purchased and repos — 5,748 8,708 — 14,456 Change in short-term borrowings 49 2,212 11,490 — 13,751 Net change in short-term borrowings and other advances—intercompany (22,152 ) 3,931 18,221 — — Capital contributions from parent — (748 ) 748 — — Other financing activities (405 ) — — — (405 ) Net cash provided by (used in) financing activities of continuing operations $ (34,302 ) $ 14,021 $ 87,135 $ — $ 66,854 Effect of exchange rate changes on cash and due from banks $ — $ — $ 693 $ — $ 693 Change in cash and due from banks $ (129 ) $ (562 ) $ 1,423 $ — $ 732 Cash and due from banks at beginning of period 142 4,690 18,211 — 23,043 Cash and due from banks at end of period $ 13 $ 4,128 $ 19,634 $ — $ 23,775 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ (3,730 ) $ 678 $ 5,135 $ — $ 2,083 Cash paid during the year for interest 4,151 4,513 7,011 — 15,675 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 5,900 $ — $ 5,900 Transfers to OREO and other repossessed assets — — 113 — 113 Condensed Consolidating Statement of Cash Flows Year ended December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by operating activities of continuing operations $ 12,777 $ 20,662 $ 20,493 $ — $ 53,932 Cash flows from investing activities of continuing operations Purchases of investments $ — $ (4 ) $ (211,398 ) $ — $ (211,402 ) Proceeds from sales of investments 3,024 — 129,159 — 132,183 Proceeds from maturities of investments 234 — 65,291 — 65,525 Change in deposits with banks — (3,643 ) (21,668 ) — (25,311 ) Change in loans — — (39,761 ) — (39,761 ) Proceeds from sales and securitizations of loans — — 18,140 — 18,140 Proceeds from significant disposals — — 265 — 265 Change in federal funds sold and resales — (15,293 ) (1,845 ) — (17,138 ) Changes in investments and advances—intercompany (18,083 ) (5,574 ) 23,657 — — Other investing activities — — (2,089 ) — (2,089 ) Net cash used in investing activities of continuing operations $ (14,825 ) $ (24,514 ) $ (40,249 ) $ — $ (79,588 ) Cash flows from financing activities of continuing operations Dividends paid $ (2,287 ) $ — $ — $ — $ (2,287 ) Issuance of preferred stock 2,498 — — — 2,498 Treasury stock acquired (9,290 ) — — — (9,290 ) Proceeds (repayments) from issuance of long-term debt, net 7,005 5,916 (4,575 ) — 8,346 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (9,453 ) 9,453 — — Change in deposits — — 24,394 — 24,394 Change in federal funds purchased and repos — 3,236 (7,911 ) — (4,675 ) Change in short-term borrowings (164 ) 1,168 8,618 — 9,622 Net change in short-term borrowings and other advances—intercompany 4,620 680 (5,300 ) — — Capital contributions from parent — 5,000 (5,000 ) — — Other financing activities (316 ) — — — (316 ) Net cash provided by financing activities of continuing operations $ 2,066 $ 6,547 $ 19,679 $ — $ 28,292 Effect of exchange rate changes on cash and due from banks $ — $ — $ (493 ) $ — $ (493 ) Change in cash and due from banks $ 18 $ 2,695 $ (570 ) $ — $ 2,143 Cash and due from banks at beginning of period 124 1,995 18,781 — 20,900 Cash and due from banks at end of period $ 142 $ 4,690 $ 18,211 $ — $ 23,043 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ 351 $ 92 $ 3,916 $ — $ 4,359 Cash paid during the year for interest 4,397 3,115 4,555 — 12,067 Non-cash investing activities Transfers to loans held-for-sale from loans $ — $ — $ 13,900 $ — $ 13,900 Transfers to OREO and other repossessed assets — — 165 — 165 Condensed Consolidating Statements of Cash Flows Year ended December 31, 2015 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by (used in) operating activities of continuing operations $ 27,825 $ 12,336 $ (424 ) $ — $ 39,737 Cash flows from investing activities of continuing operations Purchases of investments $ — $ (4 ) $ (242,358 ) $ — $ (242,362 ) Proceeds from sales of investments — 53 141,417 — 141,470 Proceeds from maturities of investments 237 — 81,810 — 82,047 Change in deposits with banks — (8,414 ) 23,902 — 15,488 Change in loans — — 1,353 — 1,353 Proceeds from sales and securitizations of loans — — 9,610 — 9,610 Change in federal funds sold and resales — 8,037 14,858 — 22,895 Proceeds from significant disposals — — 5,932 — 5,932 Payments due to transfers of net liabilities associated with significant disposals — — (18,929 ) — (18,929 ) Changes in investments and advances—intercompany (35,548 ) 1,044 34,504 — — Other investing activities 3 (101 ) (2,523 ) — (2,621 ) Net cash provided by (used in) investing activities of continuing operations $ (35,308 ) $ 615 $ 49,576 $ — $ 14,883 Cash flows from financing activities of continuing operations Dividends paid $ (1,253 ) $ — $ — $ — $ (1,253 ) Issuance of preferred stock 6,227 — — — 6,227 Treasury stock acquired (5,452 ) — — — (5,452 ) Proceeds (repayments) from issuance of long-term debt, net 127 (139 ) (8,212 ) — (8,224 ) Proceeds (repayments) from issuance of long-term debt—intercompany, net — 12,557 (12,557 ) — — Change in deposits — — 8,555 — 8,555 Change in federal funds purchased and repos — (27,442 ) 500 — (26,942 ) Change in short-term borrowings (845 ) (1,737 ) (34,674 ) — (37,256 ) Net change in short-term borrowings and other advances—intercompany 9,106 4,054 (13,160 ) — — Other financing activities (428 ) — — — (428 ) Net cash provided by (used in) financing activities of continuing operations $ 7,482 $ (12,707 ) $ (59,548 ) $ — $ (64,773 ) Effect of exchange rate changes on cash and due from banks $ — $ — $ (1,055 ) $ — $ (1,055 ) Change in cash and due from banks $ (1 ) $ 244 $ (11,451 ) $ — $ (11,208 ) Cash and due from banks at beginning of period 125 1,751 30,232 — 32,108 Cash and due from banks at end of period $ 124 $ 1,995 $ 18,781 $ — $ 20,900 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ 111 $ 175 $ 4,692 $ — $ 4,978 Cash paid during the year for interest 4,916 2,346 4,769 — 12,031 Non-cash investing activities Decrease in net loans associated with significant disposals reclassified to HFS $ — $ — $ (9,063 ) $ — $ (9,063 ) Decrease in investments associated with significant disposals reclassified to HFS — — (1,402 ) — (1,402 ) Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS — — (223 ) — (223 ) Decrease in deposits with banks with significant disposals reclassified to HFS — — (404 ) — (404 ) Transfers to loans held-for-sale from loans — — 28,600 — 28,600 Transfers to OREO and other repossessed assets — — 276 — 276 Non-cash financing activities Decrease in long-term debt associated with significant disposals reclassified to HFS $ — $ — $ (4,673 ) $ — $ (4,673 )

SELECTED QUARTERLY FINANCIAL DA

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) 2017 2016 In millions of dollars, except per share amounts Fourth (1) Third Second First Fourth Third Second First Revenues, net of interest expense $ 17,255 $ 18,173 $ 17,901 $ 18,120 $ 17,012 $ 17,760 $ 17,548 $ 17,555 Operating expenses 10,083 10,171 10,506 10,477 10,120 10,404 10,369 10,523 Provisions for credit losses and for benefits and claims 2,073 1,999 1,717 1,662 1,792 1,736 1,409 2,045 Income from continuing operations before income taxes $ 5,099 $ 6,003 $ 5,678 $ 5,981 $ 5,100 $ 5,620 $ 5,770 $ 4,987 Income taxes 23,864 1,866 1,795 1,863 1,509 1,733 1,723 1,479 Income (loss) from continuing operations $ (18,765 ) $ 4,137 $ 3,883 $ 4,118 $ 3,591 $ 3,887 $ 4,047 $ 3,508 Income (loss) from discontinued operations, net of taxes (109 ) (5 ) 21 (18 ) (3 ) (30 ) (23 ) (2 ) Net income before attribution of noncontrolling interests $ (18,874 ) $ 4,132 $ 3,904 $ 4,100 $ 3,588 $ 3,857 $ 4,024 $ 3,506 Noncontrolling interests 19 (1 ) 32 10 15 17 26 5 Citigroup’s net income (loss) $ (18,893 ) $ 4,133 $ 3,872 $ 4,090 $ 3,573 $ 3,840 $ 3,998 $ 3,501 Earnings per share (2) Basic Income (loss) from continuing operations $ (7.33 ) $ 1.42 $ 1.27 $ 1.36 $ 1.14 $ 1.25 $ 1.25 $ 1.11 Net income (loss) (7.38 ) 1.42 1.28 1.35 1.14 1.24 1.24 1.10 Diluted Income (loss) from continuing operations (7.33 ) 1.42 1.27 1.36 1.14 1.25 1.25 1.11 Net income (loss) (7.38 ) 1.42 1.28 1.35 1.14 1.24 1.24 1.10 Common stock price per share High close during the quarter 77.10 72.74 66.98 61.54 61.09 47.90 47.33 51.13 Low close during the quarter 71.33 65.95 57.72 55.68 47.03 40.78 38.48 34.98 Quarter end 74.41 72.74 66.88 59.82 59.43 47.23 42.39 41.75 Dividends per share of common stock 0.32 0.32 0.16 0.16 0.16 0.16 0.05 0.05 This Note to the Consolidated Financial Statements is unaudited due to the Company’s individual quarterly results not being subject to an audit. (1) The fourth quarter of 2017 includes the impact of Tax Reform. See Notes 1 and 9 to the Consolidated Financial Statements. (2) Due to averaging of shares, quarterly earnings per share may not sum to the totals reported for the full year.

SUMMARY OF SIGNIFICANT ACCOUN39

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements include the accounts of Citigroup and its subsidiaries prepared in accordance with U.S. generally accepted accounting principles (GAAP). The Company consolidates subsidiaries in which it holds, directly or indirectly, more than 50% of the voting rights or where it exercises control. Entities where the Company holds 20% to 50% of the voting rights and/or has the ability to exercise significant influence, other than investments of designated venture capital subsidiaries or investments accounted for at fair value under the fair value option, are accounted for under the equity method, and the pro rata share of their income (loss) is included in Other revenue . Income from investments in less-than- 20% -owned companies is recognized when dividends are received. As discussed in more detail in Note 21 to the Consolidated Financial Statements, Citigroup also consolidates entities deemed to be variable interest entities when Citigroup is determined to be the primary beneficiary. Gains and losses on the disposition of branches, subsidiaries, affiliates, buildings and other investments are included in Other revenue . Citibank Citibank, N.A. (Citibank) is a commercial bank and wholly owned subsidiary of Citigroup. Citibank’s principal offerings include consumer finance, mortgage lending and retail banking (including commercial banking) products and services; investment banking, cash management and trade finance; and private banking products and services.
Variable Interest Entities	Variable Interest Entities An entity is a variable interest entity (VIE) if it meets either of the criteria outlined in Accounting Standards Codification (ASC) Topic 810, Consolidation , which are (i) the entity has equity that is insufficient to permit the entity to finance its activities without additional subordinated financial support from other parties, or (ii) the entity has equity investors that cannot make significant decisions about the entity’s operations or that do not absorb their proportionate share of the entity’s expected losses or expected returns. The Company consolidates a VIE when it has both the power to direct the activities that most significantly impact the VIE’s economic performance and a right to receive benefits or the obligation to absorb losses of the entity that could be potentially significant to the VIE (that is, Citi is the primary beneficiary). In addition to variable interests held in consolidated VIEs, the Company has variable interests in other VIEs that are not consolidated because the Company is not the primary beneficiary. All unconsolidated VIEs are monitored by the Company to assess whether any events have occurred to cause its primary beneficiary status to change. All entities not deemed to be VIEs with which the Company has involvement are evaluated for consolidation under other subtopics of ASC 810.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of Citi’s foreign operations are translated from their respective functional currencies into U.S. dollars using period-end spot foreign exchange rates. The effects of those translation adjustments are reported in Accumulated other comprehensive income (loss) , a component of stockholders’ equity, net of any related hedge and tax effects, until realized upon sale or substantial liquidation of the foreign operation. Revenues and expenses of Citi’s foreign operations are translated monthly from their respective functional currencies into U.S. dollars at amounts that approximate weighted average exchange rates. For transactions that are denominated in a currency other than the functional currency, including transactions denominated in the local currencies of foreign operations that use the U.S. dollar as their functional currency, the effects of changes in exchange rates are primarily included in Principal transactions , along with the related effects of any economic hedges. Instruments used to hedge foreign currency exposures include foreign currency forward, option and swap contracts and, in certain instances, designated issues of non-U.S. dollar debt. Foreign operations in countries with highly inflationary economies designate the U.S. dollar as their functional currency, with the effects of changes in exchange rates primarily included in Other revenue .
Investment Securities	Investment Securities Investments include fixed income and equity securities. Fixed income instruments include bonds, notes and redeemable preferred stocks, as well as certain loan-backed and structured securities that are subject to prepayment risk. Equity securities include common and nonredeemable preferred stock. Investment securities are classified and accounted for as follows: • Fixed income securities classified as “held-to-maturity” are securities that the Company has both the ability and the intent to hold until maturity and are carried at amortized cost. Interest income on such securities is included in Interest revenue . • Fixed income securities and marketable equity securities classified as “available-for-sale” are carried at fair value with changes in fair value reported in Accumulated other comprehensive income (loss) , a component of stockholders’ equity, net of applicable income taxes and hedges. Realized gains and losses on sales are included in income primarily on a specific identification cost basis. Interest and dividend income on such securities is included in Interest revenue . • Certain investments in non-marketable equity securities and certain investments that would otherwise have been accounted for using the equity method are carried at fair value, since the Company has elected to apply fair value accounting. Changes in fair value of such investments are recorded in earnings. • Certain non-marketable equity securities are carried at cost. For investments in fixed income securities classified as held-to-maturity or available-for-sale, the accrual of interest income is suspended for investments that are in default or for which it is likely that future interest payments will not be made as scheduled. Investment securities are subject to evaluation for other-than-temporary impairment as described in Note 13 to the Consolidated Financial Statements. The Company uses a number of valuation techniques for investments carried at fair value, which are described in Note 24 to the Consolidated Financial Statements. Realized gains and losses on sales of investments are included in earnings.
Trading Account Assets and Liabilities	Trading Account Assets and Liabilities Trading account assets include debt and marketable equity securities, derivatives in a receivable position, residual interests in securitizations and physical commodities inventory. In addition, as described in Note 25 to the Consolidated Financial Statements, certain assets that Citigroup has elected to carry at fair value under the fair value option, such as loans and purchased guarantees, are also included in Trading account assets . Trading account liabilities include securities sold, not yet purchased (short positions) and derivatives in a net payable position, as well as certain liabilities that Citigroup has elected to carry at fair value (as described in Note 25 to the Consolidated Financial Statements). Other than physical commodities inventory, all trading account assets and liabilities are carried at fair value. Revenues generated from trading assets and trading liabilities are generally reported in Principal transactions and include realized gains and losses as well as unrealized gains and losses resulting from changes in the fair value of such instruments. Interest income on trading assets is recorded in Interest revenue reduced by interest expense on trading liabilities. Physical commodities inventory is carried at the lower of cost or market with related losses reported in Principal transactions . Realized gains and losses on sales of commodities inventory are included in Principal transactions . Investments in unallocated precious metals accounts (gold, silver, platinum and palladium) are accounted for as hybrid instruments containing a debt host contract and an embedded non-financial derivative instrument indexed to the price of the relevant precious metal. The embedded derivative instrument is separated from the debt host contract and accounted for at fair value. The debt host contract is carried at fair value under the fair value option, as described in Note 25 to the Consolidated Financial Statements. Derivatives used for trading purposes include interest rate, currency, equity, credit and commodity swap agreements, options, caps and floors, warrants, and financial and commodity futures and forward contracts. Derivative asset and liability positions are presented net by counterparty on the Consolidated Balance Sheet when a valid master netting agreement exists and the other conditions set out in ASC Topic 210-20, Balance Sheet—Offsetting , are met. See Note 22 to the Consolidated Financial Statements. The Company uses a number of techniques to determine the fair value of trading assets and liabilities, which are described in Note 24 to the Consolidated Financial Statements.
Securities Borrowed and Securities Loaned	Securities Borrowed and Securities Loaned Securities borrowing and lending transactions do not constitute a sale of the underlying securities for accounting purposes and are treated as collateralized financing transactions. Such transactions are recorded at the amount of proceeds advanced or received plus accrued interest. As described in Note 25 to the Consolidated Financial Statements, the Company has elected to apply fair value accounting to a number of securities borrowing and lending transactions. Fees paid or received for all securities lending and borrowing transactions are recorded in Interest expense or Interest revenue at the contractually specified rate. The Company monitors the fair value of securities borrowed or loaned on a daily basis and obtains or posts additional collateral in order to maintain contractual margin protection. As described in Note 24 to the Consolidated Financial Statements, the Company uses a discounted cash flow technique to determine the fair value of securities lending and borrowing transactions.
Repurchase and Resale Agreements	Repurchase and Resale Agreements Securities sold under agreements to repurchase (repos) and securities purchased under agreements to resell (reverse repos) do not constitute a sale (or purchase) of the underlying securities for accounting purposes and are treated as collateralized financing transactions. As described in Note 25 to the Consolidated Financial Statements, the Company has elected to apply fair value accounting to the majority of such transactions, with changes in fair value reported in earnings. Any transactions for which fair value accounting has not been elected are recorded at the amount of cash advanced or received plus accrued interest. Irrespective of whether the Company has elected fair value accounting, interest paid or received on all repo and reverse repo transactions is recorded in Interest expense or Interest revenue at the contractually specified rate. Where the conditions of ASC 210-20-45-11, Balance Sheet—Offsetting: Repurchase and Reverse Repurchase Agreements , are met, repos and reverse repos are presented net on the Consolidated Balance Sheet. The Company’s policy is to take possession of securities purchased under reverse repurchase agreements. The Company monitors the fair value of securities subject to repurchase or resale on a daily basis and obtains or posts additional collateral in order to maintain contractual margin protection. As described in Note 24 to the Consolidated Financial Statements, the Company uses a discounted cash flow technique to determine the fair value of repo and reverse repo transactions.
Loans	Loans Loans are reported at their outstanding principal balances net of any unearned income and unamortized deferred fees and costs except that credit card receivable balances also include accrued interest and fees. Loan origination fees and certain direct origination costs are generally deferred and recognized as adjustments to income over the lives of the related loans. As described in Note 25 to the Consolidated Financial Statements, Citi has elected fair value accounting for certain loans. Such loans are carried at fair value with changes in fair value reported in earnings. Interest income on such loans is recorded in Interest revenue at the contractually specified rate. Loans that are held-for-investment are classified as Loans, net of unearned income on the Consolidated Balance Sheet, and the related cash flows are included within the cash flows from investing activities category in the Consolidated Statement of Cash Flows on the line Change in loans . However, when the initial intent for holding a loan has changed from held-for-investment to HFS, the loan is reclassified to held-for-sale, but the related cash flows continue to be reported in cash flows from investing activities in the Consolidated Statement of Cash Flows on the line Proceeds from sales and securitizations of loans . Consumer Loans Consumer loans represent loans and leases managed primarily by the Global Consumer Banking (GCB) businesses and Corporate/Other . Consumer Non-accrual and Re-aging Policies As a general rule, interest accrual ceases for installment and real estate (both open- and closed-end) loans when payments are 90 days contractually past due. For credit cards and other unsecured revolving loans, however, Citi generally accrues interest until payments are 180 days past due. As a result of OCC guidance, home equity loans in regulated bank entities are classified as non-accrual if the related residential first mortgage is 90 days or more past due. Also as a result of OCC guidance, mortgage loans in regulated bank entities within 60 days of notification that the borrower has filed for bankruptcy, other than FHA-insured loans, are classified as non-accrual. Commercial market loans are placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due. Loans that have been modified to grant a concession to a borrower in financial difficulty may not be accruing interest at the time of the modification. The policy for returning such modified loans to accrual status varies by product and/or region. In most cases, a minimum number of payments (ranging from one to six ) is required, while in other cases the loan is never returned to accrual status. For regulated bank entities, such modified loans are returned to accrual status if a credit evaluation at the time of, or subsequent to, the modification indicates the borrower is able to meet the restructured terms, and the borrower is current and has demonstrated a reasonable period of sustained payment performance (minimum six months of consecutive payments). For U.S. consumer loans, generally one of the conditions to qualify for modification is that a minimum number of payments (typically ranging from one to three ) must be made. Upon modification, the loan is re-aged to current status. However, re-aging practices for certain open-ended consumer loans, such as credit cards, are governed by Federal Financial Institutions Examination Council (FFIEC) guidelines. For open-ended consumer loans subject to FFIEC guidelines, one of the conditions for the loan to be re-aged to current status is that at least three consecutive minimum monthly payments, or the equivalent amount, must be received. In addition, under FFIEC guidelines, the number of times that such a loan can be re-aged is subject to limitations (generally once in 12 months and twice in five years). Furthermore, Federal Housing Administration (FHA) and Department of Veterans Affairs (VA) loans may only be modified under those respective agencies’ guidelines, and payments are not always required in order to re-age a modified loan to current. Consumer Charge-Off Policies Citi’s charge-off policies follow the general guidelines below: • Unsecured installment loans are charged off at 120 days contractually past due. • Unsecured revolving loans and credit card loans are charged off at 180 days contractually past due. • Loans secured with non-real estate collateral are written down to the estimated value of the collateral, less costs to sell, at 120 days contractually past due. • Real estate-secured loans are written down to the estimated value of the property, less costs to sell, at 180 days contractually past due. • Real estate-secured loans are charged off no later than 180 days contractually past due if a decision has been made not to foreclose on the loans. • Unsecured loans in bankruptcy are charged off within 60 days of notification of filing by the bankruptcy court or in accordance with Citi’s charge-off policy, whichever occurs earlier. • Real estate-secured loans in bankruptcy, other than FHA-insured loans, are written down to the estimated value of the property, less costs to sell, within 60 days of notification that the borrower has filed for bankruptcy or in accordance with Citi’s charge-off policy, whichever is earlier. • Commercial market loans are written down to the extent that principal is judged to be uncollectable. Corporate Loans Corporate loans represent loans and leases managed by Institutional Clients Group (ICG) . Corporate loans are identified as impaired and placed on a cash (non-accrual) basis when it is determined, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful or when interest or principal is 90 days past due, except when the loan is well collateralized and in the process of collection. Any interest accrued on impaired corporate loans and leases is reversed at 90 days past due and charged against current earnings, and interest is thereafter included in earnings only to the extent actually received in cash. When there is doubt regarding the ultimate collectability of principal, all cash receipts are thereafter applied to reduce the recorded investment in the loan. Impaired corporate loans and leases are written down to the extent that principal is deemed to be uncollectable. Impaired collateral-dependent loans and leases, where repayment is expected to be provided solely by the sale of the underlying collateral and there are no other available and reliable sources of repayment, are written down to the lower of cost or collateral value. Cash-basis loans are returned to accrual status when all contractual principal and interest amounts are reasonably assured of repayment and there is a sustained period of repayment performance in accordance with the contractual terms.
Loans Held-for-Sale	Loans Held-for-Sale Corporate and consumer loans that have been identified for sale are classified as loans held-for-sale and included in Other assets . The practice of Citi’s U.S. prime mortgage business has been to sell substantially all of its conforming loans. As such, U.S. prime mortgage conforming loans are classified as held-for-sale and the fair value option is elected at origination, with changes in fair value recorded in Other revenue . With the exception of those loans for which the fair value option has been elected, held-for-sale loans are accounted for at the lower of cost or market value, with any write-downs or subsequent recoveries charged to Other revenue . The related cash flows are classified in the Consolidated Statement of Cash Flows in the cash flows from operating activities category on the line Change in loans held-for-sale .
Allowance for Loan Losses	Allowance for Loan Losses Allowance for loan losses represents management’s best estimate of probable losses inherent in the portfolio, including probable losses related to large individually evaluated impaired loans and troubled debt restructurings. Attribution of the allowance is made for analytical purposes only, and the entire allowance is available to absorb probable loan losses inherent in the overall portfolio. Additions to the allowance are made through the Provision for loan losses . Loan losses are deducted from the allowance and subsequent recoveries are added. Assets received in exchange for loan claims in a restructuring are initially recorded at fair value, with any gain or loss reflected as a recovery or charge-off to the provision. Consumer Loans For consumer loans, each portfolio of non-modified smaller-balance homogeneous loans is independently evaluated for impairment by product type (e.g., residential mortgage, credit card, etc.) in accordance with ASC 450, Contingencies . The allowance for loan losses attributed to these loans is established via a process that estimates the probable losses inherent in the specific portfolio. This process includes migration analysis, in which historical delinquency and credit loss experience is applied to the current aging of the portfolio, together with analyses that reflect current and anticipated economic conditions, including changes in housing prices and unemployment trends. Citi’s allowance for loan losses under ASC 450 only considers contractual principal amounts due, except for credit card loans, where estimated loss amounts related to accrued interest receivable are also included. Management also considers overall portfolio indicators, including historical credit losses, delinquent, non-performing and classified loans, trends in volumes and terms of loans, an evaluation of overall credit quality, the credit process, including lending policies and procedures, and economic, geographical, product and other environmental factors. Separate valuation allowances are determined for impaired smaller-balance homogeneous loans whose terms have been modified in a troubled debt restructuring (TDR). Long-term modification programs, and short-term (less than 12 months) modifications that provide concessions (such as interest rate reductions) to borrowers in financial difficulty, are reported as TDRs. In addition, loan modifications that involve a trial period are reported as TDRs at the start of the trial period. The allowance for loan losses for TDRs is determined in accordance with ASC 310-10-35, Receivables—Subsequent Measurement , considering all available evidence, including, as appropriate, the present value of the expected future cash flows discounted at the loan’s original contractual effective rate, the secondary market value of the loan and the fair value of collateral less disposal costs. These expected cash flows incorporate modification program default rate assumptions. The original contractual effective rate for credit card loans is the pre-modification rate, which may include interest rate increases under the original contractual agreement with the borrower. Valuation allowances for commercial market loans, which are classifiably managed consumer loans, are determined in the same manner as for corporate loans and are described in more detail in the following section. Generally, an asset-specific component is calculated under ASC 310-10-35 on an individual basis for larger-balance, non-homogeneous loans that are considered impaired, and the allowance for the remainder of the classifiably managed consumer loan portfolio is calculated under ASC 450 using a statistical methodology that may be supplemented by management adjustment. Corporate Loans In the corporate portfolios, the Allowance for loan losses includes an asset-specific component and a statistically based component. The asset-specific component is calculated under ASC 310-10-35 for larger-balance, non-homogeneous loans that are considered impaired. An asset-specific allowance is established when the discounted cash flows, collateral value (less disposal costs) or observable market price of the impaired loan are lower than its carrying value. This allowance considers the borrower’s overall financial condition, resources and payment record, the prospects for support from any financially responsible guarantors (discussed further below) and, if appropriate, the realizable value of any collateral. The asset-specific component of the allowance for smaller-balance impaired loans is calculated on a pool basis considering historical loss experience. The allowance for the remainder of the loan portfolio is determined under ASC 450 using a statistical methodology, supplemented by management judgment. The statistical analysis considers the portfolio’s size, remaining tenor and credit quality as measured by internal risk ratings assigned to individual credit facilities, which reflect probability of default and loss given default. The statistical analysis considers historical default rates and historical loss severity in the event of default, including historical average levels and historical variability. The result is an estimated range for inherent losses. The best estimate within the range is then determined by management’s quantitative and qualitative assessment of current conditions, including general economic conditions, specific industry and geographic trends and internal factors including portfolio concentrations, trends in internal credit quality indicators and current and past underwriting standards. For both the asset-specific and the statistically based components of the Allowance for loan losses , management may incorporate guarantor support. The financial wherewithal of the guarantor is evaluated, as applicable, based on net worth, cash flow statements and personal or company financial statements, which are updated and reviewed at least annually. Citi seeks performance on guarantee arrangements in the normal course of business. Seeking performance entails obtaining satisfactory cooperation from the guarantor or borrower in the specific situation. This regular cooperation is indicative of pursuit and successful enforcement of the guarantee; the exposure is reduced without the expense and burden of pursuing a legal remedy. A guarantor’s reputation and willingness to work with Citigroup is evaluated based on the historical experience with the guarantor and the knowledge of the marketplace. In the rare event that the guarantor is unwilling or unable to perform or facilitate borrower cooperation, Citi pursues a legal remedy; however, enforcing a guarantee via legal action against the guarantor is not the primary means of resolving a troubled loan situation and rarely occurs. If Citi does not pursue a legal remedy, it is because Citi does not believe that the guarantor has the financial wherewithal to perform regardless of legal action or because there are legal limitations on simultaneously pursuing guarantors and foreclosure. A guarantor’s reputation does not impact Citi’s decision or ability to seek performance under the guarantee. In cases where a guarantee is a factor in the assessment of loan losses, it is included via adjustment to the loan’s internal risk rating, which in turn is the basis for the adjustment to the statistically based component of the Allowance for loan losses . To date, it is only in rare circumstances that an impaired commercial loan or commercial real estate loan is carried at a value in excess of the appraised value due to a guarantee. When Citi’s monitoring of the loan indicates that the guarantor’s wherewithal to pay is uncertain or has deteriorated, there is either no change in the risk rating, because the guarantor’s credit support was never initially factored in, or the risk rating is adjusted to reflect that uncertainty or deterioration. Accordingly, a guarantor’s ultimate failure to perform or a lack of legal enforcement of the guarantee does not materially impact the allowance for loan losses, as there is typically no further significant adjustment of the loan’s risk rating at that time. Where Citi is not seeking performance under the guarantee contract, it provides for loan losses as if the loans were non-performing and not guaranteed. Reserve Estimates and Policies Management provides reserves for an estimate of probable losses inherent in the funded loan portfolio on the Consolidated Balance Sheet in the form of an allowance for loan losses. These reserves are established in accordance with Citigroup’s credit reserve policies, as approved by the Audit Committee of the Citigroup Board of Directors. Citi’s Chief Risk Officer and Chief Financial Officer review the adequacy of the credit loss reserves each quarter with representatives from the risk management and finance staffs for each applicable business area. Applicable business areas include those having classifiably managed portfolios, where internal credit-risk ratings are assigned (primarily ICG and GCB ) or modified consumer loans, where concessions were granted due to the borrowers’ financial difficulties. The above-mentioned representatives for these business areas present recommended reserve balances for their funded and unfunded lending portfolios along with supporting quantitative and qualitative data discussed below: Estimated probable losses for non-performing, non-homogeneous exposures within a business line’s classifiably managed portfolio and impaired smaller-balance homogeneous loans whose terms have been modified due to the borrowers’ financial difficulties, where it was determined that a concession was granted to the borrower. Consideration may be given to the following, as appropriate, when determining this estimate: (i) the present value of expected future cash flows discounted at the loan’s original effective rate, (ii) the borrower’s overall financial condition, resources and payment record and (iii) the prospects for support from financially responsible guarantors or the realizable value of any collateral. In the determination of the allowance for loan losses for TDRs, management considers a combination of historical re-default rates, the current economic environment and the nature of the modification program when forecasting expected cash flows. When impairment is measured based on the present value of expected future cash flows, the entire change in present value is recorded in Provision for loan losses . Statistically calculated losses inherent in the classifiably managed portfolio for performing and de minimis non-performing exposures. The calculation is based on (i) Citi’s internal system of credit-risk ratings, which are analogous to the risk ratings of the major rating agencies, and (ii) historical default and loss data, including rating agency information regarding default rates from 1983 to 2016 and internal data dating to the early 1970s on severity of losses in the event of default. Adjustments may be made to this data. Such adjustments include (i) statistically calculated estimates to cover the historical fluctuation of the default rates over the credit cycle, the historical variability of loss severity among defaulted loans and the degree to which there are large obligor concentrations in the global portfolio, and (ii) adjustments made for specific known items, such as current environmental factors and credit trends. In addition, representatives from each of the risk management and finance staffs that cover business areas with delinquency-managed portfolios containing smaller-balance homogeneous loans present their recommended reserve balances based on leading credit indicators, including loan delinquencies and changes in portfolio size as well as economic trends, including current and future housing prices, unemployment, length of time in foreclosure, costs to sell and GDP. This methodology is applied separately for each individual product within each geographic region in which these portfolios exist. This evaluation process is subject to numerous estimates and judgments. The frequency of default, risk ratings, loss recovery rates, the size and diversity of individual large credits and the ability of borrowers with foreign currency obligations to obtain the foreign currency necessary for orderly debt servicing, among other things, are all taken into account during this review. Changes in these estimates could have a direct impact on the credit costs in any period and could result in a change in the allowance. Allowance for Unfunded Lending Commitments A similar approach to the allowance for loan losses is used for calculating a reserve for the expected losses related to unfunded lending commitments and standby letters of credit. This reserve is classified on the balance sheet in Other liabilities . Changes to the allowance for unfunded lending commitments are recorded in Provision for unfunded lending commitments .
Mortgage Servicing Rights	Mortgage Servicing Rights Mortgage servicing rights (MSRs) are recognized as intangible assets when purchased or when the Company sells or securitizes loans acquired through purchase or origination and retains the right to service the loans. Mortgage servicing rights are accounted for at fair value, with changes in value recorded in Other revenue in the Company’s Consolidated Statement of Income.
Goodwill	Goodwill Goodwill represents the excess of acquisition cost over the fair value of net tangible and intangible assets acquired in a business combination. Goodwill is subject to annual impairment testing and between annual tests if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. Under ASC Topic 350, Intangibles—Goodwill and Other , the Company has an option to assess qualitative factors to determine if it is necessary to perform the goodwill impairment test. If, after assessing the totality of events or circumstances, the Company determines that it is not more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, no further testing is necessary. If, however, the Company determines that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, then the Company must perform the first step of the two-step goodwill impairment test. The Company has an unconditional option to bypass the qualitative assessment for any reporting unit in any reporting period and proceed directly to the first step of the goodwill impairment test. The first step requires a comparison of the fair value of the individual reporting unit to its carrying value, including goodwill. If the fair value of the reporting unit is in excess of the carrying value, the related goodwill is considered not impaired and no further analysis is necessary. If the carrying value of the reporting unit exceeds the fair value, this is an indication of potential impairment and the second step of testing is performed to measure the amount of impairment, if any, for that reporting unit. If required, the second step involves calculating the implied fair value of goodwill for each of the affected reporting units. The implied fair value of goodwill is determined in the same manner as the amount of goodwill recognized in a business combination, which is the excess of the fair value of the reporting unit determined in step one over the fair value of the net assets and identifiable intangibles as if the reporting unit were being acquired. If the amount of the goodwill allocated to the reporting unit exceeds the implied fair value of the goodwill in the pro forma purchase price allocation, an impairment charge is recorded for the excess. A recognized impairment charge cannot exceed the amount of goodwill allocated to a reporting unit and cannot subsequently be reversed even if the fair value of the reporting unit recovers. Upon any business disposition, goodwill is allocated to, and derecognized with the disposed business based on the ratio of the fair value of the disposed business to the fair value of the reporting unit.
Intangible Assets	Intangible Assets Intangible assets , including core deposit intangibles, present value of future profits, purchased credit card relationships, credit card contract related intangibles, other customer relationships and other intangible assets, but excluding MSRs, are amortized over their estimated useful lives. Intangible assets that are deemed to have indefinite useful lives, primarily trade names, are not amortized and are subject to annual impairment tests. An impairment exists if the carrying value of the indefinite-lived intangible asset exceeds its fair value. For other intangible assets subject to amortization, an impairment is recognized if the carrying amount is not recoverable and exceeds the fair value of the intangible asset.
Other Assets and Other Liabilities	Other Assets and Other Liabilities Other assets include, among other items, loans held-for-sale, deferred tax assets, equity method investments, interest and fees receivable, premises and equipment (including purchased and developed software), repossessed assets and other receivables. Other liabilities include, among other items, accrued expenses and other payables, deferred tax liabilities and reserves for legal claims, taxes, unfunded lending commitments, repositioning reserves and other matters.
Other Real Estate Owned and Repossessed Assets	Other Real Estate Owned and Repossessed Assets Real estate or other assets received through foreclosure or repossession are generally reported in Other assets , net of a valuation allowance for selling costs and subsequent declines in fair value.
Securitizations	Securitizations There are two key accounting determinations that must be made relating to securitizations. Citi first makes a determination as to whether the securitization entity must be consolidated. Second, it determines whether the transfer of financial assets to the entity is considered a sale under GAAP. If the securitization entity is a VIE, the Company consolidates the VIE if it is the primary beneficiary (as discussed in “Variable Interest Entities” above). For all other securitization entities determined not to be VIEs in which Citigroup participates, consolidation is based on which party has voting control of the entity, giving consideration to removal and liquidation rights in certain partnership structures. Only securitization entities controlled by Citigroup are consolidated. Interests in the securitized and sold assets may be retained in the form of subordinated or senior interest-only strips, subordinated tranches, spread accounts and servicing rights. In credit card securitizations, the Company retains a seller’s interest in the credit card receivables transferred to the trusts, which is not in securitized form. In the case of consolidated securitization entities, including the credit card trusts, these retained interests are not reported on Citi’s Consolidated Balance Sheet. The securitized loans remain on the balance sheet. Substantially all of the consumer loans sold or securitized through non-consolidated trusts by Citigroup are U.S. prime residential mortgage loans. Retained interests in non-consolidated mortgage securitization trusts are classified as Trading account assets , except for MSRs, which are included in Mortgage servicing rights on Citigroup’s Consolidated Balance Sheet.
Debt	Debt Short-term borrowings and Long-term debt are accounted for at amortized cost, except where the Company has elected to report the debt instruments, including certain structured notes at fair value, or the debt is in a fair value hedging relationship.
Transfers of Financial Assets	Transfers of Financial Assets For a transfer of financial assets to be considered a sale (i) the assets must be legally isolated from the Company, even in bankruptcy or other receivership, (ii) the purchaser must have the right to pledge or sell the assets transferred or, if the purchaser is an entity whose sole purpose is to engage in securitization and asset-backed financing activities through the issuance of beneficial interests and that entity is constrained from pledging the assets it receives, each beneficial interest holder must have the right to sell or pledge their beneficial interests and (iii) the Company may not have an option or obligation to reacquire the assets. If these sale requirements are met, the assets are removed from the Company’s Consolidated Balance Sheet. If the conditions for sale are not met, the transfer is considered to be a secured borrowing, the assets remain on the Consolidated Balance Sheet and the sale proceeds are recognized as the Company’s liability. A legal opinion on a sale generally is obtained for complex transactions or where the Company has continuing involvement with assets transferred or with the securitization entity. For a transfer to be eligible for sale accounting, those opinions must state that the asset transfer would be considered a sale and that the assets transferred would not be consolidated with the Company’s other assets in the event of the Company’s insolvency. For a transfer of a portion of a financial asset to be considered a sale, the portion transferred must meet the definition of a participating interest. A participating interest must represent a pro rata ownership in an entire financial asset; all cash flows must be divided proportionately, with the same priority of payment; no participating interest in the transferred asset may be subordinated to the interest of another participating interest holder; and no party may have the right to pledge or exchange the entire financial asset unless all participating interest holders agree. Otherwise, the transfer is accounted for as a secured borrowing.
Risk Management Activities-Derivatives Used for Hedging Purposes	Risk Management Activities—Derivatives Used for Hedging Purposes The Company manages its exposures to market movements outside of its trading activities by modifying the asset and liability mix, either directly or through the use of derivative financial products, including interest-rate swaps, futures, forwards and purchased options, as well as foreign-exchange contracts. These end-user derivatives are carried at fair value in Other assets , Other liabilities , Trading account assets and Trading account liabilities .
Employee Benefits Expense	Employee Benefits Expense Employee benefits expense includes current service costs of pension and other postretirement benefit plans (which are accrued on a current basis), contributions and unrestricted awards under other employee plans, the amortization of restricted stock awards and costs of other employee benefits. For its most significant pension and postretirement benefit plans (Significant Plans), Citigroup measures and discloses plan obligations, plan assets and periodic plan expense quarterly, instead of annually. The effect of remeasuring the Significant Plan obligations and assets by updating plan actuarial assumptions on a quarterly basis is reflected in Accumulated other comprehensive income (loss) and periodic plan expense. All other plans (All Other Plans) are remeasured annually.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation expense related to stock and option awards over the requisite service period, generally based on the instruments’ grant-date fair value, reduced by actual forfeitures as they occur. Compensation cost related to awards granted to employees who meet certain age plus years-of-service requirements (retirement-eligible employees) is accrued in the year prior to the grant date, in the same manner as the accrual for cash incentive compensation. Certain stock awards with performance conditions or certain clawback provisions are subject to variable accounting, pursuant to which the associated compensation expense fluctuates with changes in Citigroup’s common stock price.
Income Taxes	Income Taxes The Company is subject to the income tax laws of the U.S. and its states and municipalities, as well as the non-U.S. jurisdictions in which it operates. These tax laws are complex and may be subject to different interpretations by the taxpayer and the relevant governmental taxing authorities. In establishing a provision for income tax expense, the Company must make judgments and interpretations about these tax laws. The Company must also make estimates about when in the future certain items will affect taxable income in the various tax jurisdictions, both domestic and foreign. Disputes over interpretations of the tax laws may be subject to review and adjudication by the court systems of the various tax jurisdictions, or may be settled with the taxing authority upon examination or audit. The Company treats interest and penalties on income taxes as a component of Income tax expense . Deferred taxes are recorded for the future consequences of events that have been recognized in financial statements or tax returns, based upon enacted tax laws and rates. Deferred tax assets are recognized subject to management’s judgment about whether realization is more-likely-than-not. ASC 740, Income Taxes , sets out a consistent framework to determine the appropriate level of tax reserves to maintain for uncertain tax positions. This interpretation uses a two-step approach wherein a tax benefit is recognized if a position is more-likely-than-not to be sustained. The amount of the benefit is then measured to be the highest tax benefit that is more than 50% likely to be realized. ASC 740 also sets out disclosure requirements to enhance transparency of an entity’s tax reserves. On December 22, 2017, the SEC issued Staff Accounting Bulletin (SAB) 118, which sets forth the accounting for the changes in tax law caused by the enactment of the Tax Cuts and Jobs Act (Tax Reform). The Bulletin provides guidance as to how ASC 740 should be applied for the quarterly reporting period that includes the December 22, 2017 enactment date of Tax Reform. SAB 118 covers three different fact patterns that can be applied to each aspect of Tax Reform. The first is where the accounting is complete as of December 31, 2017; in this case, a company must report the effects of Tax Reform in its financial statements that include the enactment date. The second situation is where a company cannot complete its accounting as of December 31, 2017, but can provide a reasonable estimate based upon the information available to it and its ability to prepare and analyze this information (including related computations). In the situation described, the company must include the reasonable estimate it so determined in its financial statements as a provisional amount that will then be trued up within the one-year measurement period after the date of enactment of Tax Reform. The third situation, in which no reasonable estimate can be made for an item, requires a company to apply ASC 740 using the pre-Tax Reform tax law until the first reporting period in which it can make a reasonable estimate for the item. To the extent that a company records a provisional amount in its financial statements, it must update its reporting during the one-year measurement period whenever the facts and circumstances existing at the enactment date are further analyzed. Any company providing provisional amounts must qualitatively disclose the income tax effects for which the accounting is incomplete, the reason it is incomplete and the additional information that is needed to complete the accounting. In addition, when the company revises or finalizes its provisional accounting for any item, it must disclose the nature and amount of any measurement period adjustments recognized in the reporting period, the impact of such adjustments on its effective tax rate and a confirmation when the accounting for such items is complete. Citi recorded a charge to continuing operations of $22.6 billion in the fourth quarter of 2017, composed of a $12.4 billion remeasurement due to the reduction to the U.S. corporate tax rate and a change to a quasi-territorial tax system, a $7.9 billion valuation allowance against Citi’s FTC carry-forwards and its U.S. residual DTAs related to its non-U.S. branches, and a $2.3 billion reduction in Citi’s FTC carry-forwards related to the deemed repatriation of undistributed earnings of non-U.S. subsidiaries. Of the aforementioned amounts, the following are considered to be provisional for which certain aspects of Citi’s accounting is incomplete, as described below. First, of the $12.4 billion , $6.2 billion is provisional as Citi continues to analyze the aspects of the quasi-territorial tax regime, particularly as it affects the deferred taxes, including indefinite reinvestment assertions, for non-U.S. operations, as well as the interaction with U.S. tax rate reduction. Also included as provisional is Citi’s state income tax charge for Tax Reform due to the uncertainty of how states will interpret the new federal provisions. The remaining $6.2 billion primarily relates to the reduction in the U.S. corporate tax rate and for which the accounting is complete. Second, Citi’s reported valuation allowance of $7.9 billion is a provisional amount, because there is uncertainty under Tax Reform as to the calculation of the deemed repatriation tax on non-U.S. subsidiary earnings, which itself is a provisional amount, and thus the amount of FTC carry-forwards that will be utilized to offset the resulting tax. In addition, such valuation allowance is also affected by uncertainty as to the methodology to be employed to allocate Citi’s FTC carry-forwards and related overall domestic loss among the redefined FTC baskets under Tax Reform, as well as related calculations affecting the usage of its FTCs in future periods. Transitional guidance is expected from the U.S. Treasury on these issues. Citi also continues to analyze the effects on the amount of residual U.S. tax related to its non-U.S. branches. In all other material respects, Citi has completed its accounting for Tax Reform, and there are no amounts for which a reasonable estimate was not possible. Additionally, Citi has not yet made a policy election with respect to its treatment of GILTI. Companies can either account for taxes on GILTI as incurred, or recognize deferred taxes when basis differences exist that are expected to impact the amount of the GILTI inclusion upon reversal. Citi is still in the process of analyzing the provisions of Tax Reform associated with GILTI and the expected future impact.
Commissions, Underwriting and Principal Transactions	Commissions, Underwriting and Principal Transactions Commissions revenues are recognized in income when earned. Underwriting revenues are recognized in income typically at the closing of the transaction. Principal transactions revenues are recognized in income on a trade-date basis.
Earnings per Share	Earnings per Share Earnings per share (EPS) is computed after deducting preferred stock dividends. The Company has granted restricted and deferred share awards with dividend rights that are considered to be participating securities, which are akin to a second class of common stock. Accordingly, a portion of Citigroup’s earnings is allocated to those participating securities in the EPS calculation. Basic earnings per share is computed by dividing income available to common stockholders after the allocation of dividends and undistributed earnings to the participating securities by the weighted average number of common shares outstanding for the period. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised. It is computed after giving consideration to the weighted average dilutive effect of the Company’s stock options and warrants and convertible securities and after the allocation of earnings to the participating securities. Anti-dilutive options and warrants are disregarded in the EPS calculations.
Use of Estimates	Use of Estimates Management must make estimates and assumptions that affect the Consolidated Financial Statements and the related Notes to the Consolidated Financial Statements. Such estimates are used in connection with certain fair value measurements. See Note 24 to the Consolidated Financial Statements for further discussions on estimates used in the determination of fair value. Moreover, estimates are significant in determining the amounts of other-than-temporary impairments, impairments of goodwill and other intangible assets, provisions for probable losses that may arise from credit-related exposures and probable and estimable losses related to litigation and regulatory proceedings, and income taxes. While management makes its best judgment, actual amounts or results could differ from those estimates.
Cash Flows	Cash Flows Cash equivalents are defined as those amounts included in Cash and due from banks . Cash flows from risk management activities are classified in the same category as the related assets and liabilities.
Related Party Transactions	Related Party Transactions The Company has related party transactions with certain of its subsidiaries and affiliates. These transactions, which are primarily short-term in nature, include cash accounts, collateralized financing transactions, margin accounts, derivative transactions, charges for operational support and the borrowing and lending of funds, and are entered into in the ordinary course of business.
Accounting Changes	ACCOUNTING CHANGES Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income On February 14, 2018, the Financial Accounting Standards Board (FASB) issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . The ASU allows a reclassification from Accumulated other comprehensive income (loss) (AOCI) to Retained earnings for the deferred taxes previously recorded in AOCI that exceed the current federal tax rate of 21% resulting from the newly enacted corporate tax rate in the Tax Cuts and Jobs Act (Tax Reform) and other stranded tax amounts related to the application of Tax Reform that Citi elects to reclassify. The ASU allows adjustments to reclassification amounts in subsequent periods as a result of changes to the amounts recorded under SAB 118. If adopted, the ASU is effective in years beginning after December 15, 2018, but permits early adoption in a period for which financial statements have not yet been issued. Citi has elected to early adopt the ASU, which affects only the period that the effects related to Tax Reform are recognized. In addition to the reclassification of deferred taxes recorded in AOCI that exceed the current federal tax rate, Citi has also reclassified amounts recorded in AOCI related to the effects of the shift to a territorial system related to the application of Tax Reform using the portfolio method. The effect of adopting the ASU resulted in an increase of $3.3 billion to Retained earnings at December 31, 2017 due to the reclassification of AOCI to Retained earnings . This amount is provisional because more information needs to be obtained and analyzed related to Tax Reform as noted above and, thus, the amount to be reclassified may change in 2018. Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued ASU No. 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities , which amends the amortization period for certain purchased callable debt securities held at a premium. The ASU requires entities to amortize premiums on debt securities by the first call date when the securities have fixed and determinable call dates and prices. The scope of the ASU includes all accounting premiums, such as purchase premiums and cumulative fair value hedge adjustments. The ASU does not change the accounting for discounts, which continue to be recognized over the contractual life of a security. The ASU is effective as of January 1, 2019, but it may be early adopted in any interim or year-end period after issuance. Adoption of the ASU is on a modified retrospective basis through a cumulative effect adjustment to retained earnings as of the beginning of the year of adoption. Citi early adopted the ASU in the second quarter of 2017, with an effective date of January 1, 2017. Adoption of the ASU primarily affected Citi’s available-for-sale (AFS) and held-to-maturity (HTM) portfolios of callable state and municipal securities. The ASU adoption resulted in a net reduction to total stockholders’ equity of $156 million (after tax), effective as of January 1, 2017. This amount is composed of a reduction of approximately $660 million to retained earnings for the incremental amortization of purchase premiums and cumulative hedge adjustments generated under fair value hedges of these callable debt securities, offset by an increase to AOCI of $504 million related to the cumulative fair value hedge adjustments reclassified to retained earnings for AFS securities. Financial statements for periods prior to 2017 were not subject to restatement under the provisions of this ASU. The amortization recorded in each of quarter of 2017 and cumulatively as of each quarter end under the provisions of the ASU was not materially different than the amount that would have been recorded if the ASU had not been early adopted. Accounting for Stock-Based Compensation In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting in order to simplify certain complex aspects of the accounting for income taxes and forfeitures related to employee stock-based compensation. The guidance became effective for Citi beginning on January 1, 2017. Under the new standard, excess tax benefits and deficiencies related to employee stock-based compensation are recognized directly within Income tax expense or benefit in Citi’s Consolidated Statement of Income, rather than within Additional paid-in capital . The impact of this change was not material in the first quarter of 2017 or each subsequent quarterly periods of 2017 as the majority of employees’ deferred stock-based compensation awards are granted within the first quarter of each year, and therefore vest within the first quarter of each year, commensurate with vesting in equal annual installments. For additional information on these receivables and payables, see Note 7 to the Consolidated Financial Statements. Additionally, as permitted under the new guidance, Citi made an accounting policy election to account for forfeitures of awards as they occur, which represents a change from the previous requirement to estimate forfeitures when recognizing compensation expense. This change resulted in a cumulative effect adjustment to retained earnings that was not material at January 1, 2017. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , which addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. This ASU requires entities to present separately in AOCI the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. It also requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income, thus eliminating eligibility for the current available-for-sale category. However, Federal Reserve Bank and Federal Home Loan Bank stock, as well as certain exchange seats, will continue to be presented at cost. The ASU also introduces a measurement alternative for non-marketable equity securities. Citi early adopted only the provisions of this ASU related to presentation of the change in fair value of liabilities for which the fair value option was elected, related to changes in Citigroup’s own credit spreads in AOCI effective January 1, 2016. Accordingly, since the first quarter of 2016, these amounts have been reflected as a component of AOCI, whereas these amounts were previously recognized in Citigroup’s revenues and net income. The impact of adopting this amendment resulted in a cumulative catch-up reclassification from retained earnings to AOCI of an accumulated after-tax loss of approximately $15 million at January 1, 2016. Financial statements for periods prior to 2016 were not subject to restatement under the provisions of this ASU. For additional information, see Notes 19, 24 and 25 to the Consolidated Financial Statements. Citi adopted the other provisions of ASU 2016-01 on January 1, 2018. The ASU does not have a significant impact on the Company’s Consolidated Financial Statements and related disclosures.

DISCONTINUED OPERATIONS AND S40

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS (Tables)	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Summarized financial information disposal groups including discontinued operations	Income before taxes, excluding the pretax gain on sale and loss on redemption of debt, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ — $ — $ 663 Loss before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Loss before taxes $ — $ — $ (57 ) Income before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 41 $ 139 $ 118 Income before taxes for the divested businesses, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 31 $ 55 $ 54 The following summarizes financial information for all discontinued operations: In millions of dollars 2017 2016 2015 Total revenues, net of interest expense $ — $ — $ — Income (loss) from discontinued operations $ (104 ) $ (80 ) $ (83 ) Provision (benefit) for income taxes 7 (22 ) (29 ) Loss from discontinued operations, net of taxes $ (111 ) $ (58 ) $ (54 ) Income before taxes, excluding the revenue upon novation, was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ — $ — $ 135 Income before taxes of the business was as follows: In millions of dollars 2017 2016 2015 Income before taxes $ 164 $ 155 $ 159 Loss before taxes, excluding the pretax gain on sale, was as follows: In millions of dollars 2017 2016 2015 Loss before taxes $ — $ — $ (5 )

BUSINESS SEGMENTS (Tables)

BUSINESS SEGMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Information regarding the Company's operations by segment	The following table presents certain information regarding the Company’s continuing operations by segment: Revenues, (1) Provision (benefits) (2) Income (loss) from (2)(3) Identifiable assets In millions of dollars, except identifiable assets in billions 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 Global Consumer Banking $ 32,697 $ 31,519 $ 32,251 $ 3,320 $ 2,655 $ 3,369 $ 3,893 $ 4,954 $ 6,214 $ 429 $ 412 Institutional Clients Group 35,667 33,227 33,332 7,008 4,260 4,173 9,066 9,525 9,110 1,336 1,277 Corporate/Other 3,085 5,129 10,771 19,060 (471 ) (102 ) (19,586 ) 554 2,062 77 103 Total $ 71,449 $ 69,875 $ 76,354 $ 29,388 $ 6,444 $ 7,440 $ (6,627 ) $ 15,033 $ 17,386 $ 1,842 $ 1,792 (1) Includes total revenues, net of interest expense (excluding Corporate/Other ), in North America of $33.9 billion , $32.2 billion and $32.2 billion ; in EMEA of $10.7 billion , $9.9 billion and $9.8 billion ; in Latin America of $9.4 billion , $8.9 billion and $9.7 billion ; and in Asia of $14.4 billion , $13.7 billion and $13.9 billion in 2017, 2016 and 2015, respectively. (2) Corporate/Other , GCB and ICG 2017 results include the impact of Tax Reform. See Notes 1 and 9 to the Consolidated Financial Statements. (3) Includes pretax provisions for credit losses and for benefits and claims in the GCB results of $7.6 billion , $6.4 billion and $5.5 billion ; in the ICG results of ( $15 ) million, $486 million and $962 million ; and in Corporate/Other results of ( $175 ) million, $69 million and $1.5 billion in 2017, 2016 and 2015, respectively.

INTEREST REVENUE AND EXPENSE (T

INTEREST REVENUE AND EXPENSE (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift, Interest [Abstract]
Interest revenue and expense	Interest revenue and Interest expense consisted of the following: In millions of dollars 2017 2016 2015 Interest revenue Loan interest, including fees $ 41,361 $ 39,752 $ 40,510 Deposits with banks 1,635 971 727 Federal funds sold and securities borrowed or purchased under agreements to resell 3,248 2,543 2,516 Investments, including dividends 8,295 7,582 7,017 Trading account assets (1) 5,502 5,738 5,942 Other interest (2) 1,163 1,029 1,839 Total interest revenue $ 61,204 $ 57,615 $ 58,551 Interest expense Deposits (3) $ 6,586 $ 5,300 $ 5,052 Federal funds purchased and securities loaned or sold under agreements to repurchase 2,661 1,912 1,612 Trading account liabilities (1) 638 410 217 Short-term borrowings 1,059 477 523 Long-term debt 5,573 4,412 4,517 Total interest expense $ 16,517 $ 12,511 $ 11,921 Net interest revenue $ 44,687 $ 45,104 $ 46,630 Provision for loan losses 7,503 6,749 7,108 Net interest revenue after provision for loan losses $ 37,184 $ 38,355 $ 39,522 (1) Interest expense on Trading account liabilities of ICG is reported as a reduction of interest revenue from Trading account assets . (2) During 2015, interest earned related to assets of significant disposals (primarily OneMain Financial) was reclassified to Other interest. (3) Includes deposit insurance fees and charges of $1,249 million , $1,145 million and $1,118 million for 2017 , 2016 and 2015 , respectively.

COMMISSIONS AND FEES (Tables)

COMMISSIONS AND FEES (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Commissions and fees revenues	The following table presents Commissions and fees revenue: In millions of dollars 2017 2016 2015 Investment banking $ 3,613 $ 2,847 $ 3,423 Trading-related 3,015 2,799 3,138 Trade and securities services 1,632 1,564 1,735 Credit cards and bank cards 1,510 1,324 1,786 Corporate finance (1) 713 686 493 Other consumer (2) 703 659 685 Insurance distribution revenue (3) 514 548 621 Insurance premiums (3) 122 288 1,224 Checking-related 478 467 497 Loan servicing 312 325 404 Other 327 431 479 Total commissions and fees $ 12,939 $ 11,938 $ 14,485 (1) Consists primarily of fees earned from structuring and underwriting loan syndications. (2) Primarily consists of fees for investment fund administration and management, third-party collections, commercial demand deposit accounts and certain credit card services. (3) Insurance premiums were previously separately reported on the Consolidated Statement of Income.

PRINCIPAL TRANSACTIONS (Tables)

PRINCIPAL TRANSACTIONS (Tables)	12 Months Ended
	Dec. 31, 2017
Principal Transactions Revenue, Net [Abstract]
Principal transactions revenue	The following table presents Principal transactions revenue: In millions of dollars 2017 2016 2015 Global Consumer Banking (1) $ 570 $ 629 $ 577 Institutional Clients Group 7,740 7,335 5,824 Corporate/Other (1) 858 (379 ) (393 ) Total Citigroup $ 9,168 $ 7,585 $ 6,008 Interest rate risks (2) $ 5,124 $ 4,115 $ 3,798 Foreign exchange risks (3) 2,488 1,726 1,532 Equity risks (4) 491 189 331 Commodity and other risks (5) 294 806 750 Credit products and risks (6) 771 749 (403 ) Total $ 9,168 $ 7,585 $ 6,008 (1) Primarily relates to foreign exchange risks. (2) Includes revenues from government securities and corporate debt, municipal securities, mortgage securities and other debt instruments. Also includes spot and forward trading of currencies and exchange-traded and over-the-counter (OTC) currency options, options on fixed income securities, interest rate swaps, currency swaps, swap options, caps and floors, financial futures, OTC options and forward contracts on fixed income securities. (3) Includes revenues from foreign exchange spot, forward, option and swap contracts, as well as foreign currency translation (FX translation) gains and losses. (4) Includes revenues from common, preferred and convertible preferred stock, convertible corporate debt, equity-linked notes and exchange-traded and OTC equity options and warrants. (5) Primarily includes revenues from crude oil, refined oil products, natural gas and other commodities trades. (6) Includes revenues from structured credit products.

INCENTIVE PLANS (Tables)

INCENTIVE PLANS (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the status of unvested stock awards	A summary of the performance share unit activity for 2017 is presented below: Performance Share Units Units Weighted- average grant date fair value per unit Outstanding, beginning of period 1,844,560 $ 38.22 Granted (1) 500,609 59.22 Canceled (277,546 ) 48.34 Payments (280,897 ) 48.34 Outstanding, end of period 1,786,726 $ 40.94 (1) The weighted-average grant date fair value per unit awarded in 2016 and 2015 was $27.03 and $44.07 , respectively. A summary of the status of unvested stock awards granted as discretionary annual incentive or sign-on and long-term retention awards is presented below: Unvested stock awards Shares Weighted- average grant date fair value per share Unvested at December 31, 2016 42,672,176 $ 43.24 Granted (1) 13,914,752 59.12 Canceled (1,335,297 ) 47.29 Vested (2) (18,320,591 ) 45.63 Unvested at December 31, 2017 36,931,040 $ 47.89 (1) The weighted-average fair value of the shares granted during 2016 and 2015 was $37.35 and $50.33 , respectively. (2) The weighted-average fair value of the shares vesting during 2017 was approximately $57.45 per share.
Schedule of assumptions used	Other significant assumptions for the awards are as follows: Valuation Assumptions 2017 2016 2015 Expected volatility 25.79 % 24.37 % 27.13 % Expected dividend yield 1.30 % 0.40 % 0.08 % Citigroup’s pension and postretirement plans’ weighted-average asset allocations for the non-U.S. plans and the actual ranges, and the weighted-average target allocations by asset category based on asset fair values, are as follows: Non-U.S. pension plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-63% 0-67% 0–69% 15 % 14 % Debt securities 0-100 0-99 0–100 79 79 Real estate 0-18 0-18 0–18 1 1 Other investments 0-100 0-100 0–100 5 6 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. Non-U.S. postretirement plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-37% 0-38% 0–38% 38 % 38 % Debt securities 58-100 58-100 57–100 58 58 Other investments 0-5 0-4 0–4 4 4 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. The following table summarizes certain assumptions used in determining the post employment benefit obligations and net benefit expense for the Company’s U.S. post employment plans: 2017 2016 Discount rate 3.20% 3.40% Expected return on assets (1) 3.00 N/A Health care cost increase rate Following year 6.50 6.50 Ultimate rate to which cost increase is assumed to decline 5.00 5.00 Year in which the ultimate rate is reached 2023 2023 1) In 2017, the VEBA Trust was funded with an expected rate of return of assets of 3.00% . N/A Not applicable Certain assumptions used in determining pension and postretirement benefit obligations and net benefit expense for the Company’s plans are shown in the following table: At year end 2017 2016 Discount rate U.S. plans Qualified pension 3.60% 4.10% Nonqualified pension 3.60 4.00 Postretirement 3.50 3.90 Non-U.S. pension plans Range 0.00 to 10.20 0.25 to 72.50 Weighted average 4.17 4.40 Non-U.S. postretirement plans Range 1.75 to 10.10 1.75 to 11.05 Weighted average 8.10 8.27 Future compensation increase rate (1) Non-U.S. pension plans Range 1.17 to 13.67 1.25 to 70.00 Weighted average 3.08 3.21 Expected return on assets U.S. plans Qualified pension 6.80 6.80 Postretirement (2) 6.80/3.00 6.80 Non-U.S. pension plans Range 0.00 to 11.50 1.00 to 11.50 Weighted average 4.52 4.55 Non-U.S. postretirement plans Range 8.00 to 9.80 8.00 to 10.30 Weighted average 8.01 8.02 (1) Not material for U.S. plans. (2) In 2017, the VEBA Trust was funded with an expected rate of return of assets of 3.00% . During the year 2017 2016 2015 Discount rate U.S. plans Qualified pension 4.10%/4.05%/ 3.80%/3.75% 4.40%/3.95%/ 3.65%/3.55% 4.00%/3.85%/ 4.45%/4.35% Nonqualified pension 4.00/3.95/ 3.75/3.65 4.35/3.90/ 3.55/3.45 3.90/3.70/ 4.30/4.25 Postretirement 3.90/3.85/ 3.60/3.55 4.20/3.75/ 3.40/3.30 3.80/3.65/ 4.20/4.10 Non-U.S. pension plans (1) Range 0.25 to 72.50 0.25 to 42.00 1.00 to 32.50 Weighted average 4.40 4.76 4.74 Non-U.S. postretirement plans (1) Range 1.75 to 11.05 2.00 to 13.20 2.25 to 12.00 Weighted average 8.27 7.90 7.50 Future compensation increase rate (2) Non-U.S. pension plans (1) Range 1.25 to 70.00 1.00 to 40.00 0.75 to 30.00 Weighted average 3.21 3.24 3.27 Expected return on assets U.S. plans Qualified pension 6.80 7.00 7.00 Postretirement 6.80 7.00 7.00 Non-U.S. pension plans (1) Range 1.00 to 11.50 1.60 to 11.50 1.30 to 11.50 Weighted average 4.55 4.95 5.08 Non-U.S. postretirement plans (1) Range 8.00 to 10.30 8.00 to 10.70 8.50 to 10.40 Weighted average 8.02 8.01 8.51 (1) Reflects rates utilized to determine the first quarter expense for Significant non-U.S. pension and postretirement plans. (2) Not material for U.S. plans. Citigroup’s pension and postretirement plans’ asset allocations for the U.S. plans and the target allocations by asset category based on asset fair values, are as follows: Target asset allocation U.S. pension assets at December 31, U.S. postretirement assets at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities (2) 0-30% 20 % 18 % 20 % 18 % Debt securities (3) 25-72 48 47 48 47 Real estate 0-10 5 5 5 5 Private equity 0-12 3 4 3 4 Other investments 0-37 24 26 24 26 Total 100 % 100 % 100 % 100 % (1) Asset allocations for the U.S. plans are set by investment strategy, not by investment product. For example, private equities with an underlying investment in real estate are classified in the real estate asset category, not private equity. (2) Equity securities in the U.S. pension and postretirement plans do not include any Citigroup common stock at the end of 2017 and 2016. (3) In December 2017, Citi contributed $140 million to the VEBA Trust for postretirement benefits, which amount was invested solely in debt securities which are not reflected in the table above.
Information with respect to stock option activity under stock option awards	Information with respect to stock option activity under Citigroup’s stock option programs is shown below: 2017 2016 2015 Options Weighted- average exercise price Intrinsic value per share Options Weighted- average exercise price Intrinsic value per share Options Weighted- average exercise price Intrinsic value per share Outstanding, beginning of period 1,527,396 $ 131.78 $ — 6,656,588 $ 67.92 $ — 26,514,119 $ 48.00 $ 6.11 Canceled — — — (25,334 ) 40.80 — (7,901 ) 40.80 — Expired — — — (2,613,909 ) 48.80 — (1,646,581 ) 40.85 — Exercised (388,583 ) 43.35 15.67 (2,489,949 ) 49.10 6.60 (18,203,048 ) 41.39 13.03 Outstanding, end of period 1,138,813 $ 161.96 $ — 1,527,396 $ 131.78 $ — 6,656,588 $ 67.92 $ — Exercisable, end of period 1,138,813 1,527,396 6,656,588
Summary of information about stock options outstanding under stock option programs	The following table summarizes information about stock options outstanding under Citigroup’s stock option programs at December 31, 2017: Options outstanding Options exercisable Range of exercise prices Number outstanding Weighted-average contractual life remaining Weighted-average exercise price Number exercisable Weighted-average exercise price $39.00—$99.99 312,309 3.0 years $ 43.56 312,309 $ 43.56 $100.00—$199.99 502,416 1.0 year 147.13 502,416 147.13 $200.00—$299.99 124,088 0.1 years 240.28 124,088 240.28 $300.00—$399.99 200,000 0.1 years 335.50 200,000 335.50 Total at December 31, 2017 1,138,813 1.3 years $ 161.96 1,138,813 $ 161.96
Components of compensation expense relating to stock-basked compensation programs and deferred cash award programs	The following table shows components of compensation expense, relating to certain of the above incentive compensation programs: In millions of dollars 2017 2016 2015 Charges for estimated awards to retirement-eligible employees $ 659 $ 555 $ 541 Amortization of deferred cash awards, deferred cash stock units and performance stock units 354 336 325 Immediately vested stock award expense (1) 70 73 61 Amortization of restricted and deferred stock awards (2) 474 509 461 Other variable incentive compensation 694 710 773 Total $ 2,251 $ 2,183 $ 2,161 (1) Represents expense for immediately vested stock awards that generally were stock payments in lieu of cash compensation. The expense is generally accrued as cash incentive compensation in the year prior to grant. (2) All periods include amortization expense for all unvested awards to non-retirement-eligible employees.
Schedule of unrecognized compensation cost and future estimated expense on awards in next fiscal year	Citi's expected future expenses, excluding the impact of forfeitures, cancelations, clawbacks and repositioning-related accelerations that have not yet occurred, are summarized in the table below: In millions of dollars 2018 2019 2020 2021 and beyond (1) Total Awards granted in 2017 and prior: Deferred stock awards $ 276 $ 146 $ 67 $ 11 $ 500 Deferred cash awards 170 94 38 8 310 Future expense related to awards already granted $ 446 $ 240 $ 105 $ 19 $ 810 Future expense related to awards granted in 2018 (2) $ 238 $ 185 $ 148 $ 111 $ 682 Total $ 684 $ 425 $ 253 $ 130 $ 1,492 (1) Principally 2021. (2) Refers to awards granted on or about February 15, 2018, as part of Citi's discretionary annual incentive awards for services performed in 2017.

RETIREMENT BENEFITS (Tables)

RETIREMENT BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Components of net (benefit) expense	The following table summarizes the components of net (benefit) expense recognized in the Consolidated Statement of Income for the Company’s pension and postretirement plans, for Significant Plans and All Other Plans: Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 2015 Benefits earned during the year $ 3 $ 4 $ 6 $ 153 $ 154 $ 168 $ — $ — $ — $ 9 $ 10 $ 12 Interest cost on benefit obligation 533 548 581 295 282 317 26 25 33 101 94 108 Expected return on plan assets (865 ) (886 ) (893 ) (299 ) (287 ) (323 ) (6 ) (9 ) (3 ) (89 ) (86 ) (105 ) Amortization of unrecognized Prior service (benefit) cost 2 2 1 (3 ) (1 ) 2 — — — (10 ) (10 ) (11 ) Net actuarial loss 173 169 148 61 69 73 — (1 ) — 35 30 43 Curtailment loss (gain) (1) 6 13 14 — (2 ) — — — — — — (1 ) Settlement loss (1) — — — 12 6 44 — — — — — — Total net (benefit) expense $ (148 ) $ (150 ) $ (143 ) $ 219 $ 221 $ 281 $ 20 $ 15 $ 30 $ 46 $ 38 $ 46 (1) Losses and gains due to curtailment and settlement benefits relate to repositioning and divestiture actions. The following table summarizes the components of net expense recognized in the Consolidated Statement of Income for the Company’s U.S. post employment plans: Net expense In millions of dollars 2017 2016 2015 Service related expense Interest cost on benefit obligation $ 2 $ 3 $ 4 Amortization of unrecognized Prior service (benefit) cost (31 ) (31 ) (31 ) Net actuarial loss 2 5 12 Total service related benefit $ (27 ) $ (23 ) $ (15 ) Non-service related expense $ 30 $ 21 $ 3 Total net expense (benefit) $ 3 $ (2 ) $ (12 )
Summary of entity's contributions	The following table summarizes the actual Company contributions for the years ended December 31, 2017 and 2016 , as well as estimated expected Company contributions for 2018. Expected contributions are subject to change, since contribution decisions are affected by various factors, such as market performance, tax considerations and regulatory requirements. Pension plans (1) Postretirement benefit plans (1) U.S. plans (2) Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2016 2018 2017 2016 2018 2017 2016 2018 2017 2016 Contributions made by the Company $ — $ 50 $ 500 $ 79 $ 90 $ 82 $ — $ 140 $ — $ 4 $ 4 $ 4 Benefits paid directly by the Company 60 55 56 49 45 44 6 36 6 6 5 5 (1) Amounts reported for 2018 are expected amounts. (2) The U.S. pension plans include benefits paid directly by the Company for the nonqualified pension plans.
Summary of the funded status and amounts recognized in the Consolidated Balance Sheet for the Company's U.S. qualified, non-qualified plans and plans outside the U.S.	The following tables summarize the funded status and amounts recognized in the Consolidated Balance Sheet for the Company’s pension and postretirement plans: Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans 2017 2016 2017 2016 2017 2016 2017 2016 Change in projected benefit obligation Projected benefit obligation at beginning of year $ 14,000 $ 13,943 $ 6,522 $ 6,534 $ 686 $ 817 $ 1,141 $ 1,291 Benefits earned during the year 3 4 153 154 — — 9 10 Interest cost on benefit obligation 533 548 295 282 26 25 101 94 Plan amendments — — 4 (28 ) — — — — Actuarial loss (gain) 536 367 127 589 43 (105 ) 19 3 Benefits paid, net of participants’ contributions and government subsidy (769 ) (780 ) (278 ) (324 ) (56 ) (51 ) (64 ) (59 ) Divestitures — — (29 ) (22 ) — — (4 ) — Settlement gain (1) — — (192 ) (38 ) — — — — Curtailment (gain) loss (1) 6 13 (3 ) (15 ) — — — (4 ) Foreign exchange impact and other (2) (269 ) (95 ) 834 (610 ) — — 59 (194 ) Projected benefit obligation at year end $ 14,040 $ 14,000 $ 7,433 $ 6,522 $ 699 $ 686 $ 1,261 $ 1,141 (1) Curtailment and settlement (gains) losses relate to repositioning and divestiture activities. (2) With respect to the U.S. Plan, de-risking activities during 2017 resulted in a reduction to plan obligations and assets. Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2017 2016 2017 2016 2017 2016 2017 2016 Change in plan assets Plan assets at fair value at beginning of year $ 12,363 $ 12,137 $ 6,149 $ 6,104 $ 129 $ 166 $ 1,015 $ 1,133 Actual return on plan assets 1,295 572 462 967 13 8 113 122 Company contributions 105 556 135 126 176 6 9 9 Divestitures — — (31 ) (5 ) — — — — Settlements — — (192 ) (38 ) — — — — Benefits paid, net of participants’ contributions and government subsidy (769 ) (779 ) (278 ) (324 ) (56 ) (51 ) (64 ) (59 ) Foreign exchange impact and other (1) (269 ) (123 ) 883 (681 ) — — 46 (190 ) Plan assets at fair value at year end $ 12,725 $ 12,363 $ 7,128 $ 6,149 $ 262 $ 129 $ 1,119 $ 1,015 Funded status of the plans Qualified plans (2) $ (565 ) $ (908 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Nonqualified plans (3) (750 ) (729 ) — — — — — — Funded status of the plans at year end $ (1,315 ) $ (1,637 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Net amount recognized Qualified plans Benefit asset $ — $ — $ 900 $ 711 $ — $ — $ 181 $ 166 Benefit liability (565 ) (908 ) (1,205 ) (1,084 ) (437 ) (557 ) (323 ) (292 ) Qualified plans $ (565 ) $ (908 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Nonqualified plans (750 ) (729 ) — — — — — — Net amount recognized on the balance sheet $ (1,315 ) $ (1,637 ) $ (305 ) $ (373 ) $ (437 ) $ (557 ) $ (142 ) $ (126 ) Amounts recognized in Accumulated other comprehensive income (loss) Net transition obligation $ — $ — $ (1 ) $ (1 ) $ — $ — $ — $ — Prior service benefit (15 ) (17 ) 22 29 — — 92 98 Net actuarial gain (loss) (6,823 ) (6,891 ) (1,318 ) (1,302 ) 72 106 (382 ) (399 ) Net amount recognized in equity (pretax) $ (6,838 ) $ (6,908 ) $ (1,297 ) $ (1,274 ) $ 72 $ 106 $ (290 ) $ (301 ) Accumulated benefit obligation at year end $ 14,034 $ 13,994 $ 7,038 $ 6,090 $ 699 $ 686 $ 1,261 $ 1,141 (1) With respect to the U.S. Plan, de-risking activities during 2017 resulted in a reduction to plan obligations and assets. (2) The U.S. qualified pension plan is fully funded under specified Employee Retirement Income Security Act (ERISA) funding rules as of January 1, 2018 and no minimum required funding is expected for 2018. (3) The nonqualified plans of the Company are unfunded.
Change in accumulated other comprehensive income (loss)	The following table shows the change in Accumulated other comprehensive income (loss) related to the Company’s pension, postretirement and post employment plans: In millions of dollars 2017 2016 2015 Beginning of year balance, net of tax (1)(2) $ (5,164 ) $ (5,116 ) $ (5,159 ) Actuarial assumptions changes and plan experience (760 ) (854 ) 898 Net asset gain (loss) due to difference between actual and expected returns 625 400 (1,457 ) Net amortizations 229 232 236 Prior service (cost) credit (4 ) 28 (6 ) Curtailment/settlement gain (3) 17 17 57 Foreign exchange impact and other (93 ) 99 291 Impact of Tax Reform (4) (1,020 ) — — Change in deferred taxes, net (13 ) 30 24 Change, net of tax $ (1,019 ) $ (48 ) $ 43 End of year balance, net of tax (1)(2) $ (6,183 ) $ (5,164 ) $ (5,116 ) (1) See Note 19 to the Consolidated Financial Statements for further discussion of net Accumulated other comprehensive income (loss) balance. (2) Includes net-of-tax amounts for certain profit sharing plans outside the U.S. (3) Curtailment and settlement gains broadly relate to repositioning and divestiture activities. (4) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings. See Note 1 to the Consolidated Financial Statements.
Aggregate projected benefit obligation (PBO), accumulated benefit obligation (ABO), and fair value of plan assets for pension plans with a PBO or ABO that exceeds the fair value of plan assets	At December 31, 2017 and 2016, the aggregate projected benefit obligation (PBO), the aggregate accumulated benefit obligation (ABO) and the aggregate fair value of plan assets are presented for all defined benefit pension plans with a PBO in excess of plan assets and for all defined benefit pension plans with an ABO in excess of plan assets as follows: PBO exceeds fair value of plan assets ABO exceeds fair value of plan assets U.S. plans (1) Non-U.S. plans U.S. plans (1) Non-U.S. plans In millions of dollars 2017 2016 2017 2016 2017 2016 2017 2016 Projected benefit obligation $ 14,040 $ 14,000 $ 2,721 $ 2,484 $ 14,040 $ 14,000 $ 2,596 $ 2,282 Accumulated benefit obligation 14,034 13,994 2,381 2,168 14,034 13,994 2,296 2,012 Fair value of plan assets 12,725 12,363 1,516 1,399 12,725 12,363 1,407 1,224 (1) At December 31, 2017 and 2016, for both the U.S. qualified plan and nonqualified plans, the aggregate PBO and the aggregate ABO exceeded plan assets.
Assumptions used in determining benefit obligations and net benefit expense	Other significant assumptions for the awards are as follows: Valuation Assumptions 2017 2016 2015 Expected volatility 25.79 % 24.37 % 27.13 % Expected dividend yield 1.30 % 0.40 % 0.08 % Citigroup’s pension and postretirement plans’ weighted-average asset allocations for the non-U.S. plans and the actual ranges, and the weighted-average target allocations by asset category based on asset fair values, are as follows: Non-U.S. pension plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-63% 0-67% 0–69% 15 % 14 % Debt securities 0-100 0-99 0–100 79 79 Real estate 0-18 0-18 0–18 1 1 Other investments 0-100 0-100 0–100 5 6 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. Non-U.S. postretirement plans Target asset allocation Actual range at December 31, Weighted-average at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities 0-37% 0-38% 0–38% 38 % 38 % Debt securities 58-100 58-100 57–100 58 58 Other investments 0-5 0-4 0–4 4 4 Total 100 % 100 % (1) Similar to the U.S. plans, asset allocations for certain non-U.S. plans are set by investment strategy, not by investment product. The following table summarizes certain assumptions used in determining the post employment benefit obligations and net benefit expense for the Company’s U.S. post employment plans: 2017 2016 Discount rate 3.20% 3.40% Expected return on assets (1) 3.00 N/A Health care cost increase rate Following year 6.50 6.50 Ultimate rate to which cost increase is assumed to decline 5.00 5.00 Year in which the ultimate rate is reached 2023 2023 1) In 2017, the VEBA Trust was funded with an expected rate of return of assets of 3.00% . N/A Not applicable Certain assumptions used in determining pension and postretirement benefit obligations and net benefit expense for the Company’s plans are shown in the following table: At year end 2017 2016 Discount rate U.S. plans Qualified pension 3.60% 4.10% Nonqualified pension 3.60 4.00 Postretirement 3.50 3.90 Non-U.S. pension plans Range 0.00 to 10.20 0.25 to 72.50 Weighted average 4.17 4.40 Non-U.S. postretirement plans Range 1.75 to 10.10 1.75 to 11.05 Weighted average 8.10 8.27 Future compensation increase rate (1) Non-U.S. pension plans Range 1.17 to 13.67 1.25 to 70.00 Weighted average 3.08 3.21 Expected return on assets U.S. plans Qualified pension 6.80 6.80 Postretirement (2) 6.80/3.00 6.80 Non-U.S. pension plans Range 0.00 to 11.50 1.00 to 11.50 Weighted average 4.52 4.55 Non-U.S. postretirement plans Range 8.00 to 9.80 8.00 to 10.30 Weighted average 8.01 8.02 (1) Not material for U.S. plans. (2) In 2017, the VEBA Trust was funded with an expected rate of return of assets of 3.00% . During the year 2017 2016 2015 Discount rate U.S. plans Qualified pension 4.10%/4.05%/ 3.80%/3.75% 4.40%/3.95%/ 3.65%/3.55% 4.00%/3.85%/ 4.45%/4.35% Nonqualified pension 4.00/3.95/ 3.75/3.65 4.35/3.90/ 3.55/3.45 3.90/3.70/ 4.30/4.25 Postretirement 3.90/3.85/ 3.60/3.55 4.20/3.75/ 3.40/3.30 3.80/3.65/ 4.20/4.10 Non-U.S. pension plans (1) Range 0.25 to 72.50 0.25 to 42.00 1.00 to 32.50 Weighted average 4.40 4.76 4.74 Non-U.S. postretirement plans (1) Range 1.75 to 11.05 2.00 to 13.20 2.25 to 12.00 Weighted average 8.27 7.90 7.50 Future compensation increase rate (2) Non-U.S. pension plans (1) Range 1.25 to 70.00 1.00 to 40.00 0.75 to 30.00 Weighted average 3.21 3.24 3.27 Expected return on assets U.S. plans Qualified pension 6.80 7.00 7.00 Postretirement 6.80 7.00 7.00 Non-U.S. pension plans (1) Range 1.00 to 11.50 1.60 to 11.50 1.30 to 11.50 Weighted average 4.55 4.95 5.08 Non-U.S. postretirement plans (1) Range 8.00 to 10.30 8.00 to 10.70 8.50 to 10.40 Weighted average 8.02 8.01 8.51 (1) Reflects rates utilized to determine the first quarter expense for Significant non-U.S. pension and postretirement plans. (2) Not material for U.S. plans. Citigroup’s pension and postretirement plans’ asset allocations for the U.S. plans and the target allocations by asset category based on asset fair values, are as follows: Target asset allocation U.S. pension assets at December 31, U.S. postretirement assets at December 31, Asset category (1) 2018 2017 2016 2017 2016 Equity securities (2) 0-30% 20 % 18 % 20 % 18 % Debt securities (3) 25-72 48 47 48 47 Real estate 0-10 5 5 5 5 Private equity 0-12 3 4 3 4 Other investments 0-37 24 26 24 26 Total 100 % 100 % 100 % 100 % (1) Asset allocations for the U.S. plans are set by investment strategy, not by investment product. For example, private equities with an underlying investment in real estate are classified in the real estate asset category, not private equity. (2) Equity securities in the U.S. pension and postretirement plans do not include any Citigroup common stock at the end of 2017 and 2016. (3) In December 2017, Citi contributed $140 million to the VEBA Trust for postretirement benefits, which amount was invested solely in debt securities which are not reflected in the table above.
Schedule of expected long term rates of return on assets	The following table shows the expected rates of return used in determining the Company’s pension expense compared to the actual rate of return on plan assets during 2017, 2016 and 2015 for the U.S. pension and postretirement plans: 2017 2016 2015 Expected rate of return (1) 6.80%/3.00% 7.00% 7.00% Actual rate of return (2) 10.90 4.90 (1.70) (1) In 2017, the VEBA Trust was funded for postretirement benefits with an expected rate of return of assets of 3.00% . (2) Actual rates of return are presented net of fees.
Retirement plan and mortality projections	At December 31, 2017, the Company maintained the Retirement Plan 2014 (RP-2014) mortality table and adopted the Mortality Projection 2017 (MP-2017) projection table for the U.S. plans. U.S. plans 2017 (1) 2016 (2) Mortality Pension RP-2014/MP-2017 RP-2014/MP-2016 Postretirement RP-2014/MP-2017 RP-2014/MP-2016 (1) The RP-2014 table is the white-collar RP-2014 table. The MP-2017 projection scale is projected from 2006, with convergence to .75% ultimate rate of annual improvement by 2033. (2) The RP-2014 table is the white-collar RP-2014 table, with a 4% increase in rates to reflect the lower life expectancy of Citi plan participants. The MP-2016 projection scale is projected from 2011, with convergence to 0.75% ultimate rate of annual improvement by 2032.
Effect of one-percentage-point change in the discount rates on pension expense	The following tables summarize the effect on pension expense of a one-percentage-point change in the discount rate: One-percentage-point increase In millions of dollars 2017 2016 2015 U.S. plans $ 29 $ 31 $ 26 Non-U.S. plans (27 ) (33 ) (32 ) One-percentage-point decrease In millions of dollars 2017 2016 2015 U.S. plans $ (44 ) $ (47 ) $ (44 ) Non-U.S. plans 41 37 44
Schedule of effect of one percentage point change in expected rates of return	The following tables summarize the effect on pension expense of a one-percentage-point change in the expected rates of return: One-percentage-point increase In millions of dollars 2017 2016 2015 U.S. plans $ (127 ) $ (127 ) $ (128 ) Non-U.S. plans (64 ) (61 ) (63 ) One-percentage-point decrease In millions of dollars 2017 2016 2015 U.S. plans $ 127 $ 127 $ 128 Non-U.S. plans 64 61 63
Schedule of health care cost trend rates	Assumed health care cost trend rates were as follows: 2017 2016 Health care cost increase rate for U.S. plans Following year 6.50% 6.50% Ultimate rate to which cost increase is assumed to decline 5.00 5.00 Year in which the ultimate rate is reached (1) 2023 2023 (1) Weighted average for plans with different following year and ultimate rates. 2017 2016 Health care cost increase rate for Non-U.S. plans (weighted average) Following year 6.87% 6.86% Ultimate rate to which cost increase is assumed to decline 6.87 6.85 Range of years in which the ultimate rate is reached 2018–2019 2017–2029
Schedule of effect of one percentage point change in assumed health care cost trend rates	A one-percentage-point change in assumed health care cost trend rates would have the following effects: One- percentage- point increase One- percentage- point decrease In millions of dollars 2017 2016 2017 2016 U.S. plans Effect on benefits earned and interest cost for postretirement plans $ 1 $ 1 $ (1 ) $ (1 ) Effect on accumulated postretirement benefit obligation for postretirement plans 33 30 (29 ) (26 ) One-percentage- point increase One- percentage- point decrease In millions of dollars 2017 2016 2017 2016 Non-U.S. plans Effect on benefits earned and interest cost for postretirement plans $ 13 $ 12 $ (10 ) $ (10 ) Effect on accumulated postretirement benefit obligation for postretirement plans 150 144 (125 ) (118 )
Schedule of fair value of plan assets by measurement levels	Plan assets by detailed asset categories and the fair value hierarchy are as follows: U.S. pension and postretirement benefit plans (1) In millions of dollars Fair value measurement at December 31, 2017 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 726 $ — $ — $ 726 Non-U.S. equities 926 — — 926 Mutual funds 271 — — 271 Commingled funds — 1,184 — 1,184 Debt securities 1,381 3,080 — 4,461 Annuity contracts — — 1 1 Derivatives 11 323 — 334 Other investments — — 22 22 Total investments $ 3,315 $ 4,587 $ 23 $ 7,925 Cash and short-term investments $ 257 $ 1,004 $ — $ 1,261 Other investment liabilities (60 ) (343 ) — (403 ) Net investments at fair value $ 3,512 $ 5,248 $ 23 $ 8,783 Other investment receivables redeemed at NAV $ 16 Securities valued at NAV 4,189 Total net assets $ 12,988 (1) The investments of the U.S. pension and postretirement plans are commingled in one trust. At December 31, 2017, the allocable interests of the U.S. pension and postretirement plans were 99.0% and 1.0% , respectively. In 2017, the VEBA Trust was funded for postretirement benefits. U.S. pension and postretirement benefit plans (1) In millions of dollars Fair value measurement at December 31, 2016 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 639 $ — $ — $ 639 Non-U.S. equities 773 — — 773 Mutual funds 216 — — 216 Commingled funds — 866 — 866 Debt securities 1,297 2,845 — 4,142 Annuity contracts — — 1 1 Derivatives 8 543 — 551 Other investments — — 4 4 Total investments $ 2,933 $ 4,254 $ 5 $ 7,192 Cash and short-term investments $ 116 $ 1,239 $ — $ 1,355 Other investment liabilities (106 ) (553 ) — (659 ) Net investments at fair value $ 2,943 $ 4,940 $ 5 $ 7,888 Other investment receivables redeemed at NAV $ 100 Securities valued at NAV 4,504 Total net assets $ 12,492 (1) The investments of the U.S. pension and postretirement plans are commingled in one trust. At December 31, 2016, the allocable interests of the U.S. pension and postretirement plans were 99.0% and 1.0% , respectively. Non-U.S. pension and postretirement benefit plans In millions of dollars Fair value measurement at December 31, 2017 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 4 $ 12 $ — $ 16 Non-U.S. equities 103 122 1 226 Mutual funds 3,098 74 — 3,172 Commingled funds 24 — — 24 Debt securities 3,999 1,555 7 5,561 Real estate — 3 1 4 Annuity contracts — 1 9 10 Derivatives 1 3,102 — 3,103 Other investments 1 — 214 215 Total investments $ 7,230 $ 4,869 $ 232 $ 12,331 Cash and short-term investments $ 119 $ 3 $ — $ 122 Other investment liabilities (2 ) (4,220 ) — (4,222 ) Net investments at fair value $ 7,347 $ 652 $ 232 $ 8,231 Securities valued at NAV $ 16 Total net assets $ 8,247 Non-U.S. pension and postretirement benefit plans In millions of dollars Fair value measurement at December 31, 2016 Asset categories Level 1 Level 2 Level 3 Total U.S. equities $ 4 $ 11 $ — $ 15 Non-U.S. equities 87 174 1 262 Mutual funds 2,345 406 — 2,751 Commingled funds 22 — — 22 Debt securities 3,406 1,206 7 4,619 Real estate — 3 1 4 Annuity contracts — 1 8 9 Derivatives — 43 — 43 Other investments 1 — 187 188 Total investments $ 5,865 $ 1,844 $ 204 $ 7,913 Cash and short-term investments $ 116 $ 2 $ — $ 118 Other investment liabilities (1 ) (960 ) — (961 ) Net investments at fair value $ 5,980 $ 886 $ 204 $ 7,070 Securities valued at NAV $ 92 Total net assets $ 7,162
Schedule of effect of significant unobservable inputs, changes in plan assets	The reconciliations of the beginning and ending balances during the year for Level 3 assets are as follows: In millions of dollars U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2016 Realized gains (losses) Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2017 Annuity contracts $ 1 $ — $ — $ — $ — $ 1 Other investments 4 18 — 22 Total investments $ 5 $ — $ — $ 18 $ — $ 23 In millions of dollars U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2015 Realized gains (losses) Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2016 Annuity contracts $ 25 $ — $ (3 ) $ (21 ) $ — $ 1 Other investments 149 8 (10 ) (143 ) — 4 U.S. equities — (2 ) 2 — — — Total investments $ 174 $ 6 $ (11 ) $ (164 ) $ — $ 5 In millions of dollars Non-U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2016 Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2017 Non-U.S. equities $ 1 $ — $ — $ — $ 1 Debt securities 7 — — — 7 Real estate 1 — — — 1 Annuity contracts 8 1 — — 9 Other investments 187 31 (4 ) — 214 Total investments $ 204 $ 32 $ (4 ) $ — $ 232 In millions of dollars Non-U.S. pension and postretirement benefit plans Asset categories Beginning Level 3 fair value at Dec. 31, 2015 Unrealized gains (losses) Purchases, sales and issuances Transfers in and/or out of Level 3 Ending Level 3 fair value at Dec. 31, 2016 Non-U.S. equities $ 47 $ (3 ) $ (2 ) $ (41 ) $ 1 Debt securities 5 — 2 — 7 Real estate 1 — — — 1 Annuity contracts 8 — — — 8 Other investments 196 — (9 ) — 187 Total investments $ 257 $ (3 ) $ (9 ) $ (41 ) $ 204
Schedule of expected benefit payments	The Company expects to pay the following estimated benefit payments in future years: Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans 2018 $ 787 $ 432 $ 61 $ 65 2019 814 398 60 70 2020 846 425 59 75 2021 864 434 58 81 2022 876 457 56 87 2023–2027 4,480 2,532 248 532
Defined contribution plans	The following table summarizes the Company contributions for the defined contribution plans: U.S. plans In millions of dollars 2017 2016 2015 Company contributions $ 383 $ 371 $ 380 Non-U.S. plans In millions of dollars 2017 2016 2015 Company contributions $ 270 $ 268 $ 282

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax provision	Details of the Company’s income tax provision are presented below: Income Tax Provision In millions of dollars 2017 2016 2015 Current Federal $ 332 $ 1,016 $ 861 Non-U.S. 3,910 3,585 3,397 State 269 384 388 Total current income taxes $ 4,511 $ 4,985 $ 4,646 Deferred Federal $ 24,902 $ 1,280 $ 3,019 Non-U.S. (377 ) 53 (4 ) State 352 126 (221 ) Total deferred income taxes $ 24,877 $ 1,459 $ 2,794 Provision for income tax on continuing operations before non-controlling interests (1) $ 29,388 $ 6,444 $ 7,440 Provision (benefit) for income taxes on discontinued operations 7 (22 ) (29 ) Income tax expense (benefit) reported in stockholders’ equity related to: FX translation 188 (402 ) (906 ) Investment securities (149 ) 59 (498 ) Employee stock plans (4 ) 13 (35 ) Cash flow hedges (12 ) 27 176 Benefit plans 13 (30 ) (24 ) FVO DVA (250 ) (201 ) — Retained earnings (2) (295 ) — — Income taxes before non-controlling interests $ 28,886 $ 5,888 $ 6,124 (1) Includes the effect of securities transactions and other-than-temporary-impairment losses resulting in a provision (benefit) of $272 million and $(22) million in 2017, $332 million and $(217) million in 2016 and $239 million and $(93) million in 2015, respectively. (2) Reflects the tax effect of the accounting change for ASU 2017-08, “ Premium Amortization on Purchased Callable Debt Securities ”. See Note 1 to the Consolidated Financial Statements.
Schedule of effective income tax rate reconciliation	The reconciliation of the federal statutory income tax rate to the Company’s effective income tax rate applicable to income from continuing operations (before non-controlling interests and the cumulative effect of accounting changes) for each of the periods indicated is as follows: 2017 2016 2015 Federal statutory rate 35.0 % 35.0 % 35.0 % State income taxes, net of federal benefit 1.1 1.8 1.7 Non-U.S. income tax rate differential (1.6 ) (3.6 ) (4.6 ) Audit settlements (1) — (0.6 ) (1.7 ) Effect of tax law changes (2) 99.7 — 0.4 Basis difference in affiliates (2.1 ) (0.1 ) — Tax advantaged investments (2.2 ) (2.4 ) (1.8 ) Other, net (0.8 ) (0.1 ) 1.0 Effective income tax rate 129.1 % 30.0 % 30.0 % (1) For 2016, primarily relates to the conclusion of an IRS audit for 2012–2013. For 2015, primarily relates to the conclusion of a New York City tax audit for 2009–2011. (2) For 2017, includes the $22,594 million charge for Tax Reform. For 2015, includes the results of tax reforms enacted in New York City and several states, which resulted in a DTA charge of approximately $101 million .
Schedule of deferred tax assets and liabilities	Deferred income taxes at December 31 related to the following: In millions of dollars 2017 2016 Deferred tax assets Credit loss deduction $ 3,423 $ 5,146 Deferred compensation and employee benefits 1,585 3,798 Repositioning and settlement reserves 454 1,033 U.S. tax on non-U.S. earnings 2,452 10,050 Investment and loan basis differences 3,384 5,594 Cash flow hedges 233 327 Tax credit and net operating loss carry-forwards 21,575 20,793 Fixed assets and leases 1,090 1,739 Other deferred tax assets 1,988 2,714 Gross deferred tax assets $ 36,184 $ 51,194 Valuation allowance $ 9,387 $ — Deferred tax assets after valuation allowance $ 26,797 $ 51,194 Deferred tax liabilities Intangibles $ (1,247 ) $ (1,711 ) Debt issuances (294 ) (641 ) Non-U.S. withholding taxes (668 ) (739 ) Interest-related items (562 ) (765 ) Other deferred tax liabilities (1,545 ) (670 ) Gross deferred tax liabilities $ (4,316 ) $ (4,526 ) Net deferred tax assets $ 22,481 $ 46,668
Summary of unrecognized tax benefits	The following is a rollforward of the Company’s unrecognized tax benefits: In millions of dollars 2017 2016 2015 Total unrecognized tax benefits at January 1 $ 1,092 $ 1,235 $ 1,060 Net amount of increases for current year’s tax positions 43 34 32 Gross amount of increases for prior years’ tax positions 324 273 311 Gross amount of decreases for prior years’ tax positions (246 ) (225 ) (61 ) Amounts of decreases relating to settlements (199 ) (174 ) (45 ) Reductions due to lapse of statutes of limitation (11 ) (21 ) (22 ) Foreign exchange, acquisitions and dispositions 10 (30 ) (40 ) Total unrecognized tax benefits at December 31 $ 1,013 $ 1,092 $ 1,235
Schedule of income tax penalties and interest accrued	Interest and penalties (not included in “unrecognized tax benefits” above) are a component of Provision for income taxes . 2017 2016 2015 In millions of dollars Pretax Net of tax Pretax Net of tax Pretax Net of tax Total interest and penalties on the Consolidated Balance Sheet at January 1 $ 260 $ 164 $ 233 $ 146 $ 269 $ 169 Total interest and penalties in the Consolidated Statement of Income 5 21 105 68 (29 ) (18 ) Total interest and penalties on the Consolidated Balance Sheet at December 31 (1) 121 101 260 164 233 146 (1) Includes $3 million for non-U.S. penalties in 2017, 2016 and 2015. Also includes $3 million for state penalties in 2017, 2016 and 2015.
Schedule of major jurisdictions and earliest tax year subject to examination	The following are the major tax jurisdictions in which the Company and its affiliates operate and the earliest tax year subject to examination: Jurisdiction Tax year United States 2014 Mexico 2011 New York State and City 2009 United Kingdom 2014 India 2014 Singapore 2011 Hong Kong 2011 Ireland 2013
Schedule of deferred tax assets and liabilities by jurisdiction	The following table summarizes Citi’s DTAs: In billions of dollars Jurisdiction/component (1) DTAs balance December 31, 2017 DTAs balance December 31, 2016 U.S. federal (2) Net operating losses (NOLs) (3) $ 2.3 $ 3.5 Foreign tax credits (FTCs) 7.6 14.2 General business credits (GBCs) 1.4 0.9 Future tax deductions and credits 4.8 21.9 Total U.S. federal $ 16.1 $ 40.5 State and local New York NOLs $ 2.3 $ 2.2 Other state NOLs 0.2 0.2 Future tax deductions 1.3 1.7 Total state and local $ 3.8 $ 4.1 Non-U.S. NOLs $ 0.6 $ 0.6 Future tax deductions 2.0 1.5 Total non-U.S. $ 2.6 $ 2.1 Total $ 22.5 $ 46.7 (1) All amounts are net of valuation allowances. (2) Included in the net U.S. federal DTAs of $16.1 billion as of December 31, 2017 were deferred tax liabilities of $2.4 billion that will reverse in the relevant carry-forward period and may be used to support the DTAs. (3) Consists of non-consolidated tax return NOL carry-forwards that are eventually expected to be utilized in Citigroup’s consolidated tax return.
Summary of tax carryforwards	The following table summarizes the amounts of tax carry-forwards and their expiration dates: In billions of dollars Year of expiration December 31, 2017 December 31, 2016 U.S. tax return foreign tax credit carry-forwards (1) 2018 $ 0.4 $ 2.7 2019 1.3 1.3 2020 3.2 3.1 2021 2.0 1.9 2022 3.4 3.3 2023 (2) 0.4 0.5 2025 (2) 1.4 1.4 2027 (2) 1.2 — Total U.S. tax return foreign tax credit carry-forwards $ 13.3 $ 14.2 U.S. tax return general business credit carry-forwards 2032 $ 0.2 $ — 2033 0.3 0.3 2034 0.2 0.2 2035 0.2 0.2 2036 0.2 0.2 2037 0.3 — Total U.S. tax return general business credit carry-forwards $ 1.4 $ 0.9 U.S. subsidiary separate federal NOL carry-forwards 2027 $ 0.2 $ 0.2 2028 0.1 0.1 2030 0.3 0.3 2032 0.1 — 2033 1.6 1.7 2034 2.3 2.3 2035 3.3 3.2 2036 2.1 2.2 2037 1.0 — Total U.S. subsidiary separate federal NOL carry-forwards (3) $ 11.0 $ 10.0 New York State NOL carry-forwards (3) 2034 $ 13.6 $ 13.0 New York City NOL carry-forwards (3) 2034 $ 13.1 $ 12.2 Non-U.S. NOL carry-forwards (1) Various $ 2.0 $ 2.1 (1) Before valuation allowance. (2) The $3.0 billion in FTC carry-forwards that expire in 2023, 2025 and 2027 are in a non-consolidated tax return entity but are eventually expected to be utilized (net of valuation allowances) in Citigroup’s consolidated tax return. (3) Pretax.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Reconciliation of the income and share data used in the basic and diluted earnings per share computations	The following table reconciles the income and share data used in the basic and diluted earnings per share (EPS) computations: In millions, except per-share amounts 2017 2016 2015 Income (loss) from continuing operations before attribution of noncontrolling interests $ (6,627 ) $ 15,033 $ 17,386 Less: Noncontrolling interests from continuing operations 60 63 90 Net income (loss) from continuing operations (for EPS purposes) $ (6,687 ) $ 14,970 $ 17,296 Income (loss) from discontinued operations, net of taxes (111 ) (58 ) (54 ) Citigroup's net income (loss) $ (6,798 ) $ 14,912 $ 17,242 Less: Preferred dividends (1) 1,213 1,077 769 Net income (loss) available to common shareholders $ (8,011 ) $ 13,835 $ 16,473 Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS 37 195 224 Net income (loss) allocated to common shareholders for basic EPS $ (8,048 ) $ 13,640 $ 16,249 Add: Interest expense, net of tax, and dividends on convertible securities and adjustment of undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to diluted EPS — — — Net income (loss) allocated to common shareholders for diluted EPS $ (8,048 ) $ 13,640 $ 16,249 Weighted-average common shares outstanding applicable to basic EPS 2,698.5 2,888.1 3,004.0 Effect of dilutive securities (2) Options (3) — 0.1 3.6 Other employee plans non-dividend eligible — 0.1 0.1 Adjusted weighted-average common shares outstanding applicable to diluted EPS (4) 2,698.5 2,888.3 3,007.7 Basic earnings per share (5) Income (loss) from continuing operations $ (2.94 ) $ 4.74 $ 5.43 Discontinued operations (0.04 ) (0.02 ) (0.02 ) Net income (loss) $ (2.98 ) $ 4.72 $ 5.41 Diluted earnings per share (5) Income (loss) from continuing operations $ (2.94 ) $ 4.74 $ 5.42 Discontinued operations (0.04 ) (0.02 ) (0.02 ) Net income (loss) $ (2.98 ) $ 4.72 $ 5.40 (1) See Note 20 to the Consolidated Financial Statements for the potential future impact of preferred stock dividends. (2) Warrants issued to the U.S. Treasury as part of the Troubled Asset Relief Program (TARP) and the loss-sharing agreement (all of which were subsequently sold to the public in January 2011), with exercise prices of $178.50 and $104.96 per share for approximately 21.0 million and 25.5 million shares of Citigroup common stock, respectively. Both warrants were not included in the computation of earnings per share in 2017 , 2016 and 2015 because they were anti-dilutive. (3) During 2017 , 2016 and 2015 , weighted-average options to purchase 0.8 million , 4.2 million and 0.9 million shares of common stock, respectively, were outstanding but not included in the computation of earnings per share because the weighted-average exercise prices of $204.80 , $98.01 and $199.16 per share, respectively, were anti-dilutive. (4) Due to rounding, common shares outstanding applicable to basic EPS and the effect of dilutive securities may not sum to common shares outstanding applicable to diluted EPS. (5) Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.

FEDERAL FUNDS, SECURITIES BOR49

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	Federal funds sold and securities borrowed or purchased under agreements to resell , at their respective carrying values, consisted of the following: December 31 December 31 In millions of dollars 2017 2016 Federal funds sold $ — $ — Securities purchased under agreements to resell 130,984 131,473 Deposits paid for securities borrowed 101,494 105,340 Total (1) $ 232,478 $ 236,813
Federal funds purchased and securities loaned or sold under agreements to repurchase	Federal funds purchased and securities loaned or sold under agreements to repurchase , at their respective carrying values, consisted of the following: December 31 December 31 In millions of dollars 2017 2016 Federal funds purchased $ 326 $ 178 Securities sold under agreements to repurchase 142,646 125,685 Deposits received for securities loaned 13,305 15,958 Total (1) $ 156,277 $ 141,821 (1) The above tables do not include securities-for-securities lending transactions of $14.0 billion and $9.3 billion at December 31, 2017 and December 31, 2016, respectively, where the Company acts as lender and receives securities that can be sold or pledged as collateral. In these transactions, the Company recognizes the securities received at fair value within Other assets and the obligation to return those securities as a liability within Brokerage payables .
Schedule of gross and net resale agreements and securities borrowing agreements and the related offsetting amount permitted as well as not permitted under ASC 210-20-45	The following tables present the gross and net resale and repurchase agreements and securities borrowing and lending agreements and the related offsetting amount permitted under ASC 210-20-45. The tables also include amounts related to financial instruments that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default occurred and a legal opinion supporting enforceability of the offsetting rights has been obtained. Remaining exposures continue to be secured by financial collateral, but the Company may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right. As of December 31, 2017 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 204,460 $ 73,476 $ 130,984 $ 103,022 $ 27,962 Deposits paid for securities borrowed 101,494 — 101,494 22,271 79,223 Total $ 305,954 $ 73,476 $ 232,478 $ 125,293 $ 107,185 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 216,122 $ 73,476 $ 142,646 $ 73,716 $ 68,930 Deposits received for securities loaned 13,305 — 13,305 4,079 9,226 Total $ 229,427 $ 73,476 $ 155,951 $ 77,795 $ 78,156 As of December 31, 2016 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 176,284 $ 44,811 $ 131,473 $ 102,874 $ 28,599 Deposits paid for securities borrowed 105,340 — 105,340 16,200 89,140 Total $ 281,624 $ 44,811 $ 236,813 $ 119,074 $ 117,739 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 170,496 $ 44,811 $ 125,685 $ 63,517 $ 62,168 Deposits received for securities loaned 15,958 — 15,958 3,529 12,429 Total $ 186,454 $ 44,811 $ 141,643 $ 67,046 $ 74,597 (1) Includes financial instruments subject to enforceable master netting agreements that are permitted to be offset under ASC 210-20-45. (2) The total of this column for each period excludes federal funds sold/purchased. See tables above. (3) Includes financial instruments subject to enforceable master netting agreements that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default has occurred and a legal opinion supporting enforceability of the offsetting right has been obtained. (4) Remaining exposures continue to be secured by financial collateral, but Citi may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right.
Schedule of gross and net repurchase agreements and securities lending agreements and the related offsetting amount permitted as well as not permitted under ASC 210-20-45	The following tables present the gross and net resale and repurchase agreements and securities borrowing and lending agreements and the related offsetting amount permitted under ASC 210-20-45. The tables also include amounts related to financial instruments that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default occurred and a legal opinion supporting enforceability of the offsetting rights has been obtained. Remaining exposures continue to be secured by financial collateral, but the Company may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right. As of December 31, 2017 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 204,460 $ 73,476 $ 130,984 $ 103,022 $ 27,962 Deposits paid for securities borrowed 101,494 — 101,494 22,271 79,223 Total $ 305,954 $ 73,476 $ 232,478 $ 125,293 $ 107,185 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 216,122 $ 73,476 $ 142,646 $ 73,716 $ 68,930 Deposits received for securities loaned 13,305 — 13,305 4,079 9,226 Total $ 229,427 $ 73,476 $ 155,951 $ 77,795 $ 78,156 As of December 31, 2016 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 176,284 $ 44,811 $ 131,473 $ 102,874 $ 28,599 Deposits paid for securities borrowed 105,340 — 105,340 16,200 89,140 Total $ 281,624 $ 44,811 $ 236,813 $ 119,074 $ 117,739 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 170,496 $ 44,811 $ 125,685 $ 63,517 $ 62,168 Deposits received for securities loaned 15,958 — 15,958 3,529 12,429 Total $ 186,454 $ 44,811 $ 141,643 $ 67,046 $ 74,597 (1) Includes financial instruments subject to enforceable master netting agreements that are permitted to be offset under ASC 210-20-45. (2) The total of this column for each period excludes federal funds sold/purchased. See tables above. (3) Includes financial instruments subject to enforceable master netting agreements that are not permitted to be offset under ASC 210-20-45 but would be eligible for offsetting to the extent that an event of default has occurred and a legal opinion supporting enforceability of the offsetting right has been obtained. (4) Remaining exposures continue to be secured by financial collateral, but Citi may not have sought or been able to obtain a legal opinion evidencing enforceability of the offsetting right.
Gross amount of liabilities associated with repurchase agreements and securities lending agreements	The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by remaining contractual maturity: As of December 31, 2017 In millions of dollars Open and overnight Up to 30 days 31–90 days Greater than 90 days Total Securities sold under agreements to repurchase $ 82,073 $ 68,372 $ 33,846 $ 31,831 $ 216,122 Deposits received for securities loaned 9,946 266 1,912 1,181 13,305 Total $ 92,019 $ 68,638 $ 35,758 $ 33,012 $ 229,427 As of December 31, 2016 In millions of dollars Open and overnight Up to 30 days 31–90 days Greater than 90 days Total Securities sold under agreements to repurchase $ 79,740 $ 50,399 $ 19,396 $ 20,961 $ 170,496 Deposits received for securities loaned 10,813 2,169 2,044 932 15,958 Total $ 90,553 $ 52,568 $ 21,440 $ 21,893 $ 186,454 The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by class of underlying collateral: As of December 31, 2017 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 58,774 $ — $ 58,774 State and municipal securities 1,605 — 1,605 Foreign government securities 89,576 105 89,681 Corporate bonds 20,194 657 20,851 Equity securities 20,724 11,907 32,631 Mortgage-backed securities 17,791 — 17,791 Asset-backed securities 5,479 — 5,479 Other 1,979 636 2,615 Total $ 216,122 $ 13,305 $ 229,427 As of December 31, 2016 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 66,263 $ — $ 66,263 State and municipal securities 334 — 334 Foreign government securities 52,988 1,390 54,378 Corporate bonds 17,164 630 17,794 Equity securities 12,206 13,913 26,119 Mortgage-backed securities 11,421 — 11,421 Asset-backed securities 5,428 — 5,428 Other 4,692 25 4,717 Total $ 170,496 $ 15,958 $ 186,454

BROKERAGE RECEIVABLES AND BRO50

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES (Tables)	12 Months Ended
	Dec. 31, 2017
Brokers and Dealers [Abstract]
Brokerage receivables and Brokerage payables	Brokerage receivables and Brokerage payables consisted of the following: December 31, In millions of dollars 2017 2016 Receivables from customers $ 19,215 $ 10,374 Receivables from brokers, dealers and clearing organizations 19,169 18,513 Total brokerage receivables (1) $ 38,384 $ 28,887 Payables to customers $ 38,741 $ 37,237 Payables to brokers, dealers and clearing organizations 22,601 19,915 Total brokerage payables (1) $ 61,342 $ 57,152 (1) Includes brokerage receivables and payables recorded by Citi broker-dealer entities that are accounted for in accordance with the AICPA Accounting Guide for Brokers and Dealers in Securities as codified in ASC 940-320.

INVESTMENTS (Tables)

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of investments	The following table presents Citi’s investments by category: December 31, In millions of dollars 2017 2016 Securities available-for-sale (AFS) $ 290,914 $ 299,424 Debt securities held-to-maturity (HTM) (1) 53,320 45,667 Non-marketable equity securities carried at fair value (2) 1,206 1,774 Non-marketable equity securities carried at cost (3) 6,850 6,439 Total investments $ 352,290 $ 353,304 (1) Carried at adjusted amortized cost basis, net of any credit-related impairment. (2) Unrealized gains and losses for non-marketable equity securities carried at fair value are recognized in earnings. (3) Primarily consists of shares issued by the Federal Reserve Bank, Federal Home Loan Banks, and various clearing houses of which Citigroup is a member.
Interest and dividends on investments	The following table presents interest and dividend income on investments: In millions of dollars 2017 2016 2015 Taxable interest $ 7,538 $ 6,858 $ 6,433 Interest exempt from U.S. federal income tax 535 549 196 Dividend income 222 175 388 Total interest and dividend income $ 8,295 $ 7,582 $ 7,017
Realized gains and losses on investments	The following table presents realized gains and losses on the sale of investments, which excludes losses from other-than-temporary impairment (OTTI): In millions of dollars 2017 2016 2015 Gross realized investment gains $ 1,039 $ 1,460 $ 1,124 Gross realized investment losses (261 ) (512 ) (442 ) Net realized gains on sale of investments $ 778 $ 948 $ 682
Schedule of gain (loss) on HTM securities sold, securities reclassified to AFS and OTTI recorded on AFS securities reclassified	The following table sets forth, for the periods indicated, the carrying value of HTM securities sold and reclassified to AFS, as well as the related gain (loss) or the OTTI losses recorded on these securities. In millions of dollars 2017 2016 2015 Carrying value of HTM securities sold $ 81 $ 49 $ 392 Net realized gain (loss) on sale of HTM securities 13 14 10 Carrying value of securities reclassified to AFS 74 150 243 OTTI losses on securities reclassified to AFS — (6 ) (15 )
Amortized cost and fair value of AFS	The amortized cost and fair value of AFS securities were as follows: 2017 2016 In millions of dollars Amortized cost Gross unrealized gains Gross unrealized losses Fair value Amortized cost Gross unrealized gains Gross unrealized losses Fair value Debt securities AFS Mortgage-backed securities (1) U.S. government-sponsored agency guaranteed $ 42,116 $ 125 $ 500 $ 41,741 $ 38,663 $ 248 $ 506 $ 38,405 Prime 11 6 — 17 2 — — 2 Alt-A 26 90 — 116 43 7 — 50 Non-U.S. residential 2,744 13 6 2,751 3,852 13 7 3,858 Commercial 334 — 2 332 357 2 1 358 Total mortgage-backed securities $ 45,231 $ 234 $ 508 $ 44,957 $ 42,917 $ 270 $ 514 $ 42,673 U.S. Treasury and federal agency securities U.S. Treasury $ 108,344 $ 77 $ 971 $ 107,450 $ 113,606 $ 629 $ 452 $ 113,783 Agency obligations 10,813 7 124 10,696 9,952 21 85 9,888 Total U.S. Treasury and federal agency securities $ 119,157 $ 84 $ 1,095 $ 118,146 $ 123,558 $ 650 $ 537 $ 123,671 State and municipal (2) $ 8,870 $ 140 $ 245 $ 8,765 $ 10,797 $ 80 $ 757 $ 10,120 Foreign government 100,615 508 590 100,533 98,112 590 554 98,148 Corporate 14,144 51 86 14,109 17,195 105 176 17,124 Asset-backed securities (1) 3,906 14 2 3,918 6,810 6 22 6,794 Other debt securities 297 — — 297 503 — — 503 Total debt securities AFS $ 292,220 $ 1,031 $ 2,526 $ 290,725 $ 299,892 $ 1,701 $ 2,560 $ 299,033 Marketable equity securities AFS $ 186 $ 4 $ 1 $ 189 $ 377 $ 20 $ 6 $ 391 Total securities AFS $ 292,406 $ 1,035 $ 2,527 $ 290,914 $ 300,269 $ 1,721 $ 2,566 $ 299,424 (1) The Company invests in mortgage-backed and asset-backed securities. These securitizations are generally considered VIEs. The Company’s maximum exposure to loss from these VIEs is equal to the carrying amount of the securities, which is reflected in the table above. For mortgage-backed and asset-backed securitizations in which the Company has other involvement, see Note 21 to the Consolidated Financial Statements. (2) In the second quarter of 2017, Citi early adopted ASU 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of purchase premiums and cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements.
Fair value of securities in unrealized loss position	The table below shows the fair value of debt securities HTM that have been in an unrecognized loss position: Less than 12 months 12 months or longer Total In millions of dollars Fair Gross Fair Gross Fair Gross December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities $ 46 $ — $ 15,096 $ 157 $ 15,142 $ 157 State and municipal 353 5 835 68 1,188 73 Foreign government 723 18 — — 723 18 Asset-backed securities 71 3 134 19 205 22 Total debt securities held-to-maturity $ 1,193 $ 26 $ 16,065 $ 244 $ 17,258 $ 270 December 31, 2016 Debt securities held-to-maturity Mortgage-backed securities $ 17 $ — $ 17,176 $ 188 $ 17,193 $ 188 State and municipal 2,200 58 1,210 180 3,410 238 Foreign government 1,313 26 — — 1,313 26 Asset-backed securities 2 — 2,503 5 2,505 5 Total debt securities held-to-maturity $ 3,532 $ 84 $ 20,889 $ 373 $ 24,421 $ 457 Note: Excluded from the gross unrecognized losses presented in the above table are $(117) million and $(496) million of net unrealized losses recorded in AOCI as of December 31, 2017 and December 31, 2016 , respectively, primarily related to the difference between the amortized cost and carrying value of HTM securities that were reclassified from AFS. Substantially all of these net unrecognized losses relate to securities that have been in a loss position for 12 months or longer at December 31, 2017 and December 31, 2016 . The following table shows the fair value of AFS securities that have been in an unrealized loss position: Less than 12 months 12 months or longer Total In millions of dollars Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses December 31, 2017 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 30,994 $ 438 $ 2,206 $ 62 $ 33,200 $ 500 Prime — — — — — — Non-U.S. residential 753 6 — — 753 6 Commercial 150 1 57 1 207 2 Total mortgage-backed securities $ 31,897 $ 445 $ 2,263 $ 63 $ 34,160 $ 508 U.S. Treasury and federal agency securities U.S. Treasury $ 79,050 $ 856 $ 7,404 $ 115 $ 86,454 $ 971 Agency obligations 8,857 110 1,163 14 10,020 124 Total U.S. Treasury and federal agency securities $ 87,907 $ 966 $ 8,567 $ 129 $ 96,474 $ 1,095 State and municipal $ 1,009 $ 11 $ 1,155 $ 234 $ 2,164 $ 245 Foreign government 53,206 356 9,051 234 62,257 590 Corporate 6,737 74 859 12 7,596 86 Asset-backed securities 449 1 25 1 474 2 Other debt securities — — — — — — Marketable equity securities AFS 11 1 — — 11 1 Total securities AFS $ 181,216 $ 1,854 $ 21,920 $ 673 $ 203,136 $ 2,527 December 31, 2016 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 23,534 $ 436 $ 2,236 $ 70 $ 25,770 $ 506 Prime 1 — — — 1 — Non-U.S. residential 486 — 1,276 7 1,762 7 Commercial 75 1 58 — 133 1 Total mortgage-backed securities $ 24,096 $ 437 $ 3,570 $ 77 $ 27,666 $ 514 U.S. Treasury and federal agency securities U.S. Treasury $ 44,342 $ 445 $ 1,335 $ 7 $ 45,677 $ 452 Agency obligations 6,552 83 250 2 6,802 85 Total U.S. Treasury and federal agency securities $ 50,894 $ 528 $ 1,585 $ 9 $ 52,479 $ 537 State and municipal $ 1,616 $ 55 $ 3,116 $ 702 $ 4,732 $ 757 Foreign government 38,226 243 8,973 311 47,199 554 Corporate 7,011 129 1,877 47 8,888 176 Asset-backed securities 411 — 3,213 22 3,624 22 Other debt securities 5 — — — 5 — Marketable equity securities AFS 19 2 24 4 43 6 Total securities AFS $ 122,278 $ 1,394 $ 22,358 $ 1,172 $ 144,636 $ 2,566
Amortized cost and fair value of debt securities by contractual maturity dates	The following table presents the carrying value and fair value of HTM debt securities by contractual maturity dates: December 31, 2017 2016 In millions of dollars Carrying value Fair value Carrying value Fair value Mortgage-backed securities Due within 1 year $ — $ — $ — $ — After 1 but within 5 years 720 720 760 766 After 5 but within 10 years 148 149 54 55 After 10 years (1) 25,231 25,235 23,830 23,810 Total $ 26,099 $ 26,104 $ 24,644 $ 24,631 State and municipal Due within 1 year $ 407 $ 425 $ 406 $ 406 After 1 but within 5 years 259 270 112 110 After 5 but within 10 years 512 524 363 367 After 10 years (1) 7,719 7,983 7,702 7,591 Total $ 8,897 $ 9,202 $ 8,583 $ 8,474 Foreign government Due within 1 year $ 381 $ 381 $ 824 $ 818 After 1 but within 5 years 359 341 515 495 After 5 but within 10 years — — — — After 10 years (1) — — — — Total $ 740 $ 722 $ 1,339 $ 1,313 All other (2) Due within 1 year $ — $ — $ — $ — After 1 but within 5 years — — — — After 5 but within 10 years 1,669 1,680 513 514 After 10 years (1) 15,915 16,044 10,588 10,623 Total $ 17,584 $ 17,724 $ 11,101 $ 11,137 Total debt securities held-to-maturity $ 53,320 $ 53,752 $ 45,667 $ 45,555 (1) Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment rights. (2) Includes corporate and asset-backed securities. The following table presents the amortized cost and fair value of AFS debt securities by contractual maturity dates: December 31, 2017 2016 In millions of dollars Amortized cost Fair value Amortized cost Fair value Mortgage-backed securities (1) Due within 1 year $ 45 $ 45 $ 132 $ 132 After 1 but within 5 years 1,306 1,304 736 738 After 5 but within 10 years 1,376 1,369 2,279 2,265 After 10 years (2) 42,504 42,239 39,770 39,538 Total $ 45,231 $ 44,957 $ 42,917 $ 42,673 U.S. Treasury and federal agency securities Due within 1 year $ 4,913 $ 4,907 $ 4,945 $ 4,945 After 1 but within 5 years 111,236 110,238 101,369 101,323 After 5 but within 10 years 3,008 3,001 17,153 17,314 After 10 years (2) — — 91 89 Total $ 119,157 $ 118,146 $ 123,558 $ 123,671 State and municipal Due within 1 year $ 1,792 $ 1,792 $ 2,093 $ 2,092 After 1 but within 5 years 2,579 2,576 2,668 2,662 After 5 but within 10 years 514 528 335 334 After 10 years (2) 3,985 3,869 5,701 5,032 Total $ 8,870 $ 8,765 $ 10,797 $ 10,120 Foreign government Due within 1 year $ 32,130 $ 32,100 $ 32,540 $ 32,547 After 1 but within 5 years 53,034 53,165 51,008 50,881 After 5 but within 10 years 12,949 12,680 12,388 12,440 After 10 years (2) 2,502 2,588 2,176 2,280 Total $ 100,615 $ 100,533 $ 98,112 $ 98,148 All other (3) Due within 1 year $ 3,998 $ 3,991 $ 2,629 $ 2,628 After 1 but within 5 years 9,047 9,027 12,339 12,334 After 5 but within 10 years 3,415 3,431 6,566 6,528 After 10 years (2) 1,887 1,875 2,974 2,931 Total $ 18,347 $ 18,324 $ 24,508 $ 24,421 Total debt securities AFS $ 292,220 $ 290,725 $ 299,892 $ 299,033 (1) Includes mortgage-backed securities of U.S. government-sponsored agencies. (2) Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment rights. (3) Includes corporate, asset-backed and other debt securities.
Carrying value and fair value of debt securities HTM	The carrying value and fair value of debt securities HTM were as follows: In millions of dollars Adjusted amortized cost basis (1) Net unrealized gains (losses) recognized in AOCI Carrying value (2) Gross unrealized gains Gross unrealized (losses) Fair value December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 23,854 $ 26 $ 23,880 $ 40 $ (157 ) $ 23,763 Prime — — — — — — Alt-A 206 (65 ) 141 57 — 198 Non-U.S. residential 1,887 (46 ) 1,841 65 — 1,906 Commercial 237 — 237 — — 237 Total mortgage-backed securities $ 26,184 $ (85 ) $ 26,099 $ 162 $ (157 ) $ 26,104 State and municipal (4) $ 8,925 $ (28 ) $ 8,897 $ 378 $ (73 ) $ 9,202 Foreign government 740 — 740 — (18 ) 722 Asset-backed securities (3) 17,588 (4 ) 17,584 162 (22 ) 17,724 Total debt securities held-to-maturity $ 53,437 $ (117 ) $ 53,320 $ 702 $ (270 ) $ 53,752 December 31, 2016 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 22,462 $ 33 $ 22,495 $ 47 $ (186 ) $ 22,356 Prime 31 (7 ) 24 10 (1 ) 33 Alt-A 314 (27 ) 287 69 (1 ) 355 Non-U.S. residential 1,871 (47 ) 1,824 49 — 1,873 Commercial 14 — 14 — — 14 Total mortgage-backed securities $ 24,692 $ (48 ) $ 24,644 $ 175 $ (188 ) $ 24,631 State and municipal $ 9,025 $ (442 ) $ 8,583 $ 129 $ (238 ) $ 8,474 Foreign government 1,339 — 1,339 — (26 ) 1,313 Asset-backed securities (3) 11,107 (6 ) 11,101 41 (5 ) 11,137 Total debt securities held-to-maturity (5) $ 46,163 $ (496 ) $ 45,667 $ 345 $ (457 ) $ 45,555 (1) For securities transferred to HTM from Trading account assets , adjusted amortized cost basis is defined as the fair value of the securities at the date of transfer plus any accretion income and less any impairments recognized in earnings subsequent to transfer. For securities transferred to HTM from AFS, adjusted amortized cost basis is defined as the original purchase cost, adjusted for the cumulative accretion or amortization of any purchase discount or premium, plus or minus any cumulative fair value hedge adjustments, net of accretion or amortization, and less any other-than-temporary impairment recognized in earnings. (2) HTM securities are carried on the Consolidated Balance Sheet at adjusted amortized cost basis, plus or minus any unamortized unrealized gains and losses and fair value hedge adjustments recognized in AOCI prior to reclassifying the securities from AFS to HTM. Changes in the values of these securities are not reported in the financial statements, except for the amortization of any difference between the carrying value at the transfer date and par value of the securities, and the recognition of any non-credit fair value adjustments in AOCI in connection with the recognition of any credit impairment in earnings related to securities the Company continues to intend to hold until maturity. (3) The Company invests in mortgage-backed and asset-backed securities. These securitizations are generally considered VIEs. The Company’s maximum exposure to loss from these VIEs is equal to the carrying amount of the securities, which is reflected in the table above. For mortgage-backed and asset-backed securitizations in which the Company has other involvement, see Note 21 to the Consolidated Financial Statements. (4) In the second quarter of 2017, Citi early adopted ASU 2017-08. Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of purchase premiums and cumulative fair value hedge adjustments that would have been recorded under the ASU on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. (5) During the fourth quarter of 2016, securities with a total fair value of approximately $5.8 billion were transferred from AFS to HTM, composed of $5 billion of U.S. government agency mortgage-backed securities and $830 million of municipal securities. The transfer reflects the Company’s intent to hold these securities to maturity or to issuer call, in part, in order to reduce the impact of price volatility on AOCI and certain capital measures under Basel III. While these securities were transferred to HTM at fair value as of the transfer date, no subsequent changes in value may be recorded, other than in connection with the recognition of any subsequent other-than-temporary impairment and the amortization of differences between the carrying values at the transfer date and the par values of each security as an adjustment of yield. Any net unrealized holding losses within AOCI related to the respective securities at the date of transfer, inclusive of any cumulative fair value hedge adjustments, will be amortized as an adjustment of yield in a manner consistent with the amortization of any premium or discount.
Total other-than-temporary impairments recognized	The following tables present total OTTI recognized in earnings: OTTI on Investments and Other Assets Year ended In millions of dollars AFS (1) HTM Other assets Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 2 $ — $ — $ 2 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 2 $ — $ — $ 2 Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise 59 2 — 61 Total impairment losses recognized in earnings $ 61 $ 2 $ — $ 63 (1) Includes OTTI on non-marketable equity securities. OTTI on Investments and Other Assets Year ended In millions of dollars AFS (1)(2) HTM Other (3) Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 3 $ 1 $ — $ 4 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 3 $ 1 $ — $ 4 Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise 246 38 332 616 Total impairment losses recognized in earnings $ 249 $ 39 $ 332 $ 620 (1) Includes OTTI on non-marketable equity securities. (2) Includes a $160 million impairment related to AFS securities affected by changes in the Venezuela exchange rate during the year ended December 31, 2016. (3) The impairment charge is related to the carrying value of an equity investment, which was sold in 2016. OTTI on Investments and Other Assets Year ended December 31, 2015 In millions of dollars AFS (1) HTM Other Total Impairment losses related to securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ 33 $ 1 $ — $ 34 Less: portion of impairment loss recognized in AOCI (before taxes) — — — — Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell $ 33 $ 1 $ — $ 34 Impairment losses recognized in earnings for securities that the Company intends to sell or more-likely-than-not will be required to sell before recovery 182 43 6 231 Total impairment losses recognized in earnings $ 215 $ 44 $ 6 $ 265 (1) Includes OTTI on non-marketable equity securities.
Cumulative other-than-temporary impairment credit losses recognized in earnings	The following are 12-month rollforwards of the credit-related impairments recognized in earnings for AFS and HTM debt securities held that the Company does not intend to sell nor likely will be required to sell: Cumulative OTTI credit losses recognized in earnings on securities still held In millions of dollars Dec. 31, 2016 balance Credit Credit Reductions due to (1) Dec. 31, 2017 balance AFS debt securities Mortgage-backed securities (1)(2) $ — $ — $ — $ 38 $ 38 State and municipal 4 — — — 4 Foreign government securities — — — — — Corporate 5 — — (1 ) 4 All other debt securities 22 — 2 (22 ) 2 Total OTTI credit losses recognized for AFS debt securities $ 31 $ — $ 2 $ 15 $ 48 HTM debt securities Mortgage-backed securities (1)(3) $ 101 $ — $ — $ (47 ) $ 54 State and municipal 3 — — — 3 Total OTTI credit losses recognized for HTM debt securities $ 104 $ — $ — $ (47 ) $ 57 (1) Includes $38 million in cumulative OTTI reclassified from HTM to AFS due to the transfer of the related securities from HTM to AFS. (2) Primarily consists of Prime securities. (3) Primarily consists of Alt-A securities. Cumulative OTTI credit losses recognized in earnings on securities still held In millions of dollars Dec. 31, 2015 balance Credit Credit Reductions due to Dec. 31, 2016 balance AFS debt securities Mortgage-backed securities $ — $ 1 $ — $ (1 ) $ — State and municipal 12 — — (8 ) 4 Foreign government securities 5 — — (5 ) — Corporate 9 1 1 (6 ) 5 All other debt securities 47 — — (25 ) 22 Total OTTI credit losses recognized for AFS debt securities $ 73 $ 2 $ 1 $ (45 ) $ 31 HTM debt securities Mortgage-backed securities (1) $ 132 $ — $ — $ (31 ) $ 101 State and municipal 4 1 — (2 ) 3 Total OTTI credit losses recognized for HTM debt securities $ 136 $ 1 $ — $ (33 ) $ 104 (1) Primarily consists of Alt-A securities.
Investments in alternative investment funds	Fair value Unfunded Redemption frequency (if currently eligible) monthly, quarterly, annually Redemption notice period In millions of dollars December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Hedge funds $ 1 $ 4 $ — $ — Generally quarterly 10–95 days Private equity funds (1)(2) 372 348 62 82 — — Real estate funds (2)(3) 31 56 20 20 — — Total $ 404 $ 408 $ 82 $ 102 — — (1) Private equity funds include funds that invest in infrastructure, emerging markets and venture capital. (2) With respect to the Company’s investments in private equity funds and real estate funds, distributions from each fund will be received as the underlying assets held by these funds are liquidated. It is estimated that the underlying assets of these funds will be liquidated over a period of several years as market conditions allow. Private equity and real estate funds do not allow redemption of investments by their investors. Investors are permitted to sell or transfer their investments, subject to the approval of the general partner or investment manager of these funds, which generally may not be unreasonably withheld. (3) Includes several real estate funds that invest primarily in commercial real estate in the U.S., Europe and Asia.

LOANS (Tables)

LOANS (Tables)	12 Months Ended
	Dec. 31, 2017
Consumer
Loans receivable
Schedule of loans	The following table provides Citi’s consumer loans by loan type: December 31, In millions of dollars 2017 2016 In U.S. offices Mortgage and real estate (1) $ 65,467 $ 72,957 Installment, revolving credit and other 3,398 3,395 Cards 139,006 132,654 Commercial and industrial 7,840 7,159 $ 215,711 $ 216,165 In offices outside the U.S. Mortgage and real estate (1) $ 44,081 $ 42,803 Installment, revolving credit and other 26,556 24,887 Cards 26,257 23,783 Commercial and industrial 20,238 16,568 Lease financing 76 81 $ 117,208 $ 108,122 Total consumer loans $ 332,919 $ 324,287 Net unearned income $ 737 $ 776 Consumer loans, net of unearned income $ 333,656 $ 325,063 (1) Loans secured primarily by real estate.
Schedule of loan delinquency and non-accrual details	Consumer Loan Delinquency and Non-Accrual Details at December 31, 2017 In millions of dollars Total current (1)(2) 30–89 days past due (3) ≥ 90 days past due (3) Past due government guaranteed (4) Total loans (2) Total non-accrual 90 days past due and accruing In North America offices Residential first mortgages (5) $ 47,366 $ 505 $ 280 $ 1,225 $ 49,376 $ 665 $ 941 Home equity loans (6)(7) 14,268 207 352 — 14,827 750 — Credit cards 136,588 1,528 1,613 — 139,729 — 1,596 Installment and other 3,395 45 16 — 3,456 22 1 Commercial market loans 9,395 51 65 — 9,511 213 15 Total $ 211,012 $ 2,336 $ 2,326 $ 1,225 $ 216,899 $ 1,650 $ 2,553 In offices outside North America Residential first mortgages (5) $ 37,062 $ 209 $ 148 $ — $ 37,419 $ 400 $ — Credit cards 24,934 427 366 — 25,727 323 259 Installment and other 25,634 275 123 — 26,032 157 — Commercial market loans 27,449 57 72 — 27,578 160 — Total $ 115,079 $ 968 $ 709 $ — $ 116,756 $ 1,040 $ 259 Total GCB and Corporate/Other— consumer $ 326,091 $ 3,304 $ 3,035 $ 1,225 $ 333,655 $ 2,690 $ 2,812 Other (8) 1 — — — 1 — — Total Citigroup $ 326,092 $ 3,304 $ 3,035 $ 1,225 $ 333,656 $ 2,690 $ 2,812 (1) Loans less than 30 days past due are presented as current. (2) Includes $25 million of residential first mortgages recorded at fair value. (3) Excludes loans guaranteed by U.S. government-sponsored entities. (4) Consists of residential first mortgages that are guaranteed by U.S. government-sponsored entities that are 30–89 days past due of $0.2 billion and 90 days or more past due of $1.0 billion . (5) Includes approximately $0.1 billion of residential first mortgage loans in process of foreclosure. (6) Includes approximately $0.1 billion of home equity loans in process of foreclosure. (7) Fixed-rate home equity loans and loans extended under home equity lines of credit, which are typically in junior lien positions. (8) Represents loans classified as consumer loans on the Consolidated Balance Sheet that are not included in GCB or Corporate/Other consumer credit metrics. Consumer Loan Delinquency and Non-Accrual Details at December 31, 2016 In millions of dollars Total current (1)(2) 30–89 days past due (3) ≥ 90 days past due (3) Past due government guaranteed (4) Total loans (2) Total non-accrual 90 days past due and accruing In North America offices Residential first mortgages (5) $ 50,766 $ 522 $ 371 $ 1,474 $ 53,133 $ 848 $ 1,227 Home equity loans (6)(7) 18,767 249 438 — 19,454 914 — Credit cards 130,327 1,465 1,509 — 133,301 — 1,509 Installment and other 4,486 106 38 — 4,630 70 2 Commercial market loans 8,876 23 74 — 8,973 328 14 Total $ 213,222 $ 2,365 $ 2,430 $ 1,474 $ 219,491 $ 2,160 $ 2,752 In offices outside North America Residential first mortgages (5) $ 35,862 $ 206 $ 135 $ — $ 36,203 $ 360 $ — Credit cards 22,363 368 324 — 23,055 258 239 Installment and other 22,683 264 126 — 23,073 163 — Commercial market loans 23,054 72 112 — 23,238 217 — Total $ 103,962 $ 910 $ 697 $ — $ 105,569 $ 998 $ 239 Total GCB and Corporate/Other— consumer $ 317,184 $ 3,275 $ 3,127 $ 1,474 $ 325,060 $ 3,158 $ 2,991 Other (9) 3 — — — 3 — — Total Citigroup $ 317,187 $ 3,275 $ 3,127 $ 1,474 $ 325,063 $ 3,158 $ 2,991 (1) Loans less than 30 days past due are presented as current. (2) Includes $29 million of residential first mortgages recorded at fair value. (3) Excludes loans guaranteed by U.S. government-sponsored entities. (4) Consists of residential first mortgages that are guaranteed by U.S. government-sponsored entities that are 30–89 days past due of $0.2 billion and 90 days or more past due of $1.3 billion . (5) Includes approximately $0.1 billion of residential first mortgage loans in process of foreclosure. (6) Includes approximately $0.1 billion of home equity loans in process of foreclosure. (7) Fixed-rate home equity loans and loans extended under home equity lines of credit, which are typically in junior lien positions. (8) Represents loans classified as consumer loans on the Consolidated Balance Sheet that are not included in the Corporate/Other consumer credit metrics.
Schedule of loans credit quality indicators	The following tables provide details on the LTV ratios for Citi’s U.S. consumer mortgage portfolios. LTV ratios are updated monthly using the most recent Core Logic Home Price Index data available for substantially all of the portfolio applied at the Metropolitan Statistical Area level, if available, or the state level if not. The remainder of the portfolio is updated in a similar manner using the Federal Housing Finance Agency indices. LTV distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 43,626 $ 2,578 $ 247 Home equity loans 11,403 2,147 800 Total $ 55,029 $ 4,725 $ 1,047 LTV distribution in U.S. portfolio (1)(2) December 31, 2016 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 45,849 $ 3,467 $ 324 Home equity loans 12,869 3,653 1,305 Total $ 58,718 $ 7,120 $ 1,629 (1) Excludes loans guaranteed by U.S. government entities, loans subject to LTSCs with U.S. government-sponsored entities and loans recorded at fair value. (2) Excludes balances where LTV was not available. Such amounts are not material. The following tables provide details on the FICO scores for Citi’s U.S. consumer loan portfolio based on end-of-period receivables (commercial market loans are excluded from the table since they are business based and FICO scores are not a primary driver in their credit evaluation). FICO scores are updated monthly for substantially all of the portfolio or, otherwise, on a quarterly basis for the remaining portfolio. FICO score distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than 620 ≥ 620 but less than 660 Equal to or Residential first mortgages $ 2,100 $ 1,932 $ 42,265 Home equity loans 1,379 1,081 11,976 Credit cards 9,079 11,651 115,577 Installment and other 276 250 2,485 Total $ 12,834 $ 14,914 $ 172,303 FICO score distribution in U.S. portfolio (1)(2) December 31, 2016 In millions of dollars Less than 620 ≥ 620 but less than 660 Equal to or greater than 660 Residential first mortgages $ 2,744 $ 2,422 $ 44,279 Home equity loans 1,750 1,418 14,743 Credit cards 8,310 11,320 110,522 Installment and other 284 271 2,601 Total $ 13,088 $ 15,431 $ 172,145 (1) Excludes loans guaranteed by U.S. government entities, loans subject to long-term standby commitments (LTSCs) with U.S. government-sponsored entities and loans recorded at fair value. (2) Excludes balances where FICO was not available. Such amounts are not material.
Schedule of impaired loans	The following tables present information about impaired consumer loans and interest income recognized on impaired consumer loans: At and for the year ended December 31, 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income recognized (5) Mortgage and real estate Residential first mortgages $ 2,877 $ 3,121 $ 278 $ 3,155 $ 119 Home equity loans 1,151 1,590 216 1,181 28 Credit cards 1,787 1,819 614 1,803 150 Installment and other Individual installment and other 431 460 175 415 25 Commercial market loans 334 541 51 429 20 Total $ 6,580 $ 7,531 $ 1,334 $ 6,983 $ 342 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount and direct write-downs and includes accrued interest only on credit card loans. (2) $607 million of residential first mortgages, $370 million of home equity loans and $10 million of commercial market loans do not have a specific allowance. (3) Included in the Allowance for loan losses . (4) Average carrying value represents the average recorded investment ending balance for the last four quarters and does not include the related specific allowance. (5) Includes amounts recognized on both an accrual and cash basis. At and for the year ended December 31, 2016 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income (5)(6) Mortgage and real estate Residential first mortgages $ 3,786 $ 4,157 $ 540 $ 4,632 $ 170 Home equity loans 1,298 1,824 189 1,326 35 Credit cards 1,747 1,781 566 1,831 158 Installment and other Individual installment and other 455 481 215 475 27 Commercial market loans 513 744 98 538 12 Total $ 7,799 $ 8,987 $ 1,608 $ 8,802 $ 402 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount and direct write-downs and includes accrued interest only on credit card loans. (2) $740 million of residential first mortgages, $406 million of home equity loans and $97 million of commercial market loans do not have a specific allowance. (3) Included in the Allowance for loan losses . (4) Average carrying value represents the average recorded investment ending balance for the last four quarters and does not include the related specific allowance. (5) Includes amounts recognized on both an accrual and cash basis. (6) Interest income recognized for the year ended December 31, 2015 was $ 728 million .
Schedule of troubled debt restructurings	At and for the year ended December 31, 2017 In millions of dollars except number of loans modified Number of loans modified Post- modification recorded investment (1)(2) Deferred principal (3) Contingent principal forgiveness (4) Principal forgiveness (5) Average interest rate reduction North America Residential first mortgages 4,063 $ 580 $ 6 $ — $ 2 1 % Home equity loans 2,807 247 16 — 1 1 Credit cards 230,042 880 — — — 17 Installment and other revolving 1,088 8 — — — 5 Commercial banking (6) 112 117 — — — — Total (8) 238,112 $ 1,832 $ 22 $ — $ 3 International Residential first mortgages 4,477 $ 123 $ — $ — $ — — % Credit cards 115,941 399 — — 7 11 Installment and other revolving 44,880 254 — — 11 9 Commercial banking (6) 370 50 — — — — Total (8) 165,668 $ 826 $ — $ — $ 18 At and for the year ended December 31, 2016 In millions of dollars except number of loans modified Number of loans modified Post- modification recorded investment (1)(7) Deferred principal (3) Contingent principal forgiveness (4) Principal forgiveness (5) Average interest rate reduction North America Residential first mortgages 5,023 $ 726 $ 6 $ — $ 3 1 % Home equity loans 4,100 200 6 — 1 2 Credit cards 196,004 762 — — — 17 Installment and other revolving 5,649 47 — — — 14 Commercial banking (6) 132 91 — — — — Total (8) 210,908 $ 1,826 $ 12 $ — $ 4 International Residential first mortgages 2,722 $ 80 $ — $ — $ — — % Credit cards 137,466 385 — — 9 12 Installment and other revolving 60,094 276 — — 7 7 Commercial banking (6) 162 109 — — — — Total (8) 200,444 $ 850 $ — $ — $ 16 (1) Post-modification balances include past due amounts that are capitalized at the modification date. (2) Post-modification balances in North America include $ 53 million of residential first mortgages and $ 21 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the year ended December 31, 2017 . These amounts include $ 36 million of residential first mortgages and $ 18 million of home equity loans that were newly classified as TDRs during 2017, based on previously received OCC guidance. (3) Represents portion of contractual loan principal that is non-interest bearing, but still due from the borrower. Such deferred principal is charged off at the time of permanent modification to the extent that the related loan balance exceeds the underlying collateral value. (4) Represents portion of contractual loan principal that is non-interest bearing and, depending upon borrower performance, eligible for forgiveness. (5) Represents portion of contractual loan principal that was forgiven at the time of permanent modification. (6) Commercial banking loans are generally borrower-specific modifications and incorporate changes in the amount and/or timing of principal and/or interest. (7) Post-modification balances in North America include $ 74 million of residential first mortgages and $ 22 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the year ended December 31, 2016 . These amounts include $ 48 million of residential first mortgages and $ 20 million of home equity loans that were newly classified as TDRs during 2016, based on previously received OCC guidance. (8) The above tables reflect activity for loans outstanding as of the end of the reporting period that were considered TDRs.
Schedule of troubled debt restructuring loans that defaulted	The following table presents consumer TDRs that defaulted, for which the payment default occurred within one year of a permanent modification. Default is defined as 60 days past due, except for classifiably managed commercial banking loans, where default is defined as 90 days past due. In millions of dollars 2017 2016 North America Residential first mortgages $ 253 $ 229 Home equity loans 46 25 Credit cards 221 188 Installment and other revolving 2 9 Commercial banking 2 15 Total $ 524 $ 466 International Residential first mortgages $ 11 $ 11 Credit cards 185 148 Installment and other revolving 96 90 Commercial banking 1 37 Total $ 293 $ 286
Corporate
Loans receivable
Schedule of loans	The following table presents information by corporate loan type: In millions of dollars December 31, December 31, In U.S. offices Commercial and industrial $ 51,319 $ 49,586 Financial institutions 39,128 35,517 Mortgage and real estate (1) 44,683 38,691 Installment, revolving credit and other 33,181 34,501 Lease financing 1,470 1,518 $ 169,781 $ 159,813 In offices outside the U.S. Commercial and industrial $ 93,750 $ 81,882 Financial institutions 35,273 26,886 Mortgage and real estate (1) 7,309 5,363 Installment, revolving credit and other 22,638 19,965 Lease financing 190 251 Governments and official institutions 5,200 5,850 $ 164,360 $ 140,197 Total corporate loans $ 334,141 $ 300,010 Net unearned income $ (763 ) $ (704 ) Corporate loans, net of unearned income $ 333,378 $ 299,306 (1) Loans secured primarily by real estate.
Schedule of loan delinquency and non-accrual details	Corporate Loan Delinquency and Non-Accrual Details at December 31, 2017 In millions of dollars 30–89 days past due and accruing (1) ≥ 90 days past due and accruing (1) Total past due and accruing Total non-accrual (2) Total current (3) Total loans (4) Commercial and industrial $ 249 $ 13 $ 262 $ 1,506 $ 139,554 $ 141,322 Financial institutions 93 15 108 92 73,557 73,757 Mortgage and real estate 147 59 206 195 51,563 51,964 Leases 68 8 76 46 1,533 1,655 Other 70 13 83 103 60,145 60,331 Loans at fair value 4,349 Total $ 627 $ 108 $ 735 $ 1,942 $ 326,352 $ 333,378 Corporate Loan Delinquency and Non-Accrual Details at December 31, 2016 In millions of dollars 30–89 days past due and accruing (1) ≥ 90 days past due and accruing (1) Total past due and accruing Total non-accrual (2) Total current (3) Total loans (4) Commercial and industrial $ 143 $ 52 $ 195 $ 1,909 $ 127,012 $ 129,116 Financial institutions 119 2 121 185 61,254 61,560 Mortgage and real estate 148 137 285 139 43,607 44,031 Leases 27 8 35 56 1,678 1,769 Other 349 12 361 132 58,880 59,373 Loans at fair value 3,457 Total $ 786 $ 211 $ 997 $ 2,421 $ 292,431 $ 299,306 (1) Corporate loans that are 90 days past due are generally classified as non-accrual. Corporate loans are considered past due when principal or interest is contractually due but unpaid. (2) Non-accrual loans generally include those loans that are ≥ 90 days past due or those loans for which Citi believes, based on actual experience and a forward-looking assessment of the collectability of the loan in full, that the payment of interest or principal is doubtful. (3) Loans less than 30 days past due are presented as current. (4) Total loans include loans at fair value, which are not included in the various delinquency columns.
Schedule of loans credit quality indicators	Corporate Loans Credit Quality Indicators Recorded investment in loans (1) In millions of dollars December 31, 2017 December 31, Investment grade (2) Commercial and industrial $ 101,313 $ 87,201 Financial institutions 60,404 50,597 Mortgage and real estate 23,213 18,718 Leases 1,090 1,303 Other 56,306 52,828 Total investment grade $ 242,326 $ 210,647 Non-investment grade (2) Accrual Commercial and industrial $ 38,503 $ 39,874 Financial institutions 13,261 10,873 Mortgage and real estate 2,881 1,821 Leases 518 410 Other 3,924 6,450 Non-accrual Commercial and industrial 1,506 1,909 Financial institutions 92 185 Mortgage and real estate 195 139 Leases 46 56 Other 103 132 Total non-investment grade $ 61,029 $ 61,849 Private bank loans managed on a delinquency basis (2) $ 25,674 $ 23,353 Loans at fair value 4,349 3,457 Corporate loans, net of unearned income $ 333,378 $ 299,306 (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount, less any direct write-downs. (2) Held-for-investment loans are accounted for on an amortized cost basis.
Schedule of impaired loans	The following tables present non-accrual loan information by corporate loan type and interest income recognized on non-accrual corporate loans: Non-Accrual Corporate Loans At and for the year ended December 31, 2017 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Interest income recognized (3) Non-accrual corporate loans Commercial and industrial $ 1,506 $ 1,775 $ 368 $ 1,547 $ 23 Financial institutions 92 102 41 212 1 Mortgage and real estate 195 324 11 183 10 Lease financing 46 46 4 59 — Other 103 212 2 108 1 Total non-accrual corporate loans $ 1,942 $ 2,459 $ 426 $ 2,109 $ 35 At and for the year ended December 31, 2016 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Interest income recognized (3) Non-accrual corporate loans Commercial and industrial $ 1,909 $ 2,259 $ 362 $ 1,919 $ 25 Financial institutions 185 192 16 183 3 Mortgage and real estate 139 250 10 174 6 Lease financing 56 56 4 44 — Other 132 197 — 87 6 Total non-accrual corporate loans $ 2,421 $ 2,954 $ 392 $ 2,407 $ 40 December 31, 2017 December 31, 2016 In millions of dollars Recorded investment (1) Related specific allowance Recorded investment (1) Related specific allowance Non-accrual corporate loans with valuation allowances Commercial and industrial $ 1,017 $ 368 $ 1,343 $ 362 Financial institutions 88 41 45 16 Mortgage and real estate 51 11 41 10 Lease financing 46 4 55 4 Other 13 2 1 — Total non-accrual corporate loans with specific allowance $ 1,215 $ 426 $ 1,485 $ 392 Non-accrual corporate loans without specific allowance Commercial and industrial $ 489 $ 566 Financial institutions 4 140 Mortgage and real estate 144 98 Lease financing — 1 Other 90 131 Total non-accrual corporate loans without specific allowance $ 727 N/A $ 936 N/A (1) Recorded investment in a loan includes net deferred loan fees and costs, unamortized premium or discount, less any direct write-downs. (2) Average carrying value represents the average recorded investment balance and does not include related specific allowance. (3) Interest income recognized for the year ended December 31, 2015 was $11 million . N/A Not applicable
Schedule of troubled debt restructurings	Corporate Troubled Debt Restructurings The following table presents corporate TDR activity at and for the year ended December 31, 2017 : In millions of dollars Carrying Value TDRs involving changes in the amount and/or timing of principal payments (1) TDRs involving changes in the amount and/or timing of interest payments (2) TDRs involving changes in the amount and/or timing of both principal and interest payments Commercial and industrial $ 509 $ 131 $ 7 $ 371 Financial institutions 15 — — 15 Mortgage and real estate 36 — — 36 Total $ 560 $ 131 $ 7 $ 422 The following table presents corporate TDR activity at and for the year ended December 31, 2016 : In millions of dollars Carrying Value TDRs involving changes in the amount and/or timing of principal payments (1) TDRs involving changes in the amount and/or timing of interest payments (2) TDRs involving changes in the amount and/or timing of both principal and interest payments Commercial and industrial $ 338 $ 176 $ 34 $ 128 Financial institutions 10 10 — — Mortgage and real estate 15 6 — 9 Other 142 — 142 — Total $ 505 $ 192 $ 176 $ 137 (1) TDRs involving changes in the amount or timing of principal payments may involve principal forgiveness or deferral of periodic and/or final principal payments. Because forgiveness of principal is rare for corporate loans, modifications typically have little to no impact on the loans’ projected cash flows and thus little to no impact on the allowance established for the loans. Charge-offs for amounts deemed uncollectable may be recorded at the time of the restructuring or may have already been recorded in prior periods such that no charge-off is required at the time of the modification. (2) TDRs involving changes in the amount or timing of interest payments may involve a below-market interest rate.
Schedule of troubled debt restructuring loans that defaulted	The following table presents total corporate loans modified in a TDR as well as those TDRs that defaulted and for which the payment default occurred within one year of a permanent modification. Default is defined as 60 days past due, except for classifiably managed commercial banking loans, where default is defined as 90 days past due. In millions of dollars TDR balances at December 31, 2017 TDR loans in payment default during the year ended December 31, 2017 TDR balances at December 31, 2016 TDR loans in payment default during the year ended December 31, 2016 Commercial and industrial $ 617 $ 72 $ 408 $ 7 Financial institutions 48 — 9 — Mortgage and real estate 101 — 87 8 Lease financing 7 — — — Other 45 — 228 — Total (1) $ 818 $ 72 $ 732 $ 15 (1) The above tables reflect activity for loans outstanding as of the end of the reporting period that were considered TDRs.

ALLOWANCE FOR CREDIT LOSSES (Ta

ALLOWANCE FOR CREDIT LOSSES (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for credit losses	In millions of dollars 2017 2016 2015 Allowance for loan losses at beginning of period $ 12,060 $ 12,626 $ 15,994 Gross credit losses (8,673 ) (8,222 ) (9,041 ) Gross recoveries (1) 1,597 1,661 1,739 Net credit losses (NCLs) $ (7,076 ) $ (6,561 ) $ (7,302 ) NCLs $ 7,076 $ 6,561 $ 7,302 Net reserve builds (releases) 544 340 139 Net specific reserve releases (117 ) (152 ) (333 ) Total provision for loan losses $ 7,503 $ 6,749 $ 7,108 Other, net (see table below) (132 ) (754 ) (3,174 ) Allowance for loan losses at end of period $ 12,355 $ 12,060 $ 12,626 Allowance for credit losses on unfunded lending commitments at beginning of period $ 1,418 $ 1,402 $ 1,063 Provision (release) for unfunded lending commitments (161 ) 29 74 Other, net (2) 1 (13 ) 265 Allowance for credit losses on unfunded lending commitments at end of period (3) $ 1,258 $ 1,418 $ 1,402 Total allowance for loans, leases and unfunded lending commitments $ 13,613 $ 13,478 $ 14,028 (1) Recoveries have been reduced by certain collection costs that are incurred only if collection efforts are successful. (2) 2015 includes a reclassification of $271 million of Allowance for loan losses to Allowance for unfunded lending commitments, included in Other, net. This reclassification reflects the re-attribution of $271 million in Allowances for credit losses between the funded and unfunded portions of the corporate credit portfolios and does not reflect a change in the underlying credit performance of these portfolios. (3) Represents additional credit loss reserves for unfunded lending commitments and letters of credit recorded in Other liabilities on the Consolidated Balance Sheet. Other, net details: In millions of dollars 2017 2016 2015 Sales or transfers of various consumer loan portfolios to held-for-sale Transfer of real estate loan portfolios $ (106 ) $ (106 ) $ (1,462 ) Transfer of other loan portfolios (155 ) (468 ) (948 ) Sales or transfers of various consumer loan portfolios to held-for-sale $ (261 ) $ (574 ) $ (2,410 ) FX translation, consumer 115 (199 ) (474 ) Other 14 19 (290 ) Other, net $ (132 ) $ (754 ) $ (3,174 )
Schedule of allowance for credit losses and investment in loans by portfolio segment	Allowance for Credit Losses and Investment in Loans at December 31, 2017 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,702 $ 9,358 $ 12,060 Charge-offs (491 ) (8,182 ) (8,673 ) Recoveries 112 1,485 1,597 Replenishment of net charge-offs 379 6,697 7,076 Net reserve builds (releases) (267 ) 811 544 Net specific reserve builds (releases) 28 (145 ) (117 ) Other 23 (155 ) (132 ) Ending balance $ 2,486 $ 9,869 $ 12,355 Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,060 $ 8,531 $ 10,591 Individually evaluated in accordance with ASC 310-10-35 426 1,334 1,760 Purchased credit-impaired in accordance with ASC 310-30 — 4 4 Total allowance for loan losses $ 2,486 $ 9,869 $ 12,355 Loans, net of unearned income Collectively evaluated for impairment in accordance with ASC 450 $ 327,142 $ 326,884 $ 654,026 Individually evaluated for impairment in accordance with ASC 310-10-35 1,887 6,580 8,467 Purchased credit-impaired in accordance with ASC 310-30 — 167 167 Held at fair value 4,349 25 4,374 Total loans, net of unearned income $ 333,378 $ 333,656 $ 667,034 Allowance for Credit Losses and Investment in Loans at December 31, 2016 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,791 $ 9,835 $ 12,626 Charge-offs (580 ) (7,642 ) (8,222 ) Recoveries 67 1,594 1,661 Replenishment of net charge-offs 513 6,048 6,561 Net reserve builds (releases) (85 ) 425 340 Net specific reserve builds (releases) — (152 ) (152 ) Other (4 ) (750 ) (754 ) Ending balance $ 2,702 $ 9,358 $ 12,060 Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,310 $ 7,744 $ 10,054 Individually evaluated in accordance with ASC 310-10-35 392 1,608 2,000 Purchased credit-impaired in accordance with ASC 310-30 — 6 6 Total allowance for loan losses $ 2,702 $ 9,358 $ 12,060 Loans, net of unearned income Collectively evaluated for impairment in accordance with ASC 450 $ 293,218 $ 317,048 $ 610,266 Individually evaluated for impairment in accordance with ASC 310-10-35 2,631 7,799 10,430 Purchased credit-impaired in accordance with ASC 310-30 — 187 187 Held at fair value 3,457 29 3,486 Total loans, net of unearned income $ 299,306 $ 325,063 $ 624,369 Allowance for Credit Losses at December 31, 2015 In millions of dollars Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,447 $ 13,547 $ 15,994 Charge-offs (349 ) (8,692 ) (9,041 ) Recoveries 105 1,634 1,739 Replenishment of net charge-offs 244 7,058 7,302 Net reserve builds (releases) 550 (411 ) 139 Net specific reserve builds (releases) 86 (419 ) (333 ) Other (292 ) (2,882 ) (3,174 ) Ending balance $ 2,791 $ 9,835 $ 12,626

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The changes in Goodwill were as follows: In millions of dollars Balance at December 31, 2014 $ 23,592 Foreign exchange translation and other $ (1,000 ) Divestitures (1) (212 ) Impairment of goodwill (2) (31 ) Balance at December 31, 2015 $ 22,349 Foreign exchange translation and other $ (613 ) Divestitures (3) (77 ) Balance at December 31, 2016 $ 21,659 Foreign exchange translation and other $ 729 Divestitures (4) (104 ) Impairment of goodwill (5) (28 ) Balance at December 31, 2017 $ 22,256 The changes in Goodwill by segment were as follows: In millions of dollars Global Consumer Banking Institutional Clients Group Corporate/Other (6) Total Balance at December 31, 2015 (7) $ 12,704 $ 9,545 $ 100 $ 22,349 Foreign exchange translation and other $ (174 ) $ (447 ) $ 8 $ (613 ) Divestitures (3) — (13 ) (64 ) (77 ) Balance at December 31, 2016 $ 12,530 $ 9,085 $ 44 $ 21,659 Foreign exchange translation and other $ 286 $ 443 $ — $ 729 Divestitures (4) (32 ) (72 ) — (104 ) Impairment of goodwill (5) — — (28 ) (28 ) Balance at December 31, 2017 $ 12,784 $ 9,456 $ 16 $ 22,256 (1) Primarily related to the sales of the Latin America Retirement Services and Japan cards businesses completed in 2015, and agreements to sell certain businesses in Citi Holdings as of December 31, 2015. See Note 2 to the Consolidated Financial Statements. (2) Goodwill impairment related to reporting units subsequently sold, including Citi Holdings— Consumer Finance South Korea of $16 million and Citi Holdings— Consumer Latin America of $15 million . (3) Primarily related to the sale of the private equity services business completed in 2016 and agreements to sell Argentina and Brazil consumer operations as of December 31, 2016. (4) Primarily related to the sale of a fixed income analytics business and a fixed income index business completed in 2017 and an agreement to sell a Mexico asset management business as of December 31, 2017. See Note 2 to the Consolidated Financial Statements. (5) Goodwill impairment related to the mortgage servicing business upon transfer from North America GCB to Corporate/Other effective January 1, 2017. (6) All Citi Holdings reporting units are presented in Corporate/Other. See Note 3 to the Consolidated Financial Statements. (7) December 31, 2015 has been restated to reflect intersegment goodwill allocations that resulted from the reorganizations in 2016 and on January 1, 2017 including transfers of GCB businesses to ICG and to Corporate/Other . See Note 3 to the Consolidated Financial Statements.
Components of intangible assets, finite-lived	The components of intangible assets were as follows: December 31, 2017 December 31, 2016 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,375 $ 3,836 $ 1,539 $ 8,215 $ 6,549 $ 1,666 Credit card contract related intangibles 5,045 2,456 2,589 5,149 2,177 2,972 Core deposit intangibles 639 628 11 801 771 30 Other customer relationships 459 272 187 474 272 202 Present value of future profits 32 28 4 31 27 4 Indefinite-lived intangible assets 244 — 244 210 — 210 Other 100 86 14 504 474 30 Intangible assets (excluding MSRs) $ 11,894 $ 7,306 $ 4,588 $ 15,384 $ 10,270 $ 5,114 Mortgage servicing rights (MSRs) (1) 558 — 558 1,564 — 1,564 Total intangible assets $ 12,452 $ 7,306 $ 5,146 $ 16,948 $ 10,270 $ 6,678 (1) In January 2017, Citi signed agreements to effectively exit its U.S. mortgage servicing operations by the end of 2018 and intensify its focus on loan originations. For additional information on these transactions, see Note 2 to the Consolidated Financial Statements.
Components of intangible assets, indefinite-lived	The components of intangible assets were as follows: December 31, 2017 December 31, 2016 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,375 $ 3,836 $ 1,539 $ 8,215 $ 6,549 $ 1,666 Credit card contract related intangibles 5,045 2,456 2,589 5,149 2,177 2,972 Core deposit intangibles 639 628 11 801 771 30 Other customer relationships 459 272 187 474 272 202 Present value of future profits 32 28 4 31 27 4 Indefinite-lived intangible assets 244 — 244 210 — 210 Other 100 86 14 504 474 30 Intangible assets (excluding MSRs) $ 11,894 $ 7,306 $ 4,588 $ 15,384 $ 10,270 $ 5,114 Mortgage servicing rights (MSRs) (1) 558 — 558 1,564 — 1,564 Total intangible assets $ 12,452 $ 7,306 $ 5,146 $ 16,948 $ 10,270 $ 6,678 (1) In January 2017, Citi signed agreements to effectively exit its U.S. mortgage servicing operations by the end of 2018 and intensify its focus on loan originations. For additional information on these transactions, see Note 2 to the Consolidated Financial Statements.
Changes in intangible assets	The changes in intangible assets were as follows: Net carrying Net carrying amount at In millions of dollars December 31, 2016 Acquisitions/ divestitures Amortization Impairments FX translation and other December 31, Purchased credit card relationships $ 1,666 $ 20 $ (149 ) $ — $ 2 $ 1,539 Credit card contract-related intangibles (1) 2,972 9 (393 ) — 1 2,589 Core deposit intangibles 30 — (20 ) — 1 11 Other customer relationships 202 — (24 ) — 9 187 Present value of future profits 4 — — — — 4 Indefinite-lived intangible assets 210 — — — 34 244 Other 30 (14 ) (17 ) — 15 14 Intangible assets (excluding MSRs) $ 5,114 $ 15 $ (603 ) $ — $ 62 $ 4,588 Mortgage servicing rights (MSRs) (2) 1,564 558 Total intangible assets $ 6,678 $ 5,146 (1) Primarily reflects contract-related intangibles associated with the American Airlines, The Home Depot, Costco, Sears and AT&T credit card program agreements, which represent 97% of the aggregate net carrying amount as of December 31, 2017. (2) For additional information on Citi’s MSRs, including the rollforward from 2016 to 2017, see Note 21 to the Consolidated Financial Statements.

DEBT (Tables)

DEBT (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of short-term borrowings	Short-Term Borrowings December 31, 2017 2016 In millions of dollars Balance Weighted average coupon Balance Weighted average coupon Commercial paper $ 9,940 1.28 % $ 9,989 0.79 % Other borrowings (1) 34,512 1.62 20,712 1.39 Total $ 44,452 $ 30,701 (1) Includes borrowings from the Federal Home Loan Banks and other market participants. At December 31, 2017 and December 31, 2016 , collateralized short-term advances from the Federal Home Loan Banks were $23.8 billion and $12.0 billion , respectively.
Schedule of long-term debt	Long-Term Debt Balances at December 31, In millions of dollars Weighted average coupon Maturities 2017 2016 Citigroup Inc. (1) Senior debt 4.15 % 2018-2098 $ 123,488 $ 118,881 Subordinated debt (2) 4.48 2018-2046 26,963 26,758 Trust preferred securities 6.90 2036-2067 1,712 1,694 Bank (3) Senior debt 2.06 2018-2049 65,856 49,454 Broker-dealer (4) Senior debt 3.44 2018-2057 18,666 9,387 Subordinated debt (2) 5.37 2021-2037 24 4 Total 3.57 % $ 236,709 $ 206,178 Senior debt $ 208,010 $ 177,722 Subordinated debt (2) 26,987 26,762 Trust preferred securities 1,712 1,694 Total $ 236,709 $ 206,178 (1) Represents the parent holding company. (2) Includes notes that are subordinated within certain countries, regions or subsidiaries. (3) Represents Citibank entities as well as other bank entities. At December 31, 2017 and December 31, 2016 , collateralized long-term advances from the Federal Home Loan Banks were $19.3 billion and $21.6 billion , respectively. (4) Represents broker-dealer and other non-bank subsidiaries that are consolidated into Citigroup Inc., the parent holding company.
Aggregate annual maturities of long-term debt obligations	Aggregate annual maturities of long-term debt obligations (based on final maturity dates) including trust preferred securities are as follows: In millions of dollars 2018 2019 2020 2021 2022 Thereafter Total Citigroup Inc. $ 20,050 $ 16,656 $ 9,565 $ 15,499 $ 9,627 $ 80,766 $ 152,163 Bank 29,270 17,245 10,302 4,077 1,471 3,491 65,856 Broker-dealer 4,158 2,388 3,321 1,443 1,266 6,114 18,690 Total $ 53,478 $ 36,289 $ 23,188 $ 21,019 $ 12,364 $ 90,371 $ 236,709
Summary of outstanding trust preferred securities	The following table summarizes the Company’s outstanding trust preferred securities at December 31, 2017 : Junior subordinated debentures owned by trust Trust Issuance date Securities issued Liquidation value (1) Coupon rate (2) Common shares issued to parent Amount Maturity Redeemable by issuer beginning In millions of dollars, except share amounts Citigroup Capital III Dec. 1996 194,053 $ 194 7.625 % 6,003 $ 200 Dec. 1, 2036 Not redeemable Citigroup Capital XIII Sept. 2010 89,840,000 2,246 3 mo LIBOR + 637 bps 1,000 2,246 Oct. 30, 2040 Oct. 30, 2015 Citigroup Capital XVIII June 2007 99,901 135 3 mo LIBOR + 88.75 bps 50 135 June 28, 2067 June 28, 2017 Total obligated $ 2,575 $ 2,581 Note: Distributions on the trust preferred securities and interest on the subordinated debentures are payable semiannually for Citigroup Capital III and Citigroup Capital XVIII and quarterly for Citigroup Capital XIII. (1) Represents the notional value received by investors from the trusts at the time of issuance. (2) In each case, the coupon rate on the subordinated debentures is the same as that on the trust preferred securities.

REGULATORY CAPITAL (Tables)

REGULATORY CAPITAL (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of compliance with regulatory capital requirements under banking regulations	The following table sets forth for Citigroup and Citibank the regulatory capital tiers, total risk-weighted assets, quarterly adjusted average total assets, Total Leverage Exposure, risk-based capital ratios and leverage ratios in accordance with current regulatory standards (reflecting Basel III Transition Arrangements): In millions of dollars, except ratios Stated minimum Citigroup Citibank Well- capitalized minimum December 31, 2017 Well- capitalized minimum December 31, 2017 Common Equity Tier 1 Capital $ 147,891 $ 124,733 Tier 1 Capital 164,841 126,303 Total Capital (Tier 1 Capital + Tier 2 Capital) (1) 190,331 139,351 Total risk-weighted assets (2) 1,138,167 1,014,242 Quarterly adjusted average total assets (3) 1,869,206 1,401,615 Total Leverage Exposure (4) 2,433,371 1,901,069 Common Equity Tier 1 Capital ratio (5) 4.5 % N/A 12.99 % 6.5 % 12.30 % Tier 1 Capital ratio (5) 6.0 6.0 % 14.48 8.0 12.45 Total Capital ratio (5) 8.0 10.0 16.77 10.0 14.60 Tier 1 Leverage ratio 4.0 N/A 8.82 5.0 9.01 Supplementary Leverage ratio (6) N/A N/A 6.77 N/A 6.64 (1) Reflected in the table above is Citigroup’s and Citibank’s Total Capital as derived under the Basel III Advanced Approaches framework. At December 31, 2017 , Citigroup’s and Citibank’s Total Capital as derived under the Basel III Standardized Approach was $202 billion and $150 billion , respectively. (2) Reflected in the table above are Citigroup’s and Citibank’s total risk-weighted assets as derived under the Basel III Standardized Approach. At December 31, 2017, Citigroup’s and Citibank’s total risk-weighted assets as derived under the Basel III Advanced Approaches were $1,135 billion and $955 billion , respectively. (3) Tier 1 Leverage ratio denominator. (4) Supplementary Leverage ratio denominator. (5) As of December 31, 2017 , Citigroup’s and Citibank’s reportable Common Equity Tier 1 Capital and Tier 1 Capital ratios were the lower derived under the Basel III Standardized Approach, whereas the reportable Total Capital ratios were the lower derived under the Basel III Advanced Approaches framework. (6) Commencing on January 1, 2018, Citigroup and Citibank will be required to maintain a stated minimum Supplementary Leverage ratio of 3% , and Citibank will be required to maintain a Supplementary Leverage ratio of 6% to be considered “well capitalized.” N/A Not applicable

CHANGES IN ACCUMULATED OTHER 57

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) (Tables)	12 Months Ended
	Dec. 31, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Changes in each component of Accumulated Other Comprehensive Income (Loss)	Changes in each component of Citigroup’s Accumulated other comprehensive income (loss) : In millions of dollars Net Debt valuation adjustment (DVA) (1) Cash flow hedges (2) Benefit plans (3) Foreign (4) Accumulated Balance, December 31, 2014 $ 57 $ — $ (909 ) $ (5,159 ) $ (17,205 ) $ (23,216 ) Other comprehensive income before reclassifications (695 ) — 83 (143 ) (5,465 ) (6,220 ) Increase (decrease) due to amounts reclassified from AOCI (269 ) — 209 186 (34 ) 92 Change, net of taxes $ (964 ) $ — $ 292 $ 43 $ (5,499 ) $ (6,128 ) Balance, December 31, 2015 $ (907 ) $ — $ (617 ) $ (5,116 ) $ (22,704 ) $ (29,344 ) Adjustment to opening balance, net of taxes (1) $ — $ (15 ) $ — $ — $ — $ (15 ) Adjusted balance, beginning of period $ (907 ) $ (15 ) $ (617 ) $ (5,116 ) $ (22,704 ) $ (29,359 ) Other comprehensive income before reclassifications $ 530 $ (335 ) $ (88 ) $ (208 ) $ (2,802 ) $ (2,903 ) Increase (decrease) due to amounts reclassified from AOCI (422 ) (2 ) 145 160 — (119 ) Change, net of taxes $ 108 $ (337 ) $ 57 $ (48 ) $ (2,802 ) $ (3,022 ) Balance, December 31, 2016 $ (799 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ (32,381 ) Adjustment to opening balance, net of taxes (5) $ 504 $ — $ — $ — $ — $ 504 Adjusted balance, beginning of period $ (295 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ (31,877 ) Impact of Tax Reform (6) (223 ) (139 ) (113 ) (1,020 ) (1,809 ) (3,304 ) Other comprehensive income before reclassifications (186 ) (426 ) (111 ) (158 ) 1,607 726 Increase (decrease) due to amounts reclassified from AOCI (454 ) (4 ) 86 159 — (213 ) Change, net of taxes $ (863 ) $ (569 ) $ (138 ) $ (1,019 ) $ (202 ) $ (2,791 ) Balance at December 31, 2017 $ (1,158 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ (34,668 ) (1) Beginning in the first quarter of 2016, changes in DVA are reflected as a component of AOCI, pursuant to the adoption of only the provisions of ASU 2016-01 relating to the presentation of DVA on fair value option liabilities. See Note 1 to the Consolidated Financial Statements for further information regarding this change. (2) Primarily driven by Citi’s pay fixed/receive floating interest rate swap programs that hedge the floating rates on liabilities. (3) Primarily reflects adjustments based on the quarterly actuarial valuations of Citi’s significant pension and postretirement plans, annual actuarial valuations of all other plans and amortization of amounts previously recognized in Other comprehensive income. (4) Primarily reflects the movements in (by order of impact) the Euro, Mexican peso, Polish zloty and Korean won against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2017 . Primarily reflects the movements in (by order of impact) the Mexican peso, Euro, British pound and Indian rupee against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2016 . Primarily reflects the movements in (by order of impact) the Mexican peso, Brazilian real, Korean won and Euro against the U.S. dollar and changes in related tax effects and hedges for the year ended December 31, 2015 . (5) In the second quarter of 2017, Citi early adopted ASU No. 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements. (6) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings . See Note 1 to the Consolidated Financial Statements.
Schedule of pretax and after-tax changes in each component of Accumulated other comprehensive income (loss)	The pretax and after-tax changes in each component of Accumulated other comprehensive income (loss) are as follows: In millions of dollars Pretax Tax Effect Adoption of ASU 2018-02 (1) After-tax Balance, December 31, 2014 $ (31,060 ) $ 7,844 $ — $ (23,216 ) Change in net unrealized gains (losses) on investment securities (1,462 ) 498 — (964 ) Cash flow hedges 468 (176 ) — 292 Benefit plans 19 24 — 43 Foreign currency translation adjustment (6,405 ) 906 — (5,499 ) Change $ (7,380 ) $ 1,252 $ — $ (6,128 ) Balance, December 31, 2015 $ (38,440 ) $ 9,096 $ — $ (29,344 ) Adjustment to opening balance (2) (26 ) 11 — (15 ) Adjusted balance, beginning of period $ (38,466 ) $ 9,107 $ — $ (29,359 ) Change in net unrealized gains (losses) on investment securities 167 (59 ) — 108 Debt valuation adjustment (DVA) (538 ) 201 — (337 ) Cash flow hedges 84 (27 ) — 57 Benefit plans (78 ) 30 — (48 ) Foreign currency translation adjustment (3,204 ) 402 — (2,802 ) Change $ (3,569 ) $ 547 $ — $ (3,022 ) Balance, December 31, 2016 $ (42,035 ) $ 9,654 $ — $ (32,381 ) Adjustment to opening balance (3) 803 (299 ) — 504 Adjusted balance, beginning of period $ (41,232 ) $ 9,355 $ — $ (31,877 ) Change in net unrealized gains (losses) on investment securities (1,088 ) 448 (223 ) (863 ) Debt valuation adjustment (DVA) (680 ) 250 (139 ) (569 ) Cash flow hedges (37 ) 12 (113 ) (138 ) Benefit plans 14 (13 ) (1,020 ) (1,019 ) Foreign currency translation adjustment 1,795 (188 ) (1,809 ) (202 ) Change $ 4 $ 509 $ (3,304 ) $ (2,791 ) Balance, December 31, 2017 $ (41,228 ) $ 9,864 $ (3,304 ) $ (34,668 ) (1) In the fourth quarter of 2017, Citi adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings . See Note 1 to the Consolidated Financial Statements. (2) Represents the $(15) million adjustment related to the initial adoption of ASU 2016-01. See Note 1 to the Consolidated Financial Statements. (3) In the second quarter of 2017, Citi early adopted ASU 2017-08 . Upon adoption, a cumulative effect adjustment was recorded to reduce retained earnings, effective January 1, 2017, for the incremental amortization of cumulative fair value hedge adjustments on callable state and municipal debt securities. See Note 1 to the Consolidated Financial Statements.
Summary of amounts reclassified out of Accumulated other comprehensive income (loss) into the Consolidated Statement of income	The Company recognized pretax gain (loss) related to amounts in AOCI reclassified in the Consolidated Statement of Income as follows: Increase (decrease) in AOCI due to amounts reclassified to Consolidated Statement of Income Year ended December 31, In millions of dollars 2017 2016 2015 Realized (gains) losses on sales of investments $ (778 ) $ (948 ) $ (682 ) OTTI gross impairment losses 63 288 265 Subtotal, pretax $ (715 ) $ (660 ) $ (417 ) Tax effect 261 238 148 Net realized (gains) losses on investment securities, after-tax (1) $ (454 ) $ (422 ) $ (269 ) Realized DVA (gains) losses on fair value option liabilities $ (7 ) $ (3 ) $ — Subtotal, pretax $ (7 ) $ (3 ) $ — Tax effect 3 1 — Net realized debt valuation adjustment, after-tax $ (4 ) $ (2 ) $ — Interest rate contracts $ 126 $ 140 $ 186 Foreign exchange contracts 10 93 146 Subtotal, pretax $ 136 $ 233 $ 332 Tax effect (50 ) (88 ) (123 ) Amortization of cash flow hedges, after-tax (2) $ 86 $ 145 $ 209 Amortization of unrecognized Prior service cost (benefit) $ (42 ) $ (40 ) $ (40 ) Net actuarial loss 271 272 276 Curtailment/settlement impact (3) 17 18 57 Subtotal, pretax $ 246 $ 250 $ 293 Tax effect (87 ) (90 ) (107 ) Amortization of benefit plans, after-tax (3) $ 159 $ 160 $ 186 Foreign currency translation adjustment $ — $ — $ (53 ) Tax effect — — 19 Foreign currency translation adjustment $ — $ — $ (34 ) Total amounts reclassified out of AOCI, pretax $ (340 ) $ (180 ) $ 155 Total tax effect 127 61 (63 ) Total amounts reclassified out of AOCI, after-tax $ (213 ) $ (119 ) $ 92 (1) The pretax amount is reclassified to Realized gains (losses) on sales of investments, net and Gross impairment losses in the Consolidated Statement of Income. See Note 13 to the Consolidated Financial Statements for additional details. (2) See Note 22 to the Consolidated Financial Statements for additional details. (3) See Note 8 to the Consolidated Financial Statements for additional details.

PREFERRED STOCK (Tables)

PREFERRED STOCK (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Summary of preferred stock outstanding	The following table summarizes the Company’s preferred stock outstanding: Redemption Carrying value in millions of dollars Issuance date Redeemable by issuer beginning Dividend Number December 31, December 31, Series AA (1) January 25, 2008 February 15, 2018 8.125 % $ 25 3,870,330 $ 97 $ 97 Series E (2) April 28, 2008 April 30, 2018 8.400 1,000 121,254 121 121 Series A (3) October 29, 2012 January 30, 2023 5.950 1,000 1,500,000 1,500 1,500 Series B (4) December 13, 2012 February 15, 2023 5.900 1,000 750,000 750 750 Series C (5) March 26, 2013 April 22, 2018 5.800 25 23,000,000 575 575 Series D (6) April 30, 2013 May 15, 2023 5.350 1,000 1,250,000 1,250 1,250 Series J (7) September 19, 2013 September 30, 2023 7.125 25 38,000,000 950 950 Series K (8) October 31, 2013 November 15, 2023 6.875 25 59,800,000 1,495 1,495 Series L (9) February 12, 2014 February 12, 2019 6.875 25 19,200,000 480 480 Series M (10) April 30, 2014 May 15, 2024 6.300 1,000 1,750,000 1,750 1,750 Series N (11) October 29, 2014 November 15, 2019 5.800 1,000 1,500,000 1,500 1,500 Series O (12) March 20, 2015 March 27, 2020 5.875 1,000 1,500,000 1,500 1,500 Series P (13) April 24, 2015 May 15, 2025 5.950 1,000 2,000,000 2,000 2,000 Series Q (14) August 12, 2015 August 15, 2020 5.950 1,000 1,250,000 1,250 1,250 Series R (15) November 13, 2015 November 15, 2020 6.125 1,000 1,500,000 1,500 1,500 Series S (16) February 2, 2016 February 12, 2021 6.300 25 41,400,000 1,035 1,035 Series T (17) April 25, 2016 August 15, 2026 6.250 1,000 1,500,000 1,500 1,500 $ 19,253 $ 19,253 (1) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 15, May 15, August 15 and November 15, in each case when, as and if declared by the Citi Board of Directors. (2) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on April 30 and October 30 at a fixed rate until April 30, 2018, thereafter payable quarterly on January 30, April 30, July 30 and October 30 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (3) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on January 30 and July 30 at a fixed rate until January 30, 2023, thereafter payable quarterly on January 30, April 30, July 30 and October 30 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (4) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until February 15, 2023, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (5) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on January 22, April 22, July 22 and October 22 when, as and if declared by the Citi Board of Directors. (6) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until May 15, 2023, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (7) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on March 30, June 30, September 30 and December 30 at a fixed rate until September 30, 2023, thereafter payable quarterly on the same dates at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (8) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 15, May 15, August 15 and November 15 at a fixed rate until November 15, 2023, thereafter payable quarterly on the same dates at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (9) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 12, May 12, August 12 and November 12 at a fixed rate, in each case when, as and if declared by the Citi Board of Directors. (10) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until May 15, 2024, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (11) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, November 15, 2019, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (12) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on March 27 and September 27 at a fixed rate until, but excluding, March 27, 2020, and thereafter payable quarterly on March 27, June 27, September 27 and December 27 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (13) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, May 15, 2025, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (14) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until, but excluding, August 15, 2020, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (15) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on May 15 and November 15 at a fixed rate until, but excluding, November 15, 2020, and thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors. (16) Issued as depositary shares, each representing a 1/1,000 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 12, May 12, August 12 and November 12 at a fixed rate, in each case when, as and if declared by the Citi Board of Directors. (17) Issued as depositary shares, each representing a 1/25 th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable semiannually on February 15 and August 15 at a fixed rate until August 15, 2026, thereafter payable quarterly on February 15, May 15, August 15 and November 15 at a floating rate, in each case when, as and if declared by the Citi Board of Directors.

SECURITIZATIONS AND VARIABLE 59

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2017
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Schedule of consolidated and unconsolidated VIEs with which the Company holds significant variable interests	Citigroup’s involvement with consolidated and unconsolidated VIEs with which the Company holds significant variable interests or has continuing involvement through servicing a majority of the assets in a VIE is presented below: As of December 31, 2017 Maximum exposure to loss in significant unconsolidated VIEs (1) Funded exposures (2) Unfunded exposures In millions of dollars Total involvement with SPE assets Consolidated VIE/SPE assets Significant unconsolidated VIE assets (3) Debt investments Equity investments Funding commitments Guarantees and derivatives Total Credit card securitizations $ 50,795 $ 50,795 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored (5) 116,610 — 116,610 2,647 — — 74 2,721 Non-agency-sponsored 22,251 2,035 20,216 330 — — 1 331 Citi-administered asset-backed commercial paper conduits (ABCP) 19,282 19,282 — — — — — — Collateralized loan obligations (CLOs) 20,588 — 20,588 5,956 — — 9 5,965 Asset-based financing 60,472 633 59,839 19,478 583 5,878 — 25,939 Municipal securities tender option bond trusts (TOBs) 6,925 2,166 4,759 138 — 3,035 — 3,173 Municipal investments 19,119 7 19,112 2,709 3,640 2,344 — 8,693 Client intermediation 958 824 134 32 — — 9 41 Investment funds 1,892 616 1,276 14 7 13 — 34 Other 677 36 641 27 9 34 47 117 Total $ 319,569 $ 76,394 $ 243,175 $ 31,331 $ 4,239 $ 11,304 $ 140 $ 47,014 As of December 31, 2016 Maximum exposure to loss in significant unconsolidated VIEs (1) Funded exposures (2) Unfunded exposures In millions of dollars Total involvement with SPE assets Consolidated VIE/SPE assets Significant unconsolidated VIE assets (3) Debt investments Equity investments Funding commitments Guarantees and derivatives Total Credit card securitizations $ 50,171 $ 50,171 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored 214,458 — 214,458 3,852 — — 78 3,930 Non-agency-sponsored 15,965 1,092 14,873 312 35 — 1 348 Citi-administered asset-backed commercial paper conduits (ABCP) 19,693 19,693 — — — — — — Collateralized loan obligations (CLOs) 18,886 — 18,886 5,128 — — 62 5,190 Asset-based financing 53,168 733 52,435 16,553 475 4,915 — 21,943 Municipal securities tender option bond trusts (TOBs) 7,070 2,843 4,227 40 — 2,842 — 2,882 Municipal investments 17,679 14 17,665 2,441 3,578 2,580 — 8,599 Client intermediation 515 371 144 49 — — 3 52 Investment funds 2,788 767 2,021 32 120 27 3 182 Other 1,429 607 822 116 11 58 43 228 Total $ 401,822 $ 76,291 $ 325,531 $ 28,523 $ 4,219 $ 10,422 $ 190 $ 43,354 (1) The definition of maximum exposure to loss is included in the text that follows this table. (2) Included on Citigroup’s December 31, 2017 and 2016 Consolidated Balance Sheet. (3) A significant unconsolidated VIE is an entity in which the Company has any variable interest or continuing involvement considered to be significant, regardless of the likelihood of loss. (4) Citigroup mortgage securitizations also include agency and non-agency (private-label) re-securitization activities. These SPEs are not consolidated. See “Re-securitizations” below for further discussion. (5) See Note 2 to the Consolidated Financial Statements for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs.
Schedule of funding commitments of unconsolidated Variable Interest Entities	The following table presents the notional amount of liquidity facilities and loan commitments that are classified as funding commitments in the VIE tables above: December 31, 2017 December 31, 2016 In millions of dollars Liquidity facilities Loan/equity commitments Liquidity facilities Loan/equity commitments Asset-based financing $ — $ 5,878 $ 5 $ 4,910 Municipal securities tender option bond trusts (TOBs) 3,035 — 2,842 — Municipal investments — 2,344 — 2,580 Investment funds — 13 — 27 Other — 34 — 58 Total funding commitments $ 3,035 $ 8,269 $ 2,847 $ 7,575
Schedule of significant interests in unconsolidated VIEs - balance sheet classification	The following table presents the carrying amounts and classification of significant variable interests in unconsolidated VIEs: In billions of dollars December 31, 2017 December 31, 2016 Cash $ — $ 0.1 Trading account assets 8.5 8.0 Investments 4.4 4.4 Total loans, net of allowance 22.2 18.8 Other 0.5 1.5 Total assets $ 35.6 $ 32.8
Schedule of securitized credit card receivables	The following table reflects amounts related to the Company’s securitized credit card receivables: In billions of dollars December 31, 2017 December 31, 2016 Ownership interests in principal amount of trust credit card receivables Sold to investors via trust-issued securities $ 28.8 $ 22.7 Retained by Citigroup as trust-issued securities 7.6 7.4 Retained by Citigroup via non-certificated interests 14.4 20.6 Total $ 50.8 $ 50.7 The following table summarizes selected cash flow information related to Citigroup’s credit card securitizations: In billions of dollars 2017 2016 2015 Proceeds from new securitizations $ 11.1 $ 3.3 $ — Pay down of maturing notes (5.0 ) (10.3 ) (7.4 )
Schedule of Master Trust liabilities (at par value)	Master Trust Liabilities (at Par Value) In billions of dollars Dec. 31, 2017 Dec. 31, 2016 Term notes issued to third parties $ 27.8 $ 21.7 Term notes retained by Citigroup affiliates 5.7 5.5 Total Master Trust liabilities $ 33.5 $ 27.2
Schedule of Omni Trust liabilities (at par value)	Omni Trust Liabilities (at Par Value) In billions of dollars Dec. 31, 2017 Dec. 31, 2016 Term notes issued to third parties $ 1.0 $ 1.0 Term notes retained by Citigroup affiliates 1.9 1.9 Total Omni Trust liabilities $ 2.9 $ 2.9
Schedule of cash flow information, mortgage securitizations	The following table summarizes selected cash flow information related to Citigroup mortgage securitizations: 2017 2016 2015 In billions of dollars U.S. agency- Non-agency- U.S. agency- Non-agency- U.S. agency- Non-agency- Proceeds from new securitizations (1) $ 33.9 $ 7.9 $ 41.3 $ 11.8 $ 35.0 $ 12.1 Contractual servicing fees received 0.2 — 0.4 — 0.5 — Cash flows received on retained interests and other net cash flows — — 0.1 — 0.1 — (1) The proceeds from new securitizations in 2016 and 2015 include $0.5 billion and $0.7 billion , respectively, related to personal loan securitizations.
Schedule of key assumptions used in measuring fair value of retained interest at the date of sale or securitization of mortgage receivables	Key assumptions used in measuring the fair value of retained interests at the date of sale or securitization of mortgage receivables were as follows: December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 1.8% to 19.9% — — Weighted average discount rate 8.6 % — — Constant prepayment rate 3.8% to 31.6% — — Weighted average constant prepayment rate 9.4 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 2.5 to 20.7 years — — December 31, 2016 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 0.8% to 13.7% — — Weighted average discount rate 9.9 % — — Constant prepayment rate 3.8% to 30.9% — — Weighted average constant prepayment rate 11.1 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 0.5 to 17.5 years — — (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. (2) Anticipated net credit losses represent estimated loss severity associated with defaulted mortgage loans underlying the mortgage securitizations disclosed above. Anticipated net credit losses, in this instance, do not represent total credit losses incurred to date, nor do they represent credit losses expected on retained interests in mortgage securitizations. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees.
Schedule of key assumptions used to value retained interests and sensitivity of adverse changes of 10% and 20%, mortgage securitizations	The key assumptions used to value retained interests, and the sensitivity of the fair value to adverse changes of 10% and 20% in each of the key assumptions, are set forth in the tables below. The negative effect of each change is calculated independently, holding all other assumptions constant. Because the key assumptions may not be independent, the net effect of simultaneous adverse changes in the key assumptions may be less than the sum of the individual effects shown below. December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 1.8% to 84.2% 5.8% to 100.0% 2.8% to 35.1% Weighted average discount rate 7.1 % 5.8 % 9.0 % Constant prepayment rate 6.9% to 27.8% 8.9% to 15.5% 8.6% to 13.1% Weighted average constant prepayment rate 11.6 % 8.9 % 10.6 % Anticipated net credit losses (2) NM 0.4% to 46.9% 35.1% to 52.1% Weighted average anticipated net credit losses NM 46.9 % 44.9 % Weighted average life 0.1 to 27.8 years 4.8 to 5.3 years 0.2 to 18.6 years December 31, 2016 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 0.7% to 28.2% 0.0% to 8.1% 5.1% to 26.4% Weighted average discount rate 9.0 % 2.1 % 13.1 % Constant prepayment rate 6.8% to 22.8% 4.2% to 14.7% 0.5% to 37.5% Weighted average constant prepayment rate 10.2 % 11.0 % 10.8 % Anticipated net credit losses (2) NM 0.5% to 85.6% 8.0% to 63.7% Weighted average anticipated net credit losses NM 31.4 % 48.3 % Weighted average life 0.2 to 28.8 years 5.0 to 8.5 years 1.2 to 12.1 years (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. (2) Anticipated net credit losses represent estimated loss severity associated with defaulted mortgage loans underlying the mortgage securitizations disclosed above. Anticipated net credit losses, in this instance, do not represent total credit losses incurred to date, nor do they represent credit losses expected on retained interests in mortgage securitizations. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees. December 31, 2017 Non-agency-sponsored mortgages In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests (1) $ 1,634 $ 214 $ 139 Discount rates Adverse change of 10% $ (44 ) $ (2 ) $ (3 ) Adverse change of 20% (85 ) (4 ) (5 ) Constant prepayment rate Adverse change of 10% (41 ) (1 ) (1 ) Adverse change of 20% (84 ) (1 ) (2 ) Anticipated net credit losses Adverse change of 10% NM (3 ) — Adverse change of 20% NM (7 ) — December 31, 2016 Non-agency-sponsored mortgages In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests (1) $ 2,258 $ 26 $ 161 Discount rates Adverse change of 10% $ (71 ) $ (7 ) $ (8 ) Adverse change of 20% (138 ) (14 ) (16 ) Constant prepayment rate Adverse change of 10% (80 ) (2 ) (4 ) Adverse change of 20% (160 ) (3 ) (8 ) Anticipated net credit losses Adverse change of 10% NM (7 ) (1 ) Adverse change of 20% NM (14 ) (2 ) (1) Disclosure of non-agency-sponsored mortgages as senior and subordinated interests is indicative of the interests’ position in the capital structure of the securitization. NM Anticipated net credit losses are not meaningful due to U.S. agency guarantees.
Schedule of changes in capitalized MSRs	The following table summarizes the changes in capitalized MSRs: In millions of dollars 2017 2016 Balance, beginning of year $ 1,564 $ 1,781 Originations 96 152 Changes in fair value of MSRs due to changes in inputs and assumptions 65 (36 ) Other changes (1) (110 ) (313 ) Sale of MSRs (2) (1,057 ) (20 ) Balance, as of December 31 $ 558 $ 1,564 (1) Represents changes due to customer payments and passage of time. (2) See Note 2 to the Consolidated Financial Statements for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs. 2016 amount includes sales of credit-challenged MSRs for which Citi paid the new servicer.
Schedule of fees received on servicing previously securitized mortgages	The Company receives fees during the course of servicing previously securitized mortgages. The amounts of these fees were as follows: In millions of dollars 2017 2016 2015 Servicing fees $ 276 $ 484 $ 552 Late fees 10 14 16 Ancillary fees 13 17 31 Total MSR fees $ 299 $ 515 $ 599
Schedule of key assumptions for measuring fair value of retained interests at the date of sale or securitization of CDOs and CLOs	The following table summarizes selected cash flow information related to Citigroup CLOs: In billions of dollars 2017 2016 2015 Proceeds from new securitizations $ 3.5 $ 5.0 $ 5.9 Cash flows received on retained interests and other net cash flows 0.1 — — The key assumptions used to value retained interests in CLOs, and the sensitivity of the fair value to adverse changes of 10% and 20%, are set forth in the tables below: Dec. 31, 2017 Dec. 31, 2016 Discount rate 1.1% to 1.6% 1.3% to 1.7%
Schedule of sensitivity of adverse changes of 10% and 20% to discount rate, CDOs and CLOs	In millions of dollars Dec. 31, 2017 Dec. 31, 2016 Carrying value of retained interests $ 3,607 $ 4,261 Discount rates Adverse change of 10% $ (24 ) $ (30 ) Adverse change of 20% (47 ) (62 )
Schedule of asset-based financing	The primary types of Citi’s asset-based financings, total assets of the unconsolidated VIEs with significant involvement and Citi’s maximum exposure to loss are shown below. For Citi to realize the maximum loss, the VIE (borrower) would have to default with no recovery from the assets held by the VIE. December 31, 2017 In millions of dollars Total unconsolidated VIE assets Maximum exposure to unconsolidated VIEs Type Commercial and other real estate $ 15,370 $ 5,445 Corporate loans 4,725 3,587 Hedge funds and equities 542 58 Airplanes, ships and other assets 39,202 16,849 Total $ 59,839 $ 25,939 December 31, 2016 In millions of dollars Total unconsolidated VIE assets Maximum exposure to unconsolidated VIEs Type Commercial and other real estate $ 8,784 $ 2,368 Corporate loans 4,051 2,684 Hedge funds and equities 370 54 Airplanes, ships and other assets 39,230 16,837 Total $ 52,435 $ 21,943

DERIVATIVES ACTIVITIES (Tables)

DERIVATIVES ACTIVITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative notionals	Derivative Notionals Hedging instruments under (1)(2) Other derivative instruments Trading derivatives Management hedges (3) In millions of dollars December 31, December 31, December 31, December 31, December 31, December 31, Interest rate contracts Swaps $ 189,779 $ 151,331 $ 18,718,224 $ 19,145,250 $ 35,995 $ 47,324 Futures and forwards — 97 6,447,886 6,864,276 12,653 30,834 Written options — — 3,513,759 2,921,070 2,372 4,759 Purchased options — — 3,230,915 2,768,528 3,110 7,320 Total interest rate contract notionals $ 189,779 $ 151,428 $ 31,910,784 $ 31,699,124 $ 54,130 $ 90,237 Foreign exchange contracts Swaps $ 37,162 $ 19,042 $ 5,538,231 $ 5,492,145 $ 38,126 $ 22,676 Futures, forwards and spot 33,103 56,964 3,080,361 3,251,132 17,339 3,419 Written options 3,951 — 1,127,728 1,194,325 — — Purchased options 6,427 — 1,148,686 1,215,961 — — Total foreign exchange contract notionals $ 80,643 $ 76,006 $ 10,895,006 $ 11,153,563 $ 55,465 $ 26,095 Equity contracts Swaps $ — $ — $ 215,834 $ 192,366 $ — $ — Futures and forwards — — 72,616 37,557 — — Written options — — 389,961 304,579 — — Purchased options — — 328,154 266,070 — — Total equity contract notionals $ — $ — $ 1,006,565 $ 800,572 $ — $ — Commodity and other contracts Swaps $ — $ — $ 82,039 $ 70,774 $ — $ — Futures and forwards 23 182 153,248 142,530 — — Written options — — 62,045 74,627 — — Purchased options — — 60,526 69,629 — — Total commodity and other contract notionals $ 23 $ 182 $ 357,858 $ 357,560 $ — $ — Credit derivatives (4) Protection sold $ — $ — $ 735,142 $ 859,420 $ — $ — Protection purchased — — 766,565 883,003 11,148 19,470 Total credit derivatives $ — $ — $ 1,501,707 $ 1,742,423 $ 11,148 $ 19,470 Total derivative notionals $ 270,445 $ 227,616 $ 45,671,920 $ 45,753,242 $ 120,743 $ 135,802 (1) The notional amounts presented in this table do not include hedge accounting relationships under ASC 815 where Citigroup is hedging the foreign currency risk of a net investment in a foreign operation by issuing a foreign currency-denominated debt instrument. The notional amount of such debt was $63 million and $1,825 million at December 31, 2017 and December 31, 2016 , respectively. (2) Derivatives in hedge accounting relationships accounted for under ASC Topic 815 are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities on the Consolidated Balance Sheet. (3) Management hedges represent derivative instruments used to mitigate certain economic risks, but for which hedge accounting is not applied. These derivatives are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities on the Consolidated Balance Sheet. (4) Credit derivatives are arrangements designed to allow one party (protection buyer) to transfer the credit risk of a “reference asset” to another party (protection seller). These arrangements allow a protection seller to assume the credit risk associated with the reference asset without directly purchasing that asset. The Company enters into credit derivative positions for purposes such as risk management, yield enhancement, reduction of credit concentrations and diversification of overall risk.
Derivative mark-to-market (MTM) receivables/payables	Derivative Mark-to-Market (MTM) Receivables/Payables In millions of dollars at December 31, 2017 Derivatives classified (1)(2)(3) Derivatives classified (2)(3) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Assets Liabilities Over-the-counter $ 644 $ 121 $ 1,325 $ 13 Cleared 71 24 39 68 Interest rate contracts $ 715 $ 145 $ 1,364 $ 81 Over-the-counter $ 885 $ 1,064 $ 258 $ 86 Foreign exchange contracts $ 885 $ 1,064 $ 258 $ 86 Total derivative instruments designated as ASC 815 hedges $ 1,600 $ 1,209 $ 1,622 $ 167 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 195,648 $ 173,921 $ 29 $ 16 Cleared 7,051 10,268 78 113 Exchange traded 102 95 — — Interest rate contracts $ 202,801 $ 184,284 $ 107 $ 129 Over-the-counter $ 118,611 $ 116,962 $ 481 $ 511 Cleared 1,690 2,028 — — Exchange traded 34 121 — — Foreign exchange contracts $ 120,335 $ 119,111 $ 481 $ 511 Over-the-counter $ 17,221 $ 21,201 $ — $ — Cleared 21 25 — — Exchange traded 9,736 10,147 — — Equity contracts $ 26,978 $ 31,373 $ — $ — Over-the-counter $ 13,499 $ 16,362 $ — $ — Exchange traded 604 665 — — Commodity and other contracts $ 14,103 $ 17,027 $ — $ — Over-the-counter $ 12,954 $ 12,895 $ 18 $ 63 Cleared 7,530 8,327 32 248 Credit derivatives $ 20,484 $ 21,222 $ 50 $ 311 Total derivatives instruments not designated as ASC 815 hedges $ 384,701 $ 373,017 $ 638 $ 951 Total derivatives $ 386,301 $ 374,226 $ 2,260 $ 1,118 Cash collateral paid/received (4)(5) $ 7,541 $ 14,296 $ — $ 12 Less: Netting agreements (6) (306,401 ) (306,401 ) — — Less: Netting cash collateral received/paid (7) (37,506 ) (35,659 ) (1,026 ) (7 ) Net receivables/payables included on the Consolidated Balance Sheet (8) $ 49,935 $ 46,462 $ 1,234 $ 1,123 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (872 ) $ (121 ) $ — $ — Less: Non-cash collateral received/paid (12,453 ) (6,929 ) (286 ) — Total net receivables/payables (8) $ 36,610 $ 39,412 $ 948 $ 1,123 (1) The trading derivatives fair values are presented in Note 24 to the Consolidated Financial Statements. (2) Derivative mark-to-market receivables/payables related to management hedges are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities . (3) Over-the-counter (OTC) derivatives are derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. Cleared derivatives include derivatives executed bilaterally with a counterparty in the OTC market, but then novated to a central clearing house, whereby the central clearing house becomes the counterparty to both of the original counterparties. Exchange traded derivatives include derivatives executed directly on an organized exchange that provides pre-trade price transparency. (4) For the trading account assets/liabilities, reflects the net amount of the $43,200 million and $51,801 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $35,659 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $37,506 million was used to offset trading derivative assets. (5) For cash collateral paid with respect to non-trading derivative assets, reflects the net amount of $7 million of gross cash collateral paid, of which $7 million is netted against non-trading derivative positions within Other liabilities . For cash collateral received with respect to non-trading derivative liabilities, reflects the net amount of $1,038 million of gross cash collateral received, of which $1,026 million is netted against OTC non-trading derivative positions within Other assets . (6) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $283 billion , $14 billion and $9 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange traded derivatives, respectively. (7) Represents the netting of cash collateral paid and received by counterparty under enforceable credit support agreements. Substantially all cash collateral received and paid is netted against OTC derivative assets and liabilities, respectively. (8) The net receivables/payables include approximately $6 billion of derivative asset and $8 billion of derivative liability fair values not subject to enforceable master netting agreements, respectively. In millions of dollars at December 31, 2016 Derivatives classified in Trading (1)(2)(3) Derivatives classified in Other assets/liabilities (2)(3) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Assets Liabilities Over-the-counter $ 716 $ 171 $ 1,927 $ 22 Cleared 3,530 2,154 47 82 Interest rate contracts $ 4,246 $ 2,325 $ 1,974 $ 104 Over-the-counter $ 2,494 $ 393 $ 747 $ 645 Foreign exchange contracts $ 2,494 $ 393 $ 747 $ 645 Total derivative instruments designated as ASC 815 hedges $ 6,740 $ 2,718 $ 2,721 $ 749 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 244,072 $ 221,534 $ 225 $ 5 Cleared 120,920 130,855 240 349 Exchange traded 87 47 — — Interest rate contracts $ 365,079 $ 352,436 $ 465 $ 354 Over-the-counter $ 182,659 $ 186,867 $ — $ 60 Cleared 482 470 — — Exchange traded 27 31 — — Foreign exchange contracts $ 183,168 $ 187,368 $ — $ 60 Over-the-counter $ 15,625 $ 19,119 $ — $ — Cleared 1 21 — — Exchange traded 8,484 7,376 — — Equity contracts $ 24,110 $ 26,516 $ — $ — Over-the-counter $ 13,046 $ 14,234 $ — $ — Exchange traded 719 798 — — Commodity and other contracts $ 13,765 $ 15,032 $ — $ — Over-the-counter $ 19,033 $ 19,563 $ 159 $ 78 Cleared 5,582 5,874 47 310 Credit derivatives $ 24,615 $ 25,437 $ 206 $ 388 Total derivatives instruments not designated as ASC 815 hedges $ 610,737 $ 606,789 $ 671 $ 802 Total derivatives $ 617,477 $ 609,507 $ 3,392 $ 1,551 Cash collateral paid/received (4)(5) $ 11,188 $ 15,731 $ 8 $ 1 Less: Netting agreements (6) (519,000 ) (519,000 ) — — Less: Netting cash collateral received/paid (7) (45,912 ) (49,811 ) (1,345 ) (53 ) Net receivables/payables included on the Consolidated Balance Sheet (8) $ 63,753 $ 56,427 $ 2,055 $ 1,499 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (819 ) $ (19 ) $ — $ — Less: Non-cash collateral received/paid (11,767 ) (5,883 ) (530 ) — Total net receivables/payables (8) $ 51,167 $ 50,525 $ 1,525 $ 1,499 (1) The trading derivatives fair values are presented in Note 24 to the Consolidated Financial Statements. (2) Derivative mark-to-market receivables/payables related to management hedges are recorded in either Other assets/Other liabilities or Trading account assets/Trading account liabilities . (3) Over-the-counter (OTC) derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. Cleared derivatives include derivatives executed bilaterally with a counterparty in the OTC market, but then novated to a central clearing house, whereby the central clearing house becomes the counterparty to both of the original counterparties. Exchange traded derivatives include derivatives executed directly on an organized exchange that provides pre-trade price transparency. (4) For the trading account assets/liabilities, reflects the net amount of the $60,999 million and $61,643 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $49,811 million was used to offset derivative liabilities and, of the gross cash collateral received, $45,912 million was used to offset derivative assets. (5) For cash collateral paid with respect to non-trading derivative assets, reflects the net amount of $61 million of the gross cash collateral paid, of which $53 million is netted against non-trading derivative positions within Other liabilities . For cash collateral received with respect to non-trading derivative liabilities, reflects the net amount of $1,346 million of gross cash collateral received of which $1,345 million is netted against non-trading derivative positions within Other assets . (6) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $383 billion , $128 billion and $8 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange traded derivatives, respectively. (7) Represents the netting of cash collateral paid and received by counterparty under enforceable credit support agreements. Substantially all cash collateral received and paid is netted against OTC derivative assets and liabilities, respectively. (8) The net receivables/payables include approximately $7 billion of derivative asset and $9 billion of liability fair values not subject to enforceable master netting agreements, respectively.
Schedule of gains (losses) on derivatives not designated in a qualifying hedging relationship recognized in Other revenue and gains (losses) on fair value hedges	The following table summarizes the gains (losses) on the Company’s fair value hedges: Gains (losses) on fair value hedges (1) Year ended December 31, In millions of dollars 2017 2016 2015 Gain (loss) on the derivatives in designated and qualifying fair value hedges Interest rate contracts $ (891 ) $ (753 ) $ (847 ) Foreign exchange contracts (824 ) (1,415 ) 1,315 Commodity contracts (17 ) 182 41 Total gain (loss) on the derivatives in designated and qualifying fair value hedges $ (1,732 ) $ (1,986 ) $ 509 Gain (loss) on the hedged item in designated and qualifying fair value hedges Interest rate hedges $ 853 $ 668 $ 792 Foreign exchange hedges 969 1,573 (1,258 ) Commodity hedges 18 (210 ) (35 ) Total gain (loss) on the hedged item in designated and qualifying fair value hedges $ 1,840 $ 2,031 $ (501 ) Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges Interest rate hedges $ (31 ) $ (84 ) $ (47 ) Foreign exchange hedges 49 4 (23 ) Total hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges $ 18 $ (80 ) $ (70 ) Net gain (loss) excluded from assessment of the effectiveness of fair value hedges Interest rate contracts $ (7 ) $ (1 ) $ (8 ) Foreign exchange contracts (2) 96 154 80 Commodity hedges (2) 1 (28 ) 6 Total net gain (loss) excluded from assessment of the effectiveness of fair value hedges $ 90 $ 125 $ 78 (1) Amounts are included in Other revenue or Principal Transactions in the Consolidated Statement of Income. The accrued interest income on fair value hedges is recorded in Net interest revenue and is excluded from this table. (2) Amounts relate to the premium associated with forward contracts (differential between spot and contractual forward rates). These amounts are excluded from the assessment of hedge effectiveness and are reflected directly in earnings. The table below does not include any offsetting gains/losses on the economically hedged items to the extent such amounts are also recorded in Other revenue . Gains (losses) included in Other revenue In millions of dollars 2017 2016 2015 Interest rate contracts $ (54 ) $ (81 ) $ 117 Foreign exchange 244 12 (39 ) Credit derivatives (494 ) (1,009 ) 476 Total $ (304 ) $ (1,078 ) $ 554
Schedule of pretax change in accumulated other comprehensive income (loss) from cash flow hedges	The pretax change in AOCI from cash flow hedges is presented in the table below: Year ended December 31, In millions of dollars 2017 2016 2015 Effective portion of cash flow hedges included in AOCI Interest rate contracts $ (165 ) $ (219 ) $ 357 Foreign exchange contracts (8 ) 69 (220 ) Total effective portion of cash flow hedges included in AOCI $ (173 ) $ (150 ) $ 137 Effective portion of cash flow hedges reclassified from AOCI to earnings Interest rate contracts $ (126 ) $ (140 ) $ (186 ) Foreign exchange contracts (10 ) (93 ) (146 ) Total effective portion of cash flow hedges reclassified from AOCI to earnings (1) $ (136 ) $ (233 ) $ (332 ) (1) Included primarily in Other revenue and Net interest revenue in the Consolidated Statement of Income.
Schedule of key characteristics of credit derivative portfolio	The following tables summarize the key characteristics of Citi’s credit derivatives portfolio by counterparty and derivative form: Fair values Notionals In millions of dollars at December 31, 2017 Receivable (1) Payable (2) Protection Protection By industry/counterparty Banks $ 7,471 $ 6,669 $ 264,414 $ 273,711 Broker-dealers 2,325 2,285 73,273 83,229 Non-financial 70 91 1,288 1,140 Insurance and other financial institutions 10,668 12,488 438,738 377,062 Total by industry/counterparty $ 20,534 $ 21,533 $ 777,713 $ 735,142 By instrument Credit default swaps and options $ 20,251 $ 20,554 $ 754,114 $ 724,228 Total return swaps and other 283 979 23,599 10,914 Total by instrument $ 20,534 $ 21,533 $ 777,713 $ 735,142 By rating Investment grade $ 10,473 $ 10,616 $ 588,324 $ 557,987 Non-investment grade 10,061 10,917 189,389 177,155 Total by rating $ 20,534 $ 21,533 $ 777,713 $ 735,142 By maturity Within 1 year $ 2,477 $ 2,914 $ 231,878 $ 218,097 From 1 to 5 years 16,098 16,435 498,606 476,345 After 5 years 1,959 2,184 47,229 40,700 Total by maturity $ 20,534 $ 21,533 $ 777,713 $ 735,142 (1) The fair value amount receivable is composed of $3,195 million under protection purchased and $17,339 million under protection sold. (2) The fair value amount payable is composed of $3,147 million under protection purchased and $18,386 million under protection sold. Fair values Notionals In millions of dollars at December 31, 2016 Receivable (1) Payable (2) Protection Protection By industry/counterparty Banks $ 11,895 $ 10,930 $ 407,992 $ 414,720 Broker-dealers 3,536 3,952 115,013 119,810 Non-financial 82 99 4,014 2,061 Insurance and other financial institutions 9,308 10,844 375,454 322,829 Total by industry/counterparty $ 24,821 $ 25,825 $ 902,473 $ 859,420 By instrument Credit default swaps and options $ 24,502 $ 24,631 $ 883,719 $ 852,900 Total return swaps and other 319 1,194 18,754 6,520 Total by instrument $ 24,821 $ 25,825 $ 902,473 $ 859,420 By rating Investment grade $ 9,605 $ 9,995 $ 675,138 $ 648,247 Non-investment grade 15,216 15,830 227,335 211,173 Total by rating $ 24,821 $ 25,825 $ 902,473 $ 859,420 By maturity Within 1 year $ 4,113 $ 4,841 $ 293,059 $ 287,262 From 1 to 5 years 17,735 17,986 551,155 523,371 After 5 years 2,973 2,998 58,259 48,787 Total by maturity $ 24,821 $ 25,825 $ 902,473 $ 859,420 (1) The fair value amount receivable is composed of $9,077 million under protection purchased and $15,744 million under protection sold. (2) The fair value amount payable is composed of $17,110 million under protection purchased and $8,715 million under protection sold.

FAIR VALUE MEASUREMENT (Tables)

FAIR VALUE MEASUREMENT (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of CVA and FVA applied to fair value of derivative instruments	The table below summarizes the CVA and FVA applied to the fair value of derivative instruments at December 31, 2017 and 2016: Credit and funding valuation adjustments contra-liability (contra-asset) In millions of dollars December 31, December 31, Counterparty CVA $ (970 ) $ (1,488 ) Asset FVA (447 ) (536 ) Citigroup (own-credit) CVA 287 459 Liability FVA 47 62 Total CVA—derivative instruments (1) $ (1,083 ) $ (1,503 ) (1) FVA is included with CVA for presentation purposes.
Schedule of pretax gains (losses) related to changes in CVA, FVA and DVA	The table below summarizes pretax gains (losses) related to changes in CVA on derivative instruments, net of hedges, FVA on derivatives and debt valuation adjustments (DVA) on Citi’s own fair value option (FVO) liabilities for the years indicated: Credit/funding/debt valuation adjustments gain (loss) In millions of dollars 2017 2016 2015 Counterparty CVA $ 276 $ 157 $ (115 ) Asset FVA 90 47 (66 ) Own-credit CVA (153 ) 17 (28 ) Liability FVA (15 ) (44 ) 97 Total CVA—derivative instruments $ 198 $ 177 $ (112 ) DVA related to own FVO liabilities (1) $ (680 ) $ (538 ) $ 367 Total CVA and DVA (2) $ (482 ) $ (361 ) $ 255 (1) Effective January 1, 2016, Citigroup early adopted on a prospective basis only the provisions of ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , related to the presentation of DVA on fair value option liabilities. Accordingly, beginning in the first quarter of 2016, the portion of the change in fair value of these liabilities related to changes in Citigroup’s own credit spreads (DVA) is reflected as a component of AOCI; previously these amounts were recognized in Citigroup’s revenues and net income. DVA amounts in AOCI will be recognized in revenue and net income if realized upon the settlement of the related liability. (2) FVA is included with CVA for presentation purposes.
Items measured at fair value on a recurring basis	The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis at December 31, 2017 and December 31, 2016 . The Company may hedge positions that have been classified in the Level 3 category with other financial instruments (hedging instruments) that may be classified as Level 3, but also with financial instruments classified as Level 1 or Level 2 of the fair value hierarchy. The effects of these hedges are presented gross in the following tables: Fair Value Levels In millions of dollars at December 31, 2017 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ — $ 188,571 $ 16 $ 188,587 $ (55,638 ) $ 132,949 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,801 163 22,964 — 22,964 Residential — 649 164 813 — 813 Commercial — 1,309 57 1,366 — 1,366 Total trading mortgage-backed securities $ — $ 24,759 $ 384 $ 25,143 $ — $ 25,143 U.S. Treasury and federal agency securities $ 17,524 $ 3,613 $ — $ 21,137 $ — $ 21,137 State and municipal — 4,426 274 4,700 — 4,700 Foreign government 39,347 20,843 16 60,206 — 60,206 Corporate 301 15,129 275 15,705 — 15,705 Equity securities 53,305 6,794 120 60,219 — 60,219 Asset-backed securities — 1,198 1,590 2,788 — 2,788 Other trading assets (3) 3 11,105 615 11,723 — 11,723 Total trading non-derivative assets $ 110,480 $ 87,867 $ 3,274 $ 201,621 $ — $ 201,621 Trading derivatives Interest rate contracts $ 145 $ 201,663 $ 1,708 $ 203,516 Foreign exchange contracts 19 120,624 577 121,220 Equity contracts 2,364 24,170 444 26,978 Commodity contracts 282 13,252 569 14,103 Credit derivatives — 19,574 910 20,484 Total trading derivatives $ 2,810 $ 379,283 $ 4,208 $ 386,301 Cash collateral paid (4) $ 7,541 Netting agreements $ (306,401 ) Netting of cash collateral received (37,506 ) Total trading derivatives $ 2,810 $ 379,283 $ 4,208 $ 393,842 $ (343,907 ) $ 49,935 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 41,717 $ 24 $ 41,741 $ — $ 41,741 Residential — 2,884 — 2,884 — 2,884 Commercial — 329 3 332 — 332 Total investment mortgage-backed securities $ — $ 44,930 $ 27 $ 44,957 $ — $ 44,957 U.S. Treasury and federal agency securities $ 106,964 $ 11,182 $ — $ 118,146 $ — $ 118,146 State and municipal — 8,028 737 8,765 — 8,765 Foreign government 56,456 43,985 92 100,533 — 100,533 Corporate 1,911 12,127 71 14,109 — 14,109 Equity securities 176 11 2 189 — 189 Asset-backed securities — 3,091 827 3,918 — 3,918 Other debt securities — 297 — 297 — 297 Non-marketable equity securities (5) — 121 681 802 — 802 Total investments $ 165,507 $ 123,772 $ 2,437 $ 291,716 $ — $ 291,716 Table continues on the next page, including footnotes. In millions of dollars at December 31, 2017 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Loans $ — $ 3,824 $ 550 $ 4,374 $ — $ 4,374 Mortgage servicing rights — — 558 558 — 558 Non-trading derivatives and other financial assets measured on a recurring basis, gross $ 13,903 $ 6,900 $ 16 $ 20,819 Cash collateral paid (6) — Netting of cash collateral received $ (1,026 ) Non-trading derivatives and other financial assets measured on a recurring basis $ 13,903 $ 6,900 $ 16 $ 20,819 $ (1,026 ) $ 19,793 Total assets $ 292,700 $ 790,217 $ 11,059 $ 1,101,517 $ (400,571 ) $ 700,946 Total as a percentage of gross assets (7) 26.8 % 72.2 % 1.0 % Liabilities Interest-bearing deposits $ — $ 1,179 $ 286 $ 1,465 $ — $ 1,465 Federal funds purchased and securities loaned or sold under agreements to repurchase — 95,550 726 96,276 (55,638 ) 40,638 Trading account liabilities Securities sold, not yet purchased 65,843 10,306 22 76,171 — 76,171 Other trading liabilities — 1,409 5 1,414 — 1,414 Total trading liabilities $ 65,843 $ 11,715 $ 27 $ 77,585 $ — $ 77,585 Trading derivatives Interest rate contracts $ 137 $ 182,162 $ 2,130 $ 184,429 Foreign exchange contracts 9 119,719 447 120,175 Equity contracts 2,430 26,472 2,471 31,373 Commodity contracts 115 14,482 2,430 17,027 Credit derivatives — 19,513 1,709 21,222 Total trading derivatives $ 2,691 $ 362,348 $ 9,187 $ 374,226 Cash collateral received (8) $ 14,296 Netting agreements $ (306,401 ) Netting of cash collateral paid (35,659 ) Total trading derivatives $ 2,691 $ 362,348 $ 9,187 $ 388,522 $ (342,060 ) $ 46,462 Short-term borrowings $ — $ 4,609 $ 18 $ 4,627 $ — $ 4,627 Long-term debt — 18,310 13,082 31,392 — 31,392 Non-trading derivatives and other financial liabilities measured on a recurring basis, gross $ 13,903 $ 1,168 $ 8 $ 15,079 Cash collateral received (9) 12 Netting of cash collateral paid $ (7 ) Total non-trading derivatives and other financial liabilities measured on a recurring basis $ 13,903 $ 1,168 $ 8 $ 15,091 $ (7 ) $ 15,084 Total liabilities $ 82,437 $ 494,879 $ 23,334 $ 614,958 $ (397,705 ) $ 217,253 Total as a percentage of gross liabilities (7) 13.7 % 82.4 % 3.9 % (1) In 2017, the Company transferred assets of approximately $4.8 billion from Level 1 to Level 2, primarily related to foreign government securities and equity securities not traded in active markets. In 2017, the Company transferred assets of approximately $4.0 billion from Level 2 to Level 1, primarily related to foreign government bonds and equity securities traded with sufficient frequency to constitute a liquid market. In 2017, the Company transferred liabilities of approximately $0.4 billion from Level 1 to Level 2. In 2017, the Company transferred liabilities of approximately $0.3 billion from Level 2 to Level 1. (2) Represents netting of (i) the amounts due under securities purchased under agreements to resell and the amounts owed under securities sold under agreements to repurchase and (ii) derivative exposures covered by a qualifying master netting agreement and cash collateral offsetting. (3) Includes positions related to investments in unallocated precious metals, as discussed in Note 25 to the Consolidated Financial Statements. Also includes physical commodities accounted for at the lower of cost or fair value and unfunded credit products. (4) Reflects the net amount of $43,200 million of gross cash collateral paid, of which $35,659 million was used to offset trading derivative liabilities. (5) Amounts exclude $0.4 billion of investments measured at Net Asset Value (NAV) in accordance with ASU No. 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). (6) Reflects the net amount of $7 million of gross cash collateral paid, all of which was used to offset non-trading derivative liabilities. (7) Because the amount of the cash collateral paid/received has not been allocated to the Level 1, 2 and 3 subtotals, these percentages are calculated based on total assets and liabilities measured at fair value on a recurring basis, excluding the cash collateral paid/received on derivatives. (8) Reflects the net amount of $51,802 million of gross cash collateral received, of which $37,506 million was used to offset trading derivative assets. (9) Reflects the net amount of $1,038 million of gross cash collateral received, of which $1,026 million was used to offset non-trading derivatives. Fair Value Levels In millions of dollars at December 31, 2016 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ — $ 172,394 $ 1,496 $ 173,890 $ (40,686 ) $ 133,204 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,718 176 22,894 — 22,894 Residential — 291 399 690 — 690 Commercial — 1,000 206 1,206 — 1,206 Total trading mortgage-backed securities $ — $ 24,009 $ 781 $ 24,790 $ — $ 24,790 U.S. Treasury and federal agency securities $ 16,368 $ 4,811 $ 1 $ 21,180 $ — $ 21,180 State and municipal — 3,780 296 4,076 — 4,076 Foreign government 32,164 17,492 40 49,696 — 49,696 Corporate 424 14,199 324 14,947 — 14,947 Equity securities 45,056 5,260 127 50,443 — 50,443 Asset-backed securities — 892 1,868 2,760 — 2,760 Other trading assets (3) — 9,466 2,814 12,280 — 12,280 Total trading non-derivative assets $ 94,012 $ 79,909 $ 6,251 $ 180,172 $ — $ 180,172 Trading derivatives Interest rate contracts $ 105 $ 366,995 $ 2,225 $ 369,325 Foreign exchange contracts 53 184,776 833 185,662 Equity contracts 2,306 21,209 595 24,110 Commodity contracts 261 12,999 505 13,765 Credit derivatives — 23,021 1,594 24,615 Total trading derivatives $ 2,725 $ 609,000 $ 5,752 $ 617,477 Cash collateral paid (4) $ 11,188 Netting agreements $ (519,000 ) Netting of cash collateral received (45,912 ) Total trading derivatives $ 2,725 $ 609,000 $ 5,752 $ 628,665 $ (564,912 ) $ 63,753 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 38,304 $ 101 $ 38,405 $ — $ 38,405 Residential — 3,860 50 3,910 — 3,910 Commercial — 358 — 358 — 358 Total investment mortgage-backed securities $ — $ 42,522 $ 151 $ 42,673 $ — $ 42,673 U.S. Treasury and federal agency securities $ 112,916 $ 10,753 $ 2 $ 123,671 $ — $ 123,671 State and municipal — 8,909 1,211 10,120 — 10,120 Foreign government 54,028 43,934 186 98,148 — 98,148 Corporate 3,215 13,598 311 17,124 — 17,124 Equity securities 336 46 9 391 — 391 Asset-backed securities — 6,134 660 6,794 — 6,794 Other debt securities — 503 — 503 — 503 Non-marketable equity securities (5) — 35 1,331 1,366 — 1,366 Total investments $ 170,495 $ 126,434 $ 3,861 $ 300,790 $ — $ 300,790 In millions of dollars at December 31, 2016 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Loans $ — $ 2,918 $ 568 $ 3,486 $ — $ 3,486 Mortgage servicing rights — — 1,564 1,564 — 1,564 Non-trading derivatives and other financial assets measured on a recurring basis, gross $ 9,300 $ 7,732 $ 34 $ 17,066 Cash collateral paid (6) 8 Netting of cash collateral received $ (1,345 ) Non-trading derivatives and other financial assets measured on a recurring basis $ 9,300 $ 7,732 $ 34 $ 17,074 $ (1,345 ) $ 15,729 Total assets $ 276,532 $ 998,387 $ 19,526 $ 1,305,641 $ (606,943 ) $ 698,698 Total as a percentage of gross assets (7) 21.4 % 77.1 % 1.5 % Liabilities Interest-bearing deposits $ — $ 919 $ 293 $ 1,212 $ — $ 1,212 Federal funds purchased and securities loaned or sold under agreements to repurchase — 73,500 849 74,349 (40,686 ) 33,663 Trading account liabilities Securities sold, not yet purchased 67,429 12,184 1,177 80,790 — 80,790 Other trading liabilities — 1,827 1 1,828 — 1,828 Total trading liabilities $ 67,429 $ 14,011 $ 1,178 $ 82,618 $ — $ 82,618 Trading account derivatives Interest rate contracts $ 107 $ 351,766 $ 2,888 $ 354,761 Foreign exchange contracts 13 187,328 420 187,761 Equity contracts 2,245 22,119 2,152 26,516 Commodity contracts 196 12,386 2,450 15,032 Credit derivatives — 22,842 2,595 25,437 Total trading derivatives $ 2,561 $ 596,441 $ 10,505 $ 609,507 Cash collateral received (8) $ 15,731 Netting agreements $ (519,000 ) Netting of cash collateral paid (49,811 ) Total trading derivatives $ 2,561 $ 596,441 $ 10,505 $ 625,238 $ (568,811 ) $ 56,427 Short-term borrowings $ — $ 2,658 $ 42 $ 2,700 $ — $ 2,700 Long-term debt — 16,510 9,744 26,254 — 26,254 Non-trading derivatives and other financial liabilities measured on a recurring basis, gross $ 9,300 $ 1,540 $ 8 $ 10,848 Cash collateral received (9) 1 Netting of cash collateral paid $ (53 ) Non-trading derivatives and other financial liabilities measured on a recurring basis $ 9,300 $ 1,540 $ 8 $ 10,849 $ (53 ) $ 10,796 Total liabilities $ 79,290 $ 705,579 $ 22,619 $ 823,220 $ (609,550 ) $ 213,670 Total as a percentage of gross liabilities (6) 9.8 % 87.4 % 2.8 % (1) In 2016, the Company transferred assets of approximately $2.6 billion from Level 1 to Level 2, respectively, primarily related to foreign government securities and equity securities not traded in active markets. In 2016, the Company transferred assets of approximately $4.0 billion from Level 2 to Level 1, respectively, primarily related to foreign government bonds and equity securities traded with sufficient frequency to constitute a liquid market. In 2016, the Company transferred liabilities of approximately $0.4 billion from Level 2 to Level 1. In 2016, the Company transferred liabilities of approximately $0.3 billion from Level 1 to Level 2. (2) Represents netting of (i) the amounts due under securities purchased under agreements to resell and the amounts owed under securities sold under agreements to repurchase; and (ii) derivative exposures covered by a qualifying master netting agreement and cash collateral offsetting. (3) Includes positions related to investments in unallocated precious metals, as discussed in Note 25 to the Consolidated Financial Statements. Also includes physical commodities accounted for at the lower of cost or fair value and unfunded credit products. (4) Reflects the net amount of $60,999 million of gross cash collateral paid, of which $49,811 million was used to offset trading derivative liabilities. (5) Amounts exclude $0.4 billion investments measured at Net Asset Value (NAV) in accordance with ASU 2015-07 . (6) Reflects the net amount of $61 million of gross cash collateral paid, of which $53 million was used to offset non-trading derivative liabilities. (7) Because the amount of the cash collateral paid/received has not been allocated to the Level 1, 2 and 3 subtotals, these percentages are calculated based on total assets and liabilities measured at fair value on a recurring basis, excluding the cash collateral paid/received on derivatives. (8) Reflects the net amount of $61,643 million of gross cash collateral received, of which $45,912 million was used to offset trading derivative assets. (9) Reflects the net amount of $1,346 million of gross cash collateral received, of which $1,345 million was used to offset non-trading derivative assets.
Changes in level 3 fair value category	The hedged items and related hedges are presented gross in the following tables: Level 3 Fair Value Rollforward Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Dec. 31, 2017 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 1,496 $ (281 ) $ — $ — $ (1,198 ) $ — $ — $ — $ (1 ) $ 16 $ 1 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed 176 23 — 176 (174 ) 463 — (504 ) 3 163 2 Residential 399 86 — 95 (118 ) 126 — (424 ) — 164 14 Commercial 206 15 — 69 (57 ) 450 — (626 ) — 57 (5 ) Total trading mortgage-backed securities $ 781 $ 124 $ — $ 340 $ (349 ) $ 1,039 $ — $ (1,554 ) $ 3 $ 384 $ 11 U.S. Treasury and federal agency securities $ 1 $ — $ — $ — $ — $ — $ — $ (1 ) $ — $ — $ — State and municipal 296 28 — 24 (48 ) 161 (23 ) (164 ) — 274 8 Foreign government 40 1 — 89 (228 ) 291 — (177 ) — 16 — Corporate 324 344 — 140 (185 ) 482 (8 ) (828 ) 6 275 81 Equity securities 127 54 — 210 (58 ) 51 (3 ) (261 ) — 120 — Asset-backed securities 1,868 284 — 44 (178 ) 1,457 — (1,885 ) — 1,590 36 Other trading assets 2,814 117 — 474 (2,691 ) 2,195 11 (2,285 ) (20 ) 615 60 Total trading non-derivative assets $ 6,251 $ 952 $ — $ 1,321 $ (3,737 ) $ 5,676 $ (23 ) $ (7,155 ) $ (11 ) $ 3,274 $ 196 Trading derivatives, net (4) Interest rate contracts $ (663 ) $ (44 ) $ — $ (28 ) $ 610 $ 154 $ (13 ) $ (322 ) $ (116 ) $ (422 ) $ 77 Foreign exchange contracts 413 (438 ) — 54 (60 ) 33 14 (21 ) 135 130 (139 ) Equity contracts (1,557 ) 129 — (159 ) 28 184 (216 ) (333 ) (103 ) (2,027 ) (214 ) Commodity contracts (1,945 ) (384 ) — 77 35 — 23 (3 ) 336 (1,861 ) 149 Credit derivatives (1,001 ) (484 ) — (28 ) 18 6 16 (6 ) 680 (799 ) (169 ) Total trading derivatives, net (4) $ (4,753 ) $ (1,221 ) $ — $ (84 ) $ 631 $ 377 $ (176 ) $ (685 ) $ 932 $ (4,979 ) $ (296 ) Table continues on the next page, including footnotes. Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Dec. 31, 2017 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 101 $ — $ 16 $ 1 $ (94 ) $ — $ — $ — $ — $ 24 $ (2 ) Residential 50 — 2 — (47 ) — — (5 ) — — — Commercial — — — 3 — 12 — (12 ) — 3 — Total investment mortgage-backed securities $ 151 $ — $ 18 $ 4 $ (141 ) $ 12 $ — $ (17 ) $ — $ 27 $ (2 ) U.S. Treasury and federal agency securities $ 2 $ — $ — $ — $ — $ — $ — $ (2 ) $ — $ — $ — State and municipal 1,211 — 58 70 (517 ) 127 — (212 ) — 737 44 Foreign government 186 — — 2 (284 ) 523 — (335 ) — 92 1 Corporate 311 — 9 77 (47 ) 227 — (506 ) — 71 — Equity securities 9 — (1 ) — — — — (6 ) — 2 — Asset-backed securities 660 — (89 ) 31 (32 ) 883 — (626 ) — 827 12 Other debt securities — — — — — 21 — (21 ) — — — Non-marketable equity securities 1,331 — (170 ) 2 — 19 — (233 ) (268 ) 681 44 Total investments $ 3,861 $ — $ (175 ) $ 186 $ (1,021 ) $ 1,812 $ — $ (1,958 ) $ (268 ) $ 2,437 $ 99 Loans $ 568 $ — $ 75 $ 80 $ (16 ) $ 188 $ — $ (337 ) $ (8 ) $ 550 $ 211 Mortgage servicing rights 1,564 — 65 — — — 96 (1,057 ) (110 ) 558 74 Other financial assets measured on a recurring basis 34 — (128 ) 10 (8 ) 1 318 (14 ) (197 ) 16 (152 ) Liabilities Interest-bearing deposits $ 293 $ — $ 25 $ 40 $ — $ — $ 2 $ — $ (24 ) $ 286 $ 22 Federal funds purchased and securities loaned or sold under agreements to repurchase 849 14 — — — — 36 — (145 ) 726 10 Trading account liabilities Securities sold, not yet purchased 1,177 385 — 22 (796 ) — 17 277 (290 ) 22 8 Other trading liabilities 1 — — 4 — — — — — 5 — Short-term borrowings 42 32 — 4 (7 ) — 31 — (20 ) 18 (3 ) Long-term debt 9,744 (1,083 ) — 1,251 (1,836 ) 44 2,712 — 84 13,082 (1,554 ) Other financial liabilities measured on a recurring basis 8 — — 5 — — 5 (1 ) (9 ) 8 (1 ) (1) Changes in fair value for available-for-sale investments are recorded in AOCI, unless related to other-than-temporary impairment, while gains and losses from sales are recorded in Realized gains (losses) from sales of investments on the Consolidated Statement of Income. (2) Unrealized gains (losses) on MSRs are recorded in Other revenue on the Consolidated Statement of Income. (3) Represents the amount of total gains or losses for the period, included in earnings (and AOCI for changes in fair value of available-for-sale investments), attributable to the change in fair value relating to assets and liabilities classified as Level 3 that are still held at December 31, 2017 . (4) Total Level 3 trading derivative assets and liabilities have been netted in these tables for presentation purposes only. Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2015 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Dec. 31, 2016 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 1,337 $ (20 ) $ — $ — $ (28 ) $ 758 $ — $ — $ (551 ) $ 1,496 $ (16 ) Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed 744 6 — 510 (1,087 ) 941 — (961 ) 23 176 (7 ) Residential 1,326 104 — 189 (162 ) 324 — (1,376 ) (6 ) 399 26 Commercial 517 (1 ) — 193 (234 ) 759 — (1,028 ) — 206 (27 ) Total trading mortgage-backed securities $ 2,587 $ 109 $ — $ 892 $ (1,483 ) $ 2,024 $ — $ (3,365 ) $ 17 $ 781 $ (8 ) U.S. Treasury and federal agency securities $ 1 $ — $ — $ 2 $ — $ — $ — $ (2 ) $ — $ 1 $ — State and municipal 351 23 — 195 (256 ) 322 — (339 ) — 296 (88 ) Foreign government 197 (9 ) — 21 (49 ) 115 — (235 ) — 40 (16 ) Corporate 376 330 — 171 (132 ) 867 — (1,295 ) 7 324 69 Equity securities 3,684 (527 ) — 279 (4,057 ) 955 (11 ) (196 ) — 127 (457 ) Asset-backed securities 2,739 53 — 205 (360 ) 2,199 — (2,965 ) (3 ) 1,868 (46 ) Other trading assets 2,483 (58 ) — 2,070 (2,708 ) 2,894 19 (1,838 ) (48 ) 2,814 (101 ) Total trading non-derivative assets $ 12,418 $ (79 ) $ — $ 3,835 $ (9,045 ) $ 9,376 $ 8 $ (10,235 ) $ (27 ) $ 6,251 $ (647 ) Trading derivatives, net (4) Interest rate contracts $ (495 ) $ (146 ) $ — $ 301 $ (239 ) $ 163 $ (18 ) $ (142 ) $ (87 ) $ (663 ) $ 26 Foreign exchange contracts 620 (276 ) — 75 (106 ) 200 — (181 ) 81 413 23 Equity contracts (800 ) (89 ) — 63 (772 ) 92 38 (128 ) 39 (1,557 ) (33 ) Commodity contracts (1,861 ) (352 ) — (425 ) (39 ) 357 — (347 ) 722 (1,945 ) (164 ) Credit derivatives 307 (1,970 ) — 8 (29 ) 37 — (34 ) 680 (1,001 ) (1,854 ) Total trading derivatives, net (4) $ (2,229 ) $ (2,833 ) $ — $ 22 $ (1,185 ) $ 849 $ 20 $ (832 ) $ 1,435 $ (4,753 ) $ (2,002 ) Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 139 $ — $ (26 ) $ 25 $ (72 ) $ 45 $ — $ (9 ) $ (1 ) $ 101 $ 54 Residential 4 — 3 49 — 26 — (32 ) — 50 2 Commercial 2 — (1 ) 6 (7 ) — — — — — — Total investment mortgage-backed securities $ 145 $ — $ (24 ) $ 80 $ (79 ) $ 71 $ — $ (41 ) $ (1 ) $ 151 $ 56 U.S. Treasury and federal agency securities $ 4 $ — $ — $ — $ — $ — $ — $ (2 ) $ — $ 2 $ — State and municipal 2,192 — 39 467 (1,598 ) 351 — (240 ) — 1,211 23 Foreign government 260 — 10 38 (39 ) 259 — (339 ) (3 ) 186 (104 ) Corporate 603 — 77 11 (240 ) 693 — (468 ) (365 ) 311 — Equity securities 124 — 10 5 (5 ) 1 — (131 ) 5 9 — Asset-backed securities 596 — (92 ) 7 (61 ) 435 — (306 ) 81 660 (102 ) Other debt securities — — — 10 — 6 — (16 ) — — — Non-marketable equity securities 1,135 — 79 336 (32 ) 26 — (14 ) (199 ) 1,331 18 Total investments $ 5,059 $ — $ 99 $ 954 $ (2,054 ) $ 1,842 $ — $ (1,557 ) $ (482 ) $ 3,861 $ (109 ) Table continues on the next page, including footnotes. Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2015 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Dec. 31, 2016 Loans $ 2,166 $ — $ (61 ) $ 89 $ (1,074 ) $ 708 $ 219 $ (813 ) $ (666 ) $ 568 $ 26 Mortgage servicing rights 1,781 — (36 ) — — — 152 (20 ) (313 ) 1,564 (21 ) Other financial assets measured on a recurring basis 180 — 80 55 (47 ) 1 236 (133 ) (338 ) 34 39 Liabilities Interest-bearing deposits $ 434 $ — $ 43 $ 322 $ (309 ) $ — $ 5 $ — $ (116 ) $ 293 $ 46 Federal funds purchased and securities loaned or sold under agreements to repurchase 1,247 (6 ) — — (150 ) — — 27 (281 ) 849 (12 ) Trading account liabilities Securities sold, not yet purchased 199 17 — 1,185 (109 ) (70 ) (41 ) 367 (337 ) 1,177 (43 ) Other trading liabilities — — — 1 — — — — — 1 — Short-term borrowings 9 (16 ) — 19 (37 ) — 87 — (52 ) 42 — Long-term debt 7,543 (282 ) — 3,792 (4,350 ) — 4,845 (3 ) (2,365 ) 9,744 (419 ) Other financial liabilities measured on a recurring basis 14 — (11 ) 2 (12 ) (8 ) 12 — (11 ) 8 (13 ) (1) Changes in fair value of available-for-sale investments are recorded in AOCI, unless related to other-than-temporary impairment, while gains and losses from sales are recorded in Realized gains (losses) from sales of investments on the Consolidated Statement of Income. (2) Unrealized gains (losses) on MSRs are recorded in Other revenue on the Consolidated Statement of Income. (3) Represents the amount of total gains or losses for the period, included in earnings (and AOCI for changes in fair value of available-for-sale investments), attributable to the change in fair value relating to assets and liabilities classified as Level 3 that are still held at December 31, 2016 . (4) Total Level 3 derivative assets and liabilities have been netted in these tables for presentation purposes only.
Significant valuation techniques and most significant unobservable inputs used in Level 3 fair value measurements	The following tables present the valuation techniques covering the majority of Level 3 inventory and the most significant unobservable inputs used in Level 3 fair value measurements. Differences between this table and amounts presented in the Level 3 Fair Value Rollforward table represent individually immaterial items that have been measured using a variety of valuation techniques other than those listed. Valuation Techniques and Inputs for Level 3 Fair Value Measurements As of December 31, 2017 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 16 Model-based Interest rate 1.43 % 2.16 % 2.09 % Mortgage-backed securities $ 214 Price-based Price $ 2.96 $ 101.00 $ 56.52 184 Yield analysis Yield 2.52 % 14.06 % 5.97 State and municipal, foreign government, corporate and other debt securities $ 949 Model-based Price $ — $ 184.04 $ 91.74 914 Price-based Credit spread 35 bps 500 bps 249 bps Yield 2.36 % 14.25 % 6.03 % Equity securities (5) $ 65 Price-based Price $ — $ 25,450.00 $ 2,526.62 55 Model-based WAL 2.50 years 2.50 years 2.50 years Asset-backed securities $ 2,287 Price-based Price $ 4.25 $ 100.60 $ 74.57 Non-marketable equity $ 423 Comparables analysis EBITDA multiples 6.90 x 12.80 x 8.66 x 223 Price-based Discount to price — % 100.00 % 11.83 % Price-to-book ratio 0.05 x 1.00 x 0.32 x Derivatives—gross (6) Interest rate contracts (gross) $ 3,818 Model-based IR normal volatility 9.40 % 77.40 % 58.86 % Mean reversion 1.00 % 20.00 % 10.50 % Foreign exchange contracts (gross) $ 940 Model-based Foreign exchange (FX) volatility 4.58 % 15.02 % 8.16 % Interest rate (0.55 )% 0.28 % 0.04 % IR-IR correlation (51.00 )% 40.00 % 36.56 % IR-FX correlation (7.34 )% 60.00 % 49.04 % Credit spread 11 bps 717 bps 173 bps Equity contracts (gross) (7) $ 2,897 Model-based Equity volatility 3.00 % 68.93 % 24.66 % Forward price 69.74 % 154.19 % 92.80 % Commodity contracts (gross) $ 2,937 Model-based Forward price 3.66 % 290.59 % 114.16 % Commodity volatility 8.60 % 66.73 % 25.04 % Commodity correlation (37.64 )% 91.71 % 15.21 % Credit derivatives (gross) $ 1,797 Model-based Credit correlation 25.00 % 90.00 % 44.64 % 823 Price-based Upfront points 6.03 % 97.26 % 62.88 % Credit spread 3 bps 1,636 bps 173 bps Price $ 1.00 $ 100.24 $ 57.63 As of December 31, 2017 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) (6) $ 24 Model-based Recovery rate 25.00 % 40.00 % 31.56 % Redemption rate 10.72 % 99.50 % 74.24 % Credit spread 38 bps 275 bps 127 bps Upfront points 61.00 % 61.00 % 61.00 % Loans and leases $ 391 Model-based Equity volatility 3.00 % 68.93 % 22.52 % 148 Price-based Credit spread 134 bps 500 bps 173 bps Yield 3.09 % 4.40 % 3.13 % Mortgage servicing rights $ 471 Cash flow Yield 8.00 % 16.38 % 11.47 % 87 Model-based WAL 3.83 years 6.89 years 5.93 years Liabilities Interest-bearing deposits $ 286 Model-based Mean reversion 1.00 % 20.00 % 10.50 % Forward price 99.56 % 99.95 % 99.72 % Federal funds purchased and securities loaned or sold under agreements to repurchase $ 726 Model-based Interest rate 1.43 % 2.16 % 2.09 % Trading account liabilities Securities sold, not yet purchased $ 21 Price-based Price $ 1.00 $ 287.64 $ 88.19 Short-term borrowings and long-term debt $ 13,100 Model-based Forward price 69.74 % 161.11 % 100.70 % As of December 31, 2016 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 1,496 Model-based IR log-normal volatility 12.86 % 75.50 % 61.73 % Interest rate (0.51 )% 5.76 % 2.80 % Mortgage-backed securities $ 509 Price-based Price $ 5.50 $ 113.48 $ 61.74 368 Yield analysis Yield 1.90 % 14.54 % 4.34 % State and municipal, foreign government, corporate and other debt securities $ 3,308 Price-based Price $ 15.00 $ 103.60 $ 89.93 1,513 Cash flow Credit spread 35 bps 600 bps 230 bps Equity securities (5) $ 69 Model-based Price $ 0.48 $ 104.00 $ 22.19 58 Price-based Asset-backed securities $ 2,454 Price-based Price $ 4.00 $ 100.00 $ 71.51 Non-marketable equity $ 726 Price-based Discount to price — % 90.00 % 13.36 % 565 Comparables analysis EBITDA multiples 6.80 x 10.10 x 8.62 x Price-to-book ratio 0.32 x 1.03 x 0.87 x Price $ — $ 113.23 $ 54.40 Derivatives—gross (6) Interest rate contracts (gross) $ 4,897 Model-based IR log-normal volatility 1.00 % 93.97 % 62.72 % Mean reversion 1.00 % 20.00 % 10.50 % As of December 31, 2016 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) Foreign exchange contracts (gross) $ 1,110 Model-based Foreign exchange (FX) volatility 1.39 % 26.85 % 15.18 % 134 Cash flow Interest rate (0.85 )% (0.49 )% (0.84 )% Credit spread 4 bps 657 bps 266 bps IR-IR correlation 40.00 % 50.00 % 41.27 % IR-FX correlation 16.41 % 60.00 % 49.52 % Equity contracts (gross) (7) $ 2,701 Model-based Equity volatility 3.00 % 97.78 % 29.52 % Forward price 69.05 % 144.61 % 94.28 % Equity-FX correlation (60.70 )% 28.20 % (26.28 )% Equity-IR correlation (35.00 )% 41.00 % (15.65 )% Yield volatility 3.55 % 14.77 % 9.29 % Equity-equity correlation (87.70 )% 96.50 % 67.45 % Commodity contracts (gross) $ 2,955 Model-based Forward price 35.74 % 235.35 % 119.99 % Commodity volatility 2.00 % 32.19 % 17.07 % Commodity correlation (41.61 )% 90.42 % 52.85 % Credit derivatives (gross) $ 2,786 Model-based Recovery rate 20.00 % 75.00 % 39.75 % 1,403 Price-based Credit correlation 5.00 % 90.00 % 34.27 % Upfront points 6.00 % 99.90 % 72.89 % Price $ 1.00 $ 167.00 $ 77.35 Credit spread 3 bps 1,515 bps 256 bps Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) (6) $ 42 Model-based Recovery rate 40.00 % 40.00 % 40.00 % Redemption rate 3.92 % 99.58 % 74.69 % Upfront points 16.00 % 20.50 % 18.78 % Loans $ 258 Price-based Price $ 31.55 $ 105.74 $ 56.46 221 Yield analysis Yield 2.75 % 20.00 % 11.09 % 79 Model-based Mortgage servicing rights $ 1,473 Cash flow Yield 4.20 % 20.56 % 9.32 % WAL 3.53 years 7.24 years 5.83 years Liabilities Interest-bearing deposits $ 293 Model-based Mean reversion 1.00 % 20.00 % 10.50 % Forward price 98.79 % 104.07 % 100.19 % Federal funds purchased and securities loaned or sold under agreements to repurchase $ 849 Model-based Interest rate 0.62 % 2.19 % 1.99 % Trading account liabilities Securities sold, not yet purchased $ 1,056 Model-based IR Normal volatility 12.86 % 75.50 % 61.73 % Short-term borrowings and long-term debt $ 9,774 Model-based Mean reversion 1.00 % 20.00 % 10.50 % Commodity correlation (41.61 )% 90.42 % 52.85 % Commodity volatility 2.00 % 32.19 % 17.07 % Forward price 69.05 % 235.35 % 103.28 % (1) The fair value amounts presented in these tables represent the primary valuation technique or techniques for each class of assets or liabilities. (2) Some inputs are shown as zero due to rounding. (3) When the low and high inputs are the same, there is either a constant input applied to all positions, or the methodology involving the input applies to only one large position. (4) Weighted averages are calculated based on the fair values of the instruments. (5) For equity securities, the price and fund NAV inputs are expressed on an absolute basis, not as a percentage of the notional amount. (6) Both trading and nontrading account derivatives—assets and liabilities—are presented on a gross absolute value basis. (7) Includes hybrid products.
Items measured at fair value of a nonrecurring basis	The following table presents the carrying amounts of all assets that were still held for which a nonrecurring fair value measurement was recorded: In millions of dollars Fair value Level 2 Level 3 December 31, 2017 Loans held-for-sale (1) $ 5,675 $ 2,066 $ 3,609 Other real estate owned 54 10 44 Loans (2) 630 216 414 Total assets at fair value on a nonrecurring basis $ 6,359 $ 2,292 $ 4,067 In millions of dollars Fair value Level 2 Level 3 December 31, 2016 Loans held-for-sale (1) $ 5,802 $ 3,389 $ 2,413 Other real estate owned 75 15 60 Loans (2) 1,376 586 790 Total assets at fair value on a nonrecurring basis $ 7,253 $ 3,990 $ 3,263 (1) Net of fair value amounts on the unfunded portion of loans held-for-sale, recognized within Other liabilities on the Consolidated Balance Sheet. (2) Represents impaired loans held for investment whose carrying amount is based on the fair value of the underlying collateral, primarily real estate secured loans.
Valuation techniques and inputs for Level 3 nonrecurring fair value measurements	The following tables present the valuation techniques covering the majority of Level 3 nonrecurring fair value measurements and the most significant unobservable inputs used in those measurements: As of December 31, 2017 Fair value (1) (in millions) Methodology Input Low (2) High Weighted average (3) Loans held-for-sale $ 3,186 Price-based Price $ 77.93 $ 100.00 $ 99.26 Other real estate owned $ 42 Price-based Appraised value (4) $ 20,278 $ 8,091,760 $ 4,016,665 Discount to price 34.00 % 34.00 % 34.00 % Price $ 30.00 $ 50.36 $ 49.09 Loans (5) $ 133 Price-based Price $ 2.80 $ 100.00 $ 62.46 129 Cash flow Recovery rate 50.00 % 100.00 % 63.59 % 127 Recovery analysis Appraised value $ — $ 45,500,000 $ 38,785,667 As of December 31, 2016 Fair value (1) (in millions) Methodology Input Low (2) High Weighted average (3) Loans held-for-sale $ 2,413 Price-based Price $ — $ 100.00 $ 93.08 Other real estate owned $ 59 Price-based Discount to price (6) 0.34 % 13.00 % 3.10 % Price $ 64.65 $ 74.39 $ 66.21 Loans (4) $ 431 Cash flow Price $ 3.25 $ 105 $ 59.61 197 Recovery analysis Forward price $ 2.90 $ 210.00 $ 156.78 135 Price-based Discount to price (6) 0.25 % 13.00 % 8.34 % Appraised value (4) $ 25.80 $ 26,400,000 $ 6,462,735 (1) The fair value amounts presented in this table represent the primary valuation technique or techniques for each class of assets or liabilities. (2) Some inputs are shown as zero due to rounding. (3) Weighted averages are calculated based on the fair values of the instruments. (4) Appraised values are disclosed in whole dollars. (5) Includes estimated costs to sell. (6) Represents impaired loans held for investment whose carrying amounts are based on the fair value of the underlying collateral, primarily real estate secured loans.
Changes in total nonrecurring fair value measurements	The following table presents total nonrecurring fair value measurements for the period, included in earnings, attributable to the change in fair value relating to assets that were still held: Year ended December 31, In millions of dollars 2017 Loans held-for-sale $ (26 ) Other real estate owned (4 ) Loans (1) (87 ) Total nonrecurring fair value gains (losses) $ (117 ) Year ended December 31, In millions of dollars 2016 Loans held-for-sale $ (2 ) Other real estate owned (5 ) Loans (1) (105 ) Total nonrecurring fair value gains (losses) $ (112 ) (1) Represents loans held for investment whose carrying amount is based on the fair value of the underlying collateral, primarily real estate loans.
Estimated Fair Value of Financial Instruments	The following table presents the carrying value and fair value of Citigroup’s financial instruments that are not carried at fair value. The table below therefore excludes items measured at fair value on a recurring basis presented in the tables above. The disclosure also excludes leases, affiliate investments, pension and benefit obligations, certain insurance contracts and tax-related items. Also, as required, the disclosure excludes the effect of taxes, any premium or discount that could result from offering for sale at one time the entire holdings of a particular instrument, excess fair value associated with deposits with no fixed maturity and other expenses that would be incurred in a market transaction. In addition, the table excludes the values of non-financial assets and liabilities, as well as a wide range of franchise, relationship and intangible values, which are integral to a full assessment of Citigroup’s financial position and the value of its net assets. The fair value represents management’s best estimates based on a range of methodologies and assumptions. The carrying value of short-term financial instruments not accounted for at fair value, as well as receivables and payables arising in the ordinary course of business, approximates fair value because of the relatively short period of time between their origination and expected realization. Quoted market prices are used when available for investments and for liabilities, such as long-term debt not carried at fair value. For loans not accounted for at fair value, cash flows are discounted at quoted secondary market rates or estimated market rates if available. Otherwise, sales of comparable loan portfolios or current market origination rates for loans with similar terms and risk characteristics are used. Expected credit losses are either embedded in the estimated future cash flows or incorporated as an adjustment to the discount rate used. The value of collateral is also considered. For liabilities such as long-term debt not accounted for at fair value and without quoted market prices, market borrowing rates of interest are used to discount contractual cash flows. December 31, 2017 Estimated fair value Carrying value Estimated fair value In billions of dollars Level 1 Level 2 Level 3 Assets Investments $ 60.2 $ 60.6 $ 0.5 $ 57.5 $ 2.6 Federal funds sold and securities borrowed or purchased under agreements to resell 99.5 99.5 — 94.4 5.1 Loans (1)(2) 648.6 644.9 — 6.0 638.9 Other financial assets (2)(3) 242.6 243.0 166.4 14.1 62.5 Liabilities Deposits $ 958.4 $ 955.6 $ — $ 816.1 $ 139.5 Federal funds purchased and securities loaned or sold under agreements to repurchase 115.6 115.6 — 115.6 — Long-term debt (4) 205.3 214.0 — 187.2 26.8 Other financial liabilities (5) 129.9 129.9 — 15.5 114.4 December 31, 2016 Estimated fair value Carrying value Estimated fair value In billions of dollars Level 1 Level 2 Level 3 Assets Investments $ 52.1 $ 52.0 $ 0.8 $ 48.6 $ 2.6 Federal funds sold and securities borrowed or purchased under agreements to resell 103.6 103.6 — 98.5 5.1 Loans (1)(2) 607.0 607.3 — 7.0 600.3 Other financial assets (2)(3) 215.2 215.9 145.6 16.2 54.1 Liabilities Deposits $ 928.2 $ 927.6 $ — $ 789.7 $ 137.9 Federal funds purchased and securities loaned or sold under agreements to repurchase 108.2 108.2 — 107.8 0.4 Long-term debt (4) 179.9 185.5 — 156.5 29.0 Other financial liabilities (5) 115.3 115.3 — 16.2 99.1 (1) The carrying value of loans is net of the Allowance for loan losses of $12.4 billion for December 31, 2017 and $12.1 billion for December 31, 2016 . In addition, the carrying values exclude $1.7 billion and $1.9 billion of lease finance receivables at December 31, 2017 and December 31, 2016 , respectively. (2) Includes items measured at fair value on a nonrecurring basis. (3) Includes cash and due from banks, deposits with banks, brokerage receivables, reinsurance recoverable and other financial instruments included in Other assets on the Consolidated Balance Sheet, for all of which the carrying value is a reasonable estimate of fair value. (4) The carrying value includes long-term debt balances under qualifying fair value hedges. (5) Includes brokerage payables, short-term borrowings (carried at cost) and other financial instruments included in Other liabilities on the Consolidated Balance Sheet, for all of which the carrying value is a reasonable estimate of fair value.

FAIR VALUE ELECTIONS (Tables)

FAIR VALUE ELECTIONS (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value, Option, Aggregate Differences [Abstract]
Schedule of financial instruments selected for changes in fair value gains and losses	The following table presents the changes in fair value of those items for which the fair value option has been elected: Changes in fair value gains (losses) for the years ended December 31, In millions of dollars 2017 2016 Assets Federal funds sold and securities borrowed or purchased under agreements to resell selected portfolios of securities purchased under agreements to resell and securities borrowed $ (133 ) $ (89 ) Trading account assets 1,622 404 Investments (3 ) (25 ) Loans Certain corporate loans (537 ) 40 Certain consumer loans 3 — Total loans $ (534 ) $ 40 Other assets MSRs $ 65 $ (36 ) Certain mortgage loans held for sale (1) 142 284 Other assets — 376 Total other assets $ 207 $ 624 Total assets $ 1,159 $ 954 Liabilities Interest-bearing deposits $ (69 ) $ (50 ) Federal funds purchased and securities loaned or sold under agreements to repurchase selected portfolios of securities sold under agreements to repurchase and securities loaned 223 45 Trading account liabilities 70 105 Short-term borrowings (116 ) (61 ) Long-term debt (1,491 ) (935 ) Total liabilities $ (1,383 ) $ (896 ) (1) Includes gains (losses) associated with interest rate lock-commitments for those loans that have been originated and elected under the fair value option.
Schedule of fair value of loans and other disclosures for certain credit related products	The following table provides information about certain credit products carried at fair value: December 31, 2017 December 31, 2016 In millions of dollars Trading assets Loans Trading assets Loans Carrying amount reported on the Consolidated Balance Sheet $ 8,851 $ 4,374 $ 9,824 $ 3,486 Aggregate unpaid principal balance in excess of fair value 623 682 758 18 Balance of non-accrual loans or loans more than 90 days past due — 1 — 1 Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due — 1 — 1
Schedule of fair value of loans and other disclosures for certain mortgage loans	The following table provides information about certain mortgage loans HFS carried at fair value: In millions of dollars December 31, December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 426 $ 915 Aggregate fair value in excess of (less than) unpaid principal balance 14 8 Balance of non-accrual loans or loans more than 90 days past due — — Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due — —
Schedule of carrying value of structured notes, disaggregated by type of embedded derivative instrument	The following table provides information about the carrying value of structured notes, disaggregated by type of embedded derivative instrument: In billions of dollars December 31, 2017 December 31, 2016 Interest rate linked $ 13.9 $ 10.6 Foreign exchange linked 0.3 0.2 Equity linked 13.0 12.3 Commodity linked 0.2 0.3 Credit linked 1.9 0.9 Total $ 29.3 $ 24.3
Schedule of long-term debt carried at fair value, excluding debt issued by consolidated VIEs	The following table provides information about long-term debt carried at fair value: In millions of dollars December 31, 2017 December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 31,392 $ 26,254 Aggregate unpaid principal balance in excess of (less than) fair value (579 ) (128 )
Schedule of short-term borrowings carried at fair value	The following table provides information about short-term borrowings carried at fair value: In millions of dollars December 31, 2017 December 31, 2016 Carrying amount reported on the Consolidated Balance Sheet $ 4,627 $ 2,700 Aggregate unpaid principal balance in excess of (less than) fair value 74 (61 )

PLEDGED ASSETS, COLLATERAL, G63

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Pledged Assets, Collateral, Guarantees and Commitments [Abstract]
Schedule of carrying value of assets pledged	The approximate carrying values of the significant components of pledged assets recognized on Citi’s Consolidated Balance Sheet included: In millions of dollars 2017 2016 Investment securities $ 138,807 $ 161,914 Loans 229,552 231,833 Trading account assets 102,892 84,371 Total $ 471,251 $ 478,118
Schedule of future minimum rental payments for operating leases	Future minimum annual rentals under non-cancelable leases, net of sublease income, are as follows: In millions of dollars 2018 $ 968 2019 837 2020 676 2021 568 2022 469 Thereafter 2,593 Total $ 6,111
Schedule of guarantor obligations	The following tables present information about Citi’s guarantees: Maximum potential amount of future payments In billions of dollars at December 31, 2017 except carrying value in millions Expire within 1 year Expire after 1 year Total amount outstanding Carrying value (in millions of dollars) Financial standby letters of credit $ 27.9 $ 65.9 $ 93.8 $ 93 Performance guarantees 7.2 4.1 11.3 20 Derivative instruments considered to be guarantees 11.0 84.9 95.9 423 Loans sold with recourse — 0.2 0.2 9 Securities lending indemnifications (1) 103.7 — 103.7 — Credit card merchant processing (1)(2) 85.5 — 85.5 — Credit card arrangements with partners 0.3 1.1 1.4 205 Custody indemnifications and other — 36.0 36.0 59 Total $ 235.6 $ 192.2 $ 427.8 $ 809 Maximum potential amount of future payments In billions of dollars at December 31, 2016 except carrying value in millions Expire within Expire after Total amount Carrying value ( in millions of dollars) Financial standby letters of credit $ 26.0 $ 67.1 $ 93.1 $ 141 Performance guarantees 7.5 3.6 11.1 19 Derivative instruments considered to be guarantees 7.2 80.0 87.2 747 Loans sold with recourse — 0.2 0.2 12 Securities lending indemnifications (1) 80.3 — 80.3 — Credit card merchant processing (1)(2) 86.4 — 86.4 — Credit card arrangements with partners — 1.5 1.5 206 Custody indemnifications and other — 45.4 45.4 58 Total $ 207.4 $ 197.8 $ 405.2 $ 1,183 (1) The carrying values of securities lending indemnifications and credit card merchant processing were not material for either period presented, as the probability of potential liabilities arising from these guarantees is minimal. (2) At December 31, 2017 and 2016, this maximum potential exposure was estimated to be $86 billion and $86 billion , respectively. However, Citi believes that the maximum exposure is not representative of the actual potential loss exposure based on its historical experience. This contingent liability is unlikely to arise, as most products and services are delivered when purchased and amounts are refunded when items are returned to merchants.
Schedule of guarantor obligations by credit ratings	Presented in the tables below are the maximum potential amounts of future payments that are classified based upon internal and external credit ratings. As previously mentioned, the determination of the maximum potential future payments is based on the notional amount of the guarantees without consideration of possible recoveries under recourse provisions or from collateral held or pledged. As such, Citi believes such amounts bear no relationship to the anticipated losses, if any, on these guarantees. Maximum potential amount of future payments In billions of dollars at December 31, 2017 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 68.1 $ 10.9 $ 14.8 $ 93.8 Performance guarantees 7.9 2.4 1.0 11.3 Derivative instruments deemed to be guarantees — — 95.9 95.9 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 103.7 103.7 Credit card merchant processing — — 85.5 85.5 Credit card arrangements with partners — — 1.4 1.4 Custody indemnifications and other 23.7 12.3 — 36.0 Total $ 99.7 $ 25.6 $ 302.5 $ 427.8 Maximum potential amount of future payments In billions of dollars at December 31, 2016 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 66.8 $ 13.4 $ 12.9 $ 93.1 Performance guarantees 6.3 4.0 0.8 11.1 Derivative instruments deemed to be guarantees — — 87.2 87.2 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 80.3 80.3 Credit card merchant processing — — 86.4 86.4 Credit card arrangements with partners — — 1.5 1.5 Custody indemnifications and other 33.3 12.1 — 45.4 Total $ 106.4 $ 29.5 $ 269.3 $ 405.2
Schedule of credit commitments	The table below summarizes Citigroup’s credit commitments: In millions of dollars U.S. Outside of U.S. December 31, December 31, 2016 Commercial and similar letters of credit $ 904 $ 4,096 $ 5,000 $ 5,736 One- to four-family residential mortgages 988 1,686 2,674 2,838 Revolving open-end loans secured by one- to four-family residential properties 10,825 1,498 12,323 13,405 Commercial real estate, construction and land development 9,594 1,557 11,151 10,781 Credit card lines 578,634 99,666 678,300 664,335 Commercial and other consumer loan commitments 171,383 101,272 272,655 259,934 Other commitments and contingencies 2,182 889 3,071 3,202 Total $ 774,510 $ 210,664 $ 985,174 $ 960,231

CONDENSED CONSOLIDATING FINAN64

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed income statement and condensed statement of comprehensive income	Year ended December 31, 2015 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 13,500 $ — $ — $ (13,500 ) $ — Interest revenue 9 4,389 54,153 — 58,551 Interest revenue—intercompany 2,880 272 (3,152 ) — — Interest expense 4,563 988 6,370 — 11,921 Interest expense—intercompany (475 ) 1,304 (829 ) — — Net interest revenue $ (1,199 ) $ 2,369 $ 45,460 $ — $ 46,630 Commissions and fees $ — $ 4,872 $ 9,613 $ — $ 14,485 Commissions and fees—intercompany — 210 (210 ) — — Principal transactions 1,012 5,532 (536 ) — 6,008 Principal transactions—intercompany (1,733 ) (3,875 ) 5,608 — — Other income 3,294 403 5,534 — 9,231 Other income—intercompany (3,054 ) 1,088 1,966 — — Total non-interest revenues $ (481 ) $ 8,230 $ 21,975 $ — $ 29,724 Total revenues, net of interest expense $ 11,820 $ 10,599 $ 67,435 $ (13,500 ) $ 76,354 Provisions for credit losses and for benefits and claims $ — $ — $ 7,913 $ — $ 7,913 Operating expenses Compensation and benefits $ (58 ) $ 5,003 $ 16,824 $ — $ 21,769 Compensation and benefits—intercompany 59 — (59 ) — — Other operating 271 1,940 19,635 — 21,846 Other operating—intercompany 247 1,173 (1,420 ) — — Total operating expenses $ 519 $ 8,116 $ 34,980 $ — $ 43,615 Equity in undistributed income of subsidiaries $ 4,601 $ — $ — $ (4,601 ) $ — Income (loss) from continuing operations before income taxes $ 15,902 $ 2,483 $ 24,542 $ (18,101 ) $ 24,826 Provision (benefit) for income taxes $ (1,340 ) $ 537 $ 8,243 $ — $ 7,440 Income (loss) from continuing operations $ 17,242 $ 1,946 $ 16,299 $ (18,101 ) $ 17,386 Loss from discontinued operations, net of taxes — — (54 ) — (54 ) Net income (loss) before attribution of noncontrolling interests $ 17,242 $ 1,946 $ 16,245 $ (18,101 ) $ 17,332 Noncontrolling interests — 9 81 — 90 Net income (loss) $ 17,242 $ 1,937 $ 16,164 $ (18,101 ) $ 17,242 Comprehensive income Add: Other comprehensive income (loss) $ (6,128 ) $ (125 ) $ 1,017 $ (892 ) $ (6,128 ) Total Citigroup comprehensive income (loss) $ 11,114 $ 1,812 $ 17,181 $ (18,993 ) $ 11,114 Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ (83 ) $ — $ (83 ) Add: Net income attributable to noncontrolling interests — 9 81 — 90 Total comprehensive income (loss) $ 11,114 $ 1,821 $ 17,179 $ (18,993 ) $ 11,121 Year ended December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 15,570 $ — $ — $ (15,570 ) $ — Interest revenue 7 4,586 53,022 — 57,615 Interest revenue—intercompany 3,008 545 (3,553 ) — — Interest expense 4,419 1,418 6,674 — 12,511 Interest expense—intercompany 209 1,659 (1,868 ) — — Net interest revenue $ (1,613 ) $ 2,054 $ 44,663 $ — $ 45,104 Commissions and fees $ — $ 4,340 $ 7,598 $ — $ 11,938 Commissions and fees—intercompany (20 ) 246 (226 ) — — Principal transactions (1,025 ) 5,576 3,034 — 7,585 Principal transactions—intercompany 24 (2,842 ) 2,818 — — Other income 2,599 183 2,466 — 5,248 Other income—intercompany (2,095 ) 305 1,790 — — Total non-interest revenues $ (517 ) $ 7,808 $ 17,480 $ — $ 24,771 Total revenues, net of interest expense $ 13,440 $ 9,862 $ 62,143 $ (15,570 ) $ 69,875 Provisions for credit losses and for benefits and claims $ — $ — $ 6,982 $ — $ 6,982 Operating expenses Compensation and benefits $ 22 $ 4,719 $ 16,229 $ — $ 20,970 Compensation and benefits—intercompany 36 — (36 ) — — Other operating 482 1,634 18,330 — 20,446 Other operating—intercompany 217 1,333 (1,550 ) — — Total operating expenses $ 757 $ 7,686 $ 32,973 $ — $ 41,416 Equity in undistributed income of subsidiaries $ 871 $ — $ — $ (871 ) $ — Income (loss) from continuing operations before income taxes $ 13,554 $ 2,176 $ 22,188 $ (16,441 ) $ 21,477 Provision (benefit) for income taxes $ (1,358 ) $ 746 $ 7,056 $ — $ 6,444 Income (loss) from continuing operations $ 14,912 $ 1,430 $ 15,132 $ (16,441 ) $ 15,033 Loss from discontinued operations, net of taxes — — (58 ) — (58 ) Net income (loss) before attribution of noncontrolling interests $ 14,912 $ 1,430 $ 15,074 $ (16,441 ) $ 14,975 Noncontrolling interests — (13 ) 76 — 63 Net income (loss) $ 14,912 $ 1,443 $ 14,998 $ (16,441 ) $ 14,912 Comprehensive income Add: Other comprehensive income (loss) $ (3,022 ) $ (26 ) $ 2,364 $ (2,338 ) $ (3,022 ) Total Citigroup comprehensive income (loss) $ 11,890 $ 1,417 $ 17,362 $ (18,779 ) $ 11,890 Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ (56 ) $ — $ (56 ) Add: Net income attributable to noncontrolling interests — (13 ) 76 — 63 Total comprehensive income (loss) $ 11,890 $ 1,404 $ 17,382 $ (18,779 ) $ 11,897 Year ended December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 22,499 $ — $ — $ (22,499 ) $ — Interest revenue 1 5,274 55,929 — 61,204 Interest revenue—intercompany 3,972 1,178 (5,150 ) — — Interest expense 4,766 2,340 9,411 — 16,517 Interest expense—intercompany 829 2,297 (3,126 ) — — Net interest revenue $ (1,622 ) $ 1,815 $ 44,494 $ — $ 44,687 Commissions and fees $ — $ 5,139 $ 7,800 $ — $ 12,939 Commissions and fees—intercompany (2 ) 182 (180 ) — — Principal transactions 1,654 1,019 6,495 — 9,168 Principal transactions—intercompany 934 1,200 (2,134 ) — — Other income (2,581 ) 855 6,381 — 4,655 Other income—intercompany 5 158 (163 ) — — Total non-interest revenues $ 10 $ 8,553 $ 18,199 $ — $ 26,762 Total revenues, net of interest expense $ 20,887 $ 10,368 $ 62,693 $ (22,499 ) $ 71,449 Provisions for credit losses and for benefits and claims $ — $ — $ 7,451 $ — $ 7,451 Operating expenses Compensation and benefits $ (107 ) $ 4,403 $ 16,885 $ — $ 21,181 Compensation and benefits—intercompany 120 — (120 ) — — Other operating (318 ) 1,776 18,598 — 20,056 Other operating—intercompany (35 ) 2,219 (2,184 ) — — Total operating expenses $ (340 ) $ 8,398 $ 33,179 $ — $ 41,237 Equity in undistributed income of subsidiaries $ (18,847 ) $ — $ — $ 18,847 $ — Income (loss) from continuing operations before income taxes $ 2,380 $ 1,970 $ 22,063 $ (3,652 ) $ 22,761 Provision (benefit) for income taxes $ 9,178 $ 873 $ 19,337 $ — $ 29,388 Income (loss) from continuing operations $ (6,798 ) $ 1,097 $ 2,726 $ (3,652 ) $ (6,627 ) Loss from discontinued operations, net of taxes — — (111 ) — (111 ) Net income (loss) before attribution of noncontrolling interests $ (6,798 ) $ 1,097 $ 2,615 $ (3,652 ) $ (6,738 ) Noncontrolling interests — (1 ) 61 — 60 Net income (loss) $ (6,798 ) $ 1,098 $ 2,554 $ (3,652 ) $ (6,798 ) Comprehensive income Add: Other comprehensive income (loss) $ (2,791 ) $ (117 ) $ (5,969 ) $ 6,086 $ (2,791 ) Total Citigroup comprehensive income (loss) $ (9,589 ) $ 981 $ (3,415 ) $ 2,434 $ (9,589 ) Add: Other comprehensive income (loss) attributable to noncontrolling interests $ — $ — $ 114 $ — $ 114 Add: Net income attributable to noncontrolling interests — (1 ) 61 — 60 Total comprehensive income (loss) $ (9,589 ) $ 980 $ (3,240 ) $ 2,434 $ (9,415 )
Condensed balance sheet	December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ — $ 870 $ 22,173 $ — $ 23,043 Cash and due from banks—intercompany 142 3,820 (3,962 ) — — Federal funds sold and resale agreements — 196,236 40,577 — 236,813 Federal funds sold and resale agreements—intercompany — 12,270 (12,270 ) — — Trading account assets 6 121,484 122,435 — 243,925 Trading account assets—intercompany 1,173 907 (2,080 ) — — Investments 173 335 352,796 — 353,304 Loans, net of unearned income — 575 623,794 — 624,369 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,060 ) — (12,060 ) Total loans, net $ — $ 575 $ 611,734 $ — $ 612,309 Advances to subsidiaries $ 143,154 $ — $ (143,154 ) $ — $ — Investments in subsidiaries 226,279 — — (226,279 ) — Other assets (1) 23,734 46,095 252,854 — 322,683 Other assets—intercompany 27,845 38,207 (66,052 ) — — Total assets $ 422,506 $ 420,799 $ 1,175,051 $ (226,279 ) $ 1,792,077 Liabilities and equity Deposits $ — $ — $ 929,406 $ — $ 929,406 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 122,320 19,501 — 141,821 Federal funds purchased and securities loaned or sold—intercompany — 25,417 (25,417 ) — — Trading account liabilities — 87,714 51,331 — 139,045 Trading account liabilities—intercompany 1,006 868 (1,874 ) — — Short-term borrowings — 1,356 29,345 — 30,701 Short-term borrowings—intercompany — 35,596 (35,596 ) — — Long-term debt 147,333 8,128 50,717 — 206,178 Long-term debt—intercompany — 41,287 (41,287 ) — — Advances from subsidiaries 41,258 — (41,258 ) — — Other liabilities 3,466 57,430 57,887 — 118,783 Other liabilities—intercompany 4,323 7,894 (12,217 ) — — Stockholders’ equity 225,120 32,789 194,513 (226,279 ) 226,143 Total liabilities and equity $ 422,506 $ 420,799 $ 1,175,051 $ (226,279 ) $ 1,792,077 (1) Other assets for Citigroup parent company at December 31, 2016 included $20.7 billion of placements to Citibank and its branches, of which $6.8 billion had a remaining term of less than 30 days. December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ — $ 378 $ 23,397 $ — $ 23,775 Cash and due from banks—intercompany 13 3,750 (3,763 ) — — Federal funds sold and resale agreements — 182,685 49,793 — 232,478 Federal funds sold and resale agreements—intercompany — 16,091 (16,091 ) — — Trading account assets — 139,462 112,094 — 251,556 Trading account assets—intercompany 38 2,711 (2,749 ) — — Investments 27 181 352,082 — 352,290 Loans, net of unearned income — 900 666,134 — 667,034 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,355 ) — (12,355 ) Total loans, net $ — $ 900 $ 653,779 $ — $ 654,679 Advances to subsidiaries $ 139,722 $ — $ (139,722 ) $ — $ — Investments in subsidiaries 210,537 — — (210,537 ) — Other assets (1) 10,844 61,647 255,196 — 327,687 Other assets—intercompany 14,428 48,832 (63,260 ) — — Total assets $ 375,609 $ 456,637 $ 1,220,756 $ (210,537 ) $ 1,842,465 Liabilities and equity Deposits $ — $ — $ 959,822 $ — $ 959,822 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 134,888 21,389 — 156,277 Federal funds purchased and securities loaned or sold—intercompany — 18,597 (18,597 ) — — Trading account liabilities — 80,801 43,246 — 124,047 Trading account liabilities—intercompany 15 2,182 (2,197 ) — — Short-term borrowings 251 3,568 40,633 — 44,452 Short-term borrowings—intercompany — 32,871 (32,871 ) — — Long-term debt 152,163 18,048 66,498 — 236,709 Long-term debt—intercompany — 60,765 (60,765 ) — — Advances from subsidiaries 19,136 — (19,136 ) — — Other liabilities 2,673 62,113 54,700 — 119,486 Other liabilities—intercompany 631 9,753 (10,384 ) — — Stockholders’ equity 200,740 33,051 178,418 (210,537 ) 201,672 Total liabilities and equity $ 375,609 $ 456,637 $ 1,220,756 $ (210,537 ) $ 1,842,465 (1) Other assets for Citigroup parent company at December 31, 2017 included $ 29.7 billion of placements to Citibank and its branches, of which $ 18.9 billion had a remaining term of less than 30 days.
Condensed cash flow statement	Year ended December 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by (used in) operating activities of continuing operations $ 34,940 $ (33,359 ) $ (10,168 ) $ — $ (8,587 ) Cash flows from investing activities of continuing operations Purchases of investments $ — $ (1 ) $ (185,739 ) $ — $ (185,740 ) Proceeds from sales of investments 132 — 107,236 — 107,368 Proceeds from maturities of investments — — 84,369 — 84,369 Change in deposits with banks — 11,861 (31,151 ) — (19,290 ) Change in loans — — (58,062 ) — (58,062 ) Proceeds from sales and securitizations of loans — — 8,365 — 8,365 Proceeds from significant disposals — — 3,411 — 3,411 Change in federal funds sold and resales — 9,730 (5,395 ) — 4,335 Changes in investments and advances—intercompany (899 ) (2,790 ) 3,689 — — Other investing activities — (24 ) (2,960 ) — (2,984 ) Net cash provided by (used in) investing activities of continuing operations $ (767 ) $ 18,776 $ (76,237 ) $ — $ (58,228 ) Cash flows from financing activities of continuing operations Dividends paid $ (3,797 ) $ — $ — $ — $ (3,797 ) Treasury stock acquired (14,541 ) — — — (14,541 ) Proceeds (repayments) from issuance of long-term debt, net 6,544 4,909 15,521 — 26,974 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (2,031 ) 2,031 — — Change in deposits — — 30,416 — 30,416 Change in federal funds purchased and repos — 5,748 8,708 — 14,456 Change in short-term borrowings 49 2,212 11,490 — 13,751 Net change in short-term borrowings and other advances—intercompany (22,152 ) 3,931 18,221 — — Capital contributions from parent — (748 ) 748 — — Other financing activities (405 ) — — — (405 ) Net cash provided by (used in) financing activities of continuing operations $ (34,302 ) $ 14,021 $ 87,135 $ — $ 66,854 Effect of exchange rate changes on cash and due from banks $ — $ — $ 693 $ — $ 693 Change in cash and due from banks $ (129 ) $ (562 ) $ 1,423 $ — $ 732 Cash and due from banks at beginning of period 142 4,690 18,211 — 23,043 Cash and due from banks at end of period $ 13 $ 4,128 $ 19,634 $ — $ 23,775 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ (3,730 ) $ 678 $ 5,135 $ — $ 2,083 Cash paid during the year for interest 4,151 4,513 7,011 — 15,675 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 5,900 $ — $ 5,900 Transfers to OREO and other repossessed assets — — 113 — 113 Year ended December 31, 2015 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by (used in) operating activities of continuing operations $ 27,825 $ 12,336 $ (424 ) $ — $ 39,737 Cash flows from investing activities of continuing operations Purchases of investments $ — $ (4 ) $ (242,358 ) $ — $ (242,362 ) Proceeds from sales of investments — 53 141,417 — 141,470 Proceeds from maturities of investments 237 — 81,810 — 82,047 Change in deposits with banks — (8,414 ) 23,902 — 15,488 Change in loans — — 1,353 — 1,353 Proceeds from sales and securitizations of loans — — 9,610 — 9,610 Change in federal funds sold and resales — 8,037 14,858 — 22,895 Proceeds from significant disposals — — 5,932 — 5,932 Payments due to transfers of net liabilities associated with significant disposals — — (18,929 ) — (18,929 ) Changes in investments and advances—intercompany (35,548 ) 1,044 34,504 — — Other investing activities 3 (101 ) (2,523 ) — (2,621 ) Net cash provided by (used in) investing activities of continuing operations $ (35,308 ) $ 615 $ 49,576 $ — $ 14,883 Cash flows from financing activities of continuing operations Dividends paid $ (1,253 ) $ — $ — $ — $ (1,253 ) Issuance of preferred stock 6,227 — — — 6,227 Treasury stock acquired (5,452 ) — — — (5,452 ) Proceeds (repayments) from issuance of long-term debt, net 127 (139 ) (8,212 ) — (8,224 ) Proceeds (repayments) from issuance of long-term debt—intercompany, net — 12,557 (12,557 ) — — Change in deposits — — 8,555 — 8,555 Change in federal funds purchased and repos — (27,442 ) 500 — (26,942 ) Change in short-term borrowings (845 ) (1,737 ) (34,674 ) — (37,256 ) Net change in short-term borrowings and other advances—intercompany 9,106 4,054 (13,160 ) — — Other financing activities (428 ) — — — (428 ) Net cash provided by (used in) financing activities of continuing operations $ 7,482 $ (12,707 ) $ (59,548 ) $ — $ (64,773 ) Effect of exchange rate changes on cash and due from banks $ — $ — $ (1,055 ) $ — $ (1,055 ) Change in cash and due from banks $ (1 ) $ 244 $ (11,451 ) $ — $ (11,208 ) Cash and due from banks at beginning of period 125 1,751 30,232 — 32,108 Cash and due from banks at end of period $ 124 $ 1,995 $ 18,781 $ — $ 20,900 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ 111 $ 175 $ 4,692 $ — $ 4,978 Cash paid during the year for interest 4,916 2,346 4,769 — 12,031 Non-cash investing activities Decrease in net loans associated with significant disposals reclassified to HFS $ — $ — $ (9,063 ) $ — $ (9,063 ) Decrease in investments associated with significant disposals reclassified to HFS — — (1,402 ) — (1,402 ) Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS — — (223 ) — (223 ) Decrease in deposits with banks with significant disposals reclassified to HFS — — (404 ) — (404 ) Transfers to loans held-for-sale from loans — — 28,600 — 28,600 Transfers to OREO and other repossessed assets — — 276 — 276 Non-cash financing activities Decrease in long-term debt associated with significant disposals reclassified to HFS $ — $ — $ (4,673 ) $ — $ (4,673 ) Year ended December 31, 2016 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Net cash provided by operating activities of continuing operations $ 12,777 $ 20,662 $ 20,493 $ — $ 53,932 Cash flows from investing activities of continuing operations Purchases of investments $ — $ (4 ) $ (211,398 ) $ — $ (211,402 ) Proceeds from sales of investments 3,024 — 129,159 — 132,183 Proceeds from maturities of investments 234 — 65,291 — 65,525 Change in deposits with banks — (3,643 ) (21,668 ) — (25,311 ) Change in loans — — (39,761 ) — (39,761 ) Proceeds from sales and securitizations of loans — — 18,140 — 18,140 Proceeds from significant disposals — — 265 — 265 Change in federal funds sold and resales — (15,293 ) (1,845 ) — (17,138 ) Changes in investments and advances—intercompany (18,083 ) (5,574 ) 23,657 — — Other investing activities — — (2,089 ) — (2,089 ) Net cash used in investing activities of continuing operations $ (14,825 ) $ (24,514 ) $ (40,249 ) $ — $ (79,588 ) Cash flows from financing activities of continuing operations Dividends paid $ (2,287 ) $ — $ — $ — $ (2,287 ) Issuance of preferred stock 2,498 — — — 2,498 Treasury stock acquired (9,290 ) — — — (9,290 ) Proceeds (repayments) from issuance of long-term debt, net 7,005 5,916 (4,575 ) — 8,346 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (9,453 ) 9,453 — — Change in deposits — — 24,394 — 24,394 Change in federal funds purchased and repos — 3,236 (7,911 ) — (4,675 ) Change in short-term borrowings (164 ) 1,168 8,618 — 9,622 Net change in short-term borrowings and other advances—intercompany 4,620 680 (5,300 ) — — Capital contributions from parent — 5,000 (5,000 ) — — Other financing activities (316 ) — — — (316 ) Net cash provided by financing activities of continuing operations $ 2,066 $ 6,547 $ 19,679 $ — $ 28,292 Effect of exchange rate changes on cash and due from banks $ — $ — $ (493 ) $ — $ (493 ) Change in cash and due from banks $ 18 $ 2,695 $ (570 ) $ — $ 2,143 Cash and due from banks at beginning of period 124 1,995 18,781 — 20,900 Cash and due from banks at end of period $ 142 $ 4,690 $ 18,211 $ — $ 23,043 Supplemental disclosure of cash flow information for continuing operations Cash paid during the year for income taxes $ 351 $ 92 $ 3,916 $ — $ 4,359 Cash paid during the year for interest 4,397 3,115 4,555 — 12,067 Non-cash investing activities Transfers to loans held-for-sale from loans $ — $ — $ 13,900 $ — $ 13,900 Transfers to OREO and other repossessed assets — — 165 — 165

SELECTED QUARTERLY FINANCIAL 65

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	2017 2016 In millions of dollars, except per share amounts Fourth (1) Third Second First Fourth Third Second First Revenues, net of interest expense $ 17,255 $ 18,173 $ 17,901 $ 18,120 $ 17,012 $ 17,760 $ 17,548 $ 17,555 Operating expenses 10,083 10,171 10,506 10,477 10,120 10,404 10,369 10,523 Provisions for credit losses and for benefits and claims 2,073 1,999 1,717 1,662 1,792 1,736 1,409 2,045 Income from continuing operations before income taxes $ 5,099 $ 6,003 $ 5,678 $ 5,981 $ 5,100 $ 5,620 $ 5,770 $ 4,987 Income taxes 23,864 1,866 1,795 1,863 1,509 1,733 1,723 1,479 Income (loss) from continuing operations $ (18,765 ) $ 4,137 $ 3,883 $ 4,118 $ 3,591 $ 3,887 $ 4,047 $ 3,508 Income (loss) from discontinued operations, net of taxes (109 ) (5 ) 21 (18 ) (3 ) (30 ) (23 ) (2 ) Net income before attribution of noncontrolling interests $ (18,874 ) $ 4,132 $ 3,904 $ 4,100 $ 3,588 $ 3,857 $ 4,024 $ 3,506 Noncontrolling interests 19 (1 ) 32 10 15 17 26 5 Citigroup’s net income (loss) $ (18,893 ) $ 4,133 $ 3,872 $ 4,090 $ 3,573 $ 3,840 $ 3,998 $ 3,501 Earnings per share (2) Basic Income (loss) from continuing operations $ (7.33 ) $ 1.42 $ 1.27 $ 1.36 $ 1.14 $ 1.25 $ 1.25 $ 1.11 Net income (loss) (7.38 ) 1.42 1.28 1.35 1.14 1.24 1.24 1.10 Diluted Income (loss) from continuing operations (7.33 ) 1.42 1.27 1.36 1.14 1.25 1.25 1.11 Net income (loss) (7.38 ) 1.42 1.28 1.35 1.14 1.24 1.24 1.10 Common stock price per share High close during the quarter 77.10 72.74 66.98 61.54 61.09 47.90 47.33 51.13 Low close during the quarter 71.33 65.95 57.72 55.68 47.03 40.78 38.48 34.98 Quarter end 74.41 72.74 66.88 59.82 59.43 47.23 42.39 41.75 Dividends per share of common stock 0.32 0.32 0.16 0.16 0.16 0.16 0.05 0.05 This Note to the Consolidated Financial Statements is unaudited due to the Company’s individual quarterly results not being subject to an audit. (1) The fourth quarter of 2017 includes the impact of Tax Reform. See Notes 1 and 9 to the Consolidated Financial Statements. (2) Due to averaging of shares, quarterly earnings per share may not sum to the totals reported for the full year.

SUMMARY OF SIGNIFICANT ACCOUN66

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017paymentre-aging
Accounting Policies [Abstract]
Ownership percentage, if less than this amount then income from investments is recognized when dividends are received	20.00%
Minimum
Loans charge off and interest accrual period
Minimum number of payments on a modified loan to return to accrual status	1
Number of months in sustained period of repayment performance for cash-basis loans to return to an accrual status	6 months
Maximum
Loans charge off and interest accrual period
Minimum number of payments on a modified loan to return to accrual status	6
Installment and real estate loans
Loans charge off and interest accrual period
Past due period for consumer loans when interest accrual ceases	90 days
Credit cards and unsecured revolving loans
Loans charge off and interest accrual period
Past due period for consumer loans when interest accrual ceases	180 days
Period for consumer loans charged-off	180 days
Home equity loans | New OCC guidance
Loans charge off and interest accrual period
Number of days past due, non-accrual status	90 days
Commercial market loans
Loans charge off and interest accrual period
Period for past due interest or principal payment of commercial market loans to be considered doubtful after which loans are placed on a cash (non-accrual) basis	90 days
Consumer | Minimum
Loans charge off and interest accrual period
Minimum number of payments required for modification of loans	1
Consumer | Maximum
Loans charge off and interest accrual period
Minimum number of payments required for modification of loans	3
Open-ended consumer loans
Loans charge off and interest accrual period
Minimum number of payments required for modification of loans	3
Unsecured installment loans
Loans charge off and interest accrual period
Period for consumer loans charged-off	120 days
Mortgage and real estate
Loans charge off and interest accrual period
Period for consumer loans charged-off	180 days
Real estate-secured loans
Loans charge off and interest accrual period
Past due period of contractual payments to charge-off, if no payments in six months and if a decision has been made not to foreclose on the loans	180 days
Unsecured loans in bankruptcy
Loans charge off and interest accrual period
Maximum period from receiving bankruptcy court filing notification to charge-off	60 days
Real estate-secured loans in bankruptcy
Loans charge off and interest accrual period
Maximum past due period of contractual payments to write down secured loans to net collateral values	60 days
Corporate
Loans charge off and interest accrual period
Period for past due interest or principal payment of corporate loans to be considered doubtful	90 days
Time period for reversing accrued interest on impaired corporate loans	90 days
Consumer
Loans charge off and interest accrual period
Number of days past due, non-accrual status	60 days
Consumer | Open-ended consumer loans
Loans charge off and interest accrual period
Age modifications limitations in twelve months | re-aging	1
Age modifications limitations in five years | re-aging	2

SUMMARY OF SIGNIFICANT ACCOUN67

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounting Changes (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Dec. 31, 2017	Dec. 31, 2017	Jan. 01, 2017	Dec. 31, 2016	Jan. 01, 2016	Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle
Impact of non-cash charge related to Tax Reform		$ 22,600	$ 22,594
Charge related to remeasurement due to reduction of tax rate		12,400
Reduction in FTC carry-forwards that relate to deemed repatriation		2,300
Charge related to reduction in U.S. tax rate		6,200
Charge related to reduction in corporate tax rate for which accounting is complete		6,200
Retained earnings		138,425	138,425		$ 146,477
Stockholders’ equity		201,672	201,672		226,143		$ 223,092
Increase (decrease) to AOCI		(34,668)	(34,668)		(32,381)
Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle
Retained earnings		3,300	3,300
Cumulative effect of new accounting principle		(3,304)	(3,304)
Accounting Standards Update 2017-08 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle
Stockholders’ equity				$ (156)
Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle
Retained earnings						$ 15
Increase (decrease) to AOCI						(15)
Accounting Standards Update 2016-01 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle
Increase (decrease) to AOCI						$ (15)
Foreign Tax Credit Carryforwards
New Accounting Pronouncements or Change in Accounting Principle
Valuation allowance		7,900	7,900
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle
Stockholders’ equity		138,425	138,425		146,477		133,841	$ 117,852
Cumulative effect of new accounting principle	[1]				(660)		15
Retained earnings | Accounting Standards Update 2017-08 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect of new accounting principle				(660)
Accumulated other comprehensive income (loss)
New Accounting Pronouncements or Change in Accounting Principle
Stockholders’ equity		(34,668)	(34,668)		(32,381)		(29,344)	(23,216)
Cumulative effect of new accounting principle	[1]				504		(15)
Increase (decrease) to AOCI		$ (34,668)	$ (34,668)		$ (32,381)		$ (29,344)	$ (23,216)
Accumulated other comprehensive income (loss) | Accounting Standards Update 2017-08 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect of new accounting principle				$ 504
[1]	See Note 1 to the Consolidated Financial Statements.

DISCONTINUED OPERATIONS AND S68

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS - Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Results of Discontinued Operations
Total revenues, net of interest expense									$ 0	$ 0	$ 0
Loss from discontinued operations									(104)	(80)	(83)
Provision (benefit) for income taxes									7	(22)	(29)
Loss from discontinued operations, net of taxes	$ (109)	$ (5)	$ 21	$ (18)	$ (3)	$ (30)	$ (23)	$ (2)	$ (111)	$ (58)	$ (54)

DISCONTINUED OPERATIONS AND S69

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS - Significant Disposals (Details) loan in Thousands, customer_account in Thousands, $ in Millions		Jan. 01, 2016	Nov. 15, 2015USD ($)employeebranchcustomer_account	Mar. 31, 2017USD ($)employeebranch	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2018USD ($)	Aug. 31, 2017USD ($)	Dec. 14, 2015USD ($)employeecustomer_account	Nov. 01, 2015USD ($)employeebranchcustomer_account
Discontinued operations
Pre-tax gain (loss) on sale	[1]					$ 602	$ 404	$ 3,210
Mexico Asset Management Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						164	155	159
Fixed Income Analytics and Index Businesses | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Goodwill										$ 72
Income (loss) before taxes						31	55	54
Assets										112
Liabilities										$ 18
Pre-tax gain (loss) on sale						580
After tax gain (loss) on sale of disposal						355
US Mortgage Servicing Operations | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						0	0	0
Pre-tax gain (loss) on sale						(331)
After tax gain (loss) on sale of disposal						(207)
Loss on disposal						382
Derecognition of servicing-related assets						1,162
Derecognition of mortgage servicing rights						$ 1,046
Number of loans to be disposed of | loan						750
Loans, net						$ 93,000
CitiFinancial Canada | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						41	139	118
Assets				$ 1,900
Liabilities				1,500
Pre-tax gain (loss) on sale						350
After tax gain (loss) on sale of disposal						178
Loans, net				$ 1,700
Number of branches | branch				220
Number of employees | employee				1,400
Debt settled				$ 400
Novation of 80% Primerica Coinsurance Agreement | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						0	0	135
Liabilities							2,700
Pre-tax gain (loss) on sale							404
After tax gain (loss) on sale of disposal							263
Coinsurance agreement percentage		80.00%
Derecognition of available for sale securities and cash							1,500
Derecognition of deferred acquisition costs							950
OneMain Financial Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						0	0	663
Assets			$ 10,200
Liabilities			8,400
Pre-tax gain (loss) on sale			2,600
After tax gain (loss) on sale of disposal			1,600
Loans, net			$ 7,800
Number of branches | branch			1,100
Number of employees | employee			5,500
Number of customer accounts | customer_account			1,300
Investments			$ 1,400
Long-term debt			6,200
Short-term borrowings			$ 1,100
Gain on disposal including redemption of long term debt, net of tax					$ 800
Japan Cards Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						0	0	(5)
Pre-tax gain (loss) on sale								180
After tax gain (loss) on sale of disposal								155
Loans, net											$ 1,350
Number of employees | employee											840
Number of customer accounts | customer_account											720
Japan Retail Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Income (loss) before taxes						$ 0	$ 0	(57)
Pre-tax gain (loss) on sale								446
After tax gain (loss) on sale of disposal								$ 276
Loans, net												$ 563
Number of branches | branch												32
Number of employees | employee												1,600
Number of customer accounts | customer_account												725
Deposits												$ 20,000
Forecast | Mexico Asset Management Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Net book value derecognized									$ 72
Goodwill									$ 32
[1]	See Note 2 to the Consolidated Financial Statements for further information on significant disposals.

BUSINESS SEGMENTS (Details)

BUSINESS SEGMENTS (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)country	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)country		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Segment reporting information
Revenues, net of interest expense	$ 17,255	$ 18,173	$ 17,901	$ 18,120	$ 17,012	$ 17,760	$ 17,548	$ 17,555	$ 71,449	[1]	$ 69,875	[1]	$ 76,354	[1]
Provision (benefits) for income taxes	23,864	1,866	1,795	1,863	1,509	1,733	1,723	1,479	29,388		6,444		7,440
Income (loss) from continuing operations	(18,765)	4,137	3,883	4,118	3,591	3,887	4,047	3,508	(6,627)		15,033		17,386
Identifiable assets	1,842,465				1,792,077				1,842,465		1,792,077
Provisions for credit losses and for benefits and claims	2,073	$ 1,999	$ 1,717	$ 1,662	1,792	$ 1,736	$ 1,409	$ 2,045	7,451		6,982		7,913
Operating Segments | Citicorp | North America
Segment reporting information
Revenues, net of interest expense									33,900		32,200		32,200
Operating Segments | Citicorp | EMEA
Segment reporting information
Revenues, net of interest expense									10,700		9,900		9,800
Operating Segments | Citicorp | Latin America
Segment reporting information
Revenues, net of interest expense									9,400		8,900		9,700
Operating Segments | Citicorp | Asia
Segment reporting information
Revenues, net of interest expense									14,400		13,700		13,900
Operating Segments | Global Consumer Banking
Segment reporting information
Revenues, net of interest expense									32,697		31,519		32,251
Provision (benefits) for income taxes									3,320		2,655		3,369
Income (loss) from continuing operations									3,893		4,954		6,214
Identifiable assets	$ 429,000				412,000				429,000		412,000
Provisions for credit losses and for benefits and claims									$ 7,600		6,400		5,500
Operating Segments | Institutional Clients Group
Segment reporting information
Number of countries where the entity provides a broad range of banking and financial products and services (over) | country	97								97
Revenues, net of interest expense									$ 35,667		33,227		33,332
Provision (benefits) for income taxes									7,008		4,260		4,173
Income (loss) from continuing operations									9,066		9,525		9,110
Identifiable assets	$ 1,336,000				1,277,000				1,336,000		1,277,000
Provisions for credit losses and for benefits and claims									15		486		962
Operating Segments | Corporate/Other
Segment reporting information
Revenues, net of interest expense									3,085		5,129		10,771
Provision (benefits) for income taxes									19,060		(471)		(102)
Income (loss) from continuing operations									(19,586)		554		2,062
Identifiable assets	$ 77,000				$ 103,000				77,000		103,000
Provisions for credit losses and for benefits and claims									$ 175		$ 69		$ 1,500
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

INTEREST REVENUE AND EXPENSE (D

INTEREST REVENUE AND EXPENSE (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest revenue
Loan interest, including fees		$ 41,361	$ 39,752	$ 40,510
Deposits with banks		1,635	971	727
Federal funds sold and securities borrowed or purchased under agreements to resell		3,248	2,543	2,516
Investments, including dividends		8,295	7,582	7,017
Trading account assets		5,502	5,738	5,942
Other interest		1,163	1,029	1,839
Total interest revenue	[1]	61,204	57,615	58,551
Interest expense
Deposits		6,586	5,300	5,052
Federal funds purchased and securities loaned or sold under agreements to repurchase		2,661	1,912	1,612
Trading account liabilities		638	410	217
Short-term borrowings		1,059	477	523
Long-term debt		5,573	4,412	4,517
Total interest expense	[1]	16,517	12,511	11,921
Net interest revenue	[1]	44,687	45,104	46,630
Provision for loan losses		7,503	6,749	7,108
Net interest revenue after provision for loan losses		37,184	38,355	39,522
Insurance fees and charges		$ 1,249	$ 1,145	$ 1,118
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

COMMISSIONS AND FEES (Details)

COMMISSIONS AND FEES (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commissions and fees
Card fees amortization period		12 months
Total commissions and fees	[1]	$ 12,939	$ 11,938	$ 14,485
Investment banking
Commissions and fees
Total commissions and fees		3,613	2,847	3,423
Trading-related
Commissions and fees
Total commissions and fees		3,015	2,799	3,138
Trade and securities services
Commissions and fees
Total commissions and fees		1,632	1,564	1,735
Credit cards and bank cards
Commissions and fees
Total commissions and fees		1,510	1,324	1,786
Corporate finance
Commissions and fees
Total commissions and fees		713	686	493
Other consumer
Commissions and fees
Total commissions and fees		703	659	685
Insurance distribution revenue
Commissions and fees
Total commissions and fees		514	548	621
Insurance premiums
Commissions and fees
Total commissions and fees		122	288	1,224
Checking-related
Commissions and fees
Total commissions and fees		478	467	497
Loan servicing
Commissions and fees
Total commissions and fees		312	325	404
Other
Commissions and fees
Total commissions and fees		$ 327	$ 431	$ 479
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

PRINCIPAL TRANSACTIONS (Details

PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Principal transactions revenue
Principal transactions revenue	[1]	$ 9,168	$ 7,585	$ 6,008
Interest rate risks
Principal transactions revenue
Principal transactions revenue		5,124	4,115	3,798
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue		2,488	1,726	1,532
Equity risks
Principal transactions revenue
Principal transactions revenue		491	189	331
Commodity and other risks
Principal transactions revenue
Principal transactions revenue		294	806	750
Credit products and risks
Principal transactions revenue
Principal transactions revenue		771	749	(403)
Operating Segments | Global Consumer Banking
Principal transactions revenue
Principal transactions revenue		570	629	577
Operating Segments | Institutional Clients Group
Principal transactions revenue
Principal transactions revenue		7,740	7,335	5,824
Operating Segments | Corporate/Other
Principal transactions revenue
Principal transactions revenue		$ 858	$ (379)	$ (393)
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

INCENTIVE PLANS - Annual Incent

INCENTIVE PLANS - Annual Incentive Awards and Compensation Allowances (Details) - Annual Incentive Awards	12 Months Ended
	Dec. 31, 2017USD ($)
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Threshold value for awards paid entirely as immediate cash bonus (less than $100,000)	$ 100,000
Capital Accumulation Program Awards (CAP) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for CAP and deferred cash awards	3 years
Capital Accumulation Program Awards (CAP) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for CAP and deferred cash awards	4 years
Capital Accumulation Program Awards (CAP) | Granted February 2013 and later | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of reduction applicable in case of pretax loss	20.00%
Highly compensated employees | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of incentive pay required to be deferred	25.00%
Highly compensated employees | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of incentive pay required to be deferred	60.00%
Identified staff in the European Union (EU)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of immediate incentive delivered in the form of a stock payment	50.00%
Period of sale or transfer restriction on stock payment	12 months
Identified staff in the European Union (EU) | Deferred cash awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Holdback period on vested awards	12 months

INCENTIVE PLANS - Unvested Stoc

INCENTIVE PLANS - Unvested Stock Awards (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted- average grant date fair value per share (in dollars per share):
Weighted-average market value (in dollars per share)	$ 57.45	$ 37.35	$ 50.33
Unrecognized compensation cost of unvested stock awards	$ 530
Weighted-average period of recognition of unrecognized compensation cost of unvested stock awards (in years)	1 year 7 months 1 day
Unvested Stock Awards
Unvested stock awards (in shares):
Beginning of period (in shares)	42,672,176
Granted (in shares)	13,914,752
Canceled (in shares)	(1,335,297)
Vested (in shares)	(18,320,591)
End of period (in shares)	36,931,040	42,672,176
Weighted- average grant date fair value per share (in dollars per share):
Beginning of period (in dollars per share)	$ 43.24
Granted (in dollars per share)	59.12
Canceled (in dollars per share)	47.29
Vested (in dollars per share)	45.63
End of period (in dollars per share)	$ 47.89	$ 43.24

INCENTIVE PLANS - Performance S

INCENTIVE PLANS - Performance Share Units (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted- average grant date fair value per share (in dollars per share):
Weighted-average market value (in dollars per share)	$ 57.45	$ 37.35	$ 50.33
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period used for calculation of performance goals	3 years
Percentage of target shares earned	100.00%
Number of shares of common stock equivalent to each target share		1
Valuation Assumptions
Expected volatility	25.79%	24.37%	27.13%
Expected dividend yield	1.30%	0.40%	0.08%
Unvested stock awards (in shares):
Beginning of period (in shares)	1,844,560
Granted (in shares)	500,609
Canceled (in shares)	(277,546)
Payments (in shares)	(280,897)
End of period (in shares)	1,786,726	1,844,560
Weighted- average grant date fair value per share (in dollars per share):
Beginning of period (in dollars per share)	$ 38.22
Granted (in dollars per share)	59.22
Canceled (in dollars per share)	48.34
Payments (in dollars per share)	48.34
End of period (in dollars per share)	$ 40.94	$ 38.22
Weighted-average market value (in dollars per share)		$ 27.03	$ 44.07
Minimum | Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares earned	0.00%
Maximum | Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares earned	150.00%

INCENTIVE PLANS - Stock Option

INCENTIVE PLANS - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Options (in shares):
Outstanding, beginning of period (in shares)	1,527,396	6,656,588	26,514,119
Canceled (in shares)	0	(25,334)	(7,901)
Expired (in shares)	0	(2,613,909)	(1,646,581)
Exercised (in shares)	(388,583)	(2,489,949)	(18,203,048)
Outstanding, end of period (in shares)	1,138,813	1,527,396	6,656,588
Exercisable, end of period	1,138,813	1,527,396	6,656,588
Weighted- average exercise price (in dollars per share):
Outstanding, beginning of period (in dollars per share)	$ 131.78	$ 67.92	$ 48
Canceled (in dollars per share)	0	40.80	40.80
Expired (in dollars per share)	0	48.80	40.85
Exercised (in dollars per share)	43.35	49.10	41.39
Outstanding, end of period (in dollars per share)	161.96	131.78	67.92
Intrinsic value per share (in dollars per share):
Outstanding (in dollars per share)	0	0	0	$ 6.11
Exercised (in dollars per share)	$ 15.67	$ 6.60	$ 13.03
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period	6 years
Cash received from employee stock option exercises	$ 14

INCENTIVE PLANS - Stock Options

INCENTIVE PLANS - Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding (in shares) | shares	1,138,813
Options outstanding, Weighted-average contractual life remaining	1 year 3 months 15 days
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 161.96
Options exercisable, Number exercisable (in shares) | shares	1,138,813
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 161.96
$39.00—$99.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	39
Exercise price, high end of the range (in dollars per share)	$ 99.99
Number outstanding (in shares) | shares	312,309
Options outstanding, Weighted-average contractual life remaining	3 years
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 43.56
Options exercisable, Number exercisable (in shares) | shares	312,309
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 43.56
$100.00—$199.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	100
Exercise price, high end of the range (in dollars per share)	$ 199.99
Number outstanding (in shares) | shares	502,416
Options outstanding, Weighted-average contractual life remaining	1 year
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 147.13
Options exercisable, Number exercisable (in shares) | shares	502,416
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 147.13
$200.00—$299.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	200
Exercise price, high end of the range (in dollars per share)	$ 299.99
Number outstanding (in shares) | shares	124,088
Options outstanding, Weighted-average contractual life remaining	1 month 6 days
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 240.28
Options exercisable, Number exercisable (in shares) | shares	124,088
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 240.28
$300.00—$399.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	300
Exercise price, high end of the range (in dollars per share)	$ 399.99
Number outstanding (in shares) | shares	200,000
Options outstanding, Weighted-average contractual life remaining	1 month 6 days
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 335.50
Options exercisable, Number exercisable (in shares) | shares	200,000
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 335.50

INCENTIVE PLANS - Incentive Com

INCENTIVE PLANS - Incentive Compensation Cost (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	$ 2,251	$ 2,183	$ 2,161
Immediately Vested Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	70	73	61
Retirement Eligible Employees | Restricted and Deferred Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	659	555	541
Nonretirement Eligible Employees | Restricted and Deferred Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	474	509	461
Deferred Cash Awards and Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	354	336	325
Variable Incentive Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Incentive compensation cost	$ 694	$ 710	$ 773
2014 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of shares available for grant	39.2

INCENTIVE PLANS - Future Expens

INCENTIVE PLANS - Future Expenses (Details) $ in Millions	Dec. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock awards	$ 500
Deferred cash awards	310
Future expense related to awards already granted	810
Future expense related to awards granted in 2018	682
Total	1,492
2,018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock awards	276
Deferred cash awards	170
Future expense related to awards already granted	446
Future expense related to awards granted in 2018	238
Total	684
2,019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock awards	146
Deferred cash awards	94
Future expense related to awards already granted	240
Future expense related to awards granted in 2018	185
Total	425
2,020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock awards	67
Deferred cash awards	38
Future expense related to awards already granted	105
Future expense related to awards granted in 2018	148
Total	253
2021 and beyond
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock awards	11
Deferred cash awards	8
Future expense related to awards already granted	19
Future expense related to awards granted in 2018	111
Total	$ 130

RETIREMENT BENEFITS - Net (Bene

RETIREMENT BENEFITS - Net (Benefit) Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure
Percentage of the significant plans over global pension and postretirement liabilities, which utilize quarterly measurement policy	90.00%
Defined Benefit Plan, Net Periodic Benefit Cost
Interest cost on benefit obligation	$ 2	$ 3	$ 4
Amortization of unrecognized
Prior service (benefit) cost	(31)	(31)	(31)
Total net expense	3	(2)	(12)
Pension Plans
Amounts that will be amortized from accumulated other comprehensive income (loss) into net expense in next fiscal year
Future amortization of income (loss)	241
Future amortization of prior service cost (credit)	(2)
Postretirement Benefit Plans
Amounts that will be amortized from accumulated other comprehensive income (loss) into net expense in next fiscal year
Future amortization of income (loss)	(28)
Future amortization of prior service cost (credit)	(9)
U.S. | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost
Benefits earned during the year	3	4	6
Interest cost on benefit obligation	533	548	581
Expected return on plan assets	(865)	(886)	(893)
Amortization of unrecognized
Prior service (benefit) cost	2	2	1
Net actuarial loss	173	169	148
Curtailment loss (gain)	6	13	14
Settlement loss	0	0	0
Total net expense	(148)	(150)	(143)
U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Net Periodic Benefit Cost
Benefits earned during the year	0	0	0
Interest cost on benefit obligation	26	25	33
Expected return on plan assets	(6)	(9)	(3)
Amortization of unrecognized
Prior service (benefit) cost	0	0	0
Net actuarial loss	0	(1)	0
Curtailment loss (gain)	0	0	0
Settlement loss	0	0	0
Total net expense	20	15	30
Non-U.S. | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost
Benefits earned during the year	153	154	168
Interest cost on benefit obligation	295	282	317
Expected return on plan assets	(299)	(287)	(323)
Amortization of unrecognized
Prior service (benefit) cost	(3)	(1)	2
Net actuarial loss	61	69	73
Curtailment loss (gain)	0	(2)	0
Settlement loss	12	6	44
Total net expense	219	221	281
Non-U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Net Periodic Benefit Cost
Benefits earned during the year	9	10	12
Interest cost on benefit obligation	101	94	108
Expected return on plan assets	(89)	(86)	(105)
Amortization of unrecognized
Prior service (benefit) cost	(10)	(10)	(11)
Net actuarial loss	35	30	43
Curtailment loss (gain)	0	0	(1)
Settlement loss	0	0	0
Total net expense	$ 46	$ 38	$ 46

RETIREMENT BENEFITS - Contribut

RETIREMENT BENEFITS - Contributions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
U.S. | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	$ 0
Cash contributions paid by the Company	50	$ 500
Estimated benefits paid directly by Company	60
Benefits paid directly by the Company	55	56
U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	0
Cash contributions paid by the Company	140	0
Estimated benefits paid directly by Company	6
Benefits paid directly by the Company	36	6
Non-U.S. | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	79
Cash contributions paid by the Company	90	82
Estimated benefits paid directly by Company	49
Benefits paid directly by the Company	45	44
Non-U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	4
Cash contributions paid by the Company	4	4
Estimated benefits paid directly by Company	6
Benefits paid directly by the Company	$ 5	$ 5

RETIREMENT BENEFITS - Funded St

RETIREMENT BENEFITS - Funded Status and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in projected benefit obligation
Interest cost on benefit obligation	$ 2	$ 3	$ 4
Actuarial loss (gain)	2	5	12
U.S.
Change in plan assets
Plan assets at fair value at beginning of year	12,492
Plan assets at fair value at year end	12,988	12,492
U.S. | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	14,000	13,943
Benefits earned during the year	3	4	6
Interest cost on benefit obligation	533	548	581
Plan amendments	0	0
Actuarial loss (gain)	536	367
Benefits paid, net of participants’ contributions and government subsidy	(769)	(780)
Divestitures	0	0
Settlement gain	0	0
Curtailment (gain) loss	6	13
Foreign exchange impact and other	(269)	(95)
Projected benefit obligation at period end	14,040	14,000	13,943
Change in plan assets
Plan assets at fair value at beginning of year	12,363	12,137
Actual return on plan assets	1,295	572
Company contributions	105	556
Divestitures	0	0
Settlements	0	0
Benefits paid, net of participants’ contributions and government subsidy	(769)	(779)
Foreign exchange impact and other	(269)	(123)
Plan assets at fair value at year end	12,725	12,363	12,137
Funded status of the plans	(1,315)	(1,637)
Net amount recognized
Net amount recognized on the balance sheet	(1,315)	(1,637)
Amounts recognized in Accumulated other comprehensive income (loss)
Net transition obligation	0	0
Prior service benefit	(15)	(17)
Net actuarial gain (loss)	(6,823)	(6,891)
Net amount recognized in equity-pretax	(6,838)	(6,908)
Accumulated benefit obligation at period end	14,034	13,994
U.S. | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	686	817
Benefits earned during the year	0	0	0
Interest cost on benefit obligation	26	25	33
Plan amendments	0	0
Actuarial loss (gain)	43	(105)
Benefits paid, net of participants’ contributions and government subsidy	(56)	(51)
Divestitures	0	0
Settlement gain	0	0
Curtailment (gain) loss	0	0
Foreign exchange impact and other	0	0
Projected benefit obligation at period end	699	686	817
Change in plan assets
Plan assets at fair value at beginning of year	129	166
Actual return on plan assets	13	8
Company contributions	176	6
Divestitures	0	0
Settlements	0	0
Benefits paid, net of participants’ contributions and government subsidy	(56)	(51)
Foreign exchange impact and other	0	0
Plan assets at fair value at year end	262	129	166
Funded status of the plans	(437)	(557)
Net amount recognized
Net amount recognized on the balance sheet	(437)	(557)
Amounts recognized in Accumulated other comprehensive income (loss)
Net transition obligation	0	0
Prior service benefit	0	0
Net actuarial gain (loss)	72	106
Net amount recognized in equity-pretax	72	106
Accumulated benefit obligation at period end	699	686
Non-U.S.
Change in plan assets
Plan assets at fair value at beginning of year	7,162
Plan assets at fair value at year end	8,247	7,162
Non-U.S. | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	6,522	6,534
Benefits earned during the year	153	154	168
Interest cost on benefit obligation	295	282	317
Plan amendments	4	(28)
Actuarial loss (gain)	127	589
Benefits paid, net of participants’ contributions and government subsidy	(278)	(324)
Divestitures	(29)	(22)
Settlement gain	(192)	(38)
Curtailment (gain) loss	(3)	(15)
Foreign exchange impact and other	834	(610)
Projected benefit obligation at period end	7,433	6,522	6,534
Change in plan assets
Plan assets at fair value at beginning of year	6,149	6,104
Actual return on plan assets	462	967
Company contributions	135	126
Divestitures	(31)	(5)
Settlements	(192)	(38)
Benefits paid, net of participants’ contributions and government subsidy	(278)	(324)
Foreign exchange impact and other	883	(681)
Plan assets at fair value at year end	7,128	6,149	6,104
Funded status of the plans	(305)	(373)
Net amount recognized
Net amount recognized on the balance sheet	(305)	(373)
Amounts recognized in Accumulated other comprehensive income (loss)
Net transition obligation	(1)	(1)
Prior service benefit	22	29
Net actuarial gain (loss)	(1,318)	(1,302)
Net amount recognized in equity-pretax	(1,297)	(1,274)
Accumulated benefit obligation at period end	7,038	6,090
Non-U.S. | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,141	1,291
Benefits earned during the year	9	10	12
Interest cost on benefit obligation	101	94	108
Plan amendments	0	0
Actuarial loss (gain)	19	3
Benefits paid, net of participants’ contributions and government subsidy	(64)	(59)
Divestitures	(4)	0
Settlement gain	0	0
Curtailment (gain) loss	0	(4)
Foreign exchange impact and other	59	(194)
Projected benefit obligation at period end	1,261	1,141	1,291
Change in plan assets
Plan assets at fair value at beginning of year	1,015	1,133
Actual return on plan assets	113	122
Company contributions	9	9
Divestitures	0	0
Settlements	0	0
Benefits paid, net of participants’ contributions and government subsidy	(64)	(59)
Foreign exchange impact and other	46	(190)
Plan assets at fair value at year end	1,119	1,015	$ 1,133
Funded status of the plans	(142)	(126)
Net amount recognized
Net amount recognized on the balance sheet	(142)	(126)
Amounts recognized in Accumulated other comprehensive income (loss)
Net transition obligation	0	0
Prior service benefit	92	98
Net actuarial gain (loss)	(382)	(399)
Net amount recognized in equity-pretax	(290)	(301)
Accumulated benefit obligation at period end	1,261	1,141
Qualified | U.S. | Pension Plans
Change in plan assets
Funded status of the plans	(565)	(908)
Net amount recognized
Benefit asset	0	0
Benefit liability	(565)	(908)
Net amount recognized on the balance sheet	(565)	(908)
Qualified | U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the plans	(437)	(557)
Net amount recognized
Benefit asset	0	0
Benefit liability	(437)	(557)
Net amount recognized on the balance sheet	(437)	(557)
Qualified | Non-U.S. | Pension Plans
Change in plan assets
Funded status of the plans	(305)	(373)
Net amount recognized
Benefit asset	900	711
Benefit liability	(1,205)	(1,084)
Net amount recognized on the balance sheet	(305)	(373)
Qualified | Non-U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the plans	(142)	(126)
Net amount recognized
Benefit asset	181	166
Benefit liability	(323)	(292)
Net amount recognized on the balance sheet	(142)	(126)
Nonqualified | U.S. | Pension Plans
Change in plan assets
Funded status of the plans	(750)	(729)
Net amount recognized
Net amount recognized on the balance sheet	(750)	(729)
Nonqualified | U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the plans	0	0
Net amount recognized
Net amount recognized on the balance sheet	0	0
Nonqualified | Non-U.S. | Pension Plans
Change in plan assets
Funded status of the plans	0	0
Net amount recognized
Net amount recognized on the balance sheet	0	0
Nonqualified | Non-U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the plans	0	0
Net amount recognized
Net amount recognized on the balance sheet	$ 0	$ 0

RETIREMENT BENEFITS - Accumulat

RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in accumulated other comprehensive income (loss)
Balance, beginning of year		$ 226,143	$ 223,092
Actuarial assumptions changes and plan experience		(760)	(854)	$ 898
Net asset gain (loss) due to difference between actual and expected returns		625	400	(1,457)
Net amortizations		229	232	236
Prior service (cost) credit		(4)	28	(6)
Curtailment/settlement gain		17	17	57
Foreign exchange impact and other		(93)	99	291
Impact of Tax Reform		(3,304)
Change in deferred taxes, net		(13)	30	24
Change, net of tax	[1]	(1,019)	(48)	43
Balance, end of year		201,672	226,143	223,092
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of year		(5,164)	(5,116)	(5,159)
Impact of Tax Reform		(1,020)	0	0
Balance, end of year		$ (6,183)	$ (5,164)	$ (5,116)
[1]	See Note 8 to the Consolidated Financial Statements.

RETIREMENT BENEFITS - PBO and A

RETIREMENT BENEFITS - PBO and ABO Exceed Fair Value of Plan Assets (Details) - Pension Plans - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
U.S.
PBO exceeds fair value of plan assets
Projected benefit obligation	$ 14,040	$ 14,000
Accumulated benefit obligation	14,034	13,994
Fair value of plan assets	12,725	12,363
ABO exceeds fair value of plan assets
Projected benefit obligation	14,040	14,000
Accumulated benefit obligation	14,034	13,994
Fair value of plan assets	12,725	12,363
Non-U.S.
PBO exceeds fair value of plan assets
Projected benefit obligation	2,721	2,484
Accumulated benefit obligation	2,381	2,168
Fair value of plan assets	1,516	1,399
ABO exceeds fair value of plan assets
Projected benefit obligation	2,596	2,282
Accumulated benefit obligation	2,296	2,012
Fair value of plan assets	$ 1,407	$ 1,224

RETIREMENT BENEFITS - Assumptio

RETIREMENT BENEFITS - Assumptions Used (Details)	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Plan Assumptions - At year end
Discount rate (as a percent)	3.20%				3.40%								3.20%	3.40%
Expected return on assets (as a percent)	6.80%				6.80%				7.00%				6.80%	6.80%	7.00%
Plan Assumptions - During the year
Expected return on assets (as a percent)													6.80%	7.00%	7.00%
VEBA Trust
Plan Assumptions - During the year
Expected return on assets (as a percent)													3.00%
U.S. | Postretirement Benefit Plans
Plan Assumptions - At year end
Discount rate (as a percent)	3.50%				3.90%								3.50%	3.90%
Expected return on assets (as a percent)	6.80%				680.00%								6.80%	680.00%
Plan Assumptions - During the year
Discount rate (as a percent)	3.55%	3.60%	3.85%	3.90%	3.30%	3.40%	3.75%	4.20%	4.10%	4.20%	3.65%	3.80%
Expected return on assets (as a percent)													6.80%	7.00%	7.00%
U.S. | VEBA Trust
Plan Assumptions - At year end
Expected return on assets (as a percent)	3.00%												3.00%
Non-U.S. | Pension Plans | Weighted Average
Plan Assumptions - At year end
Discount rate (as a percent)	4.17%				4.40%								4.17%	4.40%
Future compensation increase rate (as a percent)	3.08%				3.21%								3.08%	3.21%
Expected return on assets (as a percent)	4.52%				4.55%								4.52%	4.55%
Plan Assumptions - During the year
Discount rate (as a percent)													4.40%	4.76%	4.74%
Future compensation increase rate (as a percent)													3.21%	3.24%	3.27%
Expected return on assets (as a percent)													4.55%	4.95%	5.08%
Non-U.S. | Pension Plans | Minimum
Plan Assumptions - At year end
Discount rate (as a percent)	0.00%				0.25%								0.00%	0.25%
Future compensation increase rate (as a percent)	1.17%				1.25%								1.17%	1.25%
Expected return on assets (as a percent)	0.00%				1.00%								0.00%	1.00%
Plan Assumptions - During the year
Discount rate (as a percent)													0.25%	0.25%	1.00%
Future compensation increase rate (as a percent)													1.25%	1.00%	0.75%
Expected return on assets (as a percent)													1.00%	1.60%	1.30%
Non-U.S. | Pension Plans | Maximum
Plan Assumptions - At year end
Discount rate (as a percent)	10.20%				72.50%								10.20%	72.50%
Future compensation increase rate (as a percent)	13.67%				70.00%								13.67%	70.00%
Expected return on assets (as a percent)	11.50%				11.50%								11.50%	11.50%
Plan Assumptions - During the year
Discount rate (as a percent)													72.50%	42.00%	32.50%
Future compensation increase rate (as a percent)													70.00%	40.00%	30.00%
Expected return on assets (as a percent)													11.50%	11.50%	11.50%
Non-U.S. | Postretirement Benefit Plans | Weighted Average
Plan Assumptions - At year end
Discount rate (as a percent)	8.10%				8.27%								8.10%	8.27%
Expected return on assets (as a percent)	8.01%				8.02%								8.01%	8.02%
Plan Assumptions - During the year
Discount rate (as a percent)													8.27%	7.90%	7.50%
Expected return on assets (as a percent)													8.02%	8.01%	8.51%
Non-U.S. | Postretirement Benefit Plans | Minimum
Plan Assumptions - At year end
Discount rate (as a percent)	1.75%				1.75%								1.75%	1.75%
Expected return on assets (as a percent)	8.00%				8.00%								8.00%	8.00%
Plan Assumptions - During the year
Discount rate (as a percent)													1.75%	2.00%	2.25%
Expected return on assets (as a percent)													8.00%	8.00%	8.50%
Non-U.S. | Postretirement Benefit Plans | Maximum
Plan Assumptions - At year end
Discount rate (as a percent)	10.10%				11.05%								10.10%	11.05%
Expected return on assets (as a percent)	9.80%				10.30%								9.80%	10.30%
Plan Assumptions - During the year
Discount rate (as a percent)													11.05%	13.20%	12.00%
Expected return on assets (as a percent)													10.30%	10.70%	10.40%
Qualified | U.S. | Pension Plans
Plan Assumptions - At year end
Discount rate (as a percent)	3.60%				4.10%								3.60%	4.10%
Expected return on assets (as a percent)	680.00%				680.00%								680.00%	680.00%
Plan Assumptions - During the year
Discount rate (as a percent)	3.75%	3.80%	4.05%	4.10%	3.55%	3.65%	3.95%	4.40%	4.35%	4.45%	3.85%	4.00%
Expected return on assets (as a percent)													6.80%	7.00%	7.00%
Nonqualified | U.S. | Pension Plans
Plan Assumptions - At year end
Discount rate (as a percent)	3.60%				4.00%								3.60%	4.00%
Plan Assumptions - During the year
Discount rate (as a percent)	3.65%	3.75%	3.95%	4.00%	3.45%	3.55%	3.90%	4.35%	4.25%	4.30%	3.70%	3.90%

RETIREMENT BENEFITS - Discount

RETIREMENT BENEFITS - Discount Rate and Expected Rate of Return (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans
Expected return on assets (as a percent)	6.80%	6.80%	7.00%
Expected return on assets (as a percent)	6.80%	7.00%	7.00%
Actual rate of return (as a percent)	10.90%	4.90%	(1.70%)
Top 5 Non-US Countries
Defined Benefit Plans and Other Postretirement Benefit Plans
Discount rate established rounding convention	0.0005
All Other Countries
Defined Benefit Plans and Other Postretirement Benefit Plans
Discount rate established rounding convention	0.0025
Pension Plans | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Expected return on plan assets	$ 865	$ 886	$ 893
Pension Plans | Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Expected return on plan assets	299	$ 287	$ 323
Actual return on plan assets	$ 462
VEBA Trust
Defined Benefit Plans and Other Postretirement Benefit Plans
Expected return on assets (as a percent)	3.00%
VEBA Trust | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Expected return on assets (as a percent)	3.00%

RETIREMENT BENEFITS - Mortality

RETIREMENT BENEFITS - Mortality Table (Details)	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Mortality projection, ultimate rate of annual improvement	0.75%	0.75%
Percent increase to reflect Citigroup mortality experience rate		4.00%

RETIREMENT BENEFITS - Sensitivi

RETIREMENT BENEFITS - Sensitivities of Certain Key Assumptions (Details) - Pension Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	$ 29	$ 31	$ 26
Effect of one-percentage-point decrease in discount rates	(44)	(47)	(44)
Effect of one-percentage-point increase on benefits earned and interest cost for U.S. postretirement plans	(127)	(127)	(128)
Effect of one-percentage-point decrease on benefits earned and interest cost for U.S. postretirement plans	127	127	128
Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	(27)	(33)	(32)
Effect of one-percentage-point decrease in discount rates	41	37	44
Effect of one-percentage-point increase on benefits earned and interest cost for U.S. postretirement plans	(64)	(61)	(63)
Effect of one-percentage-point decrease on benefits earned and interest cost for U.S. postretirement plans	$ 64	$ 61	$ 63

RETIREMENT BENEFITS - Health Ca

RETIREMENT BENEFITS - Health Care Cost-Trend Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans
Health care cost increase following year (as a percent)	6.50%	6.50%
Ultimate rate to which cost increase is assumed to decline (as a percent)	5.00%	5.00%
Year in which the ultimate rate is reached	2,023	2,023
U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Health care cost increase following year (as a percent)	6.50%	6.50%
Ultimate rate to which cost increase is assumed to decline (as a percent)	5.00%	5.00%
Year in which the ultimate rate is reached	2,023	2,023
Effect of one-percentage-point increase of benefits earned and interest cost for U.S. postretirement plans	$ 1	$ 1
Effect of one-percentage-point decrease on benefits earned and interest cost for U.S. postretirement plans	(1)	(1)
Effect of one-percentage-point increase on accumulated postretirement benefit obligation for U.S. postretirement plans	33	30
Effect of one-percentage-point decrease on accumulated postretirement benefit obligation for U.S. postretirement plans	$ (29)	$ (26)
Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans
Health care cost increase following year (as a percent)	6.87%	6.86%
Ultimate rate to which cost increase is assumed to decline (as a percent)	6.87%	6.85%
Effect of one-percentage-point increase of benefits earned and interest cost for U.S. postretirement plans	$ 13	$ 12
Effect of one-percentage-point decrease on benefits earned and interest cost for U.S. postretirement plans	(10)	(10)
Effect of one-percentage-point increase on accumulated postretirement benefit obligation for U.S. postretirement plans	150	144
Effect of one-percentage-point decrease on accumulated postretirement benefit obligation for U.S. postretirement plans	$ (125)	$ (118)
Non-U.S. | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans
Year in which the ultimate rate is reached	2,018	2,017
Non-U.S. | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans
Year in which the ultimate rate is reached	2,019	2,029

RETIREMENT BENEFITS - Plan Asse

RETIREMENT BENEFITS - Plan Assets (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
U.S. | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	100.00%	100.00%	100.00%
Company contributions		$ 105	$ 556
U.S. | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	100.00%	100.00%	100.00%
Company contributions		$ 176	$ 6
U.S. | Equity securities | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	20.00%	20.00%	18.00%
U.S. | Equity securities | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	20.00%	20.00%	18.00%
U.S. | Equity securities | Forecast | Minimum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
U.S. | Equity securities | Forecast | Maximum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				30.00%
U.S. | Debt securities | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	48.00%	48.00%	47.00%
U.S. | Debt securities | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	48.00%	48.00%	47.00%
U.S. | Debt securities | VEBA Trust
Defined Benefit Plan Disclosure
Company contributions	$ 140
U.S. | Debt securities | Forecast | Minimum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				25.00%
U.S. | Debt securities | Forecast | Maximum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				72.00%
U.S. | Real estate | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	5.00%	5.00%	5.00%
U.S. | Real estate | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	5.00%	5.00%	5.00%
U.S. | Real estate | Forecast | Minimum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
U.S. | Real estate | Forecast | Maximum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				10.00%
U.S. | Private equity | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	3.00%	3.00%	4.00%
U.S. | Private equity | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	3.00%	3.00%	4.00%
U.S. | Private equity | Forecast | Minimum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
U.S. | Private equity | Forecast | Maximum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				12.00%
U.S. | Other investments | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	24.00%	24.00%	26.00%
U.S. | Other investments | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	24.00%	24.00%	26.00%
U.S. | Other investments | Forecast | Minimum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
U.S. | Other investments | Forecast | Maximum
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				37.00%
Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure
Company contributions		$ 135	$ 126
Non-U.S. | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Company contributions		$ 9	$ 9
Non-U.S. | Weighted Average | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	100.00%	100.00%	100.00%
Non-U.S. | Weighted Average | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	100.00%	100.00%	100.00%
Non-U.S. | Equity securities | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Equity securities | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Equity securities | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	67.00%	67.00%	69.00%
Non-U.S. | Equity securities | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	38.00%	38.00%	38.00%
Non-U.S. | Equity securities | Weighted Average | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	15.00%	15.00%	14.00%
Non-U.S. | Equity securities | Weighted Average | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	38.00%	38.00%	38.00%
Non-U.S. | Equity securities | Forecast | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Equity securities | Forecast | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Equity securities | Forecast | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				63.00%
Non-U.S. | Equity securities | Forecast | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				37.00%
Non-U.S. | Debt securities | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Debt securities | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	58.00%	58.00%	57.00%
Non-U.S. | Debt securities | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	99.00%	99.00%	100.00%
Non-U.S. | Debt securities | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	100.00%	100.00%	100.00%
Non-U.S. | Debt securities | Weighted Average | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	79.00%	79.00%	79.00%
Non-U.S. | Debt securities | Weighted Average | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	58.00%	58.00%	58.00%
Non-U.S. | Debt securities | Forecast | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Debt securities | Forecast | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				58.00%
Non-U.S. | Debt securities | Forecast | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				100.00%
Non-U.S. | Debt securities | Forecast | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				100.00%
Non-U.S. | Real estate | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Real estate | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	18.00%	18.00%	18.00%
Non-U.S. | Real estate | Weighted Average | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	1.00%	1.00%	1.00%
Non-U.S. | Real estate | Forecast | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Real estate | Forecast | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				18.00%
Non-U.S. | Other investments | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Other investments | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	0.00%	0.00%	0.00%
Non-U.S. | Other investments | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	100.00%	100.00%	100.00%
Non-U.S. | Other investments | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)	4.00%	4.00%	4.00%
Non-U.S. | Other investments | Weighted Average | Pension Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	5.00%	5.00%	6.00%
Non-U.S. | Other investments | Weighted Average | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Weighted average allocation (as a percent)	4.00%	4.00%	4.00%
Non-U.S. | Other investments | Forecast | Minimum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Other investments | Forecast | Minimum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				0.00%
Non-U.S. | Other investments | Forecast | Maximum | Pension Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				100.00%
Non-U.S. | Other investments | Forecast | Maximum | Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Target asset allocation (as a percent)				5.00%

RETIREMENT BENEFITS - Fair Valu

RETIREMENT BENEFITS - Fair Value Disclosure (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Total investments
Defined Benefit Plan Disclosure
Plan assets valued at NAV
U.S.
Defined Benefit Plan Disclosure
Other investment liabilities	$ (403)	$ (659)
Total net assets	12,988	12,492
U.S. | Level 1
Defined Benefit Plan Disclosure
Other investment liabilities	(60)	(106)
U.S. | Level 2
Defined Benefit Plan Disclosure
Other investment liabilities	(343)	(553)
U.S. | Level 3
Defined Benefit Plan Disclosure
Other investment liabilities	0	0
U.S. | U.S. equity
Defined Benefit Plan Disclosure
Total assets	726	639
U.S. | U.S. equity | Level 1
Defined Benefit Plan Disclosure
Total assets	726	639
U.S. | U.S. equity | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | U.S. equity | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0	$ 0
U.S. | Non-U.S. equity
Defined Benefit Plan Disclosure
Total assets	926	773
U.S. | Non-U.S. equity | Level 1
Defined Benefit Plan Disclosure
Total assets	926	773
U.S. | Non-U.S. equity | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Non-U.S. equity | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Mutual funds
Defined Benefit Plan Disclosure
Total assets	271	216
U.S. | Mutual funds | Level 1
Defined Benefit Plan Disclosure
Total assets	271	216
U.S. | Mutual funds | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Mutual funds | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Commingled funds
Defined Benefit Plan Disclosure
Total assets	1,184	866
U.S. | Commingled funds | Level 1
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Commingled funds | Level 2
Defined Benefit Plan Disclosure
Total assets	1,184	866
U.S. | Commingled funds | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Debt securities
Defined Benefit Plan Disclosure
Total assets	4,461	4,142
U.S. | Debt securities | Level 1
Defined Benefit Plan Disclosure
Total assets	1,381	1,297
U.S. | Debt securities | Level 2
Defined Benefit Plan Disclosure
Total assets	3,080	2,845
U.S. | Debt securities | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Annuity contracts
Defined Benefit Plan Disclosure
Total assets	1	1
U.S. | Annuity contracts | Level 1
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Annuity contracts | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Annuity contracts | Level 3
Defined Benefit Plan Disclosure
Total assets	1	1	25
U.S. | Derivatives
Defined Benefit Plan Disclosure
Total assets	334	551
U.S. | Derivatives | Level 1
Defined Benefit Plan Disclosure
Total assets	11	8
U.S. | Derivatives | Level 2
Defined Benefit Plan Disclosure
Total assets	323	543
U.S. | Derivatives | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Other investments
Defined Benefit Plan Disclosure
Total assets	22	4
U.S. | Other investments | Level 1
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Other investments | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Other investments | Level 3
Defined Benefit Plan Disclosure
Total assets	22	4	149
U.S. | Total investments
Defined Benefit Plan Disclosure
Total assets	7,925	7,192
Net investments at fair value	8,783	7,888
U.S. | Total investments | Level 1
Defined Benefit Plan Disclosure
Total assets	3,315	2,933
Net investments at fair value	3,512	2,943
U.S. | Total investments | Level 2
Defined Benefit Plan Disclosure
Total assets	4,587	4,254
Net investments at fair value	5,248	4,940
U.S. | Total investments | Level 3
Defined Benefit Plan Disclosure
Total assets	23	5	174
Net investments at fair value	23	5
U.S. | Cash and short-term investments
Defined Benefit Plan Disclosure
Total assets	1,261	1,355
U.S. | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure
Total assets	257	116
U.S. | Cash and short-term investments | Level 2
Defined Benefit Plan Disclosure
Total assets	1,004	1,239
U.S. | Cash and short-term investments | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
U.S. | Other investment receivables
Defined Benefit Plan Disclosure
Plan assets valued at NAV	16	100
U.S. | Securities
Defined Benefit Plan Disclosure
Plan assets valued at NAV	4,189	4,504
Non-U.S.
Defined Benefit Plan Disclosure
Other investment liabilities	(4,222)	(961)
Total net assets	8,247	7,162
Non-U.S. | Level 1
Defined Benefit Plan Disclosure
Other investment liabilities	(2)	(1)
Non-U.S. | Level 2
Defined Benefit Plan Disclosure
Other investment liabilities	(4,220)	(960)
Non-U.S. | Level 3
Defined Benefit Plan Disclosure
Other investment liabilities	0	0
Non-U.S. | U.S. equity
Defined Benefit Plan Disclosure
Total assets	16	15
Non-U.S. | U.S. equity | Level 1
Defined Benefit Plan Disclosure
Total assets	4	4
Non-U.S. | U.S. equity | Level 2
Defined Benefit Plan Disclosure
Total assets	12	11
Non-U.S. | U.S. equity | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Non-U.S. equity
Defined Benefit Plan Disclosure
Total assets	226	262
Non-U.S. | Non-U.S. equity | Level 1
Defined Benefit Plan Disclosure
Total assets	103	87
Non-U.S. | Non-U.S. equity | Level 2
Defined Benefit Plan Disclosure
Total assets	122	174
Non-U.S. | Non-U.S. equity | Level 3
Defined Benefit Plan Disclosure
Total assets	1	1	47
Non-U.S. | Mutual funds
Defined Benefit Plan Disclosure
Total assets	3,172	2,751
Non-U.S. | Mutual funds | Level 1
Defined Benefit Plan Disclosure
Total assets	3,098	2,345
Non-U.S. | Mutual funds | Level 2
Defined Benefit Plan Disclosure
Total assets	74	406
Non-U.S. | Mutual funds | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Commingled funds
Defined Benefit Plan Disclosure
Total assets	24	22
Non-U.S. | Commingled funds | Level 1
Defined Benefit Plan Disclosure
Total assets	24	22
Non-U.S. | Commingled funds | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Commingled funds | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Debt securities
Defined Benefit Plan Disclosure
Total assets	5,561	4,619
Non-U.S. | Debt securities | Level 1
Defined Benefit Plan Disclosure
Total assets	3,999	3,406
Non-U.S. | Debt securities | Level 2
Defined Benefit Plan Disclosure
Total assets	1,555	1,206
Non-U.S. | Debt securities | Level 3
Defined Benefit Plan Disclosure
Total assets	7	7	5
Non-U.S. | Real estate
Defined Benefit Plan Disclosure
Total assets	4	4
Non-U.S. | Real estate | Level 1
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Real estate | Level 2
Defined Benefit Plan Disclosure
Total assets	3	3
Non-U.S. | Real estate | Level 3
Defined Benefit Plan Disclosure
Total assets	1	1	1
Non-U.S. | Annuity contracts
Defined Benefit Plan Disclosure
Total assets	10	9
Non-U.S. | Annuity contracts | Level 1
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Annuity contracts | Level 2
Defined Benefit Plan Disclosure
Total assets	1	1
Non-U.S. | Annuity contracts | Level 3
Defined Benefit Plan Disclosure
Total assets	9	8	8
Non-U.S. | Derivatives
Defined Benefit Plan Disclosure
Total assets	3,103	43
Non-U.S. | Derivatives | Level 1
Defined Benefit Plan Disclosure
Total assets	1	0
Non-U.S. | Derivatives | Level 2
Defined Benefit Plan Disclosure
Total assets	3,102	43
Non-U.S. | Derivatives | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Other investments
Defined Benefit Plan Disclosure
Total assets	215	188
Non-U.S. | Other investments | Level 1
Defined Benefit Plan Disclosure
Total assets	1	1
Non-U.S. | Other investments | Level 2
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Other investments | Level 3
Defined Benefit Plan Disclosure
Total assets	214	187	196
Non-U.S. | Total investments
Defined Benefit Plan Disclosure
Total assets	12,331	7,913
Net investments at fair value	8,231	7,070
Non-U.S. | Total investments | Level 1
Defined Benefit Plan Disclosure
Total assets	7,230	5,865
Net investments at fair value	7,347	5,980
Non-U.S. | Total investments | Level 2
Defined Benefit Plan Disclosure
Total assets	4,869	1,844
Net investments at fair value	652	886
Non-U.S. | Total investments | Level 3
Defined Benefit Plan Disclosure
Total assets	232	204	257
Net investments at fair value	232	204
Non-U.S. | Cash and short-term investments
Defined Benefit Plan Disclosure
Total assets	122	118
Non-U.S. | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure
Total assets	119	116
Non-U.S. | Cash and short-term investments | Level 2
Defined Benefit Plan Disclosure
Total assets	3	2
Non-U.S. | Cash and short-term investments | Level 3
Defined Benefit Plan Disclosure
Total assets	0	0
Non-U.S. | Securities
Defined Benefit Plan Disclosure
Plan assets valued at NAV	16	92
Pension Plans | U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 12,725	$ 12,363	12,137
Allocable interest (as a percent)	99.00%	99.00%
Pension Plans | Non-U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 7,128	$ 6,149	6,104
Postretirement Benefit Plans | U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 262	$ 129	166
Allocable interest (as a percent)	1.00%	1.00%
Postretirement Benefit Plans | Non-U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 1,119	$ 1,015	$ 1,133

RETIREMENT BENEFITS - Level 3 R

RETIREMENT BENEFITS - Level 3 Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
U.S. | Annuity contracts
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	$ 1
Plan assets at fair value at end of period	1	$ 1
U.S. | Annuity contracts | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	1	25
Realized gains (losses)	0	0
Unrealized gains (losses)	0	(3)
Purchases, sales, and issuances	0	(21)
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	1	1
U.S. | Non-U.S. equity
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	773
Plan assets at fair value at end of period	926	773
U.S. | Non-U.S. equity | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	0
Plan assets at fair value at end of period	0	0
U.S. | Debt securities
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	4,142
Plan assets at fair value at end of period	4,461	4,142
U.S. | Debt securities | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	0
Plan assets at fair value at end of period	0	0
U.S. | Other investments
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	4
Plan assets at fair value at end of period	22	4
U.S. | Other investments | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	4	149
Realized gains (losses)		8
Unrealized gains (losses)		(10)
Purchases, sales, and issuances	18	(143)
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	22	4
U.S. | U.S. equities
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	639
Plan assets at fair value at end of period	726	639
U.S. | U.S. equities | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	0	0
Realized gains (losses)		(2)
Unrealized gains (losses)		2
Purchases, sales, and issuances		0
Transfers in and/or out of Level 3		0
Plan assets at fair value at end of period	0	0
U.S. | Total investments
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	7,192
Plan assets at fair value at end of period	7,925	7,192
U.S. | Total investments | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	5	174
Realized gains (losses)	0	6
Unrealized gains (losses)	0	(11)
Purchases, sales, and issuances	18	(164)
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	23	5
Non-U.S. | Annuity contracts
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	9
Plan assets at fair value at end of period	10	9
Non-U.S. | Annuity contracts | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	8	8
Unrealized gains (losses)	1	0
Purchases, sales, and issuances	0	0
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	9	8
Non-U.S. | Non-U.S. equity
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	262
Plan assets at fair value at end of period	226	262
Non-U.S. | Non-U.S. equity | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	1	47
Unrealized gains (losses)	0	(3)
Purchases, sales, and issuances	0	(2)
Transfers in and/or out of Level 3	0	(41)
Plan assets at fair value at end of period	1	1
Non-U.S. | Debt securities
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	4,619
Plan assets at fair value at end of period	5,561	4,619
Non-U.S. | Debt securities | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	7	5
Unrealized gains (losses)	0	0
Purchases, sales, and issuances	0	2
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	7	7
Non-U.S. | Real estate
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	4
Plan assets at fair value at end of period	4	4
Non-U.S. | Real estate | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	1	1
Unrealized gains (losses)	0	0
Purchases, sales, and issuances	0	0
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	1	1
Non-U.S. | Other investments
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	188
Plan assets at fair value at end of period	215	188
Non-U.S. | Other investments | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	187	196
Unrealized gains (losses)	31	0
Purchases, sales, and issuances	(4)	(9)
Transfers in and/or out of Level 3	0	0
Plan assets at fair value at end of period	214	187
Non-U.S. | U.S. equities
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	15
Plan assets at fair value at end of period	16	15
Non-U.S. | U.S. equities | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	0
Plan assets at fair value at end of period	0	0
Non-U.S. | Total investments
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	7,913
Plan assets at fair value at end of period	12,331	7,913
Non-U.S. | Total investments | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at fair value at beginning of period	204	257
Unrealized gains (losses)	32	(3)
Purchases, sales, and issuances	(4)	(9)
Transfers in and/or out of Level 3	0	(41)
Plan assets at fair value at end of period	$ 232	$ 204

RETIREMENT BENEFITS - Estimated

RETIREMENT BENEFITS - Estimated Future Benefit Payments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Postretirement Medical Plan with Prescription Drug Benefits [Abstract]
Reduction in accumulated postretirement benefit obligation due to subsidy	$ 4	$ 5
Reduction in postretirement expense due to subsidy	0.1	0.2
Subsidy received under the EGWP	15	$ 12.9
U.S. | Pension Plans
Defined Benefit Plan, Postretirement Medical Plan with Prescription Drug Benefits [Abstract]
2,018	787
2,019	814
2,020	846
2,021	864
2,022	876
2023-2027	4,480
U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Postretirement Medical Plan with Prescription Drug Benefits [Abstract]
2,018	61
2,019	60
2,020	59
2,021	58
2,022	56
2023-2027	248
Non-U.S. | Pension Plans
Defined Benefit Plan, Postretirement Medical Plan with Prescription Drug Benefits [Abstract]
2,018	432
2,019	398
2,020	425
2,021	434
2,022	457
2023-2027	2,532
Non-U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Postretirement Medical Plan with Prescription Drug Benefits [Abstract]
2,018	65
2,019	70
2,020	75
2,021	81
2,022	87
2023-2027	$ 532

RETIREMENT BENEFITS - Post Empl

RETIREMENT BENEFITS - Post Employment and Defined Contribution Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure
Funded status	$ (46,000,000)	$ (157,000,000)
Amount recognized in accumulated other comprehensive income (loss)	3,000,000	34,000,000
Service related expense
Interest cost on benefit obligation	2,000,000	3,000,000	$ 4,000,000
Amortization of unrecognized
Prior service (benefit) cost	(31,000,000)	(31,000,000)	(31,000,000)
Net actuarial loss	2,000,000	5,000,000	12,000,000
Total service-related benefit	(27,000,000)	(23,000,000)	(15,000,000)
Non-service-related (benefit) expense	30,000,000	21,000,000	3,000,000
Total net expense	$ 3,000,000	$ (2,000,000)	(12,000,000)
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate (as a percent)	3.20%	3.40%
Expected return on assets (as a percent)	3.00%
Health care cost increase following year (as a percent)	6.50%	6.50%
Ultimate rate to which cost increase is assumed to decline (as a percent)	5.00%	5.00%
Year in which the ultimate rate is reached	2,023	2,023
Defined Contribution Plans
Maximum percentage contribution by employer of employees eligible pay	6.00%	6.00%
Maximum compensation to be eligible for fixed contribution from employer	$ 100,000
Percentage of fixed contribution by employer, for eligible employees whose compensation is $100,000 or less	2.00%
VEBA Trust
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Expected return on assets (as a percent)	3.00%
U.S.
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Health care cost increase following year (as a percent)	6.50%	6.50%
Ultimate rate to which cost increase is assumed to decline (as a percent)	5.00%	5.00%
Year in which the ultimate rate is reached	2,023	2,023
Defined Contribution Plans
Pretax expense associated with Citigroup 401(k) plan	$ 383,000,000	$ 371,000,000	380,000,000
Non-U.S.
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Health care cost increase following year (as a percent)	6.87%	6.86%
Ultimate rate to which cost increase is assumed to decline (as a percent)	6.87%	6.85%
Defined Contribution Plans
Pretax expense associated with Citigroup 401(k) plan	$ 270,000,000	$ 268,000,000	$ 282,000,000

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Provision (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal										$ 332	$ 1,016	$ 861
Non-U.S.										3,910	3,585	3,397
State										269	384	388
Total current income taxes										4,511	4,985	4,646
Deferred
Federal										24,902	1,280	3,019
Non-U.S.										(377)	53	(4)
State										352	126	(221)
Total deferred income taxes	[1]									24,877	1,459	2,794
Provision for income tax on continuing operations before non-controlling interests		$ 23,864	$ 1,866	$ 1,795	$ 1,863	$ 1,509	$ 1,733	$ 1,723	$ 1,479	29,388	6,444	7,440
Provision (benefit) for income taxes on discontinued operations										7	(22)	(29)
Income tax expense (benefit) reported in stockholders’ equity related to:
FX translation										188	(402)	(906)
Investment securities										(149)	59	(498)
Employee stock plans										(4)	13	(35)
Cash flow hedges										(12)	27	176
Benefit plans										13	(30)	(24)
FVO DVA										(250)	(201)	0
Retained earnings										(295)	0	0
Income taxes before non-controlling interests										28,886	5,888	6,124
Provision (benefit) for effect of securities transactions										272	332	239
Benefit for effect of other-than-temporary-impairment losses										$ (22)	$ (217)	$ (93)
[1]	Includes the full impact of the $22.6 billion non-cash charge related to the Tax Cuts and Jobs Act (Tax Reform). See Notes 1 and 9 to the Consolidated Financial Statements for further information.

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory rate		35.00%	35.00%	35.00%
State income taxes, net of federal benefit		1.10%	1.80%	1.70%
Non-U.S. income tax rate differential		(1.60%)	(3.60%)	(4.60%)
Audit settlements		0.00%	(0.60%)	(1.70%)
Effect of tax law changes		99.70%	0.00%	0.40%
Basis difference in affiliates		(2.10%)	(0.10%)	(0.00%)
Tax advantaged investments		(2.20%)	(2.40%)	(1.80%)
Other, net		(0.80%)	(0.10%)	1.00%
Effective income tax rate		129.10%	30.00%	30.00%
Impact of non-cash charge related to Tax Reform	$ 22,600	$ 22,594
DTA change in enacted tax rate				$ 101
Effect income tax rate before effect of Tax Cuts and Jobs Act		29.80%

INCOME TAXES - Deferred Income

INCOME TAXES - Deferred Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Credit loss deduction	$ 3,423	$ 5,146
Deferred compensation and employee benefits	1,585	3,798
Repositioning and settlement reserves	454	1,033
U.S. tax on non-U.S. earnings	2,452	10,050
Investment and loan basis differences	3,384	5,594
Cash flow hedges	233	327
Tax credit and net operating loss carry-forwards	21,575	20,793
Fixed assets and leases	1,090	1,739
Other deferred tax assets	1,988	2,714
Gross deferred tax assets	36,184	51,194
Valuation allowance	9,387	0
Deferred tax assets after valuation allowance	26,797	51,194
Deferred tax liabilities
Intangibles	(1,247)	(1,711)
Debt issuances	(294)	(641)
Non-U.S. withholding taxes	(668)	(739)
Interest-related items	(562)	(765)
Other deferred tax liabilities	(1,545)	(670)
Gross deferred tax liabilities	(4,316)	(4,526)
Net deferred tax assets	$ 22,481	$ 46,668

INCOME TAXES - Unrecognized Tax

INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total unrecognized tax benefits at January 1	$ 1,092	$ 1,235	$ 1,060
Net amount of increases for current year’s tax positions	43	34	32
Gross amount of increases for prior years’ tax positions	324	273	311
Gross amount of decreases for prior years’ tax positions	(246)	(225)	(61)
Amounts of decreases relating to settlements	(199)	(174)	(45)
Reductions due to lapse of statutes of limitation	(11)	(21)	(22)
Foreign exchange, acquisitions and dispositions	10	(30)	(40)
Total unrecognized tax benefits at December 31	1,013	1,092	1,235
Amount of unrecognized tax benefit which would impact effective tax rate if recognized	$ 800	$ 800	$ 900

INCOME TAXES - Interest and Pen

INCOME TAXES - Interest and Penalties (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense [Abstract]
Total interest and penalties in the Consolidated Balance Sheet at January 1, Pretax	$ 260	$ 233	$ 269
Total interest and penalties in the Consolidated Statement of Income, Pretax	5	105	(29)
Total interest and penalties in the Consolidated Balance Sheet at December 31, Pretax	121	260	233
Reconciliation of Unrecognized Tax Benefits, Including Amounts Pertaining to Examined Tax Returns, Net of Tax [Roll Forward]
Total interest and penalties in the Consolidated Balance Sheet at January 1, Net of tax	164	146	169
Total interest and penalties in the Consolidated Statement of Income, Net of tax	21	68	(18)
Total interest and penalties in the Consolidated Balance Sheet at December 31, Net of tax	101	164	146
Foreign penalties included in total interest and penalties in the balance sheet	3	3	3
State penalties included in total interest and penalties	$ 3	$ 3	$ 3

INCOME TAXES - Foreign Earnings

INCOME TAXES - Foreign Earnings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Foreign pretax earnings	$ 13,700	$ 11,600	$ 11,300
Foreign pretax loss recorded in discontinued operations	100
Accumulated undistributed profits of non-U.S. subsidiaries considered indefinitely reinvested	14,100
Additional tax liability to be provided should be undistributed earnings of foreign subsidiaries which were indefinitely invested were remitted currently	3,500
Total bad debt reserved not included in deferred tax liabilities calculation	358
Deferred tax liabilities not recognized relating to bad debt reserved	$ 75

INCOME TAXES - Deferred Tax Ass

INCOME TAXES - Deferred Tax Assets Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Valuation Allowance [Line Items]
Valuation allowance	$ 9,387	$ 0
Foreign Tax Credit Carryforwards
Valuation Allowance [Line Items]
Valuation allowance	5,700
U.S. Residual Deferred Tax Asset Related to Non-U.S. Branches
Valuation Allowance [Line Items]
Valuation allowance	2,200
Local Non-U.S. Deferred Tax Assets
Valuation Allowance [Line Items]
Valuation allowance	1,400
State Net Operating Loss Carryforwards
Valuation Allowance [Line Items]
Valuation allowance	$ 100

INCOME TAXES - Deferred Tax 103

INCOME TAXES - Deferred Tax Assets by Jurisdiction (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets by Jurisdiction
Net deferred tax assets	$ 22,481	$ 46,668
U.S. federal
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	2,300	3,500
Foreign tax credits (FTCs)	7,600	14,200
General business credits (GBCs)	1,400	900
Future tax deductions and credits	4,800	21,900
Net deferred tax assets	16,100	40,500
Deferred tax liability to be reversed in carry forward period	2,400
State and Local
Deferred Tax Assets by Jurisdiction
Future tax deductions and credits	1,300	1,700
Net deferred tax assets	3,800	4,100
New York
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	2,300	2,200
Other state
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	200	200
Foreign
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	600	600
Future tax deductions and credits	2,000	1,500
Net deferred tax assets	$ 2,600	$ 2,100

INCOME TAXES - Tax Credit Carry

INCOME TAXES - Tax Credit Carryforward and Expiration Dates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Loss and Tax Carryforwards
Foreign tax credits related to companies filing U.S. federal tax separate from Citigroup's consolidated U.S. federal tax return expected to be utilized in consolidated return	$ 3,000
Net DFA	$ 22,481	$ 46,668
U.S. Federal and New York State and City NOL carryforward period	20 years
U.S. foreign tax credit carryforward period (in years)	10 years
Limit on utilization of foreign tax credit carryforwards (as percent)	21.00%
Domestic losses allowed to be reclassified as foreign source income	$ 52,000
Decrease in deferred tax assets due to FTC carryforwards	6,600
Decrease in deferred tax assets	24,200
Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	13,300	14,200
Operating loss carryforward	2,000	2,100
Net DFA	2,600	2,100
U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	1,400	900
Operating loss carryforward	11,000	10,000
U.S. federal
Operating Loss and Tax Carryforwards
Net DFA	16,100	40,500
Foreign tax credits (FTCs)	7,600	14,200
Gross foreign tax credits	13,300
2018 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	400	2,700
2019 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	1,300	1,300
2020 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	3,200	3,100
2021 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	2,000	1,900
2022 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	3,400	3,300
2023 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	400	500
2025 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	1,400	1,400
2027 | Foreign
Operating Loss and Tax Carryforwards
Tax credit carryforward	1,200	0
2027 | U.S. federal
Operating Loss and Tax Carryforwards
Operating loss carryforward	200	200
2028 | U.S. federal
Operating Loss and Tax Carryforwards
Operating loss carryforward	100	100
2030 | U.S. federal
Operating Loss and Tax Carryforwards
Operating loss carryforward	300	300
2032 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	200	0
Operating loss carryforward	100	0
2033 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	300	300
Operating loss carryforward	1,600	1,700
2034 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	200	200
Operating loss carryforward	2,300	2,300
2034 | New York state tax authority
Operating Loss and Tax Carryforwards
Operating loss carryforward	13,600	13,000
2034 | New York City tax authority
Operating Loss and Tax Carryforwards
Operating loss carryforward	13,100	12,200
2035 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	200	200
Operating loss carryforward	3,300	3,200
2036 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	200	200
Operating loss carryforward	2,100	2,200
2037 | U.S. federal
Operating Loss and Tax Carryforwards
Tax credit carryforward	300	0
Operating loss carryforward	$ 1,000	$ 0
Minimum
Operating Loss and Tax Carryforwards
Limit on domestic losses to be reclassified as foreign source income (as a percent)	50.00%
Maximum
Operating Loss and Tax Carryforwards
Limit on domestic losses to be reclassified as foreign source income (as a percent)	100.00%

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations before attribution of noncontrolling interests		$ (18,765)	$ 4,137	$ 3,883	$ 4,118	$ 3,591	$ 3,887	$ 4,047	$ 3,508	$ (6,627)		$ 15,033		$ 17,386
Less: Noncontrolling interests from continuing operations										60		63		90
Net income (loss) from continuing operations (for EPS purposes)										(6,687)		14,970		17,296
Income (loss) from discontinued operations, net of taxes		(109)	(5)	21	(18)	(3)	(30)	(23)	(2)	(111)		(58)		(54)
Citigroup’s net income (loss)		$ (18,893)	$ 4,133	$ 3,872	$ 4,090	$ 3,573	$ 3,840	$ 3,998	$ 3,501	(6,798)		14,912		17,242
Less: Preferred dividends										1,213		1,077		769
Net income (loss) available to common shareholders										(8,011)		13,835		16,473
Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS										37		195		224
Net income (loss) allocated to common shareholders for basic EPS										(8,048)		13,640		16,249
Add: Interest expense, net of tax, and dividends on convertible securities and adjustment of undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to diluted EPS										0		0		0
Net income (loss) allocated to common shareholders for diluted EPS										$ (8,048)		$ 13,640		$ 16,249
Weighted-average common shares outstanding applicable to basic EPS (in shares)										2,698.5		2,888.1		3,004
Effect of dilutive securities
Options (in shares)										0		0.1		3.6
Other employee plans non-dividend eligible (in shares)										0		0.1		0.1
Adjusted weighted-average common shares outstanding applicable to diluted EPS (in shares)										2,698.5		2,888.3		3,007.7
Basic
Income (loss) from continuing operations (in dollars per share)		$ (7.33)	$ 1.42	$ 1.27	$ 1.36	$ 1.14	$ 1.25	$ 1.25	$ 1.11	$ (2.94)	[1]	$ 4.74	[1]	$ 5.43	[1]
Discontinued operations (in dollars per share)	[1]									(0.04)		(0.02)		(0.02)
Net income (loss) (in dollars per share)		(7.38)	1.42	1.28	1.35	1.14	1.24	1.24	1.10	(2.98)	[1]	4.72	[1]	5.41	[1]
Diluted
Income (loss) from continuing operations (in dollars per share)		(7.33)	1.42	1.27	1.36	1.14	1.25	1.25	1.11	(2.94)	[1]	4.74	[1]	5.42	[1]
Discontinued operations (in dollars per share)	[1]									(0.04)		(0.02)		(0.02)
Net income (loss) (in dollars per share)		(7.38)	$ 1.42	$ 1.28	$ 1.35	1.14	$ 1.24	$ 1.24	$ 1.10	(2.98)	[1]	4.72	[1]	5.40	[1]
Warrants issued to U.S. Treasury as part of TARP and loss-sharing agreement | Warrant with the exercise price of $178.50
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities exercise price (in dollars per share)		178.5				178.50				$ 178.5		$ 178.50		$ 178.50
Antidilutive securities excluded from computation of earnings per common share (in shares)										21		21		21
Warrants issued to U.S. Treasury as part of TARP and loss-sharing agreement | Warrant with the exercise price of $104.96
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities exercise price (in dollars per share)		104.96				104.96				$ 104.96		$ 104.96		$ 104.96
Antidilutive securities excluded from computation of earnings per common share (in shares)										25.5		25.5		25.5
Weighted-average options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities exercise price (in dollars per share)		$ 204.80				$ 98.01				$ 204.80		$ 98.01		$ 199.16
Antidilutive securities excluded from computation of earnings per common share (in shares)										0.8		4.2		0.9
[1]	Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.

FEDERAL FUNDS, SECURITIES BO106

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal funds sold	$ 0	$ 0
Securities purchased under agreements to resell	130,984	131,473
Deposits paid for securities borrowed	101,494	105,340
Total	232,478	236,813
Federal funds purchased	326	178
Securities sold under agreements to repurchase	142,646	125,685
Deposits received for securities loaned	13,305	15,958
Total	156,277	141,821
Securities-for-securities lending transactions	$ 14,000	$ 9,300

FEDERAL FUNDS, SECURITIES BO107

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 204,460	$ 176,284
Gross amounts offset on the Consolidated Balance Sheet	73,476	44,811
Net amounts of assets included on the Consolidated Balance Sheet	130,984	131,473
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	103,022	102,874
Net amounts	27,962	28,599
Deposits paid for securities borrowed
Gross amounts of recognized assets	101,494	105,340
Net amounts of assets included on the Consolidated Balance Sheet	101,494	105,340
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	22,271	16,200
Net amounts	79,223	89,140
Total
Total	305,954	281,624
Gross amounts offset on the Consolidated Balance Sheet	73,476	44,811
Net amounts of assets included on the Consolidated Balance Sheet	232,478	236,813
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	125,293	119,074
Net amounts	107,185	117,739
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	216,122	170,496
Gross amounts offset on the Consolidated Balance Sheet	73,476	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	142,646	125,685
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	73,716	63,517
Net amounts	68,930	62,168
Deposits received for securities loaned
Gross amounts of recognized liabilities	13,305	15,958
Net amounts of liabilities included on the Consolidated Balance Sheet	13,305	15,958
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	4,079	3,529
Net amounts	9,226	12,429
Total
Gross amounts of recognized liabilities	229,427	186,454
Gross amounts offset on the Consolidated Balance Sheet	73,476	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	155,951	141,643
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	77,795	67,046
Net amounts	$ 78,156	$ 74,597

FEDERAL FUNDS, SECURITIES BO108

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	$ 216,122	$ 170,496	$ 170,496
Deposits received for securities loaned	13,305	15,958	15,958
Total	229,427	186,454	186,454
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	58,774		66,263
Deposits received for securities loaned	0		0
Total	58,774		66,263
State and municipal securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	1,605		334
Deposits received for securities loaned	0		0
Total	1,605		334
Foreign government
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	89,576		52,988
Deposits received for securities loaned	105		1,390
Total	89,681		54,378
Corporate
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	20,194		17,164
Deposits received for securities loaned	657		630
Total	20,851		17,794
Equity securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	20,724		12,206
Deposits received for securities loaned	11,907		13,913
Total	32,631		26,119
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	17,791		11,421
Deposits received for securities loaned	0		0
Total	17,791		11,421
Asset-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	5,479		5,428
Deposits received for securities loaned	0		0
Total	5,479		5,428
Other debt securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	1,979		4,692
Deposits received for securities loaned	636		25
Total	2,615		$ 4,717
Open and overnight
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	82,073	79,740
Deposits received for securities loaned	9,946	10,813
Total	92,019	90,553
Up to 30 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	68,372	50,399
Deposits received for securities loaned	266	2,169
Total	68,638	52,568
31–90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	33,846	19,396
Deposits received for securities loaned	1,912	2,044
Total	35,758	21,440
Greater than 90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	31,831	20,961
Deposits received for securities loaned	1,181	932
Total	$ 33,012	$ 21,893

BROKERAGE RECEIVABLES AND BR109

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Brokers and Dealers [Abstract]
Receivables from customers	$ 19,215	$ 10,374
Receivables from brokers, dealers and clearing organizations	19,169	18,513
Total brokerage receivable	38,384	28,887
Payables to customers	38,741	37,237
Payables to brokers, dealers and clearing organizations	22,601	19,915
Total brokerage payable	$ 61,342	$ 57,152

INVESTMENTS - Overview (Details

INVESTMENTS - Overview (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017USD ($)investment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Investment Holdings
Investments		$ 352,290	$ 353,304
Interest and dividends on investments
Taxable interest		7,538	6,858	$ 6,433
Interest exempt from U.S. federal income tax		535	549	196
Dividend income		222	175	388
Total interest and dividend income		8,295	7,582	7,017
Gross realized investments losses, excluding losses from other-than-temporary impairment
Gross realized investment gains		1,039	1,460	1,124
Gross realized investment losses		(261)	(512)	(442)
Net realized gains on sale of investments	[1]	$ 778	948	682
HTM securities sold, percent of principal collected, minimum		85.00%
Available-for-sale Securities transferred from Held-to-maturity
Carrying value of HTM securities sold		$ 81	49	392
Net realized gain (loss) on sale of HTM securities		13	14	10
Carrying value of securities reclassified to AFS		74	150	243
OTTI losses on securities reclassified to AFS		0	(6)	$ (15)
Securities available-for-sale
Amortized cost		292,406	300,269
Gross unrealized gains		1,035	1,721
Gross unrealized losses		2,527	2,566
Fair value		$ 290,914	299,424
Number of investments exceeded their fair value | investment		4,600
Less than 12 months		$ 1,854	1,394
12 months or longer		673	1,172
Mortgage-backed securities - U.S. agency-sponsored
Securities available-for-sale
Amortized cost		42,116	38,663
Gross unrealized gains		125	248
Gross unrealized losses		500	506
Fair value		41,741	38,405
Less than 12 months		438	436
12 months or longer		62	70
Mortgage-backed securities - Prime
Securities available-for-sale
Amortized cost		11	2
Gross unrealized gains		6	0
Gross unrealized losses		0	0
Fair value		17	2
Less than 12 months		0	0
12 months or longer		0	0
Mortgage-backed securities - Alt-A
Securities available-for-sale
Amortized cost		26	43
Gross unrealized gains		90	7
Gross unrealized losses		0	0
Fair value		116	50
Mortgage-backed securities - Non-U.S. residential
Securities available-for-sale
Amortized cost		2,744	3,852
Gross unrealized gains		13	13
Gross unrealized losses		6	7
Fair value		2,751	3,858
Less than 12 months		6	0
12 months or longer		0	7
Mortgage-backed securities - Commercial
Securities available-for-sale
Amortized cost		334	357
Gross unrealized gains		0	2
Gross unrealized losses		2	1
Fair value		332	358
Less than 12 months		1	1
12 months or longer		1	0
Mortgage-backed securities
Securities available-for-sale
Amortized cost		45,231	42,917
Gross unrealized gains		234	270
Gross unrealized losses		508	514
Fair value		44,957	42,673
Less than 12 months		445	437
12 months or longer		63	77
U.S. Treasury
Securities available-for-sale
Amortized cost		108,344	113,606
Gross unrealized gains		77	629
Gross unrealized losses		971	452
Fair value		107,450	113,783
Less than 12 months		856	445
12 months or longer		115	7
Agency obligations
Securities available-for-sale
Amortized cost		10,813	9,952
Gross unrealized gains		7	21
Gross unrealized losses		124	85
Fair value		10,696	9,888
Less than 12 months		110	83
12 months or longer		14	2
U.S. Treasury and federal agency securities
Securities available-for-sale
Amortized cost		119,157	123,558
Gross unrealized gains		84	650
Gross unrealized losses		1,095	537
Fair value		118,146	123,671
Less than 12 months		966	528
12 months or longer		129	9
State and municipal securities
Securities available-for-sale
Amortized cost		8,870	10,797
Gross unrealized gains		140	80
Gross unrealized losses		245	757
Fair value		8,765	10,120
Less than 12 months		11	55
12 months or longer		234	702
Foreign government
Securities available-for-sale
Amortized cost		100,615	98,112
Gross unrealized gains		508	590
Gross unrealized losses		590	554
Fair value		100,533	98,148
Less than 12 months		356	243
12 months or longer		234	311
Corporate
Securities available-for-sale
Amortized cost		14,144	17,195
Gross unrealized gains		51	105
Gross unrealized losses		86	176
Fair value		14,109	17,124
Less than 12 months		74	129
12 months or longer		12	47
Asset-backed securities
Securities available-for-sale
Amortized cost		3,906	6,810
Gross unrealized gains		14	6
Gross unrealized losses		2	22
Fair value		3,918	6,794
Less than 12 months		1	0
12 months or longer		1	22
Other debt securities
Securities available-for-sale
Amortized cost		297	503
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Fair value		297	503
Less than 12 months		0	0
12 months or longer		0	0
Debt securities
Securities available-for-sale
Amortized cost		292,220	299,892
Gross unrealized gains		1,031	1,701
Gross unrealized losses		2,526	2,560
Fair value		$ 290,725	299,033
Percentage of investments gross-unrealized loss position for less than a year, rated investment grade		99.00%
Percentage of gross-unrealized loss position for a year or more rated investment grade		94.00%
Marketable equity securities AFS
Securities available-for-sale
Amortized cost		$ 186	377
Gross unrealized gains		4	20
Gross unrealized losses		1	6
Fair value		189	391
Less than 12 months		1	2
12 months or longer		0	4
Fixed income securities
Securities available-for-sale
Less than 12 months		1,854
12 months or longer		672
Securities available-for-sale (AFS)
Investment Holdings
Investments		290,914	299,424
HTM debt securities
Investment Holdings
Investments		53,320	45,667
Non-marketable equity securities | Fair value
Investment Holdings
Investments		1,206	1,774
Non-marketable equity securities | Carried at cost
Investment Holdings
Investments		$ 6,850	$ 6,439
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

INVESTMENTS - Fair Value of AFS

INVESTMENTS - Fair Value of AFS Securities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair value
Less than 12 months	$ 181,216	$ 122,278
12 months or longer	21,920	22,358
Total	203,136	144,636
Gross unrealized losses
Less than 12 months	1,854	1,394
12 months or longer	673	1,172
Total	2,527	2,566
Mortgage-backed securities - U.S. agency-sponsored
Fair value
Less than 12 months	30,994	23,534
12 months or longer	2,206	2,236
Total	33,200	25,770
Gross unrealized losses
Less than 12 months	438	436
12 months or longer	62	70
Total	500	506
Mortgage-backed securities - Prime
Fair value
Less than 12 months	0	1
12 months or longer	0	0
Total	0	1
Gross unrealized losses
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
Mortgage-backed securities - Non-U.S. residential
Fair value
Less than 12 months	753	486
12 months or longer	0	1,276
Total	753	1,762
Gross unrealized losses
Less than 12 months	6	0
12 months or longer	0	7
Total	6	7
Mortgage-backed securities - Commercial
Fair value
Less than 12 months	150	75
12 months or longer	57	58
Total	207	133
Gross unrealized losses
Less than 12 months	1	1
12 months or longer	1	0
Total	2	1
Mortgage-backed securities
Fair value
Less than 12 months	31,897	24,096
12 months or longer	2,263	3,570
Total	34,160	27,666
Gross unrealized losses
Less than 12 months	445	437
12 months or longer	63	77
Total	508	514
U.S. Treasury
Fair value
Less than 12 months	79,050	44,342
12 months or longer	7,404	1,335
Total	86,454	45,677
Gross unrealized losses
Less than 12 months	856	445
12 months or longer	115	7
Total	971	452
Agency obligations
Fair value
Less than 12 months	8,857	6,552
12 months or longer	1,163	250
Total	10,020	6,802
Gross unrealized losses
Less than 12 months	110	83
12 months or longer	14	2
Total	124	85
U.S. Treasury and federal agency securities
Fair value
Less than 12 months	87,907	50,894
12 months or longer	8,567	1,585
Total	96,474	52,479
Gross unrealized losses
Less than 12 months	966	528
12 months or longer	129	9
Total	1,095	537
State and municipal securities
Fair value
Less than 12 months	1,009	1,616
12 months or longer	1,155	3,116
Total	2,164	4,732
Gross unrealized losses
Less than 12 months	11	55
12 months or longer	234	702
Total	245	757
Foreign government
Fair value
Less than 12 months	53,206	38,226
12 months or longer	9,051	8,973
Total	62,257	47,199
Gross unrealized losses
Less than 12 months	356	243
12 months or longer	234	311
Total	590	554
Corporate
Fair value
Less than 12 months	6,737	7,011
12 months or longer	859	1,877
Total	7,596	8,888
Gross unrealized losses
Less than 12 months	74	129
12 months or longer	12	47
Total	86	176
Asset-backed securities
Fair value
Less than 12 months	449	411
12 months or longer	25	3,213
Total	474	3,624
Gross unrealized losses
Less than 12 months	1	0
12 months or longer	1	22
Total	2	22
Other debt securities
Fair value
Less than 12 months	0	5
12 months or longer	0	0
Total	0	5
Gross unrealized losses
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
Marketable equity securities AFS
Fair value
Less than 12 months	11	19
12 months or longer	0	24
Total	11	43
Gross unrealized losses
Less than 12 months	1	2
12 months or longer	0	4
Total	$ 1	$ 6

INVESTMENTS - Fair Value of 112

INVESTMENTS - Fair Value of AFS Debt Securities by Contractual Maturity Date (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities, Debt Maturities
Total amortized cost	$ 292,220	$ 299,892
Total fair value	290,725	299,033
Mortgage-backed securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	45	132
After 1 but within 5 years, amortized cost	1,306	736
After 5 but within 10 years, amortized cost	1,376	2,279
After 10 years, amortized cost	42,504	39,770
Total amortized cost	45,231	42,917
Fair value, due within 1 year	45	132
Fair value, after 1 but within 5 years	1,304	738
Fair value, after 5 but within 10 years	1,369	2,265
Fair value, after 10 years	42,239	39,538
Total fair value	44,957	42,673
U.S. Treasury and federal agency securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	4,913	4,945
After 1 but within 5 years, amortized cost	111,236	101,369
After 5 but within 10 years, amortized cost	3,008	17,153
After 10 years, amortized cost	0	91
Total amortized cost	119,157	123,558
Fair value, due within 1 year	4,907	4,945
Fair value, after 1 but within 5 years	110,238	101,323
Fair value, after 5 but within 10 years	3,001	17,314
Fair value, after 10 years	0	89
Total fair value	118,146	123,671
State and municipal securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	1,792	2,093
After 1 but within 5 years, amortized cost	2,579	2,668
After 5 but within 10 years, amortized cost	514	335
After 10 years, amortized cost	3,985	5,701
Total amortized cost	8,870	10,797
Fair value, due within 1 year	1,792	2,092
Fair value, after 1 but within 5 years	2,576	2,662
Fair value, after 5 but within 10 years	528	334
Fair value, after 10 years	3,869	5,032
Total fair value	8,765	10,120
Foreign government
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	32,130	32,540
After 1 but within 5 years, amortized cost	53,034	51,008
After 5 but within 10 years, amortized cost	12,949	12,388
After 10 years, amortized cost	2,502	2,176
Total amortized cost	100,615	98,112
Fair value, due within 1 year	32,100	32,547
Fair value, after 1 but within 5 years	53,165	50,881
Fair value, after 5 but within 10 years	12,680	12,440
Fair value, after 10 years	2,588	2,280
Total fair value	100,533	98,148
All other
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	3,998	2,629
After 1 but within 5 years, amortized cost	9,047	12,339
After 5 but within 10 years, amortized cost	3,415	6,566
After 10 years, amortized cost	1,887	2,974
Total amortized cost	18,347	24,508
Fair value, due within 1 year	3,991	2,628
Fair value, after 1 but within 5 years	9,027	12,334
Fair value, after 5 but within 10 years	3,431	6,528
Fair value, after 10 years	1,875	2,931
Total fair value	$ 18,324	$ 24,421

INVESTMENTS - Debt Securities H

INVESTMENTS - Debt Securities Held-to-Maturity (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Debt Securities Held-to-maturity
Adjust amortized cost basis	$ 46,163	$ 53,437
Net unrealized gains (losses) recognized in AOCI	(496)	(117)
Carrying value	45,667	53,320
Gross unrecognized gains	345	702
Gross unrecognized losses	(457)	(270)
Fair value	45,555	53,752
Fair value of securities transferred from AFS to HTM	5,800
Mortgage-backed securities - U.S. agency-sponsored
Debt Securities Held-to-maturity
Adjust amortized cost basis	22,462	23,854
Net unrealized gains (losses) recognized in AOCI	33	26
Carrying value	22,495	23,880
Gross unrecognized gains	47	40
Gross unrecognized losses	(186)	(157)
Fair value	22,356	23,763
Fair value of securities transferred from AFS to HTM	5,000
Mortgage-backed securities - Prime
Debt Securities Held-to-maturity
Adjust amortized cost basis	31	0
Net unrealized gains (losses) recognized in AOCI	(7)	0
Carrying value	24	0
Gross unrecognized gains	10	0
Gross unrecognized losses	(1)	0
Fair value	33	0
Mortgage-backed securities - Alt-A
Debt Securities Held-to-maturity
Adjust amortized cost basis	314	206
Net unrealized gains (losses) recognized in AOCI	(27)	(65)
Carrying value	287	141
Gross unrecognized gains	69	57
Gross unrecognized losses	(1)	0
Fair value	355	198
Mortgage-backed securities - Non-U.S. residential
Debt Securities Held-to-maturity
Adjust amortized cost basis	1,871	1,887
Net unrealized gains (losses) recognized in AOCI	(47)	(46)
Carrying value	1,824	1,841
Gross unrecognized gains	49	65
Gross unrecognized losses	0	0
Fair value	1,873	1,906
Mortgage-backed securities - Commercial
Debt Securities Held-to-maturity
Adjust amortized cost basis	14	237
Net unrealized gains (losses) recognized in AOCI	0	0
Carrying value	14	237
Gross unrecognized gains	0	0
Gross unrecognized losses	0	0
Fair value	14	237
Mortgage-backed securities
Debt Securities Held-to-maturity
Adjust amortized cost basis	24,692	26,184
Net unrealized gains (losses) recognized in AOCI	(48)	(85)
Carrying value	24,644	26,099
Gross unrecognized gains	175	162
Gross unrecognized losses	(188)	(157)
Fair value	24,631	26,104
State and municipal securities
Debt Securities Held-to-maturity
Adjust amortized cost basis	9,025	8,925
Net unrealized gains (losses) recognized in AOCI	(442)	(28)
Carrying value	8,583	8,897
Gross unrecognized gains	129	378
Gross unrecognized losses	(238)	(73)
Fair value	8,474	9,202
Fair value of securities transferred from AFS to HTM	830
Foreign government
Debt Securities Held-to-maturity
Adjust amortized cost basis	1,339	740
Net unrealized gains (losses) recognized in AOCI	0	0
Carrying value	1,339	740
Gross unrecognized gains	0	0
Gross unrecognized losses	(26)	(18)
Fair value	1,313	722
Asset-backed securities
Debt Securities Held-to-maturity
Adjust amortized cost basis	11,107	17,588
Net unrealized gains (losses) recognized in AOCI	(6)	(4)
Carrying value	11,101	17,584
Gross unrecognized gains	41	162
Gross unrecognized losses	(5)	(22)
Fair value	$ 11,137	$ 17,724

INVESTMENTS - Debt Securities i

INVESTMENTS - Debt Securities in HTM in Unrecognized Loss Position (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair value
Less than 12 months	$ 1,193	$ 3,532
12 months or longer	16,065	20,889
Total	17,258	24,421
Gross unrecognized losses
Less than 12 months	26	84
12 months or longer	244	373
Total	270	457
Unrealized loss, other than temporary impairment, not credit loss, recorded in AOCI	(117)	(496)
Mortgage-backed securities
Fair value
Less than 12 months	46	17
12 months or longer	15,096	17,176
Total	15,142	17,193
Gross unrecognized losses
Less than 12 months	0	0
12 months or longer	157	188
Total	157	188
State and municipal securities
Fair value
Less than 12 months	353	2,200
12 months or longer	835	1,210
Total	1,188	3,410
Gross unrecognized losses
Less than 12 months	5	58
12 months or longer	68	180
Total	73	238
Foreign government
Fair value
Less than 12 months	723	1,313
12 months or longer	0	0
Total	723	1,313
Gross unrecognized losses
Less than 12 months	18	26
12 months or longer	0	0
Total	18	26
Asset-backed securities
Fair value
Less than 12 months	71	2
12 months or longer	134	2,503
Total	205	2,505
Gross unrecognized losses
Less than 12 months	3	0
12 months or longer	19	5
Total	$ 22	$ 5

INVESTMENTS - Carrying Value an

INVESTMENTS - Carrying Value and Fair Value of HTM Debt Securities by Contractual Maturity Dates (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Carrying value	$ 53,320	$ 45,667
Held-to-maturity Securities, Debt Maturities, Fair Value;
Fair value	53,752	45,555
Mortgage-backed securities
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	0	0
After 1 but within 5 years, carrying value	720	760
After 5 but within 10 years, carrying value	148	54
After 10 years, carrying value	25,231	23,830
Carrying value	26,099	24,644
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	0	0
After 1 but within 5 years, fair value	720	766
After 5 but within 10 years, fair value	149	55
After 10 years, fair value	25,235	23,810
Fair value	26,104	24,631
State and municipal securities
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	407	406
After 1 but within 5 years, carrying value	259	112
After 5 but within 10 years, carrying value	512	363
After 10 years, carrying value	7,719	7,702
Carrying value	8,897	8,583
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	425	406
After 1 but within 5 years, fair value	270	110
After 5 but within 10 years, fair value	524	367
After 10 years, fair value	7,983	7,591
Fair value	9,202	8,474
Foreign government
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	381	824
After 1 but within 5 years, carrying value	359	515
After 5 but within 10 years, carrying value	0	0
After 10 years, carrying value	0	0
Carrying value	740	1,339
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	381	818
After 1 but within 5 years, fair value	341	495
After 5 but within 10 years, fair value	0	0
After 10 years, fair value	0	0
Fair value	722	1,313
All other
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	0	0
After 1 but within 5 years, carrying value	0	0
After 5 but within 10 years, carrying value	1,669	513
After 10 years, carrying value	15,915	10,588
Carrying value	17,584	11,101
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	0	0
After 1 but within 5 years, fair value	0	0
After 5 but within 10 years, fair value	1,680	514
After 10 years, fair value	16,044	10,623
Fair value	$ 17,724	$ 11,137

INVESTMENTS - Mortgage-backed S

INVESTMENTS - Mortgage-backed Securities (Details) - Mortgage-backed securities	12 Months Ended
	Dec. 31, 2017
30-59 day delinquent loans
Key assumptions for mortgage-backed securities
Default rate projection (as a percent)	25.00%
60-90 day deliquent loans
Key assumptions for mortgage-backed securities
Default rate projection (as a percent)	70.00%
91+ day deliquent loans
Key assumptions for mortgage-backed securities
Default rate projection (as a percent)	100.00%
Current loans
Key assumptions for mortgage-backed securities
Default rate projection (as a percent)	10.00%

INVESTMENTS - Recognition and M

INVESTMENTS - Recognition and Measurement of OTTI (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OTTI on Investments disclosures
Total OTTI losses recognized during the period		$ 2	$ 4	$ 34
Less: portion of impairment loss recognized in AOCI (before taxes)	[1]	0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell		2	4	34
Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise		61	616	231
Total impairment losses recognized in earnings	[1]	63	620	265
Securities available-for-sale (AFS)
OTTI on Investments disclosures
Total OTTI losses recognized during the period		2	3	33
Less: portion of impairment loss recognized in AOCI (before taxes)		0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell		2	3	33
Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise		59	246	182
Total impairment losses recognized in earnings		61	249	215
Held-to-maturity Securities
OTTI on Investments disclosures
Total OTTI losses recognized during the period		0	1	1
Less: portion of impairment loss recognized in AOCI (before taxes)		0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell		0	1	1
Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise		2	38	43
Total impairment losses recognized in earnings		2	39	44
Other assets
OTTI on Investments disclosures
Total OTTI losses recognized during the period		0	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)		0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell		0	0	0
Impairment losses recognized in earnings for securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise		0	332	6
Total impairment losses recognized in earnings		$ 0	332	$ 6
Venezuelan bolívar fuerte | Securities available-for-sale (AFS)
OTTI on Investments disclosures
Total impairment losses recognized in earnings			$ 160
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

INVESTMENTS - Cumulative OTTI C

INVESTMENTS - Cumulative OTTI Credit Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Cumulative OTTI reclassified from HTM to AFS	$ 38
AFS debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	31	$ 73
Credit impairments recognized in earnings on securities not previously impaired	0	2
Credit impairments recognized in earnings on securities that have been previously impaired	2	1
Reductions due to credit-impaired securities sold, transferred or matured	15	(45)
Balance at end of period	48	31
AFS debt securities | Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	0	0
Credit impairments recognized in earnings on securities not previously impaired	0	1
Credit impairments recognized in earnings on securities that have been previously impaired	0	0
Reductions due to credit-impaired securities sold, transferred or matured	38	(1)
Balance at end of period	38	0
AFS debt securities | State and municipal securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	4	12
Credit impairments recognized in earnings on securities not previously impaired	0	0
Credit impairments recognized in earnings on securities that have been previously impaired	0	0
Reductions due to credit-impaired securities sold, transferred or matured	0	(8)
Balance at end of period	4	4
AFS debt securities | Foreign government securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	0	5
Credit impairments recognized in earnings on securities not previously impaired	0	0
Credit impairments recognized in earnings on securities that have been previously impaired	0	0
Reductions due to credit-impaired securities sold, transferred or matured	0	(5)
Balance at end of period	0	0
AFS debt securities | Corporate
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	5	9
Credit impairments recognized in earnings on securities not previously impaired	0	1
Credit impairments recognized in earnings on securities that have been previously impaired	0	1
Reductions due to credit-impaired securities sold, transferred or matured	(1)	(6)
Balance at end of period	4	5
AFS debt securities | Other debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	22	47
Credit impairments recognized in earnings on securities not previously impaired	0	0
Credit impairments recognized in earnings on securities that have been previously impaired	2	0
Reductions due to credit-impaired securities sold, transferred or matured	(22)	(25)
Balance at end of period	2	22
HTM debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	104	136
Credit impairments recognized in earnings on securities not previously impaired	0	1
Credit impairments recognized in earnings on securities that have been previously impaired	0	0
Reductions due to credit-impaired securities sold, transferred or matured	(47)	(33)
Balance at end of period	57	104
HTM debt securities | Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	101	132
Credit impairments recognized in earnings on securities not previously impaired	0	0
Credit impairments recognized in earnings on securities that have been previously impaired	0	0
Reductions due to credit-impaired securities sold, transferred or matured	(47)	(31)
Balance at end of period	54	101
HTM debt securities | State and municipal securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	3
Credit impairments recognized in earnings on securities not previously impaired	0
Credit impairments recognized in earnings on securities that have been previously impaired	0
Reductions due to credit-impaired securities sold, transferred or matured	0
Balance at end of period	3	3
HTM debt securities | Corporate
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Balance at beginning of period	$ 3	4
Credit impairments recognized in earnings on securities not previously impaired		1
Credit impairments recognized in earnings on securities that have been previously impaired		0
Reductions due to credit-impaired securities sold, transferred or matured		(2)
Balance at end of period		$ 3

INVESTMENTS - Alternative Inves

INVESTMENTS - Alternative Investment Funds (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investments in Alternative Investment Funds
Alternative investment funds, fair value	$ 404	$ 408
Alternative investment funds, unfunded commitments	82	102
Hedge funds
Investments in Alternative Investment Funds
Alternative investment funds, fair value	1	4
Alternative investment funds, unfunded commitments	$ 0	0
Alternative investment funds, redemption frequency (if currently eligible)	Generally quarterly
Hedge funds | Minimum
Investments in Alternative Investment Funds
Alternative investment funds, redemption notice period (in days)	10 days
Hedge funds | Maximum
Investments in Alternative Investment Funds
Alternative investment funds, redemption notice period (in days)	95 days
Private equity
Investments in Alternative Investment Funds
Alternative investment funds, fair value	$ 372	348
Alternative investment funds, unfunded commitments	62	82
Real estate funds
Investments in Alternative Investment Funds
Alternative investment funds, fair value	31	56
Alternative investment funds, unfunded commitments	$ 20	$ 20

LOANS - Consumer Loans (Details

LOANS - Consumer Loans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)category	Dec. 31, 2016USD ($)
Loans
Number of loan categories | category	2
Loans, net of unearned income	$ 667,034	$ 624,369
Consumer
Loans
Total loans	332,919	324,287
Net unearned income	737	776
Loans, net of unearned income	333,656	325,063
Loans sold and/or reclassified to held-for-sale	4,900	9,700
In U.S. offices | Consumer
Loans
Total loans	215,711	216,165
In U.S. offices | Consumer | Mortgage and real estate
Loans
Total loans	65,467	72,957
In U.S. offices | Consumer | Installment, revolving credit and other
Loans
Total loans	3,398	3,395
In U.S. offices | Consumer | Cards
Loans
Total loans	139,006	132,654
In U.S. offices | Consumer | Commercial and industrial
Loans
Total loans	7,840	7,159
In offices outside the U.S. | Consumer
Loans
Total loans	117,208	108,122
In offices outside the U.S. | Consumer | Mortgage and real estate
Loans
Total loans	44,081	42,803
In offices outside the U.S. | Consumer | Installment, revolving credit and other
Loans
Total loans	26,556	24,887
In offices outside the U.S. | Consumer | Cards
Loans
Total loans	26,257	23,783
In offices outside the U.S. | Consumer | Commercial and industrial
Loans
Total loans	20,238	16,568
In offices outside the U.S. | Consumer | Lease financing
Loans
Total loans	$ 76	$ 81

LOANS - Consumer Loan Delinquen

LOANS - Consumer Loan Delinquency (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)paymentre-aging	Dec. 31, 2016USD ($)
Loans receivable
Loans, net of unearned income	$ 667,034	$ 624,369
Loans at fair value	$ 4,374	3,486
Open-ended consumer loans
Loans receivable
Minimum number of payments made consecutively for the loans to be re-aged | payment	3
Consumer
Loans receivable
Number of days past due, non-accrual status	60 days
Loans, current	$ 326,092	317,187
Loans, net of unearned income	333,656	325,063
Loans, total non-accrual	2,690	3,158
Total loans past due and accruing	$ 2,812	$ 2,991
Loans less than this number of days past due are considered current	30 days	30 days
Consumer | Minimum
Loans receivable
Minimum number of payments made consecutively for the loans to be re-aged | payment	1
Consumer | Maximum
Loans receivable
Minimum number of payments made consecutively for the loans to be re-aged | payment	3
Consumer | Less than or equal to 80%
Loans receivable
Loans	$ 55,029	$ 58,718
Consumer | 80% but less than or equal to 100%
Loans receivable
Loans	4,725	7,120
Consumer | Greater than 100%
Loans receivable
Loans	1,047	1,629
Consumer | Less than 620
Loans receivable
Loans	12,834	13,088
Consumer | ≥ 620 but less than 660
Loans receivable
Loans	14,914	15,431
Consumer | Equal to or greater than 660
Loans receivable
Loans	172,303	172,145
Consumer | Government-guaranteed
Loans receivable
Loans, past due	1,225	1,474
Consumer | 30 to 89 Days Past Due
Loans receivable
Loans, past due	3,304	3,275
Consumer | Equal to greater than 90 days past due
Loans receivable
Loans, past due	$ 3,035	$ 3,127
Consumer | Residential first mortgages
Loans receivable
Number of days past due, non-accrual status	90 days	90 days
Loans at fair value	$ 25	$ 29
Consumer | Residential first mortgages | Less than or equal to 80%
Loans receivable
Loans	43,626	45,849
Consumer | Residential first mortgages | 80% but less than or equal to 100%
Loans receivable
Loans	2,578	3,467
Consumer | Residential first mortgages | Greater than 100%
Loans receivable
Loans	247	324
Consumer | Residential first mortgages | Less than 620
Loans receivable
Loans	2,100	2,744
Consumer | Residential first mortgages | ≥ 620 but less than 660
Loans receivable
Loans	1,932	2,422
Consumer | Residential first mortgages | Equal to or greater than 660
Loans receivable
Loans	$ 42,265	44,279
Consumer | Mortage loans other than FHA-insured loans
Loans receivable
Number of days past due, non-accrual status	60 days
Consumer | Home equity loans
Loans receivable
Number of days past due, non-accrual status	90 days
Consumer | Home equity loans | Less than or equal to 80%
Loans receivable
Loans	$ 11,403	12,869
Consumer | Home equity loans | 80% but less than or equal to 100%
Loans receivable
Loans	2,147	3,653
Consumer | Home equity loans | Greater than 100%
Loans receivable
Loans	800	1,305
Consumer | Home equity loans | Less than 620
Loans receivable
Loans	1,379	1,750
Consumer | Home equity loans | ≥ 620 but less than 660
Loans receivable
Loans	1,081	1,418
Consumer | Home equity loans | Equal to or greater than 660
Loans receivable
Loans	$ 11,976	14,743
Consumer | Credit cards
Loans receivable
Number of days past due, non-accrual status	180 days
Consumer | Credit cards | Less than 620
Loans receivable
Loans	$ 9,079	8,310
Consumer | Credit cards | ≥ 620 but less than 660
Loans receivable
Loans	11,651	11,320
Consumer | Credit cards | Equal to or greater than 660
Loans receivable
Loans	$ 115,577	110,522
Consumer | Installment and other
Loans receivable
Number of days past due, non-accrual status	90 days
Consumer | Installment and other | Less than 620
Loans receivable
Loans	$ 276	284
Consumer | Installment and other | ≥ 620 but less than 660
Loans receivable
Loans	250	271
Consumer | Installment and other | Equal to or greater than 660
Loans receivable
Loans	$ 2,485	2,601
Consumer | Unsecured Revolving Loans
Loans receivable
Number of days past due, non-accrual status	180 days
Consumer | Commercial market loans
Loans receivable
Number of days past due, non-accrual status	90 days
Consumer | Open-ended consumer loans
Loans receivable
Age modifications limitations in twelve months | re-aging	1
Age modifications limitations in five years | re-aging	2
Consumer | Total GCB and Citi Holdings Consumer
Loans receivable
Loans, current	$ 326,091	317,184
Loans, net of unearned income	333,655	325,060
Loans, total non-accrual	2,690	3,158
Total loans past due and accruing	2,812	2,991
Consumer | Total GCB and Citi Holdings Consumer | Government-guaranteed
Loans receivable
Loans, past due	1,225	1,474
Consumer | Total GCB and Citi Holdings Consumer | 30 to 89 Days Past Due
Loans receivable
Loans, past due	3,304	3,275
Consumer | Total GCB and Citi Holdings Consumer | Equal to greater than 90 days past due
Loans receivable
Loans, past due	3,035	3,127
Consumer | Other
Loans receivable
Loans, current	1	3
Loans, net of unearned income	1	3
Loans, total non-accrual	0	0
Total loans past due and accruing	0	0
Consumer | Other | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | Other | 30 to 89 Days Past Due
Loans receivable
Loans, past due	0	0
Consumer | Other | Equal to greater than 90 days past due
Loans receivable
Loans, past due	0	0
Consumer | In North America offices
Loans receivable
Loans, current	211,012	213,222
Loans, net of unearned income	216,899	219,491
Loans, total non-accrual	1,650	2,160
Total loans past due and accruing	2,553	2,752
Consumer | In North America offices | Government-guaranteed
Loans receivable
Loans, past due	1,225	1,474
Consumer | In North America offices | 30 to 89 Days Past Due
Loans receivable
Loans, past due	2,336	2,365
Consumer | In North America offices | Equal to greater than 90 days past due
Loans receivable
Loans, past due	2,326	2,430
Consumer | In North America offices | Residential first mortgages
Loans receivable
Loans, current	47,366	50,766
Loans, net of unearned income	49,376	53,133
Loans, total non-accrual	665	848
Total loans past due and accruing	941	1,227
Residential first mortgage loans in process of foreclosure	100	100
Consumer | In North America offices | Residential first mortgages | Government-guaranteed
Loans receivable
Loans, past due	1,225	1,474
Consumer | In North America offices | Residential first mortgages | 30 to 89 Days Past Due
Loans receivable
Loans, past due	505	522
Consumer | In North America offices | Residential first mortgages | 30 to 89 Days Past Due | Government-guaranteed
Loans receivable
Loans, past due	200	200
Consumer | In North America offices | Residential first mortgages | Equal to greater than 90 days past due
Loans receivable
Loans, past due	280	371
Consumer | In North America offices | Residential first mortgages | Equal to greater than 90 days past due | Government-guaranteed
Loans receivable
Loans, past due	1,000	1,300
Consumer | In North America offices | Home equity loans
Loans receivable
Loans, current	14,268	18,767
Loans, net of unearned income	14,827	19,454
Loans, total non-accrual	750	914
Total loans past due and accruing	0	0
Home equity loans in process of foreclosure,	100	100
Consumer | In North America offices | Home equity loans | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In North America offices | Home equity loans | 30 to 89 Days Past Due
Loans receivable
Loans, past due	207	249
Consumer | In North America offices | Home equity loans | Equal to greater than 90 days past due
Loans receivable
Loans, past due	352	438
Consumer | In North America offices | Credit cards
Loans receivable
Loans, current	136,588	130,327
Loans, net of unearned income	139,729	133,301
Loans, total non-accrual	0	0
Total loans past due and accruing	1,596	1,509
Consumer | In North America offices | Credit cards | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In North America offices | Credit cards | 30 to 89 Days Past Due
Loans receivable
Loans, past due	1,528	1,465
Consumer | In North America offices | Credit cards | Equal to greater than 90 days past due
Loans receivable
Loans, past due	1,613	1,509
Consumer | In North America offices | Installment and other
Loans receivable
Loans, current	3,395	4,486
Loans, net of unearned income	3,456	4,630
Loans, total non-accrual	22	70
Total loans past due and accruing	1	2
Consumer | In North America offices | Installment and other | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In North America offices | Installment and other | 30 to 89 Days Past Due
Loans receivable
Loans, past due	45	106
Consumer | In North America offices | Installment and other | Equal to greater than 90 days past due
Loans receivable
Loans, past due	16	38
Consumer | In North America offices | Commercial market loans
Loans receivable
Loans, current	9,395	8,876
Loans, net of unearned income	9,511	8,973
Loans, total non-accrual	213	328
Total loans past due and accruing	15	14
Consumer | In North America offices | Commercial market loans | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In North America offices | Commercial market loans | 30 to 89 Days Past Due
Loans receivable
Loans, past due	51	23
Consumer | In North America offices | Commercial market loans | Equal to greater than 90 days past due
Loans receivable
Loans, past due	65	74
Consumer | In offices outside North America
Loans receivable
Loans, current	115,079	103,962
Loans, net of unearned income	116,756	105,569
Loans, total non-accrual	1,040	998
Total loans past due and accruing	259	239
Consumer | In offices outside North America | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In offices outside North America | 30 to 89 Days Past Due
Loans receivable
Loans, past due	968	910
Consumer | In offices outside North America | Equal to greater than 90 days past due
Loans receivable
Loans, past due	709	697
Consumer | In offices outside North America | Residential first mortgages
Loans receivable
Loans, current	37,062	35,862
Loans, net of unearned income	37,419	36,203
Loans, total non-accrual	400	360
Total loans past due and accruing	0	0
Consumer | In offices outside North America | Residential first mortgages | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In offices outside North America | Residential first mortgages | 30 to 89 Days Past Due
Loans receivable
Loans, past due	209	206
Consumer | In offices outside North America | Residential first mortgages | Equal to greater than 90 days past due
Loans receivable
Loans, past due	148	135
Consumer | In offices outside North America | Credit cards
Loans receivable
Loans, current	24,934	22,363
Loans, net of unearned income	25,727	23,055
Loans, total non-accrual	323	258
Total loans past due and accruing	259	239
Consumer | In offices outside North America | Credit cards | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In offices outside North America | Credit cards | 30 to 89 Days Past Due
Loans receivable
Loans, past due	427	368
Consumer | In offices outside North America | Credit cards | Equal to greater than 90 days past due
Loans receivable
Loans, past due	366	324
Consumer | In offices outside North America | Installment and other
Loans receivable
Loans, current	25,634	22,683
Loans, net of unearned income	26,032	23,073
Loans, total non-accrual	157	163
Total loans past due and accruing	0	0
Consumer | In offices outside North America | Installment and other | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In offices outside North America | Installment and other | 30 to 89 Days Past Due
Loans receivable
Loans, past due	275	264
Consumer | In offices outside North America | Installment and other | Equal to greater than 90 days past due
Loans receivable
Loans, past due	123	126
Consumer | In offices outside North America | Commercial market loans
Loans receivable
Loans, current	27,449	23,054
Loans, net of unearned income	27,578	23,238
Loans, total non-accrual	160	217
Total loans past due and accruing	0	0
Consumer | In offices outside North America | Commercial market loans | Government-guaranteed
Loans receivable
Loans, past due	0	0
Consumer | In offices outside North America | Commercial market loans | 30 to 89 Days Past Due
Loans receivable
Loans, past due	57	72
Consumer | In offices outside North America | Commercial market loans | Equal to greater than 90 days past due
Loans receivable
Loans, past due	$ 72	$ 112

LOANS - Impaired Consumer Loans

LOANS - Impaired Consumer Loans (Details) - Consumer $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)Q	Dec. 31, 2016USD ($)Q	Dec. 31, 2015USD ($)
Financing receivable impaired
Recorded investment	$ 6,580	$ 7,799
Unpaid principal balance	7,531	8,987
Related specific allowance	1,334	1,608
Average carrying value	6,983	8,802
Interest income recognized	$ 342	$ 402	$ 728
Number of quarters used to calculate the average recorded investment balance | Q	4	4
Residential first mortgages
Financing receivable impaired
Recorded investment	$ 2,877	$ 3,786
Unpaid principal balance	3,121	4,157
Related specific allowance	278	540
Average carrying value	3,155	4,632
Interest income recognized	119	170
Recorded investment, impaired financing receivable without specific allowance	607		740
Home equity loans
Financing receivable impaired
Recorded investment	1,151	1,298
Unpaid principal balance	1,590	1,824
Related specific allowance	216	189
Average carrying value	1,181	1,326
Interest income recognized	28	35
Recorded investment, impaired financing receivable without specific allowance	370		406
Credit cards
Financing receivable impaired
Recorded investment	1,787	1,747
Unpaid principal balance	1,819	1,781
Related specific allowance	614	566
Average carrying value	1,803	1,831
Interest income recognized	150	158
Individual installment and other
Financing receivable impaired
Recorded investment	431	455
Unpaid principal balance	460	481
Related specific allowance	175	215
Average carrying value	415	475
Interest income recognized	25	27
Commercial market loans
Financing receivable impaired
Recorded investment	334	513
Unpaid principal balance	541	744
Related specific allowance	51	98
Average carrying value	429	538
Interest income recognized	20	$ 12
Recorded investment, impaired financing receivable without specific allowance	$ 10		$ 97

LOANS - Consumer Troubled Debt

LOANS - Consumer Troubled Debt Restructurings (Details) - Consumer $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Loans receivable
Period within which default occurred post-modification	1 year
Number of days past due, non-accrual status	60 days
Residential first mortgages
Loans receivable
Number of days past due, non-accrual status	90 days	90 days
Home equity loans
Loans receivable
Number of days past due, non-accrual status	90 days
Credit cards
Loans receivable
Number of days past due, non-accrual status	180 days
Installment and other
Loans receivable
Number of days past due, non-accrual status	90 days
Commercial banking
Loans receivable
Number of days past due, non-accrual status	90 days
In North America offices
Loans receivable
Number of loans modified | loan	238,112	210,908
Post-modification recorded investment	$ 1,832	$ 1,826
Loans in default	$ 524	$ 466
In North America offices | Residential first mortgages
Loans receivable
Number of loans modified | loan	4,063	5,023
Post-modification recorded investment	$ 580	$ 726
Average interest rate reduction (as a percent)	1.00%	1.00%
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 53	$ 74
Loans in default	253	229
In North America offices | Residential first mortgages | New OCC guidance
Loans receivable
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 36	$ 48
In North America offices | Home equity loans
Loans receivable
Number of loans modified | loan	2,807	4,100
Post-modification recorded investment	$ 247	$ 200
Average interest rate reduction (as a percent)	1.00%	2.00%
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 21	$ 22
Loans in default	46	25
In North America offices | Home equity loans | New OCC guidance
Loans receivable
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 18	$ 20
In North America offices | Credit cards
Loans receivable
Number of loans modified | loan	230,042	196,004
Post-modification recorded investment	$ 880	$ 762
Average interest rate reduction (as a percent)	17.00%	17.00%
Loans in default	$ 221	$ 188
In North America offices | Installment and other
Loans receivable
Number of loans modified | loan	1,088	5,649
Post-modification recorded investment	$ 8	$ 47
Average interest rate reduction (as a percent)	5.00%	14.00%
Loans in default	$ 2	$ 9
In North America offices | Commercial banking
Loans receivable
Number of loans modified | loan	112	132
Post-modification recorded investment	$ 117	$ 91
Average interest rate reduction (as a percent)	0.00%	0.00%
Loans in default	$ 2	$ 15
In offices outside the U.S.
Loans receivable
Number of loans modified | loan	165,668	200,444
Post-modification recorded investment	$ 826	$ 850
Loans in default	$ 293	$ 286
In offices outside the U.S. | Residential first mortgages
Loans receivable
Number of loans modified | loan	4,477	2,722
Post-modification recorded investment	$ 123	$ 80
Average interest rate reduction (as a percent)	0.00%	0.00%
Loans in default	$ 11	$ 11
In offices outside the U.S. | Credit cards
Loans receivable
Number of loans modified | loan	115,941	137,466
Post-modification recorded investment	$ 399	$ 385
Average interest rate reduction (as a percent)	11.00%	12.00%
Loans in default	$ 185	$ 148
In offices outside the U.S. | Installment and other
Loans receivable
Number of loans modified | loan	44,880	60,094
Post-modification recorded investment	$ 254	$ 276
Average interest rate reduction (as a percent)	9.00%	7.00%
Loans in default	$ 96	$ 90
In offices outside the U.S. | Commercial banking
Loans receivable
Number of loans modified | loan	370	162
Post-modification recorded investment	$ 50	$ 109
Average interest rate reduction (as a percent)	0.00%	0.00%
Loans in default	$ 1	$ 37
Deferred principal | In North America offices
Loans receivable
Post-modification recorded investment	22	12
Deferred principal | In North America offices | Residential first mortgages
Loans receivable
Post-modification recorded investment	6	6
Deferred principal | In North America offices | Home equity loans
Loans receivable
Post-modification recorded investment	16	6
Deferred principal | In North America offices | Credit cards
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In North America offices | Installment and other
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In North America offices | Commercial banking
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In offices outside the U.S.
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In offices outside the U.S. | Residential first mortgages
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In offices outside the U.S. | Credit cards
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In offices outside the U.S. | Installment and other
Loans receivable
Post-modification recorded investment	0	0
Deferred principal | In offices outside the U.S. | Commercial banking
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices | Residential first mortgages
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices | Home equity loans
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices | Credit cards
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices | Installment and other
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In North America offices | Commercial banking
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In offices outside the U.S.
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In offices outside the U.S. | Residential first mortgages
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In offices outside the U.S. | Credit cards
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In offices outside the U.S. | Installment and other
Loans receivable
Post-modification recorded investment	0	0
Contingent principal forgiveness | In offices outside the U.S. | Commercial banking
Loans receivable
Post-modification recorded investment	0	0
Principal forgiveness | In North America offices
Loans receivable
Post-modification recorded investment	3	4
Principal forgiveness | In North America offices | Residential first mortgages
Loans receivable
Post-modification recorded investment	2	3
Principal forgiveness | In North America offices | Home equity loans
Loans receivable
Post-modification recorded investment	1	1
Principal forgiveness | In North America offices | Credit cards
Loans receivable
Post-modification recorded investment	0	0
Principal forgiveness | In North America offices | Installment and other
Loans receivable
Post-modification recorded investment	0	0
Principal forgiveness | In North America offices | Commercial banking
Loans receivable
Post-modification recorded investment	0	0
Principal forgiveness | In offices outside the U.S.
Loans receivable
Post-modification recorded investment	18	16
Principal forgiveness | In offices outside the U.S. | Residential first mortgages
Loans receivable
Post-modification recorded investment	0	0
Principal forgiveness | In offices outside the U.S. | Credit cards
Loans receivable
Post-modification recorded investment	7	9
Principal forgiveness | In offices outside the U.S. | Installment and other
Loans receivable
Post-modification recorded investment	11	7
Principal forgiveness | In offices outside the U.S. | Commercial banking
Loans receivable
Post-modification recorded investment	$ 0	$ 0

LOANS - Corporate Loans (Detail

LOANS - Corporate Loans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans
Loans, net of unearned income	$ 667,034	$ 624,369
Corporate
Loans
Total loans	334,141	300,010
Net unearned income (loss)	(763)	(704)
Loans, net of unearned income	333,378	299,306
Loans sold and/or reclassified to held-for-sale	1,000	4,200
Corporate | Commercial and industrial
Loans
Loans, net of unearned income	141,322	129,116
Corporate | Financial institutions
Loans
Loans, net of unearned income	73,757	61,560
Corporate | Mortgage and real estate
Loans
Loans, net of unearned income	51,964	44,031
Corporate | Lease financing
Loans
Loans, net of unearned income	1,655	1,769
In U.S. offices | Corporate
Loans
Total loans	169,781	159,813
In U.S. offices | Corporate | Commercial and industrial
Loans
Total loans	51,319	49,586
In U.S. offices | Corporate | Financial institutions
Loans
Total loans	39,128	35,517
In U.S. offices | Corporate | Mortgage and real estate
Loans
Total loans	44,683	38,691
In U.S. offices | Corporate | Installment, revolving credit and other
Loans
Total loans	33,181	34,501
In U.S. offices | Corporate | Lease financing
Loans
Total loans	1,470	1,518
In offices outside the U.S. | Corporate
Loans
Total loans	164,360	140,197
In offices outside the U.S. | Corporate | Commercial and industrial
Loans
Total loans	93,750	81,882
In offices outside the U.S. | Corporate | Financial institutions
Loans
Total loans	35,273	26,886
In offices outside the U.S. | Corporate | Mortgage and real estate
Loans
Total loans	7,309	5,363
In offices outside the U.S. | Corporate | Installment, revolving credit and other
Loans
Total loans	22,638	19,965
In offices outside the U.S. | Corporate | Lease financing
Loans
Total loans	190	251
In offices outside the U.S. | Corporate | Government and official institutions
Loans
Total loans	$ 5,200	$ 5,850

LOANS - Corporate Loan Delinque

LOANS - Corporate Loan Delinquency (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans receivable
Loans, net of unearned income	$ 667,034	$ 624,369
Loans at fair value	$ 4,374	3,486
Corporate
Loans receivable
Number of days past due, non-accrual status	90 days
Number of days past due for reversal of accrued interest and charging to earnings	90 days
Total loans past due and accruing	$ 735	997
Loans, total non-accrual	1,942	2,421
Loans, total current	326,352	292,431
Loans, net of unearned income	333,378	299,306
Loans at fair value	$ 4,349	3,457
Loans less than this number of days past due are considered current	30 days
Corporate | Commercial and industrial
Loans receivable
Total loans past due and accruing	$ 262	195
Loans, total non-accrual	1,506	1,909
Loans, total current	139,554	127,012
Loans, net of unearned income	141,322	129,116
Corporate | Financial institutions
Loans receivable
Total loans past due and accruing	108	121
Loans, total non-accrual	92	185
Loans, total current	73,557	61,254
Loans, net of unearned income	73,757	61,560
Corporate | Mortgage and real estate
Loans receivable
Total loans past due and accruing	206	285
Loans, total non-accrual	195	139
Loans, total current	51,563	43,607
Loans, net of unearned income	51,964	44,031
Corporate | Leases
Loans receivable
Total loans past due and accruing	76	35
Loans, total non-accrual	46	56
Loans, total current	1,533	1,678
Loans, net of unearned income	1,655	1,769
Corporate | Other
Loans receivable
Total loans past due and accruing	83	361
Loans, total non-accrual	103	132
Loans, total current	60,145	58,880
Loans, net of unearned income	60,331	59,373
30 to 89 Days Past Due | Corporate
Loans receivable
Total loans past due and accruing	627	786
30 to 89 Days Past Due | Corporate | Commercial and industrial
Loans receivable
Total loans past due and accruing	249	143
30 to 89 Days Past Due | Corporate | Financial institutions
Loans receivable
Total loans past due and accruing	93	119
30 to 89 Days Past Due | Corporate | Mortgage and real estate
Loans receivable
Total loans past due and accruing	147	148
30 to 89 Days Past Due | Corporate | Leases
Loans receivable
Total loans past due and accruing	68	27
30 to 89 Days Past Due | Corporate | Other
Loans receivable
Total loans past due and accruing	70	349
Equal to greater than 90 days past due | Corporate
Loans receivable
Total loans past due and accruing	108	211
Equal to greater than 90 days past due | Corporate | Commercial and industrial
Loans receivable
Total loans past due and accruing	13	52
Equal to greater than 90 days past due | Corporate | Financial institutions
Loans receivable
Total loans past due and accruing	15	2
Equal to greater than 90 days past due | Corporate | Mortgage and real estate
Loans receivable
Total loans past due and accruing	59	137
Equal to greater than 90 days past due | Corporate | Leases
Loans receivable
Total loans past due and accruing	8	8
Equal to greater than 90 days past due | Corporate | Other
Loans receivable
Total loans past due and accruing	$ 13	$ 12

LOANS - Corporate Loans Credit

LOANS - Corporate Loans Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Loans receivable
Loans, net of unearned income	$ 667,034	$ 624,369
Loans at fair value	4,374	3,486
Corporate
Loans receivable
Loans, net of unearned income	333,378	299,306
Loans, total non-accrual	1,942	2,421
Loans at fair value	4,349	3,457
Corporate | Commercial and industrial
Loans receivable
Loans, net of unearned income	141,322	129,116
Loans, total non-accrual	1,506	1,909
Corporate | Financial institutions
Loans receivable
Loans, net of unearned income	73,757	61,560
Loans, total non-accrual	92	185
Corporate | Mortgage and real estate
Loans receivable
Loans, net of unearned income	51,964	44,031
Loans, total non-accrual	195	139
Corporate | Lease financing
Loans receivable
Loans, net of unearned income	1,655	1,769
Loans, total non-accrual	46	56
Corporate | Other
Loans receivable
Loans, net of unearned income	60,331	59,373
Loans, total non-accrual	103	132
Corporate | Private Banking loans managed on a delinquency basis
Loans receivable
Loans, net of unearned income	25,674	23,353
Corporate | Investment Grade
Loans receivable
Loans, net of unearned income	242,326	210,647
Corporate | Investment Grade | Commercial and industrial
Loans receivable
Loans, net of unearned income	101,313	87,201
Corporate | Investment Grade | Financial institutions
Loans receivable
Loans, net of unearned income	60,404	50,597
Corporate | Investment Grade | Mortgage and real estate
Loans receivable
Loans, net of unearned income	23,213	18,718
Corporate | Investment Grade | Lease financing
Loans receivable
Loans, net of unearned income	1,090	1,303
Corporate | Investment Grade | Other
Loans receivable
Loans, net of unearned income	56,306	52,828
Corporate | Non-Investment Grade
Loans receivable
Loans, net of unearned income	61,029	61,849
Corporate | Non-Investment Grade | Commercial and industrial
Loans receivable
Loans, net of unearned income	38,503	39,874
Loans, total non-accrual	1,506	1,909
Corporate | Non-Investment Grade | Financial institutions
Loans receivable
Loans, net of unearned income	13,261	10,873
Loans, total non-accrual	92	185
Corporate | Non-Investment Grade | Mortgage and real estate
Loans receivable
Loans, net of unearned income	2,881	1,821
Loans, total non-accrual	195	139
Corporate | Non-Investment Grade | Lease financing
Loans receivable
Loans, net of unearned income	518	410
Loans, total non-accrual	46	56
Corporate | Non-Investment Grade | Other
Loans receivable
Loans, net of unearned income	3,924	6,450
Loans, total non-accrual	$ 103	$ 132

LOANS - Non-accrual Corporate L

LOANS - Non-accrual Corporate Loans (Details) - Corporate - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing receivable impaired
Number of months in sustained period of repayment performance for cash-basis loans to return to an accrual status	6 months
Recorded investment	$ 1,942	$ 2,421
Unpaid principal balance	2,459	2,954
Related specific allowance	426	392
Average carrying value	2,109	2,407
Interest income recognized	35	40	$ 11
Recorded investment, impaired financing receivable with specific allowance	1,215	1,485
Recorded investment, impaired financing receivable without specific allowance	727	936
Commercial and industrial
Financing receivable impaired
Recorded investment	1,506	1,909
Unpaid principal balance	1,775	2,259
Related specific allowance	368	362
Average carrying value	1,547	1,919
Interest income recognized	23	25
Recorded investment, impaired financing receivable with specific allowance	1,017	1,343
Recorded investment, impaired financing receivable without specific allowance	489	566
Financial institutions
Financing receivable impaired
Recorded investment	92	185
Unpaid principal balance	102	192
Related specific allowance	41	16
Average carrying value	212	183
Interest income recognized	1	3
Recorded investment, impaired financing receivable with specific allowance	88	45
Recorded investment, impaired financing receivable without specific allowance	4	140
Mortgage and real estate
Financing receivable impaired
Recorded investment	195	139
Unpaid principal balance	324	250
Related specific allowance	11	10
Average carrying value	183	174
Interest income recognized	10	6
Recorded investment, impaired financing receivable with specific allowance	51	41
Recorded investment, impaired financing receivable without specific allowance	144	98
Lease financing
Financing receivable impaired
Recorded investment	46	56
Unpaid principal balance	46	56
Related specific allowance	4	4
Average carrying value	59	44
Interest income recognized	0	0
Recorded investment, impaired financing receivable with specific allowance	46	55
Recorded investment, impaired financing receivable without specific allowance	0	1
Other
Financing receivable impaired
Recorded investment	103	132
Unpaid principal balance	212	197
Related specific allowance	2	0
Average carrying value	108	87
Interest income recognized	1	6
Recorded investment, impaired financing receivable with specific allowance	13	1
Recorded investment, impaired financing receivable without specific allowance	$ 90	$ 131

LOANS - Corporate Troubled Debt

LOANS - Corporate Troubled Debt Restructurings (Details) - Corporate - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing receivable impaired
Carrying Value	$ 560	$ 505
Period within which default occurred post-modification	1 year
Number of days past due, default status	60 days
Carrying Value	$ 818	732
TDR in payment default	$ 72	15
Commercial banking
Financing receivable impaired
Number of days past due, default status	90 days
Commercial and industrial
Financing receivable impaired
Carrying Value	$ 509	338
Carrying Value	617	408
TDR in payment default	72	7
Financial institutions
Financing receivable impaired
Carrying Value	15	10
Carrying Value	48	9
TDR in payment default	0	0
Mortgage and real estate
Financing receivable impaired
Carrying Value	36	15
Carrying Value	101	87
TDR in payment default	0	8
Lease financing
Financing receivable impaired
Carrying Value	7	0
TDR in payment default	0	0
Other
Financing receivable impaired
Carrying Value		142
Carrying Value	45	228
TDR in payment default	0	0
TDRs involving changes in the amount and/or timing of principal payments
Financing receivable impaired
Carrying Value	131	192
TDRs involving changes in the amount and/or timing of principal payments | Commercial and industrial
Financing receivable impaired
Carrying Value	131	176
TDRs involving changes in the amount and/or timing of principal payments | Financial institutions
Financing receivable impaired
Carrying Value	0	10
TDRs involving changes in the amount and/or timing of principal payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	0	6
TDRs involving changes in the amount and/or timing of principal payments | Other
Financing receivable impaired
Carrying Value		0
TDRs involving vhanges in the amount and/or timing of interest payments
Financing receivable impaired
Carrying Value	7	176
TDRs involving vhanges in the amount and/or timing of interest payments | Commercial and industrial
Financing receivable impaired
Carrying Value	7	34
TDRs involving vhanges in the amount and/or timing of interest payments | Financial institutions
Financing receivable impaired
Carrying Value	0	0
TDRs involving vhanges in the amount and/or timing of interest payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	0	0
TDRs involving vhanges in the amount and/or timing of interest payments | Other
Financing receivable impaired
Carrying Value		142
TDRs invovling changes in the amount and/or timing of both principal and interest payments
Financing receivable impaired
Carrying Value	422	137
TDRs invovling changes in the amount and/or timing of both principal and interest payments | Commercial and industrial
Financing receivable impaired
Carrying Value	371	128
TDRs invovling changes in the amount and/or timing of both principal and interest payments | Financial institutions
Financing receivable impaired
Carrying Value	15	0
TDRs invovling changes in the amount and/or timing of both principal and interest payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	$ 36	9
TDRs invovling changes in the amount and/or timing of both principal and interest payments | Other
Financing receivable impaired
Carrying Value		$ 0

ALLOWANCE FOR CREDIT LOSSES - A

ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,060	$ 12,626	$ 15,994
Gross credit losses	(8,673)	(8,222)	(9,041)
Gross recoveries	1,597	1,661	1,739
Net credit losses (NCLs)	(7,076)	(6,561)	(7,302)
NCLs	7,076	6,561	7,302
Net reserve builds (releases)	544	340	139
Net specific reserve releases	(117)	(152)	(333)
Total provision for loan losses	7,503	6,749	7,108
Other	(132)	(754)	(3,174)
Allowance for loan losses at the end of year	12,355	12,060	12,626
Allowance for credit losses on unfunded lending commitments
Allowance for credit losses on unfunded lending commitments at beginning of period	1,418	1,402	1,063
Provision (release) for unfunded lending commitments	(161)	29	74
Other, net	1	(13)	265
Allowance for credit losses on unfunded lending commitments at end of period	1,258	1,418	1,402
Total allowance for loans, leases and unfunded lending commitments	13,613	13,478	14,028
Allowance for loan losses included in other transferred to allowance for unfunded lending commitments			271
Sales or transfers of various consumer loan portfolios to held-for-sale
Other	(132)	(754)	(3,174)
Consumer
Sales or transfers of various consumer loan portfolios to held-for-sale
Transfer of real estate loan portfolios	(106)	(106)	(1,462)
Transfer of other loan portfolios	(155)	(468)	(948)
Sales or transfers of various consumer loan portfolios to held-for-sale	(261)	(574)	(2,410)
FX translation, consumer	115	(199)	(474)
Corporate
Allowance for credit losses
Other	14	19	(290)
Sales or transfers of various consumer loan portfolios to held-for-sale
Other	$ 14	$ 19	$ (290)

ALLOWANCE FOR CREDIT LOSSES 130

ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,060	$ 12,626	$ 15,994
Charge-offs	(8,673)	(8,222)	(9,041)
Recoveries	1,597	1,661	1,739
Replenishment of net charge-offs	7,076	6,561	7,302
Net reserve builds (releases)	544	340	139
Net specific reserve releases	(117)	(152)	(333)
Other	(132)	(754)	(3,174)
Allowance for loan losses at the end of year	12,355	12,060	12,626
Sales or transfers of various consumer loan portfolios to held-for-sale
Collectively evaluated in accordance with ASC 450				$ 10,591	$ 10,054
Individually evaluated in accordance with ASC 310-10-35				1,760	2,000
Allowance for loan losses	12,060	12,626	15,994	12,355	12,060
Loans, net of unearned income:
Collectively evaluated for impairment in accordance with ASC 450				654,026	610,266
Individually evaluated for impairment in accordance with ASC 310-10-35				8,467	10,430
Held at fair value				4,374	3,486
Loans, net of unearned income				667,034	624,369
Receivables Acquired with Deteriorated Credit Quality
Sales or transfers of various consumer loan portfolios to held-for-sale
Purchased credit-impaired in accordance with ASC 310-30				4	6
Loans, net of unearned income:
Purchased credit-impaired in accordance with ASC 310-30				167	187
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,702	2,791	2,447
Charge-offs	(491)	(580)	(349)
Recoveries	112	67	105
Replenishment of net charge-offs	379	513	244
Net reserve builds (releases)	(267)	(85)	550
Net specific reserve releases	28	0	86
Other	23	(4)	(292)
Allowance for loan losses at the end of year	2,486	2,702	2,791
Sales or transfers of various consumer loan portfolios to held-for-sale
Collectively evaluated in accordance with ASC 450				2,060	2,310
Individually evaluated in accordance with ASC 310-10-35				426	392
Allowance for loan losses	2,702	2,791	2,447	2,486	2,702
Loans, net of unearned income:
Collectively evaluated for impairment in accordance with ASC 450				327,142	293,218
Individually evaluated for impairment in accordance with ASC 310-10-35				1,887	2,631
Held at fair value				4,349	3,457
Loans, net of unearned income				333,378	299,306
Corporate | Receivables Acquired with Deteriorated Credit Quality
Sales or transfers of various consumer loan portfolios to held-for-sale
Purchased credit-impaired in accordance with ASC 310-30				0	0
Loans, net of unearned income:
Purchased credit-impaired in accordance with ASC 310-30				0	0
Consumer
Allowance for credit losses
Allowance for loan losses at beginning of period	9,358	9,835	13,547
Charge-offs	(8,182)	(7,642)	(8,692)
Recoveries	1,485	1,594	1,634
Replenishment of net charge-offs	6,697	6,048	7,058
Net reserve builds (releases)	811	425	(411)
Net specific reserve releases	(145)	(152)	(419)
Other	(155)	(750)	(2,882)
Allowance for loan losses at the end of year	9,869	9,358	9,835
Sales or transfers of various consumer loan portfolios to held-for-sale
Collectively evaluated in accordance with ASC 450				8,531	7,744
Individually evaluated in accordance with ASC 310-10-35				1,334	1,608
Allowance for loan losses	$ 9,358	$ 9,835	$ 13,547	9,869	9,358
Loans, net of unearned income:
Collectively evaluated for impairment in accordance with ASC 450				326,884	317,048
Individually evaluated for impairment in accordance with ASC 310-10-35				6,580	7,799
Held at fair value				25	29
Loans, net of unearned income				333,656	325,063
Consumer | Receivables Acquired with Deteriorated Credit Quality
Sales or transfers of various consumer loan portfolios to held-for-sale
Purchased credit-impaired in accordance with ASC 310-30				4	6
Loans, net of unearned income:
Purchased credit-impaired in accordance with ASC 310-30				$ 167	$ 187

GOODWILL AND INTANGIBLE ASSE131

GOODWILL AND INTANGIBLE ASSETS - Changes in Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill
Balance of goodwill at beginning of period	$ 21,659	$ 22,349	$ 23,592
Foreign exchange translation and other	729	(613)	(1,000)
Divestitures	(104)	(77)	(212)
Impairment of goodwill	(28)		(31)
Balance of goodwill at end of period	$ 22,256	$ 21,659	$ 22,349

GOODWILL AND INTANGIBLE ASSE132

GOODWILL AND INTANGIBLE ASSETS - Changes in Goodwill by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill
Balance of goodwill at beginning of period	$ 21,659	$ 22,349	$ 23,592
Foreign exchange translation and other	729	(613)	(1,000)
Divestitures	(104)	(77)	(212)
Impairment of goodwill	(28)		(31)
Balance of goodwill at end of period	22,256	21,659	22,349
Impairments	28		31
Global Consumer Banking
Goodwill
Balance of goodwill at beginning of period	12,530	12,704
Foreign exchange translation and other	286	(174)
Divestitures	(32)	0
Impairment of goodwill	0
Balance of goodwill at end of period	12,784	12,530	12,704
Impairments	0
Institutional Clients Group
Goodwill
Balance of goodwill at beginning of period	9,085	9,545
Foreign exchange translation and other	443	(447)
Divestitures	(72)	(13)
Impairment of goodwill	0
Balance of goodwill at end of period	9,456	9,085	9,545
Impairments	0
Corporate/Other
Goodwill
Balance of goodwill at beginning of period	44	100
Foreign exchange translation and other	0	8
Divestitures	0	(64)
Impairment of goodwill	(28)
Balance of goodwill at end of period	16	$ 44	100
Impairments	28
Citi Holdings
Goodwill
Impairment of goodwill	(28)
Impairments	$ 28
Consumer Finance South Korea | Citi Holdings
Goodwill
Impairment of goodwill			(16)
Impairments			16
Consumer Latin America | Citi Holdings
Goodwill
Impairment of goodwill			(15)
Impairments			$ 15

GOODWILL AND INTANGIBLE ASSE133

GOODWILL AND INTANGIBLE ASSETS - Goodwill Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015	Jul. 01, 2017	Dec. 31, 2016	Dec. 31, 2014
Goodwill:
Goodwill	$ 22,256	$ 22,349		$ 21,659	$ 23,592
Impairments	28	31
Citi Holdings
Goodwill:
Impairments	28
Citi Holdings | Citi Holdings-Consumer Latin America
Goodwill:
Impairments		$ 15
Operating Segments | Citi Holdings | Reporting units | Citi Holdings-Consumer Latin America
Goodwill:
Goodwill	$ 16
Fair value as a percent of allocated book value	111.00%
Minimum
Goodwill:
Percentage fair value exceed carrying value			32.00%
Maximum
Goodwill:
Percentage fair value exceed carrying value			168.00%

GOODWILL AND INTANGIBLE ASSE134

GOODWILL AND INTANGIBLE ASSETS - Components of Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	$ 11,894	$ 15,384
Accumulated amortization of Intangible assets (excluding MSRs)	7,306	10,270
Net carrying amount of intangible assets (excluding MSRs)	4,588	5,114
Gross carrying amount, Mortgage servicing rights (MSRs)	558	1,564
Mortgage servicing rights (MSRs)	558	1,564
Gross carrying amount of Intangible assets	12,452	16,948
Accumulated amortization of intangible assets	7,306	10,270
Net carrying amount of intangible assets, balance at end of period	5,146	6,678
Intangible assets amortization expense	603	595	$ 625
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,018	503
2,019	479
2,020	332
2,021	314
2,022	866
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	244	210
Accumulated amortization of Intangible assets (excluding MSRs)	0	0
Net carrying amount of intangible assets (excluding MSRs)	244	210
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	5,375	8,215
Accumulated amortization of Intangible assets (excluding MSRs)	3,836	6,549
Net carrying amount of intangible assets (excluding MSRs)	1,539	1,666
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	5,045	5,149
Accumulated amortization of Intangible assets (excluding MSRs)	2,456	2,177
Net carrying amount of intangible assets (excluding MSRs)	2,589	2,972
Core deposit intangibles
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	639	801
Accumulated amortization of Intangible assets (excluding MSRs)	628	771
Net carrying amount of intangible assets (excluding MSRs)	11	30
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	459	474
Accumulated amortization of Intangible assets (excluding MSRs)	272	272
Net carrying amount of intangible assets (excluding MSRs)	187	202
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	32	31
Accumulated amortization of Intangible assets (excluding MSRs)	28	27
Net carrying amount of intangible assets (excluding MSRs)	4	4
Other
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	100	504
Accumulated amortization of Intangible assets (excluding MSRs)	86	474
Net carrying amount of intangible assets (excluding MSRs)	$ 14	$ 30

GOODWILL AND INTANGIBLE ASSE135

GOODWILL AND INTANGIBLE ASSETS - Changes in Intangible Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	$ 5,114
Mortgage servicing rights (MSRs), beginning balance	1,564
Net carrying amount of intangible assets, beginning balance	6,678
Acquisitions/ divestitures	15
Amortization	(603)
Impairments	0
FX translation and other	62
Net carrying amount of intangible assets (excluding MSRs), ending balance	4,588
Mortgage servicing rights (MSRs), ending balance	558
Net carrying amount of intangible assets, ending balance	5,146
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	1,666
Acquisitions/ divestitures	20
Amortization	(149)
Impairments	0
FX translation and other	2
Net carrying amount of intangible assets (excluding MSRs), ending balance	1,539
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	2,972
Acquisitions/ divestitures	9
Amortization	(393)
Impairments	0
FX translation and other	1
Net carrying amount of intangible assets (excluding MSRs), ending balance	2,589
Core deposit intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	30
Acquisitions/ divestitures	0
Amortization	(20)
Impairments	0
FX translation and other	1
Net carrying amount of intangible assets (excluding MSRs), ending balance	11
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	202
Acquisitions/ divestitures	0
Amortization	(24)
Impairments	0
FX translation and other	9
Net carrying amount of intangible assets (excluding MSRs), ending balance	187
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	4
Acquisitions/ divestitures	0
Amortization	0
Impairments	0
FX translation and other	0
Net carrying amount of intangible assets (excluding MSRs), ending balance	4
Other
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	30
Acquisitions/ divestitures	(14)
Amortization	(17)
Impairments	0
FX translation and other	15
Net carrying amount of intangible assets (excluding MSRs), ending balance	14
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Net carrying amount of intangible assets (excluding MSRs), beginning balance	210
Acquisitions/ divestitures	0
Amortization	0
Impairments	0
FX translation and other	34
Net carrying amount of intangible assets (excluding MSRs), ending balance	$ 244
Intangible Assets, Excluding Mortgage Servicing Rights | Customer Concentration Risk | American Airlines, Sears, The Home Depot and Costco | Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Intangible assets, percent	97.00%

DEBT - Short-Term Borrowings (D

DEBT - Short-Term Borrowings (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Short-Term Borrowings:
Commercial paper	$ 9,940	$ 9,989
Other borrowings	34,512	20,712
Total short-term borrowings	44,452	30,701
Collateralized short-term advances from Federal Home Loan Bank	$ 23,800	$ 12,000
Commercial paper
Short-Term Borrowings:
Weighted average coupon	1.28%	0.79%
Other borrowings
Short-Term Borrowings:
Weighted average coupon	1.62%	1.39%

DEBT - Long-Term Debt (Details)

DEBT - Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument
Weighted average interest rate	3.57%
Long-term debt, at fair value	$ 236,709	$ 206,178
Weighted average interest rate including effects of derivative contracts	2.70%
Senior debt
Debt Instrument
Long-term debt, at fair value	$ 208,010	177,722
Subordinated debt
Debt Instrument
Long-term debt, at fair value	26,987	26,762
Trust preferred securities
Debt Instrument
Long-term debt, at fair value	1,712	1,694
Citigroup Inc.
Debt Instrument
Long-term debt, at fair value	$ 152,163
Citigroup Inc. | Senior debt
Debt Instrument
Weighted average interest rate	4.15%
Long-term debt, at fair value	$ 123,488	118,881
Citigroup Inc. | Subordinated debt
Debt Instrument
Weighted average interest rate	4.48%
Long-term debt, at fair value	$ 26,963	26,758
Citigroup Inc. | Trust preferred securities
Debt Instrument
Weighted average interest rate	6.90%
Long-term debt, at fair value	$ 1,712	1,694
Bank
Debt Instrument
Long-term debt, at fair value	$ 65,856
Bank | Senior debt
Debt Instrument
Weighted average interest rate	2.06%
Long-term debt, at fair value	$ 65,856	49,454
Collateralized long-term advances from Federal Home Loan Bank	19,300	21,600
Broker-dealer
Debt Instrument
Long-term debt, at fair value	$ 18,690
Broker-dealer | Senior debt
Debt Instrument
Weighted average interest rate	3.44%
Long-term debt, at fair value	$ 18,666	9,387
Broker-dealer | Subordinated debt
Debt Instrument
Weighted average interest rate	5.37%
Long-term debt, at fair value	$ 24	$ 4

DEBT - Maturities of Long-term

DEBT - Maturities of Long-term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument
2,018	$ 53,478
2,019	36,289
2,020	23,188
2,021	21,019
2,022	12,364
Thereafter	90,371
Total	236,709	$ 206,178
Citigroup Inc.
Debt Instrument
2,018	20,050
2,019	16,656
2,020	9,565
2,021	15,499
2,022	9,627
Thereafter	80,766
Total	152,163
Bank
Debt Instrument
2,018	29,270
2,019	17,245
2,020	10,302
2,021	4,077
2,022	1,471
Thereafter	3,491
Total	65,856
Broker-dealer
Debt Instrument
2,018	4,158
2,019	2,388
2,020	3,321
2,021	1,443
2,022	1,266
Thereafter	6,114
Total	$ 18,690

DEBT - Trust Preferred Securiti

DEBT - Trust Preferred Securities (Details) $ in Millions	Dec. 31, 2017USD ($)shares
Trust Preferred Securities
Liquidation value	$ 2,575
Junior subordinated debentures owned by the Trust, amount	$ 2,581
Citigroup Capital III
Trust Preferred Securities
Securities issued (in shares) | shares	194,053
Liquidation value	$ 194
Coupon rate (as a percent)	7.625%
Common shares issued to parent (in shares) | shares	6,003
Junior subordinated debentures owned by the Trust, amount	$ 200
Citigroup Capital XIII
Trust Preferred Securities
Securities issued (in shares) | shares	89,840,000
Liquidation value	$ 2,246
Common shares issued to parent (in shares) | shares	1,000
Junior subordinated debentures owned by the Trust, amount	$ 2,246
Citigroup Capital XIII | LIBOR
Trust Preferred Securities
Basis spread on variable rate	0.0637
Citigroup Capital XVIII
Trust Preferred Securities
Securities issued (in shares) | shares	99,901
Liquidation value	$ 135
Common shares issued to parent (in shares) | shares	50
Junior subordinated debentures owned by the Trust, amount	$ 135
Citigroup Capital XVIII | LIBOR
Trust Preferred Securities
Basis spread on variable rate	0.008875

REGULATORY CAPITAL - Regulatory

REGULATORY CAPITAL - Regulatory Capital Compliance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital ratio, stated minimum	4.50%
Tier 1 Capital ratio, stated minimum	6.00%
Total Capital ratio, stated minimum	8.00%
Tier 1 Leverage ratio, stated minimum	4.00%
Dividends received from Citibank N.A.	$ 7,500	$ 13,800
Citigroup Inc.
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital	147,891
Tier 1 Capital	164,841
Total Capital (Tier 1 Capital Tier 2 Capital)	190,331
Total Risk-Weighted Assets	1,138,167
Quarterly Adjusted Average Total Assets	1,869,206
Total Leverage Exposure	$ 2,433,371
Common Equity Tier 1 Capital ratio	12.99%
Tier 1 Capital ratio, well capitalized minimum	6.00%
Tier 1 Capital ratio	14.48%
Total Capital ratio, well capitalized minimum	10.00%
Total Capital ratio	16.77%
Tier 1 Leverage ratio	8.82%
Supplementary leverage ratio	6.77%
Total capital, standardized approach	$ 202,000
Risk-weighted assets, standardized approach	1,135,000
Citibank, N.A.
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital	124,733
Tier 1 Capital	126,303
Total Capital (Tier 1 Capital Tier 2 Capital)	139,351
Total Risk-Weighted Assets	1,014,242
Quarterly Adjusted Average Total Assets	1,401,615
Total Leverage Exposure	$ 1,901,069
Common Equity Tier 1 Capital ratio	12.30%
Common Equity Tier 1 Capital ratio, well capitalized minimum	6.50%
Tier 1 Capital ratio, well capitalized minimum	8.00%
Tier 1 Capital ratio	12.45%
Total Capital ratio, well capitalized minimum	10.00%
Total Capital ratio	14.60%
Tier 1 Leverage ratio	9.01%
Tier 1 Leverage ratio, well capitalized minimum	5.00%
Supplementary leverage ratio	6.64%
Total capital, standardized approach	$ 150,000
Risk-weighted assets, standardized approach	$ 955,000
Subsequent event
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Supplementary leverage ratio, stated minimum			3.00%
Supplementary leverage ratio, well capitalized minimum			6.00%

CHANGES IN ACCUMULATED OTHER141

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Change in Each Component of AOCI (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		$ (32,381)
Impact of Tax Reform related to AOCI reclassification		(3,304)
Other comprehensive income (losses) before reclassifications		726	$ (2,903)	$ (6,220)
Increase (decrease) due to amounts reclassified from AOCI		(213)	(119)	92
Change, net of taxes		(2,791)	(3,022)	(6,128)
End-of-period balance, net of tax		(34,668)	(32,381)
Net unrealized gains (losses) on investment securities
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(799)	(907)	57
Adjustment to opening balance, net of taxes			504	0
Adjusted balance, beginning of period			(295)	(907)
Impact of Tax Reform related to AOCI reclassification		(223)
Other comprehensive income (losses) before reclassifications		(186)	530	(695)
Increase (decrease) due to amounts reclassified from AOCI		(454)	(422)	(269)
Change, net of taxes		(863)	108	(964)
End-of-period balance, net of tax		(1,158)	(799)	(907)
Debt valuation adjustment (DVA)
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(352)	0	0
Adjustment to opening balance, net of taxes			0	(15)
Adjusted balance, beginning of period			(352)	(15)
Impact of Tax Reform related to AOCI reclassification		(139)
Other comprehensive income (losses) before reclassifications		(426)	(335)	0
Increase (decrease) due to amounts reclassified from AOCI		(4)	(2)	0
Change, net of taxes		(569)	(337)	0
End-of-period balance, net of tax		(921)	(352)	0
Cash flow hedges
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(560)	(617)	(909)
Adjustment to opening balance, net of taxes			0	0
Adjusted balance, beginning of period			(560)	(617)
Impact of Tax Reform related to AOCI reclassification		(113)
Other comprehensive income (losses) before reclassifications		(111)	(88)	83
Increase (decrease) due to amounts reclassified from AOCI		86	145	209
Change, net of taxes		(138)	57	292
End-of-period balance, net of tax		(698)	(560)	(617)
Benefit plans
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(5,164)	(5,116)	(5,159)
Adjustment to opening balance, net of taxes			0	0
Adjusted balance, beginning of period			(5,164)	(5,116)
Impact of Tax Reform related to AOCI reclassification		(1,020)	0	0
Other comprehensive income (losses) before reclassifications		(158)	(208)	(143)
Increase (decrease) due to amounts reclassified from AOCI		159	160	186
Change, net of taxes		(1,019)	(48)	43
End-of-period balance, net of tax		(6,183)	(5,164)	(5,116)
Foreign currency translation adjustment
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(25,506)	(22,704)	(17,205)
Adjustment to opening balance, net of taxes			0	0
Adjusted balance, beginning of period			(25,506)	(22,704)
Impact of Tax Reform related to AOCI reclassification		(1,809)
Other comprehensive income (losses) before reclassifications		1,607	(2,802)	(5,465)
Increase (decrease) due to amounts reclassified from AOCI		0	0	(34)
Change, net of taxes		(202)	(2,802)	(5,499)
End-of-period balance, net of tax		(25,708)	(25,506)	(22,704)
Accumulated other comprehensive income (loss)
Change in accumulated other comprehensive income (loss)
Beginning-of-period balance, net of tax		(32,381)	(29,344)	(23,216)
Adjustment to opening balance, net of taxes	[1]		504	(15)
Adjusted balance, beginning of period			(31,877)	(29,359)	$ (23,216)
Increase (decrease) due to amounts reclassified from AOCI		(213)	(119)	92
Change, net of taxes	[2]	(2,791)	(3,022)	(6,128)
End-of-period balance, net of tax		$ (34,668)	$ (32,381)	$ (29,344)
[1]	See Note 1 to the Consolidated Financial Statements.
[2]	Includes the impact of ASU 2018-02, which transferred those amounts from AOCI to Retained earnings. See Notes 1 and 19 to the Consolidated Financial Statements.

CHANGES IN ACCUMULATED OTHER142

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Schedule of Pre-Tax and After-Tax (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2016	Dec. 31, 2014
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, Pretax		$ (42,035)	$ (38,440)	$ (31,060)
AOCI, Tax Effect		9,654	9,096	7,844
Balance, beginning of year		226,143	223,092
Adjustment to opening balance, Pretax			803	(26)
Adjusted balance, Pretax			(41,232)	(38,466)
Adjustment to opening balance, Tax Effect			(299)	11
Adjusted Balance, Tax Effect			9,355	9,107
OCI, Net of Tax [Abstract]
Pretax		4	(3,569)	(7,380)
Tax Effect		(509)	(547)	(1,252)
Change, net of taxes		(2,791)	(3,022)	(6,128)
Impact of Tax Reform related to AOCI reclassification		(3,304)
AOCI, Tax Effect		9,864	9,654	9,096
AOCI, Pretax		(41,228)	(42,035)	(38,440)
Balance, end of year		201,672	226,143	223,092
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(34,668)	(32,381)
Net unrealized gains (losses) on investment securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Adjustment to opening balance, net of taxes			504	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(295)	(907)
OCI, Net of Tax [Abstract]
Pretax		(1,088)	167	(1,462)
Tax Effect		(448)	59	(498)
Change, net of taxes		(863)	108	(964)
Impact of Tax Reform related to AOCI reclassification		(223)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(1,158)	(799)	(907)		$ 57
Debt valuation adjustment (DVA)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Adjustment to opening balance, net of taxes			0	(15)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(352)	(15)
OCI, Net of Tax [Abstract]
Pretax		(680)	(538)
Tax Effect		(250)	(201)
Change, net of taxes		(569)	(337)	0
Impact of Tax Reform related to AOCI reclassification		(139)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(921)	(352)	0		0
Cash flow hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Adjustment to opening balance, net of taxes			0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(560)	(617)
OCI, Net of Tax [Abstract]
Pretax		(37)	84	468
Tax Effect		(12)	27	176
Change, net of taxes		(138)	57	292
Impact of Tax Reform related to AOCI reclassification		(113)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(698)	(560)	(617)		(909)
Benefit plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning of year		(5,164)	(5,116)	(5,159)
Adjustment to opening balance, net of taxes			0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(5,164)	(5,116)
OCI, Net of Tax [Abstract]
Pretax		14	(78)	19
Tax Effect		13	(30)	(24)
Change, net of taxes		(1,019)	(48)	43
Impact of Tax Reform related to AOCI reclassification		(1,020)	0	0
Balance, end of year		(6,183)	(5,164)	(5,116)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(6,183)	(5,164)	(5,116)		(5,159)
Foreign currency translation adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Adjustment to opening balance, net of taxes			0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(25,506)	(22,704)
OCI, Net of Tax [Abstract]
Pretax		1,795	(3,204)	(6,405)
Tax Effect		188	(402)	(906)
Change, net of taxes		(202)	(2,802)	(5,499)
Impact of Tax Reform related to AOCI reclassification		(1,809)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(25,708)	(25,506)	(22,704)		(17,205)
Accumulated other comprehensive income (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning of year		(32,381)	(29,344)	(23,216)
Adjustment to opening balance, net of taxes	[1]		504	(15)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance			(31,877)	(29,359)		(23,216)
OCI, Net of Tax [Abstract]
Change, net of taxes	[2]	(2,791)	(3,022)	(6,128)
Balance, end of year		(34,668)	(32,381)	(29,344)
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI		(34,668)	$ (32,381)	$ (29,344)		$ (23,216)
Accounting Standards Update 2018-02
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Adjustment to opening balance, net of taxes		(3,304)
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		(3,304)
Accounting Standards Update 2018-02 | Net unrealized gains (losses) on investment securities
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		(223)
Accounting Standards Update 2018-02 | Debt valuation adjustment (DVA)
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		(139)
Accounting Standards Update 2018-02 | Cash flow hedges
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		(113)
Accounting Standards Update 2018-02 | Benefit plans
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		(1,020)
Accounting Standards Update 2018-02 | Foreign currency translation adjustment
OCI, Net of Tax [Abstract]
Impact of Tax Reform related to AOCI reclassification		$ (1,809)
Accounting Standards Update 2016-01
Change in accumulated other comprehensive income (loss)
Increase (decrease) to AOCI					$ (15)
[1]	See Note 1 to the Consolidated Financial Statements.
[2]	Includes the impact of ASU 2018-02, which transferred those amounts from AOCI to Retained earnings. See Notes 1 and 19 to the Consolidated Financial Statements.

CHANGES IN ACCUMULATED OTHER143

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Reclassification out of AOCI (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments	[1]									$ (778)	$ (948)	$ (682)
Income from continuing operations before income taxes		$ (5,099)	$ (6,003)	$ (5,678)	$ (5,981)	$ (5,100)	$ (5,620)	$ (5,770)	$ (4,987)
Tax effect		23,864	1,866	1,795	1,863	1,509	1,733	1,723	1,479	29,388	6,444	7,440
Income from continuing operations		$ 18,765	$ (4,137)	$ (3,883)	$ (4,118)	$ (3,591)	$ (3,887)	$ (4,047)	$ (3,508)	6,627	(15,033)	(17,386)
Reclassification from AOCI, after-tax										(213)	(119)	92
Realized gains (losses) on investment securities
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, after-tax										(454)	(422)	(269)
Debt valuation adjustment (DVA)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, after-tax										(4)	(2)	0
Cash flow hedges
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, after-tax										86	145	209
Prior service cost (benefit)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, before tax										(42)	(40)	(40)
Net actuarial loss
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, before tax										271	272	276
Curtailment/settlement impact
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, before tax										17	18	57
Benefit plans
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, before tax										246	250	293
Tax effect										(87)	(90)	(107)
Reclassification from AOCI, after-tax										159	160	186
Foreign currency translation adjustment
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, after-tax										0	0	(34)
Accumulated other comprehensive income (loss)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Reclassification from AOCI, before tax										(340)	(180)	155
Tax effect										127	61	(63)
Reclassification from AOCI, after-tax										(213)	(119)	92
(Gain) loss reclassified from AOCI | Realized gains (losses) on investment securities
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments										(778)	(948)	(682)
OTTI gross impairment losses										63	288	265
Income from continuing operations before income taxes										(715)	(660)	(417)
Tax effect										261	238	148
Income from continuing operations										(454)	(422)	(269)
(Gain) loss reclassified from AOCI | Debt valuation adjustment (DVA)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments										(7)	(3)	0
Income from continuing operations before income taxes										(7)	(3)	0
Tax effect										3	1	0
Income from continuing operations										(4)	(2)	0
(Gain) loss reclassified from AOCI | Cash flow hedges
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes										136	233	332
Tax effect										(50)	(88)	(123)
Income from continuing operations										86	145	209
(Gain) loss reclassified from AOCI | Cash flow hedges | Interest rate
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes										126	140	186
(Gain) loss reclassified from AOCI | Cash flow hedges | Foreign exchange contracts
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes										10	93	146
(Gain) loss reclassified from AOCI | Foreign currency translation adjustment
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes										0	0	(53)
Tax effect										0	0	19
Income from continuing operations										$ 0	$ 0	$ (34)
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.

PREFERRED STOCK (Details)

PREFERRED STOCK (Details) $ / shares in Units, $ in Millions	Apr. 25, 2016	Feb. 02, 2016	Nov. 13, 2015	Aug. 12, 2015	Apr. 24, 2015	Mar. 20, 2015	Oct. 29, 2014	Apr. 30, 2014	Feb. 12, 2014	Oct. 31, 2013	Sep. 19, 2013	Apr. 30, 2013	Mar. 26, 2013	Dec. 13, 2012	Oct. 29, 2012	Apr. 28, 2008	Jan. 25, 2008	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)	Dec. 31, 2015$ / sharesshares
Preferred stock
Carrying value																			$ 19,253	$ 19,253
Distribution of preferred dividends																			$ 1,213
Forecast
Preferred stock
Distribution of preferred dividends																		$ 1,179
Series AA
Preferred stock
Dividend rate (as a percent)																			8.125%	8.125%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			3,870,330		3,870,330
Carrying value																			$ 97	$ 97
Depositary shares, interest in corresponding series of preferred stock																	0.001
Series E
Preferred stock
Dividend rate (as a percent)																			8.40%	8.40%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			121,254		121,254
Carrying value																			$ 121	$ 121
Depositary shares, interest in corresponding series of preferred stock																0.04
Series A
Preferred stock
Dividend rate (as a percent)																			5.95%	5.95%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,500,000		1,500,000
Carrying value																			$ 1,500	$ 1,500
Depositary shares, interest in corresponding series of preferred stock															0.04
Series B
Preferred stock
Dividend rate (as a percent)																			5.90%	5.90%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			750,000		750,000
Carrying value																			$ 750	$ 750
Depositary shares, interest in corresponding series of preferred stock														0.04
Series C
Preferred stock
Dividend rate (as a percent)																			5.80%	5.80%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			23,000,000		23,000,000
Carrying value																			$ 575	$ 575
Depositary shares, interest in corresponding series of preferred stock													0.001
Series D
Preferred stock
Dividend rate (as a percent)																			5.35%	5.35%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,250,000		1,250,000
Carrying value																			$ 1,250	$ 1,250
Depositary shares, interest in corresponding series of preferred stock												0.04
Series J
Preferred stock
Dividend rate (as a percent)																			7.125%	7.125%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			38,000,000		38,000,000
Carrying value																			$ 950	$ 950
Depositary shares, interest in corresponding series of preferred stock											0.001
Series K
Preferred stock
Dividend rate (as a percent)																			6.875%	6.875%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			59,800,000		59,800,000
Carrying value																			$ 1,495	$ 1,495
Depositary shares, interest in corresponding series of preferred stock										0.001
Series L
Preferred stock
Dividend rate (as a percent)																			6.875%	6.875%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			19,200,000		19,200,000
Carrying value																			$ 480	$ 480
Depositary shares, interest in corresponding series of preferred stock									0.001
Series M
Preferred stock
Dividend rate (as a percent)																			6.30%	6.30%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,750,000		1,750,000
Carrying value																			$ 1,750	$ 1,750
Depositary shares, interest in corresponding series of preferred stock								0.04
Series N
Preferred stock
Dividend rate (as a percent)																			5.80%	5.80%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,500,000		1,500,000
Carrying value																			$ 1,500	$ 1,500
Depositary shares, interest in corresponding series of preferred stock							0.04
Series O
Preferred stock
Dividend rate (as a percent)																			5.875%	5.875%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,500,000		1,500,000
Carrying value																			$ 1,500	$ 1,500
Depositary shares, interest in corresponding series of preferred stock						0.04
Series P
Preferred stock
Dividend rate (as a percent)																			5.95%	5.95%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			2,000,000		2,000,000
Carrying value																			$ 2,000	$ 2,000
Depositary shares, interest in corresponding series of preferred stock					0.04
Series Q
Preferred stock
Dividend rate (as a percent)																			5.95%	5.95%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,250,000		1,250,000
Carrying value																			$ 1,250	$ 1,250
Depositary shares, interest in corresponding series of preferred stock				0.04
Series R
Preferred stock
Dividend rate (as a percent)																			6.125%	6.125%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,500,000		1,500,000
Carrying value																			$ 1,500	$ 1,500
Depositary shares, interest in corresponding series of preferred stock			0.04
Series S
Preferred stock
Dividend rate (as a percent)																			6.30%	6.30%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 25		$ 25
Number of depositary shares (in shares) | shares																			41,400,000		41,400,000
Carrying value																			$ 1,035	$ 1,035
Depositary shares, interest in corresponding series of preferred stock		0.001
Series T
Preferred stock
Dividend rate (as a percent)																			6.25%	6.25%
Redemption price per depositary share/ preference share (in dollars per share) | $ / shares																			$ 1,000		$ 1,000
Number of depositary shares (in shares) | shares																			1,500,000		1,500,000
Carrying value																			$ 1,500	$ 1,500
Depositary shares, interest in corresponding series of preferred stock	0.04

SECURITIZATIONS AND VARIABLE145

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Schedule of Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity
Total involvement with SPE assets	$ 319,569	$ 401,822
Consolidated VIE / SPE assets	76,394	76,291
Significant unconsolidated VIE assets	243,175	325,531
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	31,331	28,523
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	4,239	4,219
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	11,304	10,422
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	140	190
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	47,014	43,354
Credit card securitizations
Variable Interest Entity
Total involvement with SPE assets	50,795	50,171
Consolidated VIE / SPE assets	50,795	50,171
Significant unconsolidated VIE assets	0	0
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	0
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	0	0
Mortgage securitizations - U.S. agency-sponsored
Variable Interest Entity
Total involvement with SPE assets	116,610	214,458
Consolidated VIE / SPE assets	0	0
Significant unconsolidated VIE assets	116,610	214,458
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	2,647	3,852
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	74	78
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	2,721	3,930
Mortgage securitizations - Non-agency-sponsored
Variable Interest Entity
Total involvement with SPE assets	22,251	15,965
Consolidated VIE / SPE assets	2,035	1,092
Significant unconsolidated VIE assets	20,216	14,873
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	330	312
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	35
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	1	1
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	331	348
Citi-administered asset-backed commercial paper conduits (ABCP)
Variable Interest Entity
Total involvement with SPE assets	19,282	19,693
Consolidated VIE / SPE assets	19,282	19,693
Significant unconsolidated VIE assets	0	0
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	0
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	0	0
Collateralized loan obligations (CLOs)
Variable Interest Entity
Total involvement with SPE assets	20,588	18,886
Consolidated VIE / SPE assets	0	0
Significant unconsolidated VIE assets	20,588	18,886
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	5,956	5,128
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	9	62
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	5,965	5,190
Asset-based financing
Variable Interest Entity
Total involvement with SPE assets	60,472	53,168
Consolidated VIE / SPE assets	633	733
Significant unconsolidated VIE assets	59,839	52,435
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	19,478	16,553
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	583	475
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	5,878	4,915
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	0
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	25,939	21,943
Municipal securities tender option bond trusts (TOBs)
Variable Interest Entity
Total involvement with SPE assets	6,925	7,070
Consolidated VIE / SPE assets	2,166	2,843
Significant unconsolidated VIE assets	4,759	4,227
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	138	40
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	3,035	2,842
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	0
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	3,173	2,882
Municipal investments
Variable Interest Entity
Total involvement with SPE assets	19,119	17,679
Consolidated VIE / SPE assets	7	14
Significant unconsolidated VIE assets	19,112	17,665
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	2,709	2,441
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	3,640	3,578
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	2,344	2,580
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	0
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	8,693	8,599
Client intermediation
Variable Interest Entity
Total involvement with SPE assets	958	515
Consolidated VIE / SPE assets	824	371
Significant unconsolidated VIE assets	134	144
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	32	49
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	0	0
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	9	3
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	41	52
Investment funds
Variable Interest Entity
Total involvement with SPE assets	1,892	2,788
Consolidated VIE / SPE assets	616	767
Significant unconsolidated VIE assets	1,276	2,021
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	14	32
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	7	120
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	13	27
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	0	3
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	34	182
Other
Variable Interest Entity
Total involvement with SPE assets	677	1,429
Consolidated VIE / SPE assets	36	607
Significant unconsolidated VIE assets	641	822
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	27	116
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	9	11
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	34	58
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	47	43
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	117	228
Mortgage-backed securities
Funded and Unfunded Exposure
Outstanding balance of mortgage loans securitized	$ 9,000	$ 10,000

SECURITIZATIONS AND VARIABLE146

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding Commitments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 11,304	$ 10,422
Liquidity facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,035	2,847
Liquidity facilities Citigroup | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	5
Liquidity facilities Citigroup | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,035	2,842
Liquidity facilities Citigroup | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities Citigroup | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities Citigroup | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	8,269	7,575
Loan / equity commitments Citigroup | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	5,878	4,910
Loan / equity commitments Citigroup | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments Citigroup | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	2,344	2,580
Loan / equity commitments Citigroup | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	13	27
Loan / equity commitments Citigroup | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 34	$ 58

SECURITIZATIONS AND VARIABLE147

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Carrying Amounts and Classifications of Consolidated Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity
Cash and due from banks	$ 23,775	$ 23,043	$ 20,900	$ 32,108
Trading account assets	251,556	243,925
Investments	352,290	353,304
Total loans, net of allowance	654,679	612,309
Other assets	105,160	128,008
Total assets	1,842,465	1,792,077
Significant unconsolidated VIE assets
Variable Interest Entity
Cash and due from banks	0	100
Trading account assets	8,500	8,000
Investments	4,400	4,400
Total loans, net of allowance	22,200	18,800
Other assets	500	1,500
Total assets	$ 35,600	$ 32,800

SECURITIZATIONS AND VARIABLE148

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Credit Card Securitizations (Details)	12 Months Ended
	Dec. 31, 2017USD ($)trust	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Securitized credit card receivables
Number of trusts to hold securitized credit card receivables | trust	2
Ownership interests in principal amount of trust credit card receivables
Sold to investors via trust-issued securities	$ 28,800,000,000	$ 22,700,000,000
Retained by Citigroup as trust-issued securities	7,600,000,000	7,400,000,000
Retained by Citigroup via non-certificated interests	14,400,000,000	20,600,000,000
Total ownership interests in principal amount of trust credit card receivables	50,800,000,000	50,700,000,000
Credit card securitizations
Securitized credit card receivables
Gains (losses) recognized on the securitization	0
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	11,100,000,000	3,300,000,000	$ 0
Pay down of maturing notes	$ (5,000,000,000)	$ (10,300,000,000)	$ (7,400,000,000)

SECURITIZATIONS AND VARIABLE149

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding, Liquidity Facilities and Subordinated Interests (Details) $ in Billions	12 Months Ended
	Dec. 31, 2017USD ($)trust	Dec. 31, 2016USD ($)
Funding, Liquidity Facilities and Subordinated Interests
Number of trusts to hold securitized credit card receivables | trust	2
Citibank Credit Card Master Trust (Master Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	2 years 6 months 25 days	2 years 6 months 25 days
Term notes issued to third parties	$ 27.8	$ 21.7
Term notes retained by Citigroup affiliates	5.7	5.5
Total Trust liabilities	$ 33.5	$ 27.2
Citibank OMNI Master Trust (Omni Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	1 year 11 months	1 year 11 months
Term notes issued to third parties	$ 1	$ 1
Term notes retained by Citigroup affiliates	1.9	1.9
Total Trust liabilities	$ 2.9	$ 2.9

SECURITIZATIONS AND VARIABLE150

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Mortgage Securitizations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. government-sponsored agency guaranteed
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	$ 33,900	$ 41,300	$ 35,000
Contractual servicing fees received	200	400	500
Cash flows received on retained interests and other net cash flows	0	100	100
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	1,634	2,258
Carrying value of retained interests, impact of 10% adverse change in discount rate	(44)	(71)
Carrying value of retained interests, impact of 20% adverse change in discount rate	(85)	(138)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	(41)	(80)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	$ (84)	$ (160)
U.S. government-sponsored agency guaranteed | Low end of range
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	1.80%	0.80%
Constant prepayment rate	3.80%	3.80%
Weighted average life	2 years 6 months	6 months
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	1.80%	0.70%
Constant prepayment rate	6.90%	6.80%
Weighted average life	1 month 6 days	2 months 12 days
U.S. government-sponsored agency guaranteed | High end of range
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	19.90%	13.70%
Constant prepayment rate	31.60%	30.90%
Weighted average life	20 years 8 months 12 days	17 years 6 months
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	84.20%	28.20%
Constant prepayment rate	27.80%	22.80%
Weighted average life	27 years 9 months 18 days	28 years 9 months 18 days
U.S. government-sponsored agency guaranteed | Weighted Average
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	8.60%	9.90%
Constant prepayment rate	9.40%	11.10%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	7.10%	9.00%
Constant prepayment rate	11.60%	10.20%
Mortgage securitizations - Non-agency-sponsored
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	$ 7,900	$ 11,800	12,100
Contractual servicing fees received	0	0	0
Cash flows received on retained interests and other net cash flows	$ 0	$ 0	0
Senior interests
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	0.00%	0.00%
Constant prepayment rate	0.00%	0.00%
Anticipated net credit losses	0.00%	0.00%
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	$ 214	$ 26
Carrying value of retained interests, impact of 10% adverse change in discount rate	(2)	(7)
Carrying value of retained interests, impact of 20% adverse change in discount rate	(4)	(14)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	(1)	(2)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	(1)	(3)
Carrying value of retained interests, impact of 10% adverse change in anticipated net credit losses	(3)	(7)
Carrying value of retained interests, impact of 20% adverse change in anticipated net credit losses	$ (7)	$ (14)
Senior interests | Low end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	5.80%	0.00%
Constant prepayment rate	8.90%	4.20%
Anticipated net credit losses	0.40%	0.50%
Weighted average life	4 years 9 months 18 days	5 years
Senior interests | High end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	100.00%	8.10%
Constant prepayment rate	15.50%	14.70%
Anticipated net credit losses	46.90%	85.60%
Weighted average life	5 years 3 months 18 days	8 years 6 months
Senior interests | Weighted Average
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	0.00%	0.00%
Constant prepayment rate	0.00%	0.00%
Anticipated net credit losses	0.00%	0.00%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	5.80%	2.10%
Constant prepayment rate	8.90%	11.00%
Anticipated net credit losses	46.90%	31.40%
Subordinated interests
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	0.00%	0.00%
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	$ 139	$ 161
Carrying value of retained interests, impact of 10% adverse change in discount rate	(3)	(8)
Carrying value of retained interests, impact of 20% adverse change in discount rate	(5)	(16)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	(1)	(4)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	(2)	(8)
Carrying value of retained interests, impact of 10% adverse change in anticipated net credit losses	0	(1)
Carrying value of retained interests, impact of 20% adverse change in anticipated net credit losses	$ 0	$ (2)
Subordinated interests | Low end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	2.80%	5.10%
Constant prepayment rate	8.60%	0.50%
Anticipated net credit losses	35.10%	0.80%
Weighted average life	2 months 12 days	1 year 2 months 12 days
Subordinated interests | High end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	35.10%	26.40%
Constant prepayment rate	13.10%	37.50%
Anticipated net credit losses	52.10%	63.70%
Weighted average life	18 years 7 months 6 days	12 years 1 month 6 days
Subordinated interests | Weighted Average
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate	0.00%	0.00%
Constant prepayment rate	0.00%	0.00%
Anticipated net credit losses	0.00%	0.00%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate	9.00%	13.10%
Constant prepayment rate	10.60%	10.80%
Anticipated net credit losses	44.90%	48.30%
Personal loan
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations		$ 500	700
Citicorp | U.S. government-sponsored agency guaranteed
Cash Flows Between Transferor and Transferee
Gains recognized on the securitization	$ 73	105	149
Citicorp | Mortgage securitizations - Non-agency-sponsored
Cash Flows Between Transferor and Transferee
Gains recognized on the securitization	$ 77	$ 107	$ 41

SECURITIZATIONS AND VARIABLE151

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Capitalized MSRs
Balance at beginning of period	$ 1,564
Balance at end of period	558	$ 1,564
Mortgage servicing rights
Classification of Securitizations
Fair value of capitalized mortgage servicing rights	558	1,600
Principal amount of loans and other financial instruments	66,000	168,000
Capitalized MSRs
Balance at beginning of period	1,564	1,781
Originations	96	152
Changes in fair value of MSRs due to changes in inputs and assumptions	65	(36)
Other changes	(110)	(313)
Sale of MSRs	(1,057)	(20)
Balance at end of period	558	1,564	$ 1,781
MSR fees
Servicing fees	276	484	552
Late fees	10	14	16
Ancillary fees	13	17	31
Total MSR fees	299	515	$ 599
Mortgage securitizations - Non-agency-sponsored
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	79	126
Original par value of re-securitizations deals in which the entity holds a retained interest	887	1,300
U.S. government-sponsored agency guaranteed
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	2,100	2,300
Securities transferred to re-securitization entities	26,600	26,500
Market value of retained interest related to re-securitization transaction	854	741
Original fair value of re-securitizations deals in which the entity holds a retained interest	$ 68,300	$ 71,800

SECURITIZATIONS AND VARIABLE152

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset-Backed Commercial Paper Conduits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Classification of Other Securitization Details
Commercial paper	$ 9,940,000,000	$ 9,989,000,000
Citi-administered asset-backed commercial paper conduits (ABCP)
Classification of Other Securitization Details
Purchased assets outstanding under conduits	19,300,000,000	19,700,000,000
Incremental funding commitments with clients	$ 14,500,000,000	$ 12,800,000,000
Weighted average life of commercial paper issued by conduits	51 days	55 days
Citi-administered asset-backed commercial paper conduits (ABCP) | Minimum
Classification of Other Securitization Details
Letters of credit as percentage of conduit assets	8.00%
Floor price of conduit's assets	$ 200,000,000
Citi-administered asset-backed commercial paper conduits (ABCP) | Maximum
Classification of Other Securitization Details
Letters of credit as percentage of conduit assets	10.00%
Citi-administered asset-backed consolidated commercial paper conduits (ABCP)
Classification of Other Securitization Details
Letters of credit provided to conduits	$ 1,700,000,000	$ 1,800,000,000
Commercial paper	$ 9,300,000,000	$ 9,700,000,000

SECURITIZATIONS AND VARIABLE153

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Collateralized Debt and Loan Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity
Term of collateralized loan obligation	12 years
Collateralized loan obligations (CLOs)
Variable Interest Entity
Proceeds from new securitizations	$ 3,500	$ 5,000	$ 5,900
Cash flows received on retained interests and other net cash flows	100	0	$ 0
Carrying value of retained interests	3,607	4,261
Carrying value of retained interests, impact of 10% adverse change in discount rate	(24)	(30)
Carrying value of retained interests, impact of 20% adverse change in discount rate	$ (47)	$ (62)
Minimum | Collateralized loan obligations (CLOs)
Variable Interest Entity
Discount rate	1.10%	1.30%
Maximum | Collateralized loan obligations (CLOs)
Variable Interest Entity
Discount rate	1.60%	1.70%

SECURITIZATIONS AND VARIABLE154

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset Based Financing (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity
Total unconsolidated VIE assets	$ 243,175	$ 325,531
Maximum exposure to unconsolidated VIEs	47,014	43,354
Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	59,839	52,435
Maximum exposure to unconsolidated VIEs	25,939	21,943
Commercial and other real estate | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	15,370	8,784
Maximum exposure to unconsolidated VIEs	5,445	2,368
Corporate loans | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	4,725	4,051
Maximum exposure to unconsolidated VIEs	3,587	2,684
Hedge funds and equities | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	542	370
Maximum exposure to unconsolidated VIEs	58	54
Airplanes, ships and other assets | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	39,202	39,230
Maximum exposure to unconsolidated VIEs	$ 16,849	$ 16,837

SECURITIZATIONS AND VARIABLE155

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Municipal Securities Tender Option Bond Trusts (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)trust	Dec. 31, 2016USD ($)
Variable Interest Entity
Number of TOB trusts | trust	2
Municipal securities tender option bond trusts (TOBs)
Variable Interest Entity
Municipal bonds owned by trusts, that have credit guarantee provided by the Company	$ 62	$ 82
Liquidity agreements, customer TOB trust	3,200	2,900
Notional amount of offsetting reimbursement agreements	2,000	2,100
Liquidity agreements, other trusts	$ 6,100	7,400
Maximum | Municipal securities tender option bond trusts (TOBs)
Variable Interest Entity
The threshold ownership percentage on Residual value of customers TOBs for which the reimbursement agreement applied	25.00%
Client intermediation
Variable Interest Entity
Proceeds from new securitizations	$ 1,100	$ 2,300

DERIVATIVES ACTIVITIES - Deriva

DERIVATIVES ACTIVITIES - Derivative Notionals (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Net Investment Hedging
Derivatives
Derivative notionals	$ 63	$ 1,825
Hedging instruments under ASC 815
Derivatives
Derivative notionals	270,445	227,616
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	189,779	151,428
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	189,779	151,331
Hedging instruments under ASC 815 | Interest rate futures and forwards
Derivatives
Derivative notionals	0	97
Hedging instruments under ASC 815 | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Interest rate contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contracts
Derivatives
Derivative notionals	80,643	76,006
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	37,162	19,042
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	33,103	56,964
Hedging instruments under ASC 815 | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	3,951	0
Hedging instruments under ASC 815 | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	6,427	0
Hedging instruments under ASC 815 | Equity contracts
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts
Derivatives
Derivative notionals	23	182
Hedging instruments under ASC 815 | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other futures and forwards
Derivatives
Derivative notionals	23	182
Hedging instruments under ASC 815 | Commodity and other contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Trading derivatives
Derivatives
Derivative notionals	45,671,920	45,753,242
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	31,910,784	31,699,124
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	18,718,224	19,145,250
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	6,447,886	6,864,276
Other derivative instruments, Trading derivatives | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	3,513,759	2,921,070
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,230,915	2,768,528
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	10,895,006	11,153,563
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	5,538,231	5,492,145
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	3,080,361	3,251,132
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	1,127,728	1,194,325
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,148,686	1,215,961
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,006,565	800,572
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	215,834	192,366
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	72,616	37,557
Other derivative instruments, Trading derivatives | Equity contract options | Written or Sold
Derivatives
Derivative notionals	389,961	304,579
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	328,154	266,070
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	357,858	357,560
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	82,039	70,774
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	153,248	142,530
Other derivative instruments, Trading derivatives | Commodity and other contract options | Written or Sold
Derivatives
Derivative notionals	62,045	74,627
Other derivative instruments, Trading derivatives | Commodity and other contract options | Purchased
Derivatives
Derivative notionals	60,526	69,629
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,501,707	1,742,423
Other derivative instruments, Trading derivatives | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	735,142	859,420
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	766,565	883,003
Other derivative instruments, Management hedges
Derivatives
Derivative notionals	120,743	135,802
Other derivative instruments, Management hedges | Interest rate contracts
Derivatives
Derivative notionals	54,130	90,237
Other derivative instruments, Management hedges | Interest rate swaps
Derivatives
Derivative notionals	35,995	47,324
Other derivative instruments, Management hedges | Interest rate futures and forwards
Derivatives
Derivative notionals	12,653	30,834
Other derivative instruments, Management hedges | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	2,372	4,759
Other derivative instruments, Management hedges | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,110	7,320
Other derivative instruments, Management hedges | Foreign exchange contracts
Derivatives
Derivative notionals	55,465	26,095
Other derivative instruments, Management hedges | Foreign exchange swaps
Derivatives
Derivative notionals	38,126	22,676
Other derivative instruments, Management hedges | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	17,339	3,419
Other derivative instruments, Management hedges | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contracts
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity swaps
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contracts
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other futures and forwards
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contract options | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Credit derivatives
Derivatives
Derivative notionals	11,148	19,470
Other derivative instruments, Management hedges | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 11,148	$ 19,470

DERIVATIVES ACTIVITIES - Der157

DERIVATIVES ACTIVITIES - Derivative Mark-to-Market (MTM) Receivables/Payables (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative Mark-to-Market (MTM) Receivables/Payables
Netting of cash collateral received	$ (37,506)	$ (45,912)
Netting of cash collateral paid	(35,659)	(49,811)
Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Cash collateral received, gross	7	61
Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	386,301	617,477
Cash collateral paid, net of amount used to offset derivative liabilities	7,541	11,188
Less: Netting agreements to assets	(306,401)	(519,000)
Netting of cash collateral received	(37,506)	(45,912)
Total trading account derivatives, assets	49,935	63,753
Cash collateral received	(872)	(819)
Non-cash collateral received	(12,453)	(11,767)
Total Net receivables	36,610	51,167
Cash collateral paid, gross	43,200	60,999
Does not meet applicable offsetting guidance, assets	6,000	7,000
Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(283,000)	(383,000)
Less: Netting agreements to liabilities		(383,000)
Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(14,000)	(128,000)
Less: Netting agreements to liabilities		(128,000)
Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(9,000)	(8,000)
Less: Netting agreements to liabilities		(8,000)
Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	374,226	609,507
Cash collateral received, net of amount used to offset derivative assets	14,296	15,731
Less: Netting agreements to liabilities	(306,401)	(519,000)
Netting of cash collateral paid	(35,659)	(49,811)
Total derivative liabilities	46,462	56,427
Cash collateral paid	(121)	(19)
Non-cash collateral paid	(6,929)	(5,883)
Total Net payables	39,412	50,525
Cash collateral received, gross	51,801	61,643
Does not meet applicable offsetting guidance, liabilities	8,000	9,000
Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(283,000)
Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(14,000)
Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(9,000)
Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	2,260	3,392
Cash collateral paid, net of amount used to offset derivative liabilities	0	8
Less: Netting agreements to assets	0	0
Netting of cash collateral received	(1,026)	(1,345)
Total trading account derivatives, assets	1,234	2,055
Cash collateral received	0	0
Non-cash collateral received	(286)	(530)
Total Net receivables	948	1,525
Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,118	1,551
Cash collateral received, net of amount used to offset derivative assets	12	1
Less: Netting agreements to liabilities	0	0
Netting of cash collateral received	(7)	(53)
Netting of cash collateral paid	(7)	(53)
Total derivative liabilities	1,123	1,499
Cash collateral paid	0	0
Non-cash collateral paid	0	0
Total Net payables	1,123	1,499
Cash collateral received, gross	1,038	1,346
Derivatives instruments designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,600	6,740
Derivatives instruments designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,209	2,718
Derivatives instruments designated as ASC 815 hedges | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,622	2,721
Derivatives instruments designated as ASC 815 hedges | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	167	749
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	715	4,246
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	644	716
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	71	3,530
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	145	2,325
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	121	171
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	24	2,154
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,364	1,974
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,325	1,927
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	39	47
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	81	104
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	13	22
Derivatives instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	68	82
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	885	2,494
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	885	2,494
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,064	393
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,064	393
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	258	747
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	258	747
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	86	645
Derivatives instruments designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	86	645
Derivatives not designated in a qualifying hedging relationship | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	384,701	610,737
Derivatives not designated in a qualifying hedging relationship | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	373,017	606,789
Derivatives not designated in a qualifying hedging relationship | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	638	671
Derivatives not designated in a qualifying hedging relationship | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	951	802
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	202,801	365,079
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	195,648	244,072
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	7,051	120,920
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	102	87
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	184,284	352,436
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	173,921	221,534
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	10,268	130,855
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	95	47
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	107	465
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	29	225
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	78	240
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	129	354
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	16	5
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	113	349
Derivatives not designated in a qualifying hedging relationship | Interest rate contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	120,335	183,168
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	118,611	182,659
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,690	482
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	34	27
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	119,111	187,368
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	116,962	186,867
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	2,028	470
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	121	31
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	481	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	481	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	511	60
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	511	60
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Foreign exchange contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	26,978	24,110
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	17,221	15,625
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	21	1
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	9,736	8,484
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	31,373	26,516
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	21,201	19,119
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	25	21
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	10,147	7,376
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Equity contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	14,103	13,765
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	13,499	13,046
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	604	719
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	17,027	15,032
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	16,362	14,234
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	665	798
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Commodity and other contract options | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	20,484	24,615
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	12,954	19,033
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	7,530	5,582
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	21,222	25,437
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	12,895	19,563
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	8,327	5,874
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	50	206
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	18	159
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	32	47
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	311	388
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	63	78
Derivatives not designated in a qualifying hedging relationship | Credit derivatives | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	248	$ 310
Rule Changes Adopted by Clearing Organizations
Derivative Mark-to-Market (MTM) Receivables/Payables
Reduction in derivative assets	100,000
Reduction in derivative liabilities	$ 100,000

DERIVATIVES ACTIVITIES - Gains

DERIVATIVES ACTIVITIES - Gains (Losses) Included in Other Revenue (Details) - Other revenue - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative gain (losses)
Gains (losses) included in Other revenue	$ (304)	$ (1,078)	$ 554
Interest rate contracts
Derivative gain (losses)
Gains (losses) included in Other revenue	(54)	(81)	117
Foreign exchange contracts
Derivative gain (losses)
Gains (losses) included in Other revenue	244	12	(39)
Credit derivatives
Derivative gain (losses)
Gains (losses) included in Other revenue	$ (494)	$ (1,009)	$ 476

DERIVATIVES ACTIVITIES - Fair V

DERIVATIVES ACTIVITIES - Fair Value Hedges (Details) - Other revenue - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	$ (1,732)	$ (1,986)	$ 509
Gain (loss) on the hedged item in designated and qualifying fair value hedges	1,840	2,031	(501)
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges	18	(80)	(70)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	90	125	78
Interest rate contracts
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	(891)	(753)	(847)
Gain (loss) on the hedged item in designated and qualifying fair value hedges	853	668	792
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges	(31)	(84)	(47)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	(7)	(1)	(8)
Foreign exchange contracts
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	(824)	(1,415)	1,315
Gain (loss) on the hedged item in designated and qualifying fair value hedges	969	1,573	(1,258)
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges	49	4	(23)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	96	154	80
Commodity and other contract options
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	(17)	182	41
Gain (loss) on the hedged item in designated and qualifying fair value hedges	18	(210)	(35)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	$ 1	$ (28)	$ 6

DERIVATIVES ACTIVITIES - Cash F

DERIVATIVES ACTIVITIES - Cash Flow Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pretax change in accumulated other comprehensive income (loss)
Cash flow hedges expected to be reclassified within 12 months	$ 400
Maximum length of time hedged in cash flow hedge	10 years
Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	$ (173)	$ (150)	$ 137
Effective portion of cash flow hedges reclassified from AOCI to earnings	(136)	(233)	(332)
Interest rate contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	(165)	(219)	357
Effective portion of cash flow hedges reclassified from AOCI to earnings	(126)	(140)	(186)
Foreign exchange contracts | Cash Flow Hedging
Pretax change in accumulated other comprehensive income (loss)
Effective portion of cash flow hedges included in AOCI	(8)	69	(220)
Effective portion of cash flow hedges reclassified from AOCI to earnings	$ (10)	$ (93)	$ (146)

DERIVATIVES ACTIVITIES - Net In

DERIVATIVES ACTIVITIES - Net Investment Hedges (Details) - Net Investment Hedging - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative gain (losses)
Net investment hedge ineffectiveness recorded in earnings	$ 0
Gain (loss) recognized in OCI, effective portion, net	$ 2,528,000,000	$ (220,000,000)	$ 2,475,000,000

DERIVATIVES ACTIVITIES - Credit

DERIVATIVES ACTIVITIES - Credit Derivatives (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)counterpartyagency	Dec. 31, 2016USD ($)
Credit Derivative
Percentage of receivables from counterparties with collateral agreements	98.00%	98.00%
Number of top counterparties which are banks, financial institutions, and other dealers | counterparty	15
Fair value, Receivable	$ 20,534	$ 24,821
Fair Value, Payable	21,533	25,825
Notionals, Protection purchased	777,713	902,473
Notionals, Protection sold	735,142	859,420
Fair value of derivative in liability position	29,000	26,000
Fair value of collateral already posted	$ 28,000	26,000
Number of rating agencies | agency	3
Additional collateral to be posted	$ 900
Collateral to be segregated	300
Aggregate cash obligations and collateral requirements	1,200
Purchased
Credit Derivative
Fair value, Receivable	3,195	9,077
Fair Value, Payable	3,147	17,110
Sold
Credit Derivative
Fair value, Receivable	17,339	15,744
Fair Value, Payable	18,386	8,715
Within 1 year
Credit Derivative
Fair value, Receivable	2,477	4,113
Fair Value, Payable	2,914	4,841
Notionals, Protection purchased	231,878	293,059
Notionals, Protection sold	218,097	287,262
From 1 to 5 years
Credit Derivative
Fair value, Receivable	16,098	17,735
Fair Value, Payable	16,435	17,986
Notionals, Protection purchased	498,606	551,155
Notionals, Protection sold	476,345	523,371
After 5 years
Credit Derivative
Fair value, Receivable	1,959	2,973
Fair Value, Payable	2,184	2,998
Notionals, Protection purchased	47,229	58,259
Notionals, Protection sold	40,700	48,787
Investment Grade
Credit Derivative
Fair value, Receivable	10,473	9,605
Fair Value, Payable	10,616	9,995
Notionals, Protection purchased	588,324	675,138
Notionals, Protection sold	557,987	648,247
Non-Investment Grade
Credit Derivative
Fair value, Receivable	10,061	15,216
Fair Value, Payable	10,917	15,830
Notionals, Protection purchased	189,389	227,335
Notionals, Protection sold	177,155	211,173
Credit default swaps and options
Credit Derivative
Fair value, Receivable	20,251	24,502
Fair Value, Payable	20,554	24,631
Notionals, Protection purchased	754,114	883,719
Notionals, Protection sold	724,228	852,900
Total return swaps and other
Credit Derivative
Fair value, Receivable	283	319
Fair Value, Payable	979	1,194
Notionals, Protection purchased	23,599	18,754
Notionals, Protection sold	10,914	6,520
Bank
Credit Derivative
Fair value, Receivable	7,471	11,895
Fair Value, Payable	6,669	10,930
Notionals, Protection purchased	264,414	407,992
Notionals, Protection sold	273,711	414,720
Broker-dealer
Credit Derivative
Fair value, Receivable	2,325	3,536
Fair Value, Payable	2,285	3,952
Notionals, Protection purchased	73,273	115,013
Notionals, Protection sold	83,229	119,810
Non-financial
Credit Derivative
Fair value, Receivable	70	82
Fair Value, Payable	91	99
Notionals, Protection purchased	1,288	4,014
Notionals, Protection sold	1,140	2,061
Insurance and other financial institutions
Credit Derivative
Fair value, Receivable	10,668	9,308
Fair Value, Payable	12,488	10,844
Notionals, Protection purchased	438,738	375,454
Notionals, Protection sold	377,062	322,829
Interest rate swaps
Credit Derivative
Amount derecognized	3,000	1,000
Cash proceeds received for assets derecognized	3,000	1,000
Fair value of derecognized assets	3,100	1,000
Fair value gross derivative assets	89	32
Trading derivatives, liability	$ 15	$ 23

CONCENTRATIONS OF CREDIT RISK (

CONCENTRATIONS OF CREDIT RISK (Details) - Total investments - Geographic - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
U.S.
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	$ 227.8	$ 228.5
GERMANY
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	38.3	26.7
JAPAN
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	25.8	27.3
State and Municipalities
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	$ 30.6	$ 30.7

FAIR VALUE MEASUREMENT - Market

FAIR VALUE MEASUREMENT - Market Valuation Adjustments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Credit and funding valuation adjustments contra-liability (contra-asset)
Counterparty CVA	$ (970)	$ (1,488)
Asset FVA	(447)	(536)
Citigroup (own-credit) CVA	287	459
Liability FVA	47	62
Total CVA—derivative instruments	(1,083)	(1,503)
Credit, Funding and Debt Valuation Adjustments Gain (Loss) [Abstract]
Counterparty CVA	276	157	$ (115)
Asset FVA	90	47	(66)
Own-credit CVA	(153)	17	(28)
Liability FVA	(15)	(44)	97
Total CVA—derivative instruments	198	177	(112)
DVA related to own FVO liabilities	(680)	(538)	367
Total CVA and DVA	$ (482)	$ (361)	$ 255

FAIR VALUE MEASUREMENT - Items

FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	$ (73,476)	$ (44,811)
Trading account assets	251,556	243,925
Netting of cash collateral received	(37,506)	(45,912)
Investments	352,290	353,304
Loans	4,374	3,486
Mortgage servicing rights (MSRs)	558	1,564
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(73,476)	(44,811)
Netting of cash collateral paid	(35,659)	(49,811)
Assets transferred from Level 1 to Level 2	4,800	2,600
Assets transferred from Level 2 to Level 1	4,000	4,000
Liabilities transferred from Level 1 to Level 2	400	300
Liabilities transferred from Level 2 to Level 1	300	400
Investments measured at net asset value excluded from Level 3	404	408
Accounting Standards Update 2015-07
Liabilities, Fair Value Disclosure [Abstract]
Investments measured at net asset value excluded from Level 3	400	400
Recurring
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	188,587	173,890
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	(55,638)	(40,686)
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell	132,949	133,204
Investments	291,716	300,790
Loans	4,374	3,486
Mortgage servicing rights (MSRs)	558	1,564
Assets before netting	1,101,517	1,305,641
Total assets, Netting	(400,571)	(606,943)
Total assets	700,946	698,698
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,465	1,212
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	96,276	74,349
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(55,638)	(40,686)
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase	40,638	33,663
Securities sold, not yet purchased	76,171	80,790
Trading liabilities	77,585	82,618
Short-term borrowings	4,627	2,700
Long-term debt	31,392	26,254
Total liabilities, Gross	614,958	823,220
Total liabilities, Netting	(397,705)	(609,550)
Total liabilities	217,253	213,670
Recurring | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	374,226	609,507
Cash collateral received	14,296	15,731
Total trading derivatives and cash collateral, liability	388,522	625,238
Netting agreements	(306,401)	(519,000)
Netting of cash collateral paid	(35,659)	(49,811)
Netting, Liabilities, total of netting agreements and cash collateral received	(342,060)	(568,811)
Total derivative liabilities	46,462	56,427
Cash collateral received, gross	51,802	61,643
Recurring | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	184,429	354,761
Recurring | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	120,175	187,761
Recurring | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	31,373	26,516
Recurring | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	17,027	15,032
Recurring | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	21,222	25,437
Recurring | Non-trading derivatives and other financial liabilities
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received		(1,345)
Cash collateral paid, gross	7	61
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral received	12	1
Netting of cash collateral paid	(7)	(53)
Netting, Liabilities, total of netting agreements and cash collateral received	(7)	(53)
Other liabilities, gross	15,079	10,848
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	15,091	10,849
Total other assets and cash collateral, gross	15,084	10,796
Cash collateral received, gross	1,038	1,346
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	1,414	1,828
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,964	22,894
Investments	41,741	38,405
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	813	690
Investments	2,884	3,910
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,366	1,206
Investments	332	358
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,143	24,790
Investments	44,957	42,673
Recurring | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	21,137	21,180
Investments	118,146	123,671
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,700	4,076
Investments	8,765	10,120
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	60,206	49,696
Investments	100,533	98,148
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	15,705	14,947
Investments	14,109	17,124
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	60,219	50,443
Investments	189	391
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,788	2,760
Investments	3,918	6,794
Recurring | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	11,723	12,280
Investments	297	503
Recurring | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	802	1,366
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	201,621	180,172
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	386,301	617,477
Gross cash collateral paid	7,541	11,188
Trading derivative, asset, gross net cash collateral paid	393,842	628,665
Less: Netting agreements to assets	(306,401)	(519,000)
Netting of cash collateral received	(37,506)	(45,912)
Netting, Assets, total of netting agreements and cash collateral received	(343,907)	(564,912)
Trading derivatives	49,935	63,753
Cash collateral paid, gross	43,200	60,999
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	203,516	369,325
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	121,220	185,662
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	26,978	24,110
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	14,103	13,765
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	20,484	24,615
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received	(1,026)	(1,345)
Netting, Assets, total of netting agreements and cash collateral received	(1,026)	(1,345)
Other assets, gross	20,819	17,066
Cash collateral paid, gross	0	8
Total other assets and cash collateral, gross	20,819	17,074
Other assets	19,793	15,729
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0
Investments	165,507	170,495
Loans	0	0
Mortgage servicing rights (MSRs)	0	0
Assets before netting	$ 292,700	$ 276,532
Total as a percentage of gross assets	26.80%	21.40%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 0	$ 0
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	0	0
Securities sold, not yet purchased	65,843	67,429
Trading liabilities	65,843	67,429
Short-term borrowings	0	0
Long-term debt	0	0
Total liabilities, Gross	$ 82,437	$ 79,290
Total as a percentage of gross liabilities	13.70%	9.80%
Recurring | Level 1 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 2,691	$ 2,561
Recurring | Level 1 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	137	107
Recurring | Level 1 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	9	13
Recurring | Level 1 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,430	2,245
Recurring | Level 1 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	115	196
Recurring | Level 1 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	0	0
Recurring | Level 1 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	13,903	9,300
Recurring | Level 1 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	0
Recurring | Level 1 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	17,524	16,368
Investments	106,964	112,916
Recurring | Level 1 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	39,347	32,164
Investments	56,456	54,028
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	301	424
Investments	1,911	3,215
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	53,305	45,056
Investments	176	336
Recurring | Level 1 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3	0
Investments	0	0
Recurring | Level 1 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	0	0
Recurring | Level 1 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	110,480	94,012
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,810	2,725
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	145	105
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	19	53
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,364	2,306
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	282	261
Recurring | Level 1 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	0	0
Recurring | Level 1 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	13,903	9,300
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	188,571	172,394
Investments	123,772	126,434
Loans	3,824	2,918
Mortgage servicing rights (MSRs)	0	0
Assets before netting	$ 790,217	$ 998,387
Total as a percentage of gross assets	72.20%	77.10%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 1,179	$ 919
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	95,550	73,500
Securities sold, not yet purchased	10,306	12,184
Trading liabilities	11,715	14,011
Short-term borrowings	4,609	2,658
Long-term debt	18,310	16,510
Total liabilities, Gross	$ 494,879	$ 705,579
Total as a percentage of gross liabilities	82.40%	87.40%
Recurring | Level 2 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 362,348	$ 596,441
Recurring | Level 2 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	182,162	351,766
Recurring | Level 2 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	119,719	187,328
Recurring | Level 2 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	26,472	22,119
Recurring | Level 2 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	14,482	12,386
Recurring | Level 2 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	19,513	22,842
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	1,168	1,540
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	1,409	1,827
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,801	22,718
Investments	41,717	38,304
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	649	291
Investments	2,884	3,860
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,309	1,000
Investments	329	358
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	24,759	24,009
Investments	44,930	42,522
Recurring | Level 2 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,613	4,811
Investments	11,182	10,753
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,426	3,780
Investments	8,028	8,909
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	20,843	17,492
Investments	43,985	43,934
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	15,129	14,199
Investments	12,127	13,598
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	6,794	5,260
Investments	11	46
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,198	892
Investments	3,091	6,134
Recurring | Level 2 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	11,105	9,466
Investments	297	503
Recurring | Level 2 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	121	35
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	87,867	79,909
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	379,283	609,000
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	201,663	366,995
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	120,624	184,776
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	24,170	21,209
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	13,252	12,999
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	19,574	23,021
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	6,900	7,732
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	16	1,496
Investments	2,437	3,861
Loans	550	568
Mortgage servicing rights (MSRs)	558	1,564
Assets before netting	$ 11,059	$ 19,526
Total as a percentage of gross assets	1.00%	1.50%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 286	$ 293
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	726	849
Securities sold, not yet purchased	22	1,177
Trading liabilities	27	1,178
Short-term borrowings	18	42
Long-term debt	13,082	9,744
Total liabilities, Gross	$ 23,334	$ 22,619
Total as a percentage of gross liabilities	3.90%	2.80%
Recurring | Level 3 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 9,187	$ 10,505
Recurring | Level 3 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,130	2,888
Recurring | Level 3 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	447	420
Recurring | Level 3 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,471	2,152
Recurring | Level 3 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,430	2,450
Recurring | Level 3 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1,709	2,595
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	8	8
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	5	1
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	163	176
Investments	24	101
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	164	399
Investments	0	50
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	57	206
Investments	3	0
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	384	781
Investments	27	151
Recurring | Level 3 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	1
Investments	0	2
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	274	296
Investments	737	1,211
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	16	40
Investments	92	186
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	275	324
Investments	71	311
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	120	127
Investments	2	9
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,590	1,868
Investments	827	660
Recurring | Level 3 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	615	2,814
Investments	0	0
Recurring | Level 3 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	681	1,331
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,274	6,251
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	4,208	5,752
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,708	2,225
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	577	833
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	444	595
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	569	505
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	910	1,594
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	$ 16	$ 34

FAIR VALUE MEASUREMENT - Level

FAIR VALUE MEASUREMENT - Level 3 Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Transfers out of Level 3		$ (4,000)
Non-marketable equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Transfers out of Level 3		(3,200)
Hedging derivatives
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Transfers out of Level 3		(500)
Trading account assets and liabilities
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	$ (4,753)	(2,229)
Net realized/unrealized gains (losses) included in Principal Transactions	(1,221)	(2,833)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	(84)	22
Transfers out of Level 3	631	(1,185)
Purchases	377	849
Issuances	(176)	20
Sales	(685)	(832)
Settlements	932	1,435
Balance at end of period, asset (liability), net	(4,979)	(4,753)
Unrealized gains (losses) still held	(296)	(2,002)
Trading account assets and liabilities | Interest rate contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(663)	(495)
Net realized/unrealized gains (losses) included in Principal Transactions	(44)	(146)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	(28)	301
Transfers out of Level 3	610	(239)
Purchases	154	163
Issuances	(13)	(18)
Sales	(322)	(142)
Settlements	(116)	(87)
Balance at end of period, asset (liability), net	(422)	(663)
Unrealized gains (losses) still held	77	26
Trading account assets and liabilities | Foreign exchange contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	413	620
Net realized/unrealized gains (losses) included in Principal Transactions	(438)	(276)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	54	75
Transfers out of Level 3	(60)	(106)
Purchases	33	200
Issuances	14	0
Sales	(21)	(181)
Settlements	135	81
Balance at end of period, asset (liability), net	130	413
Unrealized gains (losses) still held	(139)	23
Trading account assets and liabilities | Equity contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(1,557)	(800)
Net realized/unrealized gains (losses) included in Principal Transactions	129	(89)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	(159)	63
Transfers out of Level 3	28	(772)
Purchases	184	92
Issuances	(216)	38
Sales	(333)	(128)
Settlements	(103)	39
Balance at end of period, asset (liability), net	(2,027)	(1,557)
Unrealized gains (losses) still held	(214)	(33)
Trading account assets and liabilities | Commodity contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(1,945)	(1,861)
Net realized/unrealized gains (losses) included in Principal Transactions	(384)	(352)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	77	(425)
Transfers out of Level 3	35	(39)
Purchases	0	357
Issuances	23	0
Sales	(3)	(347)
Settlements	336	722
Balance at end of period, asset (liability), net	(1,861)	(1,945)
Unrealized gains (losses) still held	149	(164)
Trading account assets and liabilities | Credit derivatives
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(1,001)	307
Net realized/unrealized gains (losses) included in Principal Transactions	(484)	(1,970)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	(28)	8
Transfers out of Level 3	18	(29)
Purchases	6	37
Issuances	16	0
Sales	(6)	(34)
Settlements	680	680
Balance at end of period, asset (liability), net	(799)	(1,001)
Unrealized gains (losses) still held	(169)	(1,854)
Interest-bearing deposits
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	293	434
Net realized/unrealized gains (losses) included in Principal Transactions	0	0
Net realized/unrealized gains (losses) included in locations Other	25	43
Transfers into Level 3	40	322
Transfers out of Level 3	0	(309)
Purchases	0	0
Issuance	2	5
Sales	0	0
Settlements	(24)	(116)
Balance at end of period	286	293
Unrealized gains (losses) still held	22	46
Federal funds purchased and securities loaned or sold under agreements to repurchase
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	849	1,247
Net realized/unrealized gains (losses) included in Principal Transactions	14	(6)
Net realized/unrealized gains (losses) included in locations Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(150)
Purchases	0	0
Issuance	36	0
Sales	0	27
Settlements	(145)	(281)
Balance at end of period	726	849
Unrealized gains (losses) still held	10	(12)
Trading account liabilities | Securities sold, not yet purchased
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,177	199
Net realized/unrealized gains (losses) included in Principal Transactions	385	17
Net realized/unrealized gains (losses) included in locations Other	0	0
Transfers into Level 3	22	1,185
Transfers out of Level 3	(796)	(109)
Purchases	0	(70)
Issuance	17	(41)
Sales	277	367
Settlements	(290)	(337)
Balance at end of period	22	1,177
Unrealized gains (losses) still held	8	(43)
Trading account liabilities | Other trading liabilities
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1	0
Net realized/unrealized gains (losses) included in Principal Transactions	0	0
Net realized/unrealized gains (losses) included in locations Other	0	0
Transfers into Level 3	4	1
Transfers out of Level 3	0	0
Purchases	0	0
Issuance	0	0
Sales	0	0
Settlements	0	0
Balance at end of period	5	1
Unrealized gains (losses) still held	0	0
Short-term borrowings
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	42	9
Net realized/unrealized gains (losses) included in Principal Transactions	32	(16)
Net realized/unrealized gains (losses) included in locations Other	0	0
Transfers into Level 3	4	19
Transfers out of Level 3	(7)	(37)
Purchases	0	0
Issuance	31	87
Sales	0	0
Settlements	(20)	(52)
Balance at end of period	18	42
Unrealized gains (losses) still held	(3)	0
Long-term debt
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	9,744	7,543
Net realized/unrealized gains (losses) included in Principal Transactions	(1,083)	(282)
Net realized/unrealized gains (losses) included in locations Other	0	0
Transfers into Level 3	1,251	3,792
Transfers out of Level 3	(1,836)	(4,350)
Purchases	44	0
Issuance	2,712	4,845
Sales	0	(3)
Settlements	84	(2,365)
Balance at end of period	13,082	9,744
Unrealized gains (losses) still held	(1,554)	(419)
Other financial liabilities
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	8	14
Net realized/unrealized gains (losses) included in Principal Transactions	0	0
Net realized/unrealized gains (losses) included in locations Other	0	(11)
Transfers into Level 3	5	2
Transfers out of Level 3	0	(12)
Purchases	0	(8)
Issuance	5	12
Sales	(1)	0
Settlements	(9)	(11)
Balance at end of period	8	8
Unrealized gains (losses) still held	(1)	(13)
Federal funds sold and securities borrowed or purchased under agreements to resell
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,496	1,337
Net realized/unrealized gains (losses) included in principal transactions	(281)	(20)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(1,198)	(28)
Purchases	0	758
Issuance	0	0
Sales	0	0
Settlements	(1)	(551)
Balance at end of period	16	1,496
Unrealized gains (losses) still held	1	(16)
Trading non-derivative assets
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	6,251	12,418
Net realized/unrealized gains (losses) included in principal transactions	952	(79)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	1,321	3,835
Transfers out of Level 3	(3,737)	(9,045)
Purchases	5,676	9,376
Issuance	(23)	8
Sales	(7,155)	(10,235)
Settlements	(11)	(27)
Balance at end of period	3,274	6,251
Unrealized gains (losses) still held	196	(647)
Trading non-derivative assets | U.S. government-sponsored agency guaranteed
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	176	744
Net realized/unrealized gains (losses) included in principal transactions	23	6
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	176	510
Transfers out of Level 3	(174)	(1,087)
Purchases	463	941
Issuance	0	0
Sales	(504)	(961)
Settlements	3	23
Balance at end of period	163	176
Unrealized gains (losses) still held	2	(7)
Trading non-derivative assets | Mortgage-backed securities - Residential
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	399	1,326
Net realized/unrealized gains (losses) included in principal transactions	86	104
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	95	189
Transfers out of Level 3	(118)	(162)
Purchases	126	324
Issuance	0	0
Sales	(424)	(1,376)
Settlements	0	(6)
Balance at end of period	164	399
Unrealized gains (losses) still held	14	26
Trading non-derivative assets | Mortgage-backed securities - Commercial
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	206	517
Net realized/unrealized gains (losses) included in principal transactions	15	(1)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	69	193
Transfers out of Level 3	(57)	(234)
Purchases	450	759
Issuance	0	0
Sales	(626)	(1,028)
Settlements	0	0
Balance at end of period	57	206
Unrealized gains (losses) still held	(5)	(27)
Trading non-derivative assets | Mortgage-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	781	2,587
Net realized/unrealized gains (losses) included in principal transactions	124	109
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	340	892
Transfers out of Level 3	(349)	(1,483)
Purchases	1,039	2,024
Issuance	0	0
Sales	(1,554)	(3,365)
Settlements	3	17
Balance at end of period	384	781
Unrealized gains (losses) still held	11	(8)
Trading non-derivative assets | U.S. Treasury and federal agency securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1	1
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	0	2
Transfers out of Level 3	0	0
Purchases	0	0
Issuance	0	0
Sales	(1)	(2)
Settlements	0	0
Balance at end of period	0	1
Unrealized gains (losses) still held	0	0
Trading non-derivative assets | State and municipal securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	296	351
Net realized/unrealized gains (losses) included in principal transactions	28	23
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	24	195
Transfers out of Level 3	(48)	(256)
Purchases	161	322
Issuance	(23)	0
Sales	(164)	(339)
Settlements	0	0
Balance at end of period	274	296
Unrealized gains (losses) still held	8	(88)
Trading non-derivative assets | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	40	197
Net realized/unrealized gains (losses) included in principal transactions	1	(9)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	89	21
Transfers out of Level 3	(228)	(49)
Purchases	291	115
Issuance	0	0
Sales	(177)	(235)
Settlements	0	0
Balance at end of period	16	40
Unrealized gains (losses) still held	0	(16)
Trading non-derivative assets | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	324	376
Net realized/unrealized gains (losses) included in principal transactions	344	330
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	140	171
Transfers out of Level 3	(185)	(132)
Purchases	482	867
Issuance	(8)	0
Sales	(828)	(1,295)
Settlements	6	7
Balance at end of period	275	324
Unrealized gains (losses) still held	81	69
Trading non-derivative assets | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	127	3,684
Net realized/unrealized gains (losses) included in principal transactions	54	(527)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	210	279
Transfers out of Level 3	(58)	(4,057)
Purchases	51	955
Issuance	(3)	(11)
Sales	(261)	(196)
Settlements	0	0
Balance at end of period	120	127
Unrealized gains (losses) still held	0	(457)
Trading non-derivative assets | Asset-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,868	2,739
Net realized/unrealized gains (losses) included in principal transactions	284	53
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	44	205
Transfers out of Level 3	(178)	(360)
Purchases	1,457	2,199
Issuance	0	0
Sales	(1,885)	(2,965)
Settlements	0	(3)
Balance at end of period	1,590	1,868
Unrealized gains (losses) still held	36	(46)
Trading non-derivative assets | Other debt securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	2,814	2,483
Net realized/unrealized gains (losses) included in principal transactions	117	(58)
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	474	2,070
Transfers out of Level 3	(2,691)	(2,708)
Purchases	2,195	2,894
Issuance	11	19
Sales	(2,285)	(1,838)
Settlements	(20)	(48)
Balance at end of period	615	2,814
Unrealized gains (losses) still held	60	(101)
Investments
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	3,861	5,059
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	(175)	99
Transfers into Level 3	186	954
Transfers out of Level 3	(1,021)	(2,054)
Purchases	1,812	1,842
Issuance	0	0
Sales	(1,958)	(1,557)
Settlements	(268)	(482)
Balance at end of period	2,437	3,861
Unrealized gains (losses) still held	99	(109)
Investments | U.S. government-sponsored agency guaranteed
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	101	139
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	16	(26)
Transfers into Level 3	1	25
Transfers out of Level 3	(94)	(72)
Purchases	0	45
Issuance	0	0
Sales	0	(9)
Settlements	0	(1)
Balance at end of period	24	101
Unrealized gains (losses) still held	(2)	54
Investments | Mortgage-backed securities - Residential
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	50	4
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	2	3
Transfers into Level 3	0	49
Transfers out of Level 3	(47)	0
Purchases	0	26
Issuance	0	0
Sales	(5)	(32)
Settlements	0	0
Balance at end of period	0	50
Unrealized gains (losses) still held	0	2
Investments | Mortgage-backed securities - Commercial
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	0	2
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	0	(1)
Transfers into Level 3	3	6
Transfers out of Level 3	0	(7)
Purchases	12	0
Issuance	0	0
Sales	(12)	0
Settlements	0	0
Balance at end of period	3	0
Unrealized gains (losses) still held	0	0
Investments | Mortgage-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	151	145
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	18	(24)
Transfers into Level 3	4	80
Transfers out of Level 3	(141)	(79)
Purchases	12	71
Issuance	0	0
Sales	(17)	(41)
Settlements	0	(1)
Balance at end of period	27	151
Unrealized gains (losses) still held	(2)	56
Investments | U.S. Treasury and federal agency securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	2	4
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Purchases	0	0
Issuance	0	0
Sales	(2)	(2)
Settlements	0	0
Balance at end of period	0	2
Unrealized gains (losses) still held	0	0
Investments | State and municipal securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,211	2,192
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	58	39
Transfers into Level 3	70	467
Transfers out of Level 3	(517)	(1,598)
Purchases	127	351
Issuance	0	0
Sales	(212)	(240)
Settlements	0	0
Balance at end of period	737	1,211
Unrealized gains (losses) still held	44	23
Investments | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	186	260
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	0	10
Transfers into Level 3	2	38
Transfers out of Level 3	(284)	(39)
Purchases	523	259
Issuance	0	0
Sales	(335)	(339)
Settlements	0	(3)
Balance at end of period	92	186
Unrealized gains (losses) still held	1	(104)
Investments | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	311	603
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	9	77
Transfers into Level 3	77	11
Transfers out of Level 3	(47)	(240)
Purchases	227	693
Issuance	0	0
Sales	(506)	(468)
Settlements	0	(365)
Balance at end of period	71	311
Unrealized gains (losses) still held	0	0
Investments | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	9	124
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	(1)	10
Transfers into Level 3	0	5
Transfers out of Level 3	0	(5)
Purchases	0	1
Issuance	0	0
Sales	(6)	(131)
Settlements	0	5
Balance at end of period	2	9
Unrealized gains (losses) still held	0	0
Investments | Asset-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	660	596
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	(89)	(92)
Transfers into Level 3	31	7
Transfers out of Level 3	(32)	(61)
Purchases	883	435
Issuance	0	0
Sales	(626)	(306)
Settlements	0	81
Balance at end of period	827	660
Unrealized gains (losses) still held	12	(102)
Investments | Other debt securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	0	0
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	0	0
Transfers into Level 3	0	10
Transfers out of Level 3	0	0
Purchases	21	6
Issuance	0	0
Sales	(21)	(16)
Settlements	0	0
Balance at end of period	0	0
Unrealized gains (losses) still held	0	0
Investments | Non-marketable equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,331	1,135
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	(170)	79
Transfers into Level 3	2	336
Transfers out of Level 3	0	(32)
Purchases	19	26
Issuance	0	0
Sales	(233)	(14)
Settlements	(268)	(199)
Balance at end of period	681	1,331
Unrealized gains (losses) still held	44	18
Loans
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	568	2,166
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	75	(61)
Transfers into Level 3	80	89
Transfers out of Level 3	(16)	(1,074)
Purchases	188	708
Issuance	0	219
Sales	(337)	(813)
Settlements	(8)	(666)
Balance at end of period	550	568
Unrealized gains (losses) still held	211	26
Mortgage servicing rights
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	1,564	1,781
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	65	(36)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Purchases	0	0
Issuance	96	152
Sales	(1,057)	(20)
Settlements	(110)	(313)
Balance at end of period	558	1,564
Unrealized gains (losses) still held	74	(21)
Other financial assets measured on a recurring basis
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period	34	180
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in Other	(128)	80
Transfers into Level 3	10	55
Transfers out of Level 3	(8)	(47)
Purchases	1	1
Issuance	318	236
Sales	(14)	(133)
Settlements	(197)	(338)
Balance at end of period	16	34
Unrealized gains (losses) still held	$ (152)	$ 39

FAIR VALUE MEASUREMENT - Lev167

FAIR VALUE MEASUREMENT - Level 3 Roll Forward Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal funds sold and securities borrowed or purchased under agreements to resell
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	$ 1,198	$ 28
Transfers into Level 3, assets	0	0
Trading non-derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	3,737	9,045
Transfers into Level 3, assets	1,321	3,835
Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	1,021	2,054
Transfers into Level 3, assets	186	954
Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	16	1,074
Transfers into Level 3, assets	80	89
Other debt securities | Trading non-derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	2,691	2,708
Transfers into Level 3, assets	474	2,070
Other debt securities | Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	0	0
Transfers into Level 3, assets	0	10
Mortgage-backed securities - U.S. agency-sponsored | Trading non-derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	174	1,087
Transfers into Level 3, assets	176	510
Mortgage-backed securities - U.S. agency-sponsored | Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	94	72
Transfers into Level 3, assets	1	25
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets		4,000
Equity securities | Trading non-derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	58	4,057
Transfers into Level 3, assets	210	279
Equity securities | Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	0	5
Transfers into Level 3, assets	0	5
Non-marketable equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets		3,200
Non-marketable equity securities | Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	0	32
Transfers into Level 3, assets	2	336
Hedging derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets		500
State and municipal securities | Trading non-derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	48	256
Transfers into Level 3, assets	24	195
State and municipal securities | Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of Level 3, assets	517	1,598
Transfers into Level 3, assets	70	467
Long-term debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3, liabilities	1,251	3,792
Transfers out of Level 3, liabilities	1,836	4,350
Securities sold, not yet purchased | Trading account liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3, liabilities	22	1,185
Transfers out of Level 3, liabilities	$ 796	$ 109

FAIR VALUE MEASUREMENT - Valuat

FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Fair Value Measurements (Details) - Level 3 - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Interest-bearing deposits | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Liabilities, fair value	$ 286,000,000	$ 293,000,000
Interest-bearing deposits | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	1.00%	1.00%
Forward price (as a percent)	99.56%	98.79%
Interest-bearing deposits | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	20.00%	20.00%
Forward price (as a percent)	99.95%	104.07%
Interest-bearing deposits | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	10.50%	10.50%
Forward price (as a percent)	99.72%	100.19%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Liabilities, fair value	$ 726,000,000	$ 849,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	1.43%	0.62%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.16%	2.19%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.09%	1.99%
Short-term borrowings and long-term debt | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Liabilities, fair value	$ 13,100,000,000	$ 9,774,000,000
Short-term borrowings and long-term debt | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)		1.00%
Forward price (as a percent)	69.74%	69.05%
Commodity volatility (as a percent)		2.00%
Commodity correlation (as a percent)		(41.61%)
Short-term borrowings and long-term debt | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)		20.00%
Forward price (as a percent)	161.11%	235.35%
Commodity volatility (as a percent)		32.19%
Commodity correlation (as a percent)		90.42%
Short-term borrowings and long-term debt | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)		10.50%
Forward price (as a percent)	100.70%	103.28%
Commodity volatility (as a percent)		17.07%
Commodity correlation (as a percent)		52.85%
Trading account assets and liabilities | Interest rate contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 3,818,000,000	$ 4,897,000,000
Trading account assets and liabilities | Interest rate contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility	9.40%
Mean reversion (as a percent)	1.00%	1.00%
IR log-normal volatility (as a percent)		1.00%
Trading account assets and liabilities | Interest rate contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility	77.40%
Mean reversion (as a percent)	20.00%	20.00%
IR log-normal volatility (as a percent)		93.97%
Trading account assets and liabilities | Interest rate contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility	58.86%
Mean reversion (as a percent)	10.50%	10.50%
IR log-normal volatility (as a percent)		62.72%
Trading account assets and liabilities | Foreign exchange contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 940,000,000	$ 1,110,000,000
Trading account assets and liabilities | Foreign exchange contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	(0.55%)
Credit spread (as a percent)	0.11%
Foreign exchange (FX) volatility (as a percent)	4.58%	1.39%
IR-IR Correlation (as a percent)	(51.00%)
IR-FX correlation (as a percent)	(7.34%)
Trading account assets and liabilities | Foreign exchange contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	0.28%
Credit spread (as a percent)	7.17%
Foreign exchange (FX) volatility (as a percent)	15.02%	26.85%
IR-IR Correlation (as a percent)	40.00%
IR-FX correlation (as a percent)	60.00%
Trading account assets and liabilities | Foreign exchange contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	0.04%
Credit spread (as a percent)	1.73%
Foreign exchange (FX) volatility (as a percent)	8.16%	15.18%
IR-IR Correlation (as a percent)	36.56%
IR-FX correlation (as a percent)	49.04%
Trading account assets and liabilities | Foreign exchange contracts | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value		$ 134,000,000
Trading account assets and liabilities | Foreign exchange contracts | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)		(0.85%)
Credit spread (as a percent)		0.04%
IR-IR Correlation (as a percent)		40.00%
IR-FX correlation (as a percent)		16.41%
Trading account assets and liabilities | Foreign exchange contracts | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)		(0.49%)
Credit spread (as a percent)		6.57%
IR-IR Correlation (as a percent)		50.00%
IR-FX correlation (as a percent)		60.00%
Trading account assets and liabilities | Foreign exchange contracts | Cash flow | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)		(0.84%)
Credit spread (as a percent)		2.66%
IR-IR Correlation (as a percent)		41.27%
IR-FX correlation (as a percent)		49.52%
Trading account assets and liabilities | Equity contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 2,897,000,000	$ 2,701,000,000
Trading account assets and liabilities | Equity contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	3.00%	3.00%
Forward price (as a percent)	69.74%	69.05%
Equity-FX correlation (as a percent)		(60.70%)
Equity IR Correlation		(35.00%)
Yield Volatility (as a percent)		3.55%
Equity-Equity correlation (as a percent)		(87.70%)
Trading account assets and liabilities | Equity contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	68.93%	97.78%
Forward price (as a percent)	154.19%	144.61%
Equity-FX correlation (as a percent)		28.20%
Equity IR Correlation		41.00%
Yield Volatility (as a percent)		14.77%
Equity-Equity correlation (as a percent)		96.50%
Trading account assets and liabilities | Equity contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	24.66%	29.52%
Forward price (as a percent)	92.80%	94.28%
Equity-FX correlation (as a percent)		(26.28%)
Equity IR Correlation		(15.65%)
Yield Volatility (as a percent)		9.29%
Equity-Equity correlation (as a percent)		67.45%
Trading account assets and liabilities | Commodity contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 2,937,000,000	$ 2,955,000,000
Trading account assets and liabilities | Commodity contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	3.66%	35.74%
Commodity volatility (as a percent)	8.60%	2.00%
Commodity correlation (as a percent)	(37.64%)	(41.61%)
Trading account assets and liabilities | Commodity contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	290.59%	235.35%
Commodity volatility (as a percent)	66.73%	32.19%
Commodity correlation (as a percent)	91.71%	90.42%
Trading account assets and liabilities | Commodity contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	114.16%	119.99%
Commodity volatility (as a percent)	25.04%	17.07%
Commodity correlation (as a percent)	15.21%	52.85%
Trading account assets and liabilities | Credit derivatives | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 1,797,000,000	$ 2,786,000,000
Trading account assets and liabilities | Credit derivatives | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	25.00%
Recovery rate (as a percent)		20.00%
Trading account assets and liabilities | Credit derivatives | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	90.00%
Recovery rate (as a percent)		75.00%
Trading account assets and liabilities | Credit derivatives | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	44.64%
Recovery rate (as a percent)		39.75%
Trading account assets and liabilities | Credit derivatives | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 823,000,000	$ 1,403,000,000
Trading account assets and liabilities | Credit derivatives | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	$ 1	$ 1
Credit spread (as a percent)	0.03%	0.03%
Credit correlation (as a percent)		5.00%
Upfront Points (as a percent)	6.03%	6.00%
Trading account assets and liabilities | Credit derivatives | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	$ 100.24	$ 167
Credit spread (as a percent)	16.36%	15.15%
Credit correlation (as a percent)		90.00%
Upfront Points (as a percent)	97.26%	99.90%
Trading account assets and liabilities | Credit derivatives | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	$ 57.63	$ 77.35
Credit spread (as a percent)	1.73%	2.56%
Credit correlation (as a percent)		34.27%
Upfront Points (as a percent)	62.88%	72.89%
Nontrading derivatives and other financial assets and liabilities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives, fair value	$ 24,000,000	$ 42,000,000
Nontrading derivatives and other financial assets and liabilities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.38%
Upfront Points (as a percent)	61.00%	16.00%
Recovery rate (as a percent)	25.00%	40.00%
Redemption rate (as a percent)	10.72%	3.92%
Nontrading derivatives and other financial assets and liabilities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	2.75%
Upfront Points (as a percent)	61.00%	20.50%
Recovery rate (as a percent)	40.00%	40.00%
Redemption rate (as a percent)	99.50%	99.58%
Nontrading derivatives and other financial assets and liabilities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	1.27%
Upfront Points (as a percent)	61.00%	18.78%
Recovery rate (as a percent)	31.56%	40.00%
Redemption rate (as a percent)	74.24%	74.69%
Securities sold, not yet purchased | Trading account liabilities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Liabilities, fair value		$ 1,056,000,000
Securities sold, not yet purchased | Trading account liabilities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility		12.86%
Securities sold, not yet purchased | Trading account liabilities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility		75.50%
Securities sold, not yet purchased | Trading account liabilities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
IR Normal Volatility		61.73%
Securities sold, not yet purchased | Trading account liabilities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Liabilities, fair value	$ 21,000,000
Securities sold, not yet purchased | Trading account liabilities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	1
Securities sold, not yet purchased | Trading account liabilities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	287.64
Securities sold, not yet purchased | Trading account liabilities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	88.19
Fixed income securities
Fair Value Inputs Assets Liabilities Quantitative Information
Price for instrument valued at par	100
Fixed income securities | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price for instrument valued at par	0
Fixed income securities | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price for instrument valued at par	100
Mortgage-backed securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	214,000,000	$ 509,000,000
Mortgage-backed securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	2.96	5.50
Mortgage-backed securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	101	113.48
Mortgage-backed securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	56.52	61.74
Mortgage-backed securities | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 184,000,000	$ 368,000,000
Mortgage-backed securities | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	2.52%	1.90%
Mortgage-backed securities | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	14.06%	14.54%
Mortgage-backed securities | Yield analysis | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	5.97%	4.34%
State and municipal, foreign government, corporate, and other debt securities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 949,000,000
State and municipal, foreign government, corporate, and other debt securities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0
State and municipal, foreign government, corporate, and other debt securities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	184.04
State and municipal, foreign government, corporate, and other debt securities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	91.74
State and municipal, foreign government, corporate, and other debt securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 914,000,000	$ 3,308,000,000
State and municipal, foreign government, corporate, and other debt securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		15
Yield (as a percent)	2.36%
Credit spread (as a percent)	0.35%
State and municipal, foreign government, corporate, and other debt securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		103.60
Yield (as a percent)	14.25%
Credit spread (as a percent)	5.00%
State and municipal, foreign government, corporate, and other debt securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price		89.93
Yield (as a percent)	6.03%
Credit spread (as a percent)	2.49%
State and municipal, foreign government, corporate, and other debt securities | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets		$ 1,513,000,000
State and municipal, foreign government, corporate, and other debt securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)		0.35%
State and municipal, foreign government, corporate, and other debt securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)		6.00%
State and municipal, foreign government, corporate, and other debt securities | Cash flow | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)		2.30%
Equity securities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 55,000,000	$ 69,000,000
Equity securities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		0.48
WAL (in years)	2 years 6 months
Equity securities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		104
WAL (in years)	2 years 6 months
Equity securities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price		22.19
WAL (in years)	2 years 6 months
Equity securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 65,000,000	58,000,000
Equity securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0
Equity securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	25,450
Equity securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	2,526.62
Asset-backed securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	2,287,000,000	2,454,000,000
Asset-backed securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	4.25	4
Asset-backed securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100.60	100
Asset-backed securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price	74.57	71.51
Non-marketable equity securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 223,000,000	$ 726,000,000
Non-marketable equity securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price (as a percent)	0.00%	0.00%
Price-to-book ratio	0.05
Non-marketable equity securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price (as a percent)	100.00%	90.00%
Price-to-book ratio	1
Non-marketable equity securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price (as a percent)	11.83%	13.36%
Price-to-book ratio	0.32
Non-marketable equity securities | Comparables Analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 423,000,000	$ 565,000,000
Non-marketable equity securities | Comparables Analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		$ 0
EBITDA multiples	6.90	6.80
Price-to-book ratio		0.3200
Non-marketable equity securities | Comparables Analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		$ 113.23
EBITDA multiples	12.80	10.10
Price-to-book ratio		1.0300
Non-marketable equity securities | Comparables Analysis | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price		$ 54.40
EBITDA multiples	8.66	8.62
Price-to-book ratio		0.8700
Federal funds sold and securities borrowed or purchased under agreements to resell | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 16,000,000	$ 1,496,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	1.43%	(0.51%)
IR log-normal volatility (as a percent)		12.86%
Federal funds sold and securities borrowed or purchased under agreements to resell | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.16%	5.76%
IR log-normal volatility (as a percent)		75.50%
Federal funds sold and securities borrowed or purchased under agreements to resell | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.09%	2.80%
IR log-normal volatility (as a percent)		61.73%
Loans | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 391,000,000	$ 79,000,000
Loans | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	3.00%
Loans | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	68.93%
Loans | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	22.52%
Loans | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets		258,000,000
Loans | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 148,000,000
Price		31.55
Yield (as a percent)	3.09%
Credit spread (as a percent)	1.34%
Loans | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price		105.74
Yield (as a percent)	4.40%
Credit spread (as a percent)	5.00%
Loans | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price		56.46
Yield (as a percent)	3.13%
Credit spread (as a percent)	1.73%
Loans | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets		$ 221,000,000
Loans | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		2.75%
Loans | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		20.00%
Loans | Yield analysis | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		11.09%
Mortgage servicing rights | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 87,000,000
Mortgage servicing rights | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	3 years 9 months 29 days
Mortgage servicing rights | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	6 years 10 months 21 days
Mortgage servicing rights | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	5 years 11 months 5 days
Mortgage servicing rights | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 471,000,000	$ 1,473,000,000
Mortgage servicing rights | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	8.00%	4.20%
WAL (in years)		3 years 6 months 11 days
Mortgage servicing rights | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	16.38%	20.56%
WAL (in years)		7 years 2 months 27 days
Mortgage servicing rights | Cash flow | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	11.47%	9.32%
WAL (in years)		5 years 9 months 29 days

FAIR VALUE MEASUREMENT - Ite169

FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Level 2
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	$ 2,066	$ 3,389
Other real estate owned	10	15
Loans	216	586
Total assets	2,292	3,990
Level 3
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	3,609	2,413
Other real estate owned	44	60
Loans	414	790
Total assets	4,067	3,263
Fair value
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	5,675	5,802
Other real estate owned	54	75
Loans	630	1,376
Total assets	$ 6,359	$ 7,253

FAIR VALUE MEASUREMENT - Val170

FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Nonrecurring Fair Value Measurements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	$ (117,000,000)	$ (112,000,000)
Loans held-for-sale
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(26,000,000)	(2,000,000)
Other real estate owned
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(4,000,000)	(5,000,000)
Loans
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(87,000,000)	(105,000,000)
Nonrecurring | Level 3
Valuation techniques and inputs
Total assets	4,067,000,000	3,263,000,000
Nonrecurring | Level 3 | Loans held-for-sale | Price-based
Valuation techniques and inputs
Total assets	3,186,000,000	2,413,000,000
Nonrecurring | Level 3 | Loans held-for-sale | Price-based | Minimum
Valuation techniques and inputs
Price	77.93	0
Nonrecurring | Level 3 | Loans held-for-sale | Price-based | Maximum
Valuation techniques and inputs
Price	100	100
Nonrecurring | Level 3 | Loans held-for-sale | Price-based | Weighted Average
Valuation techniques and inputs
Price	99.26	93.08
Nonrecurring | Level 3 | Other real estate owned | Price-based
Valuation techniques and inputs
Total assets	42,000,000	59,000,000
Nonrecurring | Level 3 | Other real estate owned | Price-based | Minimum
Valuation techniques and inputs
Price	30	$ 64.65
Appraised Value	$ 20,278
Discount to price (as a percent)	34.00%	0.34%
Nonrecurring | Level 3 | Other real estate owned | Price-based | Maximum
Valuation techniques and inputs
Price	$ 50.36	$ 74.39
Appraised Value	$ 8,091,760
Discount to price (as a percent)	34.00%	13.00%
Nonrecurring | Level 3 | Other real estate owned | Price-based | Weighted Average
Valuation techniques and inputs
Price	$ 49.09	$ 66.21
Appraised Value	$ 4,016,665
Discount to price (as a percent)	34.00%	3.10%
Nonrecurring | Level 3 | Loans | Price-based
Valuation techniques and inputs
Total assets	$ 133,000,000	$ 135,000,000
Nonrecurring | Level 3 | Loans | Price-based | Minimum
Valuation techniques and inputs
Price	2.80
Appraised Value		$ 25.80
Discount to price (as a percent)		0.25%
Nonrecurring | Level 3 | Loans | Price-based | Maximum
Valuation techniques and inputs
Price	100
Appraised Value		$ 26,400,000
Discount to price (as a percent)		13.00%
Nonrecurring | Level 3 | Loans | Price-based | Weighted Average
Valuation techniques and inputs
Price	62.46
Appraised Value		$ 6,462,735
Discount to price (as a percent)		8.34%
Nonrecurring | Level 3 | Loans | Cash flow
Valuation techniques and inputs
Total assets	$ 129,000,000	$ 431,000,000
Nonrecurring | Level 3 | Loans | Cash flow | Minimum
Valuation techniques and inputs
Price		3.25
Recovery rate (as a percent)	50.00%
Nonrecurring | Level 3 | Loans | Cash flow | Maximum
Valuation techniques and inputs
Price		105
Recovery rate (as a percent)	100.00%
Nonrecurring | Level 3 | Loans | Cash flow | Weighted Average
Valuation techniques and inputs
Price		59.61
Recovery rate (as a percent)	63.59%
Nonrecurring | Level 3 | Loans | Recovery Analysis
Valuation techniques and inputs
Total assets	$ 127,000,000	197,000,000
Nonrecurring | Level 3 | Loans | Recovery Analysis | Minimum
Valuation techniques and inputs
Appraised Value	0
Forward price (as a percent)		2.90
Nonrecurring | Level 3 | Loans | Recovery Analysis | Maximum
Valuation techniques and inputs
Appraised Value	45,500,000
Forward price (as a percent)		210
Nonrecurring | Level 3 | Loans | Recovery Analysis | Weighted Average
Valuation techniques and inputs
Appraised Value	$ 38,785,667
Forward price (as a percent)		$ 156.78

FAIR VALUE MEASUREMENT - Estima

FAIR VALUE MEASUREMENT - Estimate Fair Value of Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Loans	$ 4,374	$ 3,486
Liabilities
Deposits	959,822	929,406
Allowance for loan losses	12,355	12,060	$ 12,626	$ 15,994
Lease finance receivables	1,700	1,900
Corporate
Assets
Loans	4,349	3,457
Carrying value
Assets
Investments	60,200	52,100
Federal funds sold and securities borrowed or purchased under agreements to resell	99,500	103,600
Loans	648,600	607,000
Other financial assets	242,600	215,200
Liabilities
Deposits	958,400	928,200
Federal funds purchased and securities loaned or sold under agreements to repurchase	115,600	108,200
Long-term debt	205,300	179,900
Other financial liabilities	129,900	115,300
Fair value
Assets
Investments	60,600	52,000
Federal funds sold and securities borrowed or purchased under agreements to resell	99,500	103,600
Loans	644,900	607,300
Other financial assets	243,000	215,900
Liabilities
Deposits	955,600	927,600
Federal funds purchased and securities loaned or sold under agreements to repurchase	115,600	108,200
Long-term debt	214,000	185,500
Other financial liabilities	129,900	115,300
Fair value | Level 1
Assets
Investments	500	800
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0
Loans	0	0
Other financial assets	166,400	145,600
Liabilities
Deposits	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase	0	0
Long-term debt	0	0
Other financial liabilities	0	0
Fair value | Level 2
Assets
Investments	57,500	48,600
Federal funds sold and securities borrowed or purchased under agreements to resell	94,400	98,500
Loans	6,000	7,000
Other financial assets	14,100	16,200
Liabilities
Deposits	816,100	789,700
Federal funds purchased and securities loaned or sold under agreements to repurchase	115,600	107,800
Long-term debt	187,200	156,500
Other financial liabilities	15,500	16,200
Fair value | Level 3
Assets
Investments	2,600	2,600
Federal funds sold and securities borrowed or purchased under agreements to resell	5,100	5,100
Loans	638,900	600,300
Other financial assets	62,500	54,100
Liabilities
Deposits	139,500	137,900
Federal funds purchased and securities loaned or sold under agreements to repurchase	0	400
Long-term debt	26,800	29,000
Other financial liabilities	114,400	99,100
Fair value | Level 3 | Corporate
Fair value measurements additional disclosures
Unfunded lending commitments	$ 3,200	$ 5,200

FAIR VALUE ELECTIONS - Changes

FAIR VALUE ELECTIONS - Changes in Fair Value Gains (Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal funds sold and securities borrowed or purchased under agreements to resell selected portfolios of securities purchased under agreements to resell and securities borrowed
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	$ (133)	$ (89)
Trading account assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	1,622	404
Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(3)	(25)
Corporate
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(537)	40
Consumer loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	3	0
Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(534)	40
Mortgage servicing rights
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	65	(36)
Certain mortgage loans (HFS)
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	142	284
Other assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	0	376
Total other assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	207	624
Total assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	1,159	954
Interest-bearing deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(69)	(50)
Federal funds purchased and securities loaned or sold under agreements to repurchase selected portfolios of securities sold under agreements to repurchase and securities loaned
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	223	45
Trading account liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	70	105
Short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(116)	(61)
Long-term debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(1,491)	(935)
Total liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	$ (1,383)	$ (896)

FAIR VALUE ELECTIONS - Valuatio

FAIR VALUE ELECTIONS - Valuation Adjustments, Fair Value Option for Financial Assets and Financial Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Option Quantitative Disclosures
Loss on change in estimated fair value of debt liabilities due to change in company's own credit risk	$ 680	$ 538
Balance of non-accrual loans or loans more than 90 days past due	0	0
Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due	0	0
Certain loans and other credit product
Fair Value Option Quantitative Disclosures
Changes in fair value due to instrument-specific credit risk gain (loss)	10	76
Certain loans and other credit product | Trading assets
Fair Value Option Quantitative Disclosures
Aggregate unpaid principal balance in excess of fair value	623	758
Balance of non-accrual loans or loans more than 90 days past due	0	0
Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due	0	0
Certain loans and other credit product | Loans
Fair Value Option Quantitative Disclosures
Aggregate unpaid principal balance in excess of fair value	682	18
Balance of non-accrual loans or loans more than 90 days past due	1	1
Aggregate unpaid principal balance in excess of fair value for non-accrual loans or loans more than 90 days past due	1	1
Certain debt host contracts across unallocated precious metals accounts
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	900	600
Certain Investments in Unallocated Precious Metals | Forward derivative contract | Purchased
Fair Value Option Quantitative Disclosures
Derivative notionals	10,300
Certain Investments in Unallocated Precious Metals | Forward derivative contract | Sold
Fair Value Option Quantitative Disclosures
Derivative notionals	9,300
Mortgage loans
Fair Value Option Quantitative Disclosures
Aggregate unpaid principal balance in excess of fair value	14	8
Carrying amount | Certain loans and other credit product | Trading assets
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	8,851	9,824
Carrying amount | Certain loans and other credit product | Loans
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	4,374	3,486
Carrying amount | Certain mortgage loans (HFS)
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	426	915
Fair value | Certain loans and other credit product
Fair Value Option Quantitative Disclosures
Unfunded lending commitments	$ 508	$ 1,828

FAIR VALUE ELECTIONS - Certain

FAIR VALUE ELECTIONS - Certain Structured and Non-Structured Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	$ 29,300	$ 24,300
Long-term debt
Certain non-structured liabilities
Aggregate unpaid principal balance in excess of (less than) fair value	(579)	(128)
Long-term debt | Carrying amount
Certain non-structured liabilities
Carrying amount reported on the Consolidated Balance Sheet	31,392	26,254
Short-term borrowings
Certain non-structured liabilities
Aggregate unpaid principal balance in excess of (less than) fair value	74	(61)
Short-term borrowings | Carrying amount
Certain non-structured liabilities
Carrying amount reported on the Consolidated Balance Sheet	4,627	2,700
Interest Rate Linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	13,900	10,600
Foreign Exchange Linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	300	200
Equity Linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	13,000	12,300
Commodity Linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	200	300
Credit Linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	$ 1,900	$ 900

PLEDGED ASSETS, COLLATERAL, 175

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS - Pledged Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying Values of Significant Components of Pledged Assets
Investment securities	$ 138,807	$ 161,914
Loans	229,552	231,833
Trading account assets	102,892	84,371
Total	471,251	478,118
Cash and due from banks	7,400	6,800
Fair value of collateral received that may be resold or repledged	457,500	378,100
Pledged collateral that may not be sold or repledged	$ 362,000	$ 388,000

PLEDGED ASSETS, COLLATERAL, 176

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS - Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pledged Assets, Collateral, Guarantees and Commitments [Abstract]
Rental expense	$ 1,100	$ 1,100	$ 1,300
Future Minimum Annual Rentals
2,018	968
2,019	837
2,020	676
2,021	568
2,022	469
Thereafter	2,593
Total	$ 6,111

PLEDGED ASSETS, COLLATERAL, 177

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS - Guarantees (Details)	12 Months Ended
	Dec. 31, 2017USD ($)margin	Dec. 31, 2016USD ($)	Dec. 31, 2000trust
Maximum potential amount of future payments
Expire Within One Year	$ 235,600,000,000	$ 207,400,000,000
Expire After One Year	192,200,000,000	197,800,000,000
Total amount outstanding	427,800,000,000	405,200,000,000
Carrying value	809,000,000	1,183,000,000
Compensation for standard representations and warranties	0
Stated or notional amounts included in the indemnification clauses	0
Number of trusts funded by the reinsurer | trust			2
Fair value of securities in trusts funded by reinsurer relating to indemnification	7,500,000,000	7,000,000,000
Liability related to long-term care insurance indemnification	0	0
Cash collateral available to reimburse losses realized under guarantees and indemnifications	46,000,000,000	48,000,000,000
Available-for-sale securities, pledged to creditors	70,000,000,000	41,000,000,000
Letters of credit in favor of the Company held as collateral	3,700,000,000	5,400,000,000
Investment Grade
Maximum potential amount of future payments
Total amount outstanding	99,700,000,000	106,400,000,000
Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	25,600,000,000	29,500,000,000
Not rated
Maximum potential amount of future payments
Total amount outstanding	302,500,000,000	269,300,000,000
Financial standby letters of credit
Maximum potential amount of future payments
Expire Within One Year	27,900,000,000	26,000,000,000
Expire After One Year	65,900,000,000	67,100,000,000
Total amount outstanding	93,800,000,000	93,100,000,000
Carrying value	93,000,000	141,000,000
Financial standby letters of credit | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	68,100,000,000	66,800,000,000
Financial standby letters of credit | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	10,900,000,000	13,400,000,000
Financial standby letters of credit | Not rated
Maximum potential amount of future payments
Total amount outstanding	14,800,000,000	12,900,000,000
Performance guarantees
Maximum potential amount of future payments
Expire Within One Year	7,200,000,000	7,500,000,000
Expire After One Year	4,100,000,000	3,600,000,000
Total amount outstanding	11,300,000,000	11,100,000,000
Carrying value	20,000,000	19,000,000
Performance guarantees | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	7,900,000,000	6,300,000,000
Performance guarantees | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	2,400,000,000	4,000,000,000
Performance guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	1,000,000,000	800,000,000
Derivative instruments considered to be guarantees
Maximum potential amount of future payments
Expire Within One Year	11,000,000,000	7,200,000,000
Expire After One Year	84,900,000,000	80,000,000,000
Total amount outstanding	95,900,000,000	87,200,000,000
Carrying value	423,000,000	747,000,000
Derivative instruments considered to be guarantees | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Derivative instruments considered to be guarantees | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Derivative instruments considered to be guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	95,900,000,000	87,200,000,000
Loans sold with recourse
Maximum potential amount of future payments
Expire Within One Year	0	0
Expire After One Year	200,000,000	200,000,000
Total amount outstanding	200,000,000	200,000,000
Carrying value	9,000,000	12,000,000
Repurchase reserve for Consumer mortgages representations and warranties	66,000,000	107,000,000
Loans sold with recourse | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Loans sold with recourse | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Loans sold with recourse | Not rated
Maximum potential amount of future payments
Total amount outstanding	200,000,000	200,000,000
Securities lending indemnifications
Maximum potential amount of future payments
Expire Within One Year	103,700,000,000	80,300,000,000
Expire After One Year	0	0
Total amount outstanding	103,700,000,000	80,300,000,000
Carrying value	0	0
Securities lending indemnifications | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Securities lending indemnifications | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Securities lending indemnifications | Not rated
Maximum potential amount of future payments
Total amount outstanding	103,700,000,000	80,300,000,000
Credit card merchant processing
Maximum potential amount of future payments
Expire Within One Year	85,500,000,000	86,400,000,000
Expire After One Year	0	0
Total amount outstanding	85,500,000,000	86,400,000,000
Carrying value	0	0
Maximum potential contingent liability related to bankcard and private-label merchant processing services	86,000,000,000	86,000,000,000
Credit card merchant processing | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Credit card merchant processing | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Credit card merchant processing | Not rated
Maximum potential amount of future payments
Total amount outstanding	85,500,000,000	86,400,000,000
Credit card arrangements with partners
Maximum potential amount of future payments
Expire Within One Year	300,000,000	0
Expire After One Year	1,100,000,000	1,500,000,000
Total amount outstanding	1,400,000,000	1,500,000,000
Carrying value	205,000,000	206,000,000
Credit card arrangements with partners | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Credit card arrangements with partners | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Credit card arrangements with partners | Not rated
Maximum potential amount of future payments
Total amount outstanding	1,400,000,000	1,500,000,000
Custody indemnifications and other
Maximum potential amount of future payments
Expire Within One Year	0	0
Expire After One Year	36,000,000,000	45,400,000,000
Total amount outstanding	36,000,000,000	45,400,000,000
Carrying value	59,000,000	58,000,000
Custody indemnifications and other | Investment Grade
Maximum potential amount of future payments
Total amount outstanding	23,700,000,000	33,300,000,000
Custody indemnifications and other | Non-Investment Grade
Maximum potential amount of future payments
Total amount outstanding	12,300,000,000	12,100,000,000
Custody indemnifications and other | Not rated
Maximum potential amount of future payments
Total amount outstanding	$ 0	0
Futures and over the counter derivatives clearing
Maximum potential amount of future payments
Number of types of margin | margin	2
Amount of cash initial margin collected and remitted	$ 10,700,000,000	$ 9,400,000,000

PLEDGED ASSETS, COLLATERAL, 178

PLEDGED ASSETS, COLLATERAL, GUARANTEES AND COMMITMENTS - Credit Commitments and Lines of Credit (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Credit Commitments
Credit commitments	$ 985,174	$ 960,231
Unsettled reverse repurchase and securities borrowing agreements	35,000	43,100
Unsettled repurchase and securities lending agreements	19,100	14,900
Commercial and similar letters of credit
Credit Commitments
Credit commitments	5,000	5,736
One-to four-family residential mortgages
Credit Commitments
Credit commitments	2,674	2,838
Revolving open-end loans secured by one-to four-family residential properties
Credit Commitments
Credit commitments	12,323	13,405
Commercial real estate, construction and land development
Credit Commitments
Credit commitments	11,151	10,781
Credit card lines
Credit Commitments
Credit commitments	678,300	664,335
Commercial and other consumer loan commitments
Credit Commitments
Credit commitments	272,655	259,934
Other commitments and contingencies
Credit Commitments
Credit commitments	3,071	$ 3,202
U.S.
Credit Commitments
Credit commitments	774,510
U.S. | Commercial and similar letters of credit
Credit Commitments
Credit commitments	904
U.S. | One-to four-family residential mortgages
Credit Commitments
Credit commitments	988
U.S. | Revolving open-end loans secured by one-to four-family residential properties
Credit Commitments
Credit commitments	10,825
U.S. | Commercial real estate, construction and land development
Credit Commitments
Credit commitments	9,594
U.S. | Credit card lines
Credit Commitments
Credit commitments	578,634
U.S. | Commercial and other consumer loan commitments
Credit Commitments
Credit commitments	171,383
U.S. | Other commitments and contingencies
Credit Commitments
Credit commitments	2,182
Outside U.S.
Credit Commitments
Credit commitments	210,664
Outside U.S. | Commercial and similar letters of credit
Credit Commitments
Credit commitments	4,096
Outside U.S. | One-to four-family residential mortgages
Credit Commitments
Credit commitments	1,686
Outside U.S. | Revolving open-end loans secured by one-to four-family residential properties
Credit Commitments
Credit commitments	1,498
Outside U.S. | Commercial real estate, construction and land development
Credit Commitments
Credit commitments	1,557
Outside U.S. | Credit card lines
Credit Commitments
Credit commitments	99,666
Outside U.S. | Commercial and other consumer loan commitments
Credit Commitments
Credit commitments	101,272
Outside U.S. | Other commitments and contingencies
Credit Commitments
Credit commitments	$ 889

CONTINGENCIES (Details)

CONTINGENCIES (Details) $ in Millions, € in Billions

Jan. 10, 2018USD ($)

Oct. 13, 2017USD ($)

Oct. 06, 2017USD ($)

Jul. 27, 2017USD ($)

Feb. 26, 2016USD ($)plaintiff

Dec. 15, 2015USD ($)

Jun. 16, 2015EUR (€)

Aug. 29, 2014USD ($)

Jan. 14, 2014USD ($)

Oct. 20, 2008USD ($)counterclaim

Dec. 31, 2017USD ($)actionsecuritization

Dec. 31, 2017USD ($)Depository_receipts

Sep. 07, 2016trust

Sep. 08, 2015trust

Nov. 24, 2014trust

Feb. 08, 2012USD ($)

Contingencies

Possible unaccrued loss

$ 1,000

$ 1,000

Number of depository receipts | Depository_receipts

35

Mortgage-backed securities trustee actions

Contingencies

Number of MBS trusts | trust

27

Number of MBS trusts dismissed from claims | trust

24

Number of MBS trusts allowed to proceed with claim | trust

3

3

Residential Mortgage-Backed Securities Investor Actions and Repurchase Claims

Contingencies

Number of actions filed | action

6

Number of private-label securitizations | securitization

4

Lehman Brothers Bankruptcy

Contingencies

Proofs of claims

$ 2,600

Bankruptcy claims clearing obligations amount to avoid from setoff related to terminated derivative contracts

$ 2,000

Tribune Company bankruptcy

Contingencies

Business acquisition price LBO

$ 11,000

$ 11,000

In Re Citigroup Inc. Securities Litigation | Mortgage-backed securities trustee actions

Contingencies

Aggregate original purchase amount of the purchases covered by tolling agreements

$ 500

$ 500

Lehman Brothers Bankruptcy Proceedings

Contingencies

Settlement amount awarded from other party

$ 350

Antitrust Litigation

Contingencies

Payments for legal settlements

$ 400

LIBOR-based Financial Instruments Antitrust Litigation

Contingencies

Settlement amount awarded to other party

$ 130

$ 33.4

Interchange Fees Litigation

Contingencies

Settlement amount awarded to other party

$ 6,050

Rebate to merchants (basis points)

0.0001

Period of collecting interchange fees

8 months

Oceanografia Fraud and Related Matters

Contingencies

Number of plaintiffs | plaintiff

39

Loss contingency damages sought

$ 1,100

Parmalat

Contingencies

Number of claims settled | counterclaim

3

Damages awarded

$ 431

$ 431

Parmalat | Milan Court of Appeal | Citibank, N.A.

Contingencies

Loss contingency damages sought | €

€ 1.8

Subsequent event | LIBOR-based Financial Instruments Antitrust Litigation

Contingencies

Settlement amount awarded to other party

$ 23

CONDENSED CONSOLIDATING FINA180

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statements of Income and Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Revenues
Dividends from subsidiaries										$ 0		$ 0		$ 0
Interest revenue	[1]									61,204		57,615		58,551
Interest revenue—intercompany										0		0		0
Interest expense	[1]									16,517		12,511		11,921
Interest expense—intercompany										0		0		0
Net interest revenue	[1]									44,687		45,104		46,630
Commissions and fees	[1]									12,939		11,938		14,485
Commissions and fees—intercompany										0		0		0
Principal transactions	[1]									9,168		7,585		6,008
Principal transactions—intercompany										0		0		0
Other income										4,655		5,248		9,231
Other income—intercompany										0		0		0
Total non-interest revenues	[1]									26,762		24,771		29,724
Total revenues, net of interest expense		$ 17,255	$ 18,173	$ 17,901	$ 18,120	$ 17,012	$ 17,760	$ 17,548	$ 17,555	71,449	[1]	69,875	[1]	76,354	[1]
Provisions for credit losses and for benefits and claims		2,073	1,999	1,717	1,662	1,792	1,736	1,409	2,045	7,451		6,982		7,913
Operating expenses
Compensation and benefits	[1]									21,181		20,970		21,769
Compensation and benefits—intercompany										0		0		0
Other operating										20,056		20,446		21,846
Other operating—intercompany										0		0		0
Total operating expenses		10,083	10,171	10,506	10,477	10,120	10,404	10,369	10,523	41,237	[1]	41,416	[1]	43,615	[1]
Equity in undistributed income of subsidiaries										0		0		0
Income (loss) from continuing operations before income taxes										22,761		21,477		24,826
Provision for income taxes (benefits)		23,864	1,866	1,795	1,863	1,509	1,733	1,723	1,479	29,388		6,444		7,440
Income (loss) from continuing operations		(18,765)	4,137	3,883	4,118	3,591	3,887	4,047	3,508	(6,627)		15,033		17,386
Loss from discontinued operations, net of taxes		(109)	(5)	21	(18)	(3)	(30)	(23)	(2)	(111)		(58)		(54)
Net income (loss) before attribution of noncontrolling interests		(18,874)	4,132	3,904	4,100	3,588	3,857	4,024	3,506	(6,738)		14,975		17,332
Noncontrolling interests		19	(1)	32	10	15	17	26	5	60		63		90
Citigroup’s net income (loss)		(18,893)	4,133	3,872	4,090	3,573	3,840	3,998	3,501	(6,798)		14,912		17,242
Comprehensive income
Add: Other comprehensive income (loss)	[2]									(2,791)		(3,022)		(6,128)
Citigroup’s total comprehensive income (loss)										(9,589)		11,890		11,114
Add: Other comprehensive income (loss) attributable to noncontrolling interests										114		(56)		(83)
Noncontrolling interests		$ 19	$ (1)	$ 32	$ 10	$ 15	$ 17	$ 26	$ 5	60		63		90
Total comprehensive income (loss)										(9,415)		11,897		11,121
Consolidating adjustments
Revenues
Dividends from subsidiaries										(22,499)		(15,570)		(13,500)
Interest revenue										0		0		0
Interest revenue—intercompany										0		0		0
Interest expense										0		0		0
Interest expense—intercompany										0		0		0
Net interest revenue										0		0		0
Commissions and fees										0		0		0
Commissions and fees—intercompany										0		0		0
Principal transactions										0		0		0
Principal transactions—intercompany										0		0		0
Other income										0		0		0
Other income—intercompany										0		0		0
Total non-interest revenues										0		0		0
Total revenues, net of interest expense										(22,499)		(15,570)		(13,500)
Provisions for credit losses and for benefits and claims										0		0		0
Operating expenses
Compensation and benefits										0		0		0
Compensation and benefits—intercompany										0		0		0
Other operating										0		0		0
Other operating—intercompany										0		0		0
Total operating expenses										0		0		0
Equity in undistributed income of subsidiaries										18,847		(871)		(4,601)
Income (loss) from continuing operations before income taxes										(3,652)		(16,441)		(18,101)
Provision for income taxes (benefits)										0		0		0
Income (loss) from continuing operations										(3,652)		(16,441)		(18,101)
Loss from discontinued operations, net of taxes										0		0		0
Net income (loss) before attribution of noncontrolling interests										(3,652)		(16,441)		(18,101)
Noncontrolling interests										0		0		0
Citigroup’s net income (loss)										(3,652)		(16,441)		(18,101)
Comprehensive income
Add: Other comprehensive income (loss)										6,086		(2,338)		(892)
Citigroup’s total comprehensive income (loss)										2,434		(18,779)		(18,993)
Add: Other comprehensive income (loss) attributable to noncontrolling interests										0		0		0
Noncontrolling interests										0		0		0
Total comprehensive income (loss)										2,434		(18,779)		(18,993)
Citigroup parent company | Reportable legal entities
Revenues
Dividends from subsidiaries										22,499		15,570		13,500
Interest revenue										1		7		9
Interest revenue—intercompany										3,972		3,008		2,880
Interest expense										4,766		4,419		4,563
Interest expense—intercompany										829		209		(475)
Net interest revenue										(1,622)		(1,613)		(1,199)
Commissions and fees										0		0		0
Commissions and fees—intercompany										(2)		(20)		0
Principal transactions										1,654		(1,025)		1,012
Principal transactions—intercompany										934		24		(1,733)
Other income										(2,581)		2,599		3,294
Other income—intercompany										5		(2,095)		(3,054)
Total non-interest revenues										10		(517)		(481)
Total revenues, net of interest expense										20,887		13,440		11,820
Provisions for credit losses and for benefits and claims										0		0		0
Operating expenses
Compensation and benefits										(107)		22		(58)
Compensation and benefits—intercompany										120		36		59
Other operating										(318)		482		271
Other operating—intercompany										(35)		217		247
Total operating expenses										(340)		757		519
Equity in undistributed income of subsidiaries										(18,847)		871		4,601
Income (loss) from continuing operations before income taxes										2,380		13,554		15,902
Provision for income taxes (benefits)										9,178		(1,358)		(1,340)
Income (loss) from continuing operations										(6,798)		14,912		17,242
Loss from discontinued operations, net of taxes										0		0		0
Net income (loss) before attribution of noncontrolling interests										(6,798)		14,912		17,242
Noncontrolling interests										0		0		0
Citigroup’s net income (loss)										(6,798)		14,912		17,242
Comprehensive income
Add: Other comprehensive income (loss)										(2,791)		(3,022)		(6,128)
Citigroup’s total comprehensive income (loss)										(9,589)		11,890		11,114
Add: Other comprehensive income (loss) attributable to noncontrolling interests										0		0		0
Noncontrolling interests										0		0		0
Total comprehensive income (loss)										(9,589)		11,890		11,114
CGMHI | Reportable legal entities
Revenues
Dividends from subsidiaries										0		0		0
Interest revenue										5,274		4,586		4,389
Interest revenue—intercompany										1,178		545		272
Interest expense										2,340		1,418		988
Interest expense—intercompany										2,297		1,659		1,304
Net interest revenue										1,815		2,054		2,369
Commissions and fees										5,139		4,340		4,872
Commissions and fees—intercompany										182		246		210
Principal transactions										1,019		5,576		5,532
Principal transactions—intercompany										1,200		(2,842)		(3,875)
Other income										855		183		403
Other income—intercompany										158		305		1,088
Total non-interest revenues										8,553		7,808		8,230
Total revenues, net of interest expense										10,368		9,862		10,599
Provisions for credit losses and for benefits and claims										0		0		0
Operating expenses
Compensation and benefits										4,403		4,719		5,003
Compensation and benefits—intercompany										0		0		0
Other operating										1,776		1,634		1,940
Other operating—intercompany										2,219		1,333		1,173
Total operating expenses										8,398		7,686		8,116
Equity in undistributed income of subsidiaries										0		0		0
Income (loss) from continuing operations before income taxes										1,970		2,176		2,483
Provision for income taxes (benefits)										873		746		537
Income (loss) from continuing operations										1,097		1,430		1,946
Loss from discontinued operations, net of taxes										0		0		0
Net income (loss) before attribution of noncontrolling interests										1,097		1,430		1,946
Noncontrolling interests										(1)		(13)		9
Citigroup’s net income (loss)										1,098		1,443		1,937
Comprehensive income
Add: Other comprehensive income (loss)										(117)		(26)		(125)
Citigroup’s total comprehensive income (loss)										981		1,417		1,812
Add: Other comprehensive income (loss) attributable to noncontrolling interests										0		0		0
Noncontrolling interests										(1)		(13)		9
Total comprehensive income (loss)										980		1,404		1,821
Other Citigroup subsidiaries and eliminations | Reportable legal entities
Revenues
Dividends from subsidiaries										0		0		0
Interest revenue										55,929		53,022		54,153
Interest revenue—intercompany										(5,150)		(3,553)		(3,152)
Interest expense										9,411		6,674		6,370
Interest expense—intercompany										(3,126)		(1,868)		(829)
Net interest revenue										44,494		44,663		45,460
Commissions and fees										7,800		7,598		9,613
Commissions and fees—intercompany										(180)		(226)		(210)
Principal transactions										6,495		3,034		(536)
Principal transactions—intercompany										(2,134)		2,818		5,608
Other income										6,381		2,466		5,534
Other income—intercompany										(163)		1,790		1,966
Total non-interest revenues										18,199		17,480		21,975
Total revenues, net of interest expense										62,693		62,143		67,435
Provisions for credit losses and for benefits and claims										7,451		6,982		7,913
Operating expenses
Compensation and benefits										16,885		16,229		16,824
Compensation and benefits—intercompany										(120)		(36)		(59)
Other operating										18,598		18,330		19,635
Other operating—intercompany										(2,184)		(1,550)		(1,420)
Total operating expenses										33,179		32,973		34,980
Equity in undistributed income of subsidiaries										0		0		0
Income (loss) from continuing operations before income taxes										22,063		22,188		24,542
Provision for income taxes (benefits)										19,337		7,056		8,243
Income (loss) from continuing operations										2,726		15,132		16,299
Loss from discontinued operations, net of taxes										(111)		(58)		(54)
Net income (loss) before attribution of noncontrolling interests										2,615		15,074		16,245
Noncontrolling interests										61		76		81
Citigroup’s net income (loss)										2,554		14,998		16,164
Comprehensive income
Add: Other comprehensive income (loss)										(5,969)		2,364		1,017
Citigroup’s total comprehensive income (loss)										(3,415)		17,362		17,181
Add: Other comprehensive income (loss) attributable to noncontrolling interests										114		(56)		(83)
Noncontrolling interests										61		76		81
Total comprehensive income (loss)										$ (3,240)		$ 17,382		$ 17,179
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.
[2]	Includes the impact of ASU 2018-02, adopted in the fourth quarter of 2017. See Note 1 to the Consolidated Financial Statements.

CONDENSED CONSOLIDATING FINA181

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 23,775	$ 23,043	$ 20,900	$ 32,108
Cash and due from banks—intercompany	0	0
Federal funds sold and resale agreements	232,478	236,813
Federal funds sold and resale agreements—intercompany	0	0
Trading account assets	251,556	243,925
Trading account assets—intercompany	0	0
Investments	352,290	353,304
Loans, net of unearned income	667,034	624,369
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	(12,355)	(12,060)	(12,626)	$ (15,994)
Total loans, net	654,679	612,309
Advances to subsidiaries	0	0
Investments in subsidiaries	0	0
Other assets	327,687	322,683
Other assets—intercompany	0	0
Total assets	1,842,465	1,792,077
Liabilities and equity
Deposits	959,822	929,406
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	156,277	141,821
Federal funds purchased and securities loaned or sold—intercompany	0	0
Trading account liabilities	124,047	139,045
Trading account liabilities—intercompany	0	0
Short-term borrowings, at fair value	44,452	30,701
Short-term borrowings—intercompany	0	0
Long-term debt, at fair value	236,709	206,178
Long-term debt—intercompany	0	0
Advances from subsidiaries	0	0
Other liabilities	119,486	118,783
Other liabilities—intercompany	0	0
Stockholders’ equity	201,672	226,143	$ 223,092
Total liabilities and equity	1,842,465	1,792,077
Other assets	105,160	128,008
Consolidating adjustments
Assets
Cash and due from banks	0	0
Cash and due from banks—intercompany	0	0
Federal funds sold and resale agreements	0	0
Federal funds sold and resale agreements—intercompany	0	0
Trading account assets	0	0
Trading account assets—intercompany	0	0
Investments	0	0
Loans, net of unearned income	0	0
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	0	0
Total loans, net	0	0
Advances to subsidiaries	0	0
Investments in subsidiaries	(210,537)	(226,279)
Other assets	0	0
Other assets—intercompany	0	0
Total assets	(210,537)	(226,279)
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	0	0
Federal funds purchased and securities loaned or sold—intercompany	0	0
Trading account liabilities	0	0
Trading account liabilities—intercompany	0	0
Short-term borrowings, at fair value	0	0
Short-term borrowings—intercompany	0	0
Long-term debt, at fair value	0	0
Long-term debt—intercompany	0	0
Advances from subsidiaries	0	0
Other liabilities	0	0
Other liabilities—intercompany	0	0
Stockholders’ equity	(210,537)	(226,279)
Total liabilities and equity	(210,537)	(226,279)
Citigroup parent company
Liabilities and equity
Long-term debt, at fair value	152,163
Other assets	29,700	20,700
Citigroup parent company | Reportable legal entities
Assets
Cash and due from banks	0	0
Cash and due from banks—intercompany	13	142
Federal funds sold and resale agreements	0	0
Federal funds sold and resale agreements—intercompany	0	0
Trading account assets	0	6
Trading account assets—intercompany	38	1,173
Investments	27	173
Loans, net of unearned income	0	0
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	0	0
Total loans, net	0	0
Advances to subsidiaries	139,722	143,154
Investments in subsidiaries	210,537	226,279
Other assets	10,844	23,734
Other assets—intercompany	14,428	27,845
Total assets	375,609	422,506
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	0	0
Federal funds purchased and securities loaned or sold—intercompany	0	0
Trading account liabilities	0	0
Trading account liabilities—intercompany	15	1,006
Short-term borrowings, at fair value	251	0
Short-term borrowings—intercompany	0	0
Long-term debt, at fair value	152,163	147,333
Long-term debt—intercompany	0	0
Advances from subsidiaries	19,136	41,258
Other liabilities	2,673	3,466
Other liabilities—intercompany	631	4,323
Stockholders’ equity	200,740	225,120
Total liabilities and equity	375,609	422,506
CGMHI | Reportable legal entities
Assets
Cash and due from banks	378	870
Cash and due from banks—intercompany	3,750	3,820
Federal funds sold and resale agreements	182,685	196,236
Federal funds sold and resale agreements—intercompany	16,091	12,270
Trading account assets	139,462	121,484
Trading account assets—intercompany	2,711	907
Investments	181	335
Loans, net of unearned income	900	575
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	0	0
Total loans, net	900	575
Advances to subsidiaries	0	0
Investments in subsidiaries	0	0
Other assets	61,647	46,095
Other assets—intercompany	48,832	38,207
Total assets	456,637	420,799
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	134,888	122,320
Federal funds purchased and securities loaned or sold—intercompany	18,597	25,417
Trading account liabilities	80,801	87,714
Trading account liabilities—intercompany	2,182	868
Short-term borrowings, at fair value	3,568	1,356
Short-term borrowings—intercompany	32,871	35,596
Long-term debt, at fair value	18,048	8,128
Long-term debt—intercompany	60,765	41,287
Advances from subsidiaries	0	0
Other liabilities	62,113	57,430
Other liabilities—intercompany	9,753	7,894
Stockholders’ equity	33,051	32,789
Total liabilities and equity	456,637	420,799
Other Citigroup subsidiaries and eliminations | Reportable legal entities
Assets
Cash and due from banks	23,397	22,173
Cash and due from banks—intercompany	(3,763)	(3,962)
Federal funds sold and resale agreements	49,793	40,577
Federal funds sold and resale agreements—intercompany	(16,091)	(12,270)
Trading account assets	112,094	122,435
Trading account assets—intercompany	(2,749)	(2,080)
Investments	352,082	352,796
Loans, net of unearned income	666,134	623,794
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	(12,355)	(12,060)
Total loans, net	653,779	611,734
Advances to subsidiaries	(139,722)	(143,154)
Investments in subsidiaries	0	0
Other assets	255,196	252,854
Other assets—intercompany	(63,260)	(66,052)
Total assets	1,220,756	1,175,051
Liabilities and equity
Deposits	959,822	929,406
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	21,389	19,501
Federal funds purchased and securities loaned or sold—intercompany	(18,597)	(25,417)
Trading account liabilities	43,246	51,331
Trading account liabilities—intercompany	(2,197)	(1,874)
Short-term borrowings, at fair value	40,633	29,345
Short-term borrowings—intercompany	(32,871)	(35,596)
Long-term debt, at fair value	66,498	50,717
Long-term debt—intercompany	(60,765)	(41,287)
Advances from subsidiaries	(19,136)	(41,258)
Other liabilities	54,700	57,887
Other liabilities—intercompany	(10,384)	(12,217)
Stockholders’ equity	178,418	194,513
Total liabilities and equity	1,220,756	1,175,051
Up to 30 days | Citigroup parent company
Liabilities and equity
Placements with term of less than 30 days	$ 18,900	$ 6,800

CONDENSED CONSOLIDATING FINA182

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities of continuing operations		$ (8,587)	$ 53,932	$ 39,737
Cash flows from investing activities of continuing operations
Purchases of investments		(185,740)	(211,402)	(242,362)
Proceeds from sales of investments	[1]	107,368	132,183	141,470
Proceeds from maturities of investments		84,369	65,525	82,047
Change in deposits with banks		(19,290)	(25,311)	15,488
Change in loans		(58,062)	(39,761)	1,353
Proceeds from sales and securitizations of loans		8,365	18,140	9,610
Proceeds from significant disposals	[2]	3,411	265	5,932
Change in federal funds sold and resales		4,335	(17,138)	22,895
Payments due to transfers of net liabilities associated with significant disposals	[2],[3]	0	0	(18,929)
Changes in investments and advances—intercompany		0	0	0
Other investing activities		(2,984)	(2,089)	(2,621)
Net cash provided by (used in) investing activities of continuing operations		(58,228)	(79,588)	14,883
Cash flows from financing activities of continuing operations
Dividends paid		(3,797)	(2,287)	(1,253)
Issuance of preferred stock		0	2,498	6,227
Treasury stock acquired		(14,541)	(9,290)	(5,452)
Proceeds (repayments) from issuance of long-term debt, net		26,974	8,346	(8,224)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0	0
Change in deposits		30,416	24,394	8,555
Change in federal funds purchased and repos		14,456	(4,675)	(26,942)
Change in short-term borrowings		13,751	9,622	(37,256)
Net change in short-term borrowings and other advances—intercompany		0	0	0
Capital contributions from parent		0	0
Other financing activities		(405)	(316)	(428)
Net cash provided by (used in) financing activities of continuing operations		66,854	28,292	(64,773)
Effect of exchange rate changes on cash and cash equivalents		693	(493)	(1,055)
Change in cash and due from banks		732	2,143	(11,208)
Cash and due from banks at beginning of period		23,043	20,900	32,108
Cash and due from banks at end of period		23,775	23,043	20,900
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		2,083	4,359	4,978
Cash paid during the year for interest		15,675	12,067	12,031
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS		0	0	(9,063)
Decrease in investments associated with significant disposals reclassified to HFS		0	0	(1,402)
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS		0	0	(223)
Decrease in deposits with banks with significant disposals reclassified to HFS				(404)
Transfers to loans HFS from loans		5,900	13,900	28,600
Transfers to OREO and other repossessed assets		113	165	276
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS		0	0	(4,673)
Consolidating adjustments
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities of continuing operations		0	0	0
Cash flows from investing activities of continuing operations
Purchases of investments		0	0	0
Proceeds from sales of investments		0	0	0
Proceeds from maturities of investments		0	0	0
Change in deposits with banks		0	0	0
Change in loans		0	0	0
Proceeds from sales and securitizations of loans		0	0	0
Proceeds from significant disposals		0	0	0
Change in federal funds sold and resales		0	0	0
Payments due to transfers of net liabilities associated with significant disposals				0
Changes in investments and advances—intercompany		0	0	0
Other investing activities		0	0	0
Net cash provided by (used in) investing activities of continuing operations		0	0	0
Cash flows from financing activities of continuing operations
Dividends paid		0	0	0
Issuance of preferred stock			0	0
Treasury stock acquired		0	0	0
Proceeds (repayments) from issuance of long-term debt, net		0	0	0
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0	0
Change in deposits		0	0	0
Change in federal funds purchased and repos		0	0	0
Change in short-term borrowings		0	0	0
Net change in short-term borrowings and other advances—intercompany		0	0	0
Capital contributions from parent		0	0
Other financing activities		0	0	0
Net cash provided by (used in) financing activities of continuing operations		0	0	0
Effect of exchange rate changes on cash and cash equivalents		0	0	0
Change in cash and due from banks		0	0	0
Cash and due from banks at beginning of period		0	0	0
Cash and due from banks at end of period		0	0	0
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		0	0	0
Cash paid during the year for interest		0	0	0
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS				0
Decrease in investments associated with significant disposals reclassified to HFS				0
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS				0
Decrease in deposits with banks with significant disposals reclassified to HFS				0
Transfers to loans HFS from loans		0	0	0
Transfers to OREO and other repossessed assets		0	0	0
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS				0
Citigroup parent company | Reportable legal entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities of continuing operations		34,940	12,777	27,825
Cash flows from investing activities of continuing operations
Purchases of investments		0	0	0
Proceeds from sales of investments		132	3,024	0
Proceeds from maturities of investments		0	234	237
Change in deposits with banks		0	0	0
Change in loans		0	0	0
Proceeds from sales and securitizations of loans		0	0	0
Proceeds from significant disposals		0	0	0
Change in federal funds sold and resales		0	0	0
Payments due to transfers of net liabilities associated with significant disposals				0
Changes in investments and advances—intercompany		(899)	(18,083)	(35,548)
Other investing activities		0	0	3
Net cash provided by (used in) investing activities of continuing operations		(767)	(14,825)	(35,308)
Cash flows from financing activities of continuing operations
Dividends paid		(3,797)	(2,287)	(1,253)
Issuance of preferred stock			2,498	6,227
Treasury stock acquired		(14,541)	(9,290)	(5,452)
Proceeds (repayments) from issuance of long-term debt, net		6,544	7,005	127
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0	0
Change in deposits		0	0	0
Change in federal funds purchased and repos		0	0	0
Change in short-term borrowings		49	(164)	(845)
Net change in short-term borrowings and other advances—intercompany		(22,152)	4,620	9,106
Capital contributions from parent		0	0
Other financing activities		(405)	(316)	(428)
Net cash provided by (used in) financing activities of continuing operations		(34,302)	2,066	7,482
Effect of exchange rate changes on cash and cash equivalents		0	0	0
Change in cash and due from banks		(129)	18	(1)
Cash and due from banks at beginning of period		142	124	125
Cash and due from banks at end of period		13	142	124
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		(3,730)	351	111
Cash paid during the year for interest		4,151	4,397	4,916
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS				0
Decrease in investments associated with significant disposals reclassified to HFS				0
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS				0
Decrease in deposits with banks with significant disposals reclassified to HFS				0
Transfers to loans HFS from loans		0	0	0
Transfers to OREO and other repossessed assets		0	0	0
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS				0
CGMHI | Reportable legal entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities of continuing operations		(33,359)	20,662	12,336
Cash flows from investing activities of continuing operations
Purchases of investments		(1)	(4)	(4)
Proceeds from sales of investments		0	0	53
Proceeds from maturities of investments		0	0	0
Change in deposits with banks		11,861	(3,643)	(8,414)
Change in loans		0	0	0
Proceeds from sales and securitizations of loans		0	0	0
Proceeds from significant disposals		0	0	0
Change in federal funds sold and resales		9,730	(15,293)	8,037
Payments due to transfers of net liabilities associated with significant disposals				0
Changes in investments and advances—intercompany		(2,790)	(5,574)	1,044
Other investing activities		(24)	0	(101)
Net cash provided by (used in) investing activities of continuing operations		18,776	(24,514)	615
Cash flows from financing activities of continuing operations
Dividends paid		0	0	0
Issuance of preferred stock			0	0
Treasury stock acquired		0	0	0
Proceeds (repayments) from issuance of long-term debt, net		4,909	5,916	(139)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		(2,031)	(9,453)	12,557
Change in deposits		0	0	0
Change in federal funds purchased and repos		5,748	3,236	(27,442)
Change in short-term borrowings		2,212	1,168	(1,737)
Net change in short-term borrowings and other advances—intercompany		3,931	680	4,054
Capital contributions from parent		(748)	5,000
Other financing activities		0	0	0
Net cash provided by (used in) financing activities of continuing operations		14,021	6,547	(12,707)
Effect of exchange rate changes on cash and cash equivalents		0	0	0
Change in cash and due from banks		(562)	2,695	244
Cash and due from banks at beginning of period		4,690	1,995	1,751
Cash and due from banks at end of period		4,128	4,690	1,995
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		678	92	175
Cash paid during the year for interest		4,513	3,115	2,346
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS				0
Decrease in investments associated with significant disposals reclassified to HFS				0
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS				0
Decrease in deposits with banks with significant disposals reclassified to HFS				0
Transfers to loans HFS from loans		0	0	0
Transfers to OREO and other repossessed assets		0	0	0
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS				0
Other Citigroup subsidiaries and eliminations | Reportable legal entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities of continuing operations		(10,168)	20,493	(424)
Cash flows from investing activities of continuing operations
Purchases of investments		(185,739)	(211,398)	(242,358)
Proceeds from sales of investments		107,236	129,159	141,417
Proceeds from maturities of investments		84,369	65,291	81,810
Change in deposits with banks		(31,151)	(21,668)	23,902
Change in loans		(58,062)	(39,761)	1,353
Proceeds from sales and securitizations of loans		8,365	18,140	9,610
Proceeds from significant disposals		3,411	265	5,932
Change in federal funds sold and resales		(5,395)	(1,845)	14,858
Payments due to transfers of net liabilities associated with significant disposals				(18,929)
Changes in investments and advances—intercompany		3,689	23,657	34,504
Other investing activities		(2,960)	(2,089)	(2,523)
Net cash provided by (used in) investing activities of continuing operations		(76,237)	(40,249)	49,576
Cash flows from financing activities of continuing operations
Dividends paid		0	0	0
Issuance of preferred stock			0	0
Treasury stock acquired		0	0	0
Proceeds (repayments) from issuance of long-term debt, net		15,521	(4,575)	(8,212)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		2,031	9,453	(12,557)
Change in deposits		30,416	24,394	8,555
Change in federal funds purchased and repos		8,708	(7,911)	500
Change in short-term borrowings		11,490	8,618	(34,674)
Net change in short-term borrowings and other advances—intercompany		18,221	(5,300)	(13,160)
Capital contributions from parent		748	(5,000)
Other financing activities		0	0	0
Net cash provided by (used in) financing activities of continuing operations		87,135	19,679	(59,548)
Effect of exchange rate changes on cash and cash equivalents		693	(493)	(1,055)
Change in cash and due from banks		1,423	(570)	(11,451)
Cash and due from banks at beginning of period		18,211	18,781	30,232
Cash and due from banks at end of period		19,634	18,211	18,781
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		5,135	3,916	4,692
Cash paid during the year for interest		7,011	4,555	4,769
Non-cash investing activities
Decrease in net loans associated with significant disposals reclassified to HFS				(9,063)
Decrease in investments associated with significant disposals reclassified to HFS				(1,402)
Decrease in goodwill and intangible assets associated with significant disposals reclassified to HFS				(223)
Decrease in deposits with banks with significant disposals reclassified to HFS				(404)
Transfers to loans HFS from loans		5,900	13,900	28,600
Transfers to OREO and other repossessed assets		$ 113	$ 165	276
Non-cash financing activities
Decrease in long-term debt associated with significant disposals reclassified to HFS				$ (4,673)
[1]	Proceeds for 2016 include approximately $3.3 billion from the sale of Citi’s investment in China Guangfa Bank.
[2]	See Note 2 to the Consolidated Financial Statements for further information on significant disposals.
[3]	The payments associated with significant disposals result primarily from the sale of deposit liabilities.

SELECTED QUARTERLY FINANCIAL183

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenues, net of interest expense	$ 17,255	$ 18,173	$ 17,901	$ 18,120	$ 17,012	$ 17,760	$ 17,548	$ 17,555					$ 71,449	[1]	$ 69,875	[1]	$ 76,354	[1]
Operating expenses	10,083	10,171	10,506	10,477	10,120	10,404	10,369	10,523					41,237	[1]	41,416	[1]	43,615	[1]
Provisions for credit losses and for benefits and claims	2,073	1,999	1,717	1,662	1,792	1,736	1,409	2,045					7,451		6,982		7,913
Income from continuing operations before income taxes	5,099	6,003	5,678	5,981	5,100	5,620	5,770	4,987
Provision for income taxes (benefits)	23,864	1,866	1,795	1,863	1,509	1,733	1,723	1,479					29,388		6,444		7,440
Income (loss) from continuing operations	(18,765)	4,137	3,883	4,118	3,591	3,887	4,047	3,508					(6,627)		15,033		17,386
Income (loss) from discontinued operations, net of taxes	(109)	(5)	21	(18)	(3)	(30)	(23)	(2)					(111)		(58)		(54)
Net income (loss) before attribution of noncontrolling interests	(18,874)	4,132	3,904	4,100	3,588	3,857	4,024	3,506					(6,738)		14,975		17,332
Noncontrolling interests	19	(1)	32	10	15	17	26	5					60		63		90
Citigroup’s net income (loss)	$ (18,893)	$ 4,133	$ 3,872	$ 4,090	$ 3,573	$ 3,840	$ 3,998	$ 3,501					$ (6,798)		$ 14,912		$ 17,242
Basic
Income (loss) from continuing operations (in dollars per share)	$ (7.33)	$ 1.42	$ 1.27	$ 1.36	$ 1.14	$ 1.25	$ 1.25	$ 1.11					$ (2.94)	[2]	$ 4.74	[2]	$ 5.43	[2]
Net income (loss) (in dollars per share)	(7.38)	1.42	1.28	1.35	1.14	1.24	1.24	1.10					(2.98)	[2]	4.72	[2]	5.41	[2]
Diluted
Income (loss) from continuing operations (in dollars per share)	(7.33)	1.42	1.27	1.36	1.14	1.25	1.25	1.11					(2.94)	[2]	4.74	[2]	5.42	[2]
Net income (loss) (in dollars per share)	(7.38)	1.42	1.28	1.35	1.14	1.24	1.24	1.10					(2.98)	[2]	4.72	[2]	$ 5.40	[2]
Common stock price per share
High (in dollars per share)	77.10	72.74	66.98	61.54	61.09	47.90	47.33	51.13					77.10		61.09
Low (in dollars per share)	71.33	65.95	57.72	55.68	47.03	40.78	38.48	34.98					71.33		47.03
Close (in dollars per share)	74.41	72.74	66.88	59.82	59.43	47.23	42.39	41.75					$ 74.41		$ 59.43
Dividends per share of common stock (in dollars per share)	$ 0.32	$ 0.32	$ 0.16	$ 0.16	$ 0.16	$ 0.16	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.01
[1]	Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.
[2]	Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.