Citigroup (C) 10-Q 1 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2018shares
Document and Entity Information
Entity Registrant Name	CITIGROUP INC
Entity Central Index Key	831,001
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	2,549,933,493
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1

CONSOLIDATED STATEMENT OF INCOM

CONSOLIDATED STATEMENT OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenues
Interest revenue		$ 16,332	$ 14,521
Interest expense		5,160	3,566
Net interest revenue		11,172	10,955
Commissions and fees		3,030	3,055
Principal transactions		3,289	3,094
Administration and other fiduciary fees		905	834
Realized gains on sales of investments, net		170	192
Impairment losses on investments
Gross impairment losses		(28)	(12)
Less: Impairments recognized in AOCI		0	0
Net impairment losses recognized in earnings		(28)	(12)
Other revenue		334	248
Total non-interest revenues		7,700	7,411
Total revenues, net of interest expense		18,872	18,366
Provisions for credit losses and for benefits and claims
Provision for loan losses		1,803	1,675
Policyholder benefits and claims		26	30
Release for unfunded lending commitments		28	(43)
Total provisions for credit losses and for benefits and claims		1,857	1,662
Operating expenses
Compensation and benefits		5,807	5,534
Premises and equipment		593	620
Technology/communication		1,758	1,663
Advertising and marketing		381	373
Other operating		2,386	2,533
Total operating expenses		10,925	10,723
Income from continuing operations before income taxes		6,090	5,981
Provision for income taxes		1,441	1,863
Income from continuing operations		4,649	4,118
Discontinued operations
Loss from discontinued operations		(7)	(28)
Benefit for income taxes		0	(10)
Loss from discontinued operations, net of taxes		(7)	(18)
Net income before attribution of noncontrolling interests		4,642	4,100
Noncontrolling interests		22	10
Citigroup’s net income		$ 4,620	$ 4,090
Basic earnings per share
Income from continuing operations (in dollars per share)	[1]	$ 1.68	$ 1.36
Income (loss) from discontinued operations, net of taxes (in dollars per share)	[1]	0	(0.01)
Net income (in dollars per share)	[1]	$ 1.68	$ 1.35
Weighted average common shares outstanding (in shares)		2,561.6	2,765.3
Diluted earnings per share
Income from continuing operations (in dollars per share)	[1]	$ 1.68	$ 1.36
Income (loss) from discontinued operations, net of taxes (in dollars per share)	[1]	0	(0.01)
Net income (in dollars per share)	[1]	$ 1.68	$ 1.35
Adjusted weighted average common shares outstanding (in shares)		2,563	2,765.5
[1]	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 (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Citigroup’s net income		$ 4,620	$ 4,090
Add: Citigroup's other comprehensive income
Net change in unrealized gains and losses on investment securities, net of taxes	[1],[2]	(1,058)	220
Net change in debt valuation adjustment (DVA), net of taxes	[2]	128	(60)
Net change in cash flow hedges, net of taxes		(222)	(2)
Benefit plans liability adjustment, net of taxes		88	(12)
Net change in foreign currency translation adjustment, net of taxes and hedges		1,120	1,318
Net change in excluded component of fair value hedges, net of taxes		(4)	0
Citigroup’s total other comprehensive income		52	1,464
Citigroup’s total comprehensive income		4,672	5,554
Add: Other comprehensive income attributable to noncontrolling interests		14	31
Add: Net income attributable to noncontrolling interests		22	10
Total comprehensive income		$ 4,708	$ 5,595
[1]	For the three months ended March 31, 2018, amount represents the net change in unrealized gains and losses on available-for-sale (AFS) debt securities. Effective January 1, 2018, the AFS category is eliminated for equity securities under ASU 2016-01.
[2]	See Note 1 to the Consolidated Financial Statements.

CONSOLIDATED BALANCE SHEET

CONSOLIDATED BALANCE SHEET - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks (including segregated cash and other deposits)	$ 21,850	$ 23,775
Deposits with banks	180,854	156,741
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	257,887	232,478
Brokerage receivables	46,572	38,384
Trading account assets (including $107,399 and $99,460 pledged to creditors at March 31, 2018 and December 31, 2017, respectively)	268,808	252,790
Investments:
Available-for-sale debt securities (including $14,312 and $9,493 pledged to creditors as of March 31, 2018 and December 31, 2017, respectively)	291,523	290,725
Held-to-maturity debt securities (including $1,063 and $435 pledged to creditors as of March 31, 2018 and December 31, 2017, respectively)	52,492	53,320
Equity securities (including $1,569 and $1,395 at fair value as of March 31, 2018 and December 31, 2017, respectively, of which $189 was available for sale as of December 31, 2017)	7,956
Equity securities (including $1,569 and $1,395 at fair value as of March 31, 2018 and December 31, 2017, respectively, of which $189 was available for sale as of December 31, 2017)		8,245
Total investments	351,971	352,290
Loans:
Loans, net of unearned income	672,938	667,034
Allowance for loan losses	(12,354)	(12,355)
Total loans, net	660,584	654,679
Goodwill	22,659	22,256
Intangible assets (other than MSRs)	4,450	4,588
Mortgage servicing rights (MSRs)	587	558
Other assets (including $20,443 and $18,559 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	105,882	103,926
Total assets	1,922,104	1,842,465
Liabilities
Non-interest-bearing deposits in U.S. offices	125,332	126,880
Interest-bearing deposits in U.S. offices (including $300 and $303 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	327,872	318,613
Non-interest-bearing deposits in offices outside the U.S.	90,477	87,440
Interest-bearing deposits in offices outside the U.S. (including $1,386 and $1,162 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	457,538	426,889
Total deposits	1,001,219	959,822
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	171,759	156,277
Brokerage payables	69,685	61,342
Trading account liabilities	143,961	125,170
Short-term borrowings (including $4,467 and $4,627 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	36,094	44,452
Long-term debt (including $33,571 and $31,392 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	237,938	236,709
Other liabilities (including $15,552 and $13,961 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	58,582	57,021
Total liabilities	1,719,238	1,640,793
Stockholders’ equity
Preferred stock ($1.00 par value; authorized shares: 30 million), issued shares: as of March 31, 2018—766,250 and as of December 31, 2017—770,120, at aggregate liquidation value	19,156	19,253
Common stock ($0.01 par value; authorized shares: 6 billion), issued shares: as of March 31, 2018—3,099,557,871 and as of December 31, 2017—3,099,523,273	31	31
Additional paid-in capital	107,599	108,008
Retained earnings	141,863	138,425
Treasury stock, at cost: March 31, 2018—549,624,378 shares and December 31, 2017—529,614,728 shares	(32,115)	(30,309)
Accumulated other comprehensive income (loss) (AOCI)	(34,619)	(34,668)
Total Citigroup stockholders’ equity	201,915	200,740
Noncontrolling interest	951	932
Total equity	202,866	201,672
Total liabilities and equity	1,922,104	1,842,465
Consumer
Loans:
Loans, net of unearned income	325,084	333,656
Allowance for loan losses	(10,039)	(9,869)
Corporate
Loans:
Loans, net of unearned income	347,854	333,378
Allowance for loan losses	(2,315)	(2,486)
Consolidated VIEs
Assets
Cash and due from banks (including segregated cash and other deposits)	34	52
Trading account assets (including $107,399 and $99,460 pledged to creditors at March 31, 2018 and December 31, 2017, respectively)	1,582	1,129
Investments:
Total investments	2,492	2,498
Loans:
Loans, net of unearned income	69,772	74,491
Allowance for loan losses	(1,923)	(1,930)
Total loans, net	67,849	72,561
Other assets (including $20,443 and $18,559 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	159	154
Total assets	72,116	76,394
Liabilities
Short-term borrowings (including $4,467 and $4,627 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	10,242	10,142
Long-term debt (including $33,571 and $31,392 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	30,406	30,492
Other liabilities (including $15,552 and $13,961 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	517	611
Total liabilities	41,165	41,245
Consolidated VIEs | Consumer
Loans:
Loans, net of unearned income	50,256	54,656
Consolidated VIEs | Corporate
Loans:
Loans, net of unearned income	$ 19,516	$ 19,835

CONSOLIDATED BALANCE SHEET (Par

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Federal funds sold and securities borrowed or purchased under agreements to resell, at fair value	$ 257,887	$ 232,478
Trading account assets, pledged to creditors	107,399	99,460
Available-for-sale securities, pledged to creditors	14,312	9,493
Held-to-maturity securities, pledged to creditors	1,063	435
Equity securities, available for sale		189
Loans, net of unearned income	672,938	667,034
Other assets, at fair value	105,882	103,926
Interest-bearing deposits in U.S. offices	327,872	318,613
Interest-bearing deposits in offices outside the U.S.	457,538	426,889
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	171,759	156,277
Short-term borrowings, at fair value	36,094	44,452
Long-term debt, at fair value	237,938	236,709
Other liabilities	$ 58,582	$ 57,021
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)	766,250	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)	3,099,557,871	3,099,523,273
Treasury stock (in shares)	549,624,378	529,614,728
Consumer
Loans, net of unearned income	$ 325,084	$ 333,656
Corporate
Loans, net of unearned income	347,854	333,378
Fair value
Federal funds sold and securities borrowed or purchased under agreements to resell, at fair value	161,537	132,949
Non-marketable equity securities, pledged to creditors	1,569	1,395
Other assets, at fair value	20,443	18,559
Interest-bearing deposits in U.S. offices	300	303
Interest-bearing deposits in offices outside the U.S.	1,386	1,162
Federal funds purchased and securities loaned or sold under agreements to repurchase, at fair value	45,840	40,638
Short-term borrowings, at fair value	4,467	4,627
Long-term debt, at fair value	33,571	31,392
Other liabilities	15,552	13,961
Fair value | Consumer
Loans, net of unearned income	23	25
Fair value | Corporate
Loans, net of unearned income	$ 4,513	$ 4,349

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ 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
Balance, beginning of period at Dec. 31, 2016				$ 19,253		$ 108,073	$ 146,477		$ (16,302)		$ (32,381)	$ 1,023
Increase (Decrease) in Stockholders' Equity
Redemption of preferred stock				0
Adjustment to opening balance, net of taxes at Dec. 31, 2016	[1]						(660)				504
Adjusted balance, beginning of period at Dec. 31, 2016							145,817				(31,877)
Increase (Decrease) in Stockholders' Equity
Employee benefit plans						(426)			507	[2]
Preferred stock issuance expense						0
Other						(3)	(90)	[3]				(42)
Citigroup’s net income		$ 4,100					4,090					10
Common dividends	[4]						(445)
Preferred dividends		(301)					(301)
Treasury stock acquired	[5]								(1,784)
Citigroup's total other comprehensive income (loss)											1,464	31
Transactions between Citigroup and the noncontrolling-interest shareholders												(1)
Net change in noncontrolling interests												(2)
Balance, end of period at Mar. 31, 2017		228,997	$ 227,976	19,253	$ 208,723	107,644	149,071		(17,579)		(30,413)	1,021
Balance, beginning of period at Dec. 31, 2017		201,672		19,253		108,039	138,425		(30,309)		(34,668)	932
Increase (Decrease) in Stockholders' Equity
Redemption of preferred stock				(97)
Adjustment to opening balance, net of taxes at Dec. 31, 2017	[1]						(84)				(3)
Adjusted balance, beginning of period at Dec. 31, 2017							138,341				(34,671)
Increase (Decrease) in Stockholders' Equity
Employee benefit plans						(405)			469	[2]
Preferred stock issuance expense						0
Other						(4)	0	[3]				(2)
Citigroup’s net income		4,642					4,620					22
Common dividends	[4]						(826)
Preferred dividends		(272)					(272)
Treasury stock acquired	[5]								(2,275)
Citigroup's total other comprehensive income (loss)											52	14
Transactions between Citigroup and the noncontrolling-interest shareholders												(15)
Net change in noncontrolling interests												19
Balance, end of period at Mar. 31, 2018		$ 202,866	$ 201,915	$ 19,156	$ 182,759	$ 107,630	$ 141,863		$ (32,115)		$ (34,619)	$ 951
[1]	See Note 1 to the Consolidated Financial Statements for additional details.
[2]	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.
[3]	Includes the impact of ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. See Note 1 to the Consolidated Financial Statements.
[4]	Common dividends declared were $0.32 per share in the first quarter of 2018 and $0.16 per share in the first quarter of 2017.
[5]	For the three months ended March 31, 2018 and 2017, primarily consists of open market purchases under Citi’s Board of Directors-approved common stock repurchase program.

CONSOLIDATED STATEMENT OF CHAN7

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Common dividends declared (in dollars per share)	$ 0.32	$ 0.16

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities of continuing operations
Net income before attribution of noncontrolling interests		$ 4,642	$ 4,100
Net income attributable to noncontrolling interests		22	10
Citigroup’s net income		4,620	4,090
Loss from discontinued operations, net of taxes		(7)	(18)
Income from continuing operations—excluding noncontrolling interests		4,627	4,108
Adjustments to reconcile net income to net cash provided by operating activities of continuing operations
Net gains on significant disposals		0	(19)
Depreciation and amortization		926	896
Provision for loan losses		1,803	1,675
Realized gains from sales of investments		(170)	(192)
Net impairment losses on investments, goodwill and intangible assets		28	40
Change in trading account assets		(16,054)	30
Change in trading account liabilities		18,791	4,457
Change in brokerage receivables net of brokerage payables		155	(5,498)
Change in loans HFS		1,627	1,949
Change in other assets		(3,503)	(1,926)
Change in other liabilities		1,561	(5,117)
Other, net		(2,835)	(3,455)
Total adjustments		2,329	(7,160)
Net cash provided by (used in) operating activities of continuing operations		6,956	(3,052)
Cash flows from investing activities of continuing operations
Change in federal funds sold and securities borrowed or purchased under agreements to resell		(25,409)	(6,116)
Change in loans		(8,717)	(7,953)
Proceeds from sales and securitizations of loans		1,654	3,191
Purchases of investments		(41,030)	(41,584)
Proceeds from sales of investments		20,688	29,456
Proceeds from maturities of investments		21,509	24,006
Proceeds from significant disposals	[1]	0	2,732
Capital expenditures on premises and equipment and capitalized software		(969)	(786)
Proceeds from sales of premises and equipment, subsidiaries and affiliates and repossessed assets		101	133
Other, net		49	46
Net cash provided by (used in) investing activities of continuing operations		(32,124)	3,125
Cash flows from financing activities of continuing operations
Dividends paid		(1,095)	(744)
Redemption of preferred stock		(97)	0
Treasury stock acquired		(2,378)	(1,858)
Stock tendered for payment of withholding taxes		(475)	(397)
Change in federal funds purchased and securities loaned or sold under agreements to repurchase		15,482	6,409
Issuance of long-term debt		20,769	18,603
Payments and redemptions of long-term debt		(17,882)	(18,885)
Change in deposits		41,397	20,584
Change in short-term borrowings		(8,358)	(4,574)
Net cash provided by financing activities of continuing operations		47,363	19,138
Effect of exchange rate changes on cash and due from banks		(7)	340
Change in cash and due from banks and deposits with banks	[2]	22,188	19,551
Cash, due from banks and deposits with banks at beginning of period	[2]	180,516	160,494
Cash, due from banks and deposits with banks at end of period	[2]	202,704	180,045
Cash and due from banks		21,850	22,272
Deposits with banks		180,854	157,773
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		738	913
Cash paid during the period for interest		4,586	3,250
Non-cash investing activities
Transfers to loans HFS from loans		900	2,800
Transfers to OREO and other repossessed assets		$ 26	$ 30
[1]	See Note 2 to the Consolidated Financial Statements for further information on significant disposals.
[2]	Includes the impact of ASU 2016-18, Restricted Cash. See Note 1 to the Consolidated Financial Statements.

BASIS OF PRESENTATION AND ACCOU

BASIS OF PRESENTATION AND ACCOUNTING CHANGES	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
BASIS OF PRESENTATION AND ACCOUNTING CHANGES	BASIS OF PRESENTATION AND ACCOUNTING CHANGES Basis of Presentation The accompanying unaudited Consolidated Financial Statements as of March 31, 2018 and for the three-month periods ended March 31, 2018 and 2017 include the accounts of Citigroup Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation have been reflected. The accompanying unaudited Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and related notes included in Citigroup’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 . Certain financial information that is normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles (GAAP), but is not required for interim reporting purposes, has been condensed or omitted. Management must make estimates and assumptions that affect the Consolidated Financial Statements and the related footnote disclosures. While management uses its best judgment, actual results could differ from those estimates. As noted above, the Notes to Consolidated Financial Statements are unaudited. 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. ACCOUNTING CHANGES Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers (Revenue Recognition), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU defines the promised good or service as the performance obligation under the contract. While the guidance replaces most existing revenue recognition guidance in GAAP, the ASU is not applicable to financial instruments and, therefore, does not impact a majority of the Company’s revenues, including net interest income, loan fees, gains on sales and mark-to-market accounting. In accordance with the new revenue recognition standard, Citi has identified the specific performance obligation (promised services) associated with the contract with the customer and has determined when that specific performance obligation has been satisfied, which may be at a point in time or over time depending on how the performance obligation is defined. The contracts with customers also contain the transaction price, which consists of fixed consideration and/or consideration that may vary (variable consideration), and is defined as the amount of consideration an entity expects to be entitled to when or as the performance obligation is satisfied, excluding amounts collected on behalf of third parties (including transaction taxes). The amounts recognized at the point in time the performance obligation is satisfied may differ from the ultimate transaction price associated with that performance obligation when a portion of it is based on variable consideration. For example some consideration is based on the client’s month-end balance or market values which are unknown at the time the contract is executed. The remaining transaction price amount, if any, will be recognized as the variable consideration becomes determinable. In certain transactions, the performance obligation is considered satisfied at a point in time in the future. In this instance, Citi defers revenue on the balance sheet that will only be recognized upon completion of the performance obligation. The new revenue recognition standard further clarified the guidance related to reporting revenue gross as principal versus net as an agent. In many cases, Citi outsources a component of its performance obligations to third parties. The Company has determined that it acts as principal in the majority of these transactions and therefore presents the amounts paid to these third parties gross within operating expenses. The Company has retrospectively adopted this standard as of January 1, 2018 and as a result was required to report amounts paid to third parties where Citi is principal to the contract within Operating expenses. The adoption resulted in an increase in both revenue and expenses of approximately $250 million for the three-month periods ended March 31, 2018 and March 31, 2017, respectively, while increasing approximately $1 billion for the year ended December 31, 2017 with similar amounts for prior periods. Prior to adoption, these expense amounts were reported as contra revenue primarily within Commissions and fees and Administration and other fiduciary fees revenue. Accordingly, prior periods have been reclassified to conform to the new presentation. See Note 5 to the Consolidated Financial Statements for a description of the Company’s revenue recognition policies for Commissions and fees and Administration and other fiduciary fees . Income Tax Impact of Intra-Entity Transfers of Assets In October 2016, the FASB issued ASU No. 2016-16, Income Taxes—Intra-Entity Transfers of Assets Other Than Inventory , which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The ASU was effective January 1, 2018 and was adopted as of that date. The impact of this standard was an increase of DTAs by approximately $300 million , a decrease of retained earnings by approximately $80 million and a decrease of prepaid tax assets by approximately $380 million . Clarifying the Definition of a Business In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The definition of a business directly and indirectly affects many areas of accounting (e.g., acquisitions, disposals, goodwill and consolidation). The ASU narrows the definition of a business by introducing a quantitative screen as the first step, such that if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the set of transferred assets and activities is not a business. If the set is not scoped out from the quantitative screen, the entity then evaluates whether the set meets the requirement that a business include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs. The ASU was effective for public entities, including Citi, as of January 1, 2018 with prospective application. The impact of the ASU will depend upon the acquisition and disposal activities of Citi. If fewer transactions qualify as a business, there could be less initial recognition of goodwill, but also less goodwill allocated to disposals. Changes in Accounting for Pension and Postretirement (Benefit) Expense In March 2017, the FASB issued ASU No. 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost , which changes the income statement presentation of net benefit expense and requires restating the Company’s financial statements for each of the earlier periods presented in Citi’s annual and interim financial statements. The change in presentation was effective for annual and interim periods starting January 1, 2018. The ASU requires that only the service cost component of net benefit expense be included in Compensation and benefits on the income statement. The other components of net benefit expense will be required to be presented outside of Compensation and benefits and will be presented in Other operating expense . Since both of these income statement line items are part of Operating expenses , total Operating expenses will not change, nor will there be any change in Net income . This change in presentation did not have a material effect on Compensation and benefits and Other operating expenses and is applied prospectively. The components of the net benefit expense are currently disclosed in Note 7 to the Consolidated Financial Statements. The new standard also changes the components of net benefit expense that are eligible for capitalization when employee costs are capitalized in connection with various activities, such as internally developed software, construction-in-progress, and loan origination costs. Prospectively from January 1, 2018, only the service cost component of net benefit expense may be capitalized. Existing capitalized balances are not affected. This change in amounts eligible for capitalization does not have a material effect on the Company’s Consolidated Financial Statements and related disclosures. Hedging In August 2017, the FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities , which better aligns an entity’s risk management activities and financial reporting for hedging relationships through changes to the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The ASU requires the change in the fair value of the hedging instrument to be presented in the same income statement line as the hedged item and also requires expanded disclosures. Citi adopted this standard on January 1, 2018 and transferred approximately $4 billion of pre-payable mortgage backed securities and municipal bonds held-to-maturity (HTM) securities into available-for-sale (AFS) classification as permitted as a one-time transfer under the standard as these assets were deemed to be eligible to be hedged under the last of layer hedge strategy. The impact to opening retained earnings was immaterial. See Note 19 to the Consolidated Financial Statements for more information. 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. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments—Overall (Subtopic 825-10) , to clarify certain provisions in ASU 2016-01. The ASUs require 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 the AFS category for equity investments. However, Federal Reserve Bank and Federal Home Loan Bank stock, as well as certain exchange seats, will continue to be presented at cost. The ASUs also provide an instrument-by-instrument election to measure non-marketable equity investments using a measurement alternative. Under the measurement alternative, the investment is carried at cost plus or minus changes resulting from observable prices in orderly transactions for the identical or a similar investment of the same issuer, less impairment (if any). Finally, the ASUs require that fair value disclosures for financial instruments not measured at fair value on the balance sheet be presented at their exit prices (e.g., held-for-investment loans). Citi early adopted the provisions of ASU 2016-01 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 Accumulated other comprehensive income (loss) (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 17, 20 and 21 to the Consolidated Financial Statements. The other provisions of ASU 2016-01 are effective January 1, 2018. The provisions of ASU 2018-03 are effective July 1, 2018 for interim financial statements, but may be early adopted in any interim period starting January 1, 2018 as long as ASU 2016-01 is also adopted. Citi has adopted both ASU 2016-01 and ASU 2018-03 as of January 1, 2018. Accordingly, as of the first quarter of 2018, the changes to accounting for equity securities and fair value disclosures have been reflected in Citigroup’s financial statements. The impact of adopting the change to AFS equity securities resulted in a cumulative catch-up reclassification from AOCI to retained earnings of an accumulated after-tax gain of approximately $3 million at January 1, 2018. Citi elected the measurement alternative for all non-marketable equity investments that no longer qualify for cost measurement under the ASUs. This provision in the ASUs was adopted prospectively. Financial statements for periods prior to 2018 were not subject to restatement under the provisions of the ASUs. For additional information, see Notes 12, 17 and 20 to the Consolidated Financial Statements. Statement of Cash Flows In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , which requires that companies present cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents (restricted cash) when reconciling beginning-of-period and end-of-period totals on the Statement of Cash Flows. In connection with the adoption of the ASU, Citigroup also changed its definition of cash and cash equivalents to include all of Cash and due from banks and predominately all of Deposits with banks. The Company has retrospectively adopted this ASU as of January 1, 2018 and as a result Net cash provided by investing activities of continuing operations on the Statement of Cash Flows increased by $20.3 billion for the three months ended March 31, 2017. Citigroup defines restricted cash (as cash subject to withdrawal restrictions) to include cash deposited with central banks that must be maintained to meet minimum regulatory requirements, and cash set aside for the benefit of customers or for other purposes such as compensating balance arrangements or debt retirement. Restricted cash includes minimum reserve requirements with the Federal Reserve Bank and certain other central banks and cash segregated to satisfy rules regarding the protection of customer assets as required by Citigroup broker-dealers’ primary regulators, including the Securities and Exchange Commission, the Commodities Futures Trading Commission and the United Kingdom’s Prudential Regulation Authority. Cash and due from banks includes restricted cash of $84 million and $39 million at March 31, 2018 and December 31, 2017, respectively. Deposits with banks includes restricted cash of $29.0 billion and $36.7 billion at March 31, 2018 and December 31, 2017, respectively. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments , which provides guidance on the classification and presentation of certain cash receipts and payments on the Statement of Cash Flows. The Company has retrospectively adopted this ASU as of January 1, 2018 which resulted in immaterial changes to Citi’s Consolidated Statement of Cash Flows. Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued Accounting Standards Update (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. For calendar-year-end entities, 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 AFS and HTM portfolios of callable state and municipal debt 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 debt securities.

DISCONTINUED OPERATIONS AND SIG

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS	3 Months Ended
	Mar. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS	DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS Summary of Discontinued Operations Citi sold the Egg Banking plc credit card business in 2011. Residual costs from the disposal resulted in losses from Discontinued operations , net of taxes, of $7 million and $18 million for the three months ended March 31, 2018 and March 31, 2017, respectively. All Discontinued operations results are recorded within Corporate/Other. The following summarizes financial information for all discontinued operations: Three Months Ended March 31, In millions of dollars 2018 2017 Total revenues, net of interest expense $ — $ — Loss from discontinued operations $ (7 ) $ (28 ) Benefit for income taxes — (10 ) Loss from discontinued operations, net of taxes $ (7 ) $ (18 ) Cash flows for discontinued operations were not material for the periods presented. Significant Disposals There were no new significant disposal transactions during the three months ended March 31, 2018. For a description of the Company’s significant disposal transactions and financial impact, see Note 2 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K.

BUSINESS SEGMENTS

BUSINESS SEGMENTS	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
BUSINESS SEGMENTS	BUSINESS SEGMENTS Citigroup’s activities are conducted through the following business segments: Global Consumer Banking (GCB) and ICG . In addition, Corporate/Other includes activities not assigned to a specific business segment, as well as certain North America and international loan portfolios, discontinued operations and other legacy assets. The prior-period balances reflect reclassifications to conform the presentation for all periods to the current period’s presentation. Effective January 1, 2018, financial data was reclassified to reflect: • adoption of ASU No. 2014-09, Revenue Recognition , which occurred on January 1, 2018 on a retrospective basis. See “Accounting Changes” in Note 1 to the Consolidated Financial Statements; • the re-attribution of certain costs between Corporate/Other and GCB and 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. For additional information regarding Citigroup’s business segments, see Note 3 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. The following table presents certain information regarding the Company’s continuing operations by segment: Three Months Ended March 31, Revenues, (1) Provision (benefits) Income (loss) from (2) Identifiable assets In millions of dollars, except identifiable assets in billions 2018 2017 2018 2017 2018 2017 March 31, December 31, 2017 Global Consumer Banking $ 8,433 $ 7,846 $ 453 $ 582 $ 1,394 $ 998 $ 423 $ 428 Institutional Clients Group 9,848 9,319 1,057 1,375 3,329 3,011 1,407 1,336 Corporate/Other 591 1,201 (69 ) (94 ) (74 ) 109 92 78 Total $ 18,872 $ 18,366 $ 1,441 $ 1,863 $ 4,649 $ 4,118 $ 1,922 $ 1,842 (1) Includes total revenues, net of interest expense (excluding Corporate/Other ), in North America of $8.4 billion and $8.5 billion ; in EMEA of $3.2 billion and $2.9 billion ; in Latin America of $2.6 billion and $2.3 billion ; and in Asia of $4.1 billion and $3.5 billion for the three months ended March 31, 2018 and 2017 , respectively. These regional numbers exclude Corporate/Other , which largely operates within the U.S. (2) Includes pretax provisions for credit losses and for benefits and claims in the GCB results of $1.9 billion and $1.8 billion ; in the ICG results of $(41) million and $(205) million ; and in the Corporate/Other results of $(7) million and $52 million for the three months ended March 31, 2018 and 2017 , respectively.

INTEREST REVENUE AND EXPENSE

INTEREST REVENUE AND EXPENSE	3 Months Ended
	Mar. 31, 2018
Banking and Thrift, Interest [Abstract]
INTEREST REVENUE AND EXPENSE	INTEREST REVENUE AND EXPENSE Interest revenue and Interest expense consisted of the following: Three Months Ended March 31, In millions of dollars 2018 2017 Interest revenue Loan interest, including fees $ 10,892 $ 10,045 Deposits with banks 432 295 Federal funds sold and securities borrowed or purchased under agreements to resell 1,039 661 Investments, including dividends 2,234 1,960 Trading account assets (1) 1,371 1,266 Other interest 364 294 Total interest revenue $ 16,332 $ 14,521 Interest expense Deposits (2) $ 1,997 $ 1,415 Federal funds purchased and securities loaned or sold under agreements to repurchase 949 493 Trading account liabilities (1) 215 147 Short-term borrowings 471 199 Long-term debt 1,528 1,312 Total interest expense $ 5,160 $ 3,566 Net interest revenue $ 11,172 $ 10,955 Provision for loan losses 1,803 1,675 Net interest revenue after provision for loan losses $ 9,369 $ 9,280 (1) Interest expense on Trading account liabilities is reported as a reduction of interest revenue from Trading account assets . (2) Includes deposit insurance fees and charges of $376 million and $305 million for the three months ended March 31, 2018 and 2017 , respectively.

COMMISSIONS AND FEES; ADMINISTR

COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES	3 Months Ended
	Mar. 31, 2018
Fees and Commissions [Abstract]
COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES	COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES The primary components of Commissions and fees revenue are investment banking fees, brokerage commissions, credit- and bank-card income and deposit-related fees. Investment banking fees are substantially composed of underwriting and advisory revenues. Such fees are recognized at the point in time when Citigroup’s performance under the terms of a contractual arrangement is completed, which is typically at the closing of a transaction. Reimbursed expenses related to this transactions are recorded as revenue and are included within investment banking fees. In certain instances for advisory contracts, Citi will receive amounts in advance of the deal closing. In these instances, the amounts received will be recognized as a liability and not recognized in revenue until the transaction closes. The contract liability amount for the years presented was negligible. Out-of-pocket expenses associated with underwriting activity are deferred and recognized at the time the related revenue is recognized, while out-of-pocket expenses associated with advisory arrangements are expensed as incurred. In general, expenses incurred related to investment banking transactions, whether consummated or not, are recorded in Other operating expenses . The Company has determined that it acts as principal in the majority of these transactions and therefore presents expenses gross within Other operating expenses . Brokerage commissions 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. Brokerage commissions are recognized in Commissions and fees at the point in time the associated service is fulfilled, generally on trade-execution date. Gains or losses, if any, on these transactions are included in Principal transactions (see Note 6 to the Consolidated Financial Statements). Sales of certain investment products include a portion of variable consideration associated with the underlying product. In these instances, a portion of the revenue associated with the sale of the product is not recognized until the variable consideration becomes fixed. The Company recognized $148 million of revenue related to such variable consideration in the first quarter of 2018, compared with $96 million in the first quarter of 2017. These amounts primarily relate to performance obligations satisfied in prior periods. Credit- and bank-card income is primarily composed of interchange fees, which are earned by card issuers based on purchase sales, and certain card fees, including annual fees. Costs related to customer reward programs and certain payments to partners (primarily based on program sales, profitability and customer acquisitions) are recorded as a reduction of Credit and bank card income. Interchange revenues are recognized as earned on a daily basis when Citi's performance obligation to transmit funds to the payment networks has been satisfied. Annual card fees, net of origination costs, are deferred and amortized on a straight-line basis over a 12-month period. Costs related to card reward programs are recognized when the rewards are earned by the cardholders. Payments to partners are recognized when incurred. Deposit-related fees consist of service charges on deposit accounts and fees earned from performing cash management activities and other deposit account services. Such fees are recognized in the period in which the related service is provided. Transactional service fees primarily consist of fees charged for processing services such as cash management, global payments, clearing, international funds transfer, and other trade services. Such fees are recognized as/when the associated service is satisfied, which normally occurs at the point in time the service is requested by the customer and provided by Citi. Insurance distribution revenue consists of commissions earned from third-party insurance companies for marketing and selling insurance policies on behalf of such entities. Such commissions are recognized in Commissions and fees at the point in time the associated service is fulfilled, generally when the insurance policy is sold to the policyholder. Sales of certain insurance products include a portion of variable consideration associated with the underlying product. In these instances, a portion of the revenue associated with the sale of the policy is not recognized until the variable consideration becomes determinable. The Company recognized $103 million of revenue related to such variable consideration in the first quarter of 2018, compared with $120 million in the first quarter of 2017. These amounts primarily relate to performance obligations satisfied in prior periods. Insurance premiums consist of premium income from insurance policies which Citi has underwritten and sold to policyholders. The following tables present Commissions and fees revenue: Three Months Ended March 31, 2018 In millions of dollars ICG GCB Corporate/Other Total Investment banking $ 822 $ — $ — $ 822 Brokerage commissions 566 248 — 814 Credit- and bank-card income Interchange fees 260 1,875 5 2,140 Card-related loan fees 14 155 6 175 Card rewards and partner payments (124 ) (1,874 ) (5 ) (2,003 ) Deposit-related fees (1) 236 183 1 420 Transactional service fees 190 21 2 213 Corporate finance (2) 142 1 — 143 Insurance distribution revenue (3) 5 143 5 153 Insurance premiums (3) — 33 (1 ) 32 Loan servicing 38 22 12 72 Other 15 32 2 49 Total commissions and fees (4) $ 2,164 $ 839 $ 27 $ 3,030 Three Months Ended March 31, 2017 In millions of dollars ICG GCB Corporate/Other Total Investment banking $ 904 $ — $ — $ 904 Brokerage commissions 482 193 1 676 Credit- and bank-card income Interchange fees 222 1,703 40 1,965 Card-related loan fees 12 167 16 195 Card rewards and partner payments (103 ) (1,685 ) (27 ) (1,815 ) Deposit-related fees (1) 208 185 4 397 Transactional service fees 174 27 24 225 Corporate finance (2) 184 1 — 185 Insurance distribution revenue (3) 2 144 25 171 Insurance premiums (3) — 33 (1 ) 32 Loan servicing 35 26 31 92 Other (20 ) 25 23 28 Total commissions and fees (4) $ 2,100 $ 819 $ 136 $ 3,055 (1) Includes $32 million and $33 million of overdraft fees in the first quarter of 2018 and the first quarter of 2017, respectively. Overdraft fees are accounted for under ASC 310. (2) Consists primarily of fees earned from structuring and underwriting loan syndications or related financing activity. This activity is accounted for under ASC 310. (3) Previously reported as insurance premiums on the Consolidated Statement of Income. (4) Commissions and fees includes $(1,545) million and $(1,278) million not accounted for under ASC 606, Revenue from Contracts with Customers , for the first quarters of 2018 and 2017, respectively. Amounts reported in Commissions and fees accounted for under other guidance primarily include card-related loan fees, card reward programs and certain partner payments, corporate finance fees, insurance premiums, and loan servicing fees. Administration and Other Fiduciary Fees Administration and other fiduciary fees are primarily composed of custody fees and fiduciary fees. The custody product is composed of numerous services related to the administration, safekeeping and reporting for both U.S. and non-U.S. denominated securities. The services offered to clients include: trade settlement, safekeeping, income collection, corporate action notification, record-keeping and reporting, tax reporting, and cash management. These services are provided for a wide range of securities, including but not limited to equities, municipal and corporate bonds, mortgage and asset-backed securities, money market instruments, U.S. Treasuries and agencies, derivative instruments, mutual funds, alternative investments and precious metals. Custody fees are recognized as/when the associated promised service is satisfied, which normally occurs at the point in time the service is requested by the customer and provided by Citi. Fiduciary fees consist of trust services and investment management services. As an escrow agent, Citi receives, safe-keeps, services and manages clients’ escrowed assets such as cash, securities, property (including intellectual property), contracts, or other collateral. Citi performs its escrow agent duties by safekeeping the funds during the specified time period agreed upon by all parties and therefore earns its revenue evenly during the contract duration. Investment management services consist of managing assets on behalf of Citi’s retail and institutional clients. Revenue from these services primarily consists of asset-based fees for advisory accounts, which are based on the market value of the client’s assets and recognized monthly, when the market value is fixed. In some instances, the Company contracts with third-party advisors and to third-party custodians. The Company has determined that it acts as principal in the majority of these transactions and therefore presents the amounts paid to third parties gross within Other operating expenses . The following table presents Administration and other fiduciary fees : Three Months Ended March 31, 2018 In millions of dollars ICG GCB Corp/Other Total Custody fees $ 368 $ 47 $ 16 $ 431 Fiduciary fees 167 147 7 321 Guarantee fees 137 14 2 153 Total administration and other fiduciary fees (1) $ 672 $ 208 $ 25 $ 905 Three Months Ended March 31, 2017 In millions of dollars ICG GCB Corp/Other Total Custody fees $ 355 $ 38 $ 13 $ 406 Fiduciary fees 141 133 11 285 Guarantee fees 128 13 2 143 Total administration and other fiduciary fees (1) $ 624 $ 184 $ 26 $ 834 (1) Administration and other fiduciary fees includes $153 million and $143 million for the first quarters of 2018 and 2017, respectively, that are not accounted for under ASC 606, Revenue from Contracts with Customers. These amounts include guarantee fees.

PRINCIPAL TRANSACTIONS

PRINCIPAL TRANSACTIONS	3 Months Ended
	Mar. 31, 2018
Principal Transactions Revenue, Net [Abstract]
PRINCIPAL TRANSACTIONS	PRINCIPAL TRANSACTIONS 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 which 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. 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) and FVA (funding valuation adjustments) on over-the-counter derivatives. These adjustments are discussed further in Note 20 to the Consolidated Financial Statements. In certain transactions, Citi incurs fees and presents these fees paid to third parties in operating expenses. The following table presents Principal transactions revenue: Three Months Ended March 31, In millions of dollars 2018 2017 Global Consumer Banking (1) $ 150 $ 155 Institutional Clients Group 2,884 2,731 Corporate/Other (1) 255 208 Total Citigroup $ 3,289 $ 3,094 Interest rate risks (2) $ 1,622 $ 1,746 Foreign exchange risks (3) 745 579 Equity risks (4) 566 212 Commodity and other risks (5) 92 153 Credit products and risks (6) 264 404 Total $ 3,289 $ 3,094 (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	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
INCENTIVE PLANS	INCENTIVE PLANS For additional information on Citi’s incentive plans, see Note 7 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K.

RETIREMENT BENEFITS

RETIREMENT BENEFITS	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
RETIREMENT BENEFITS	RETIREMENT BENEFITS For additional information on Citi’s retirement benefits, see Note 8 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. 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: Three Months Ended March 31, Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2018 2017 2018 2017 2018 2017 Benefits earned during the period $ 1 $ 1 $ 38 $ 36 $ — $ — $ 2 $ 2 Interest cost on benefit obligation 123 139 75 71 6 6 26 24 Expected return on plan assets (213 ) (216 ) (78 ) (70 ) (3 ) (1 ) (23 ) (21 ) Amortization of unrecognized Prior service benefit — — (1 ) (1 ) — — (2 ) (2 ) Net actuarial loss (gain) 47 44 13 16 — (1 ) 7 8 Settlement loss (1) — — 4 — — — — — Total net (benefit) expense $ (42 ) $ (32 ) $ 51 $ 52 $ 3 $ 4 $ 10 $ 11 (1) Losses due to settlement relate to repositioning and divestiture activities. Funded Status and Accumulated Other Comprehensive Income (AOCI) The following tables summarize the funded status and amounts recognized in the Consolidated Balance Sheet for the Company’s Significant Plans. Three Months Ended March 31, 2018 Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans Change in projected benefit obligation Projected benefit obligation at beginning of year $ 14,040 $ 7,433 $ 699 $ 1,261 Plans measured annually (28 ) (1,987 ) — (334 ) Projected benefit obligation at beginning of year—Significant Plans $ 14,012 $ 5,446 $ 699 $ 927 Benefits earned during the period 1 22 — 2 Interest cost on benefit obligation 123 63 6 23 Actuarial (gain) loss (495 ) (6 ) (21 ) 5 Benefits paid, net of participants’ contributions and government subsidy (205 ) (68 ) (17 ) (12 ) Foreign exchange impact and other — 140 — 71 Projected benefit obligation at period end—Significant Plans $ 13,436 $ 5,597 $ 667 $ 1,016 Three Months Ended March 31, 2018 Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans Change in plan assets Plan assets at fair value at beginning of year $ 12,725 $ 7,128 $ 262 $ 1,119 Plans measured annually — (1,305 ) — (10 ) Plan assets at fair value at beginning of year—Significant Plans $ 12,725 $ 5,823 $ 262 $ 1,109 Actual return on plan assets (157 ) 26 — (14 ) Company contributions, net of reimbursements 13 11 (4 ) — Benefits paid, net of participants’ contributions and government subsidy (205 ) (68 ) (17 ) (12 ) Foreign exchange impact and other — 146 — 84 Plan assets at fair value at period end—Significant Plans $ 12,376 $ 5,938 $ 241 $ 1,167 Funded status of the Significant Plans Qualified plans (1) $ (365 ) $ 341 $ (426 ) $ 151 Nonqualified plans (695 ) — — — Funded status of the plans at period end—Significant Plans $ (1,060 ) $ 341 $ (426 ) $ 151 Net amount recognized at period end Benefit asset $ — $ 829 $ — $ 151 Benefit liability (1,060 ) (488 ) (426 ) — Net amount recognized on the balance sheet—Significant Plans $ (1,060 ) $ 341 $ (426 ) $ 151 Amounts recognized in AOCI at period end Prior service benefit $ — $ 27 $ — $ 86 Net actuarial (loss) gain (6,644 ) (882 ) 89 (364 ) Net amount recognized in equity (pretax)—Significant Plans $ (6,644 ) $ (855 ) $ 89 $ (278 ) Accumulated benefit obligation at period end—Significant Plans $ 13,430 $ 5,329 $ 667 $ 1,016 (1) The U.S. qualified pension plan is fully funded pursuant to the Employee Retirement Income Security Act of 1974, as amended (ERISA), funding rules as of January 1, 2018 and no minimum required funding is expected for 2018 . The following table shows the change in AOCI related to the Company’s pension, postretirement and post employment plans: In millions of dollars Three Months Ended For Year Ended December 31, 2017 Beginning of period balance, net of tax (1)(2) $ (6,183 ) $ (5,164 ) Actuarial assumptions changes and plan experience 516 (760 ) Net asset (loss) gain due to difference between actual and expected returns (451 ) 625 Net amortization 58 229 Prior service cost — (4 ) Curtailment/settlement gain (3) 4 17 Foreign exchange impact and other (36 ) (93 ) Impact of Tax Reform (4) — (1,020 ) Change in deferred taxes, net (3 ) (13 ) Change, net of tax $ 88 $ (1,019 ) End of period balance, net of tax (1)(2) $ (6,095 ) $ (6,183 ) (1) See Note 17 to the Consolidated Financial Statements for further discussion of net AOCI balance. (2) Includes net-of-tax amounts for certain profit sharing plans outside the U.S. (3) Gains due to curtailment and settlement relate to repositioning and divestiture activities. (4) In the fourth quarter of 2017, the Company adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings. See Note 1 to the 2017 Consolidated Financial Statements. Plan Assumptions The discount rates utilized during the period in determining the pension and postretirement net (benefit) expense for the Significant Plans are as follows: Net (benefit) expense assumed discount rates during the period Three Months Ended Mar. 31, 2018 Dec. 31, 2017 Mar. 31, 2017 U.S. plans Qualified pension 3.60% 3.75% 4.10% Nonqualified pension 3.60 3.65 4.00 Postretirement 3.50 3.55 3.90 Non-U.S. plans Pension 0.6-10.20 0.65-10.35 0.60-11.00 Weighted average 4.75 4.86 5.08 Postretirement 9.55 8.95 9.65 The discount rates utilized at period-end in determining the pension and postretirement benefit obligations for the Significant Plans are as follows: Plan obligations assumed discount rates at period ended Mar. 31, 2018 Dec. 31, 2017 U.S. plans Qualified pension 3.95% 3.60% Nonqualified pension 3.95 3.60 Postretirement 3.90 3.50 Non-U.S. plans Pension 0.75 -9.90 0.6-10.20 Weighted average 4.88 4.75 Postretirement 9.50 9.55 Sensitivities of Certain Key Assumptions The following table summarizes the estimated effect on the Company’s Significant Plans quarterly expense of a one-percentage-point change in the discount rate: Three Months Ended March 31, 2018 In millions of dollars One-percentage-point increase One-percentage-point decrease Pension U.S. plans $ 8 $ (12 ) Non-U.S. plans (3 ) 6 Postretirement U.S. plans — (1 ) Non-U.S. plans (2 ) 3 Contributions For the U.S. pension plans, there were no required minimum cash contributions during the first three months of 2018 . The following table summarizes the Company’s actual contributions for the three months ended March 31, 2018 and 2017 , as well as estimated expected Company contributions for the remainder of 2018 and the actual contributions made for the remainder of 2017 . Pension plans Postretirement plans U.S. plans (1) Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2018 2017 2018 2017 2018 2017 Company contributions (2) for the three months ended March 31 $ 14 $ 13 $ 29 $ 34 $ — $ 12 $ 3 $ 2 Company contributions made or expected to be made during the remainder of the year 45 92 99 101 — 164 8 7 (1) The U.S. pension plans include benefits paid directly by the Company for the nonqualified pension plans. (2) Company contributions are composed of cash contributions made to the plans and benefits paid directly by the Company. Defined Contribution Plans The following table summarizes the Company’s contributions for the defined contribution plans: Three Months Ended March 31, In millions of dollars 2018 2017 U.S. plans $ 104 $ 98 Non-U.S. plans 76 69 Post Employment Plans 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: Three Months Ended March 31, In millions of dollars 2018 2017 Service-related expense $ — $ — Interest cost on benefit obligation — — Amortization of unrecognized Prior service benefit (8 ) (8 ) Net actuarial loss 1 1 Total service-related benefit $ (7 ) $ (7 ) Non-service-related expense $ 6 $ 8 Total net (benefit) expense $ (1 ) $ 1

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2018
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: Three Months Ended March 31, In millions, except per-share amounts 2018 2017 Income from continuing operations before attribution of noncontrolling interests $ 4,649 $ 4,118 Less: Noncontrolling interests from continuing operations 22 10 Net income from continuing operations (for EPS purposes) $ 4,627 $ 4,108 Income (loss) from discontinued operations, net of taxes (7 ) (18 ) Citigroup's net income $ 4,620 $ 4,090 Less: Preferred dividends (1) 272 301 Net income available to common shareholders $ 4,348 $ 3,789 Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS 51 55 Net income allocated to common shareholders for basic EPS $ 4,297 $ 3,734 Net income allocated to common shareholders for diluted EPS 4,297 3,734 Weighted-average common shares outstanding applicable to basic EPS 2,561.6 2,765.3 Effect of dilutive securities (2) Options (3) 0.1 0.2 Other employee plans 1.3 — Adjusted weighted-average common shares outstanding applicable to diluted EPS (4) 2,563.0 2,765.5 Basic earnings per share (5) Income from continuing operations $ 1.68 $ 1.36 Discontinued operations — (0.01 ) Net income $ 1.68 $ 1.35 Diluted earnings per share (5) Income from continuing operations $ 1.68 $ 1.36 Discontinued operations — (0.01 ) Net income $ 1.68 $ 1.35 (1) As of March 31, 2018 , Citi estimates it will distribute preferred dividends of approximately $902 million during the remainder of 2018, assuming such dividends are declared by the Citi Board of Directors. During the first quarter of 2018, Citi redeemed all of its 3.8 million Series AA preferred shares for $96.8 million at par value. Citi redeemed its Series E preferred stock in April 2018. (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 $104.67 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 the three months ended March 31, 2018 and 2017 because they were anti-dilutive. (3) During the first quarters of 2018 and 2017 , weighted-average options to purchase 0.5 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 $149.41 and $201.01 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	3 Months Ended
	Mar. 31, 2018
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 For additional information on the Company’s resale and repurchase agreements and securities borrowing and lending agreements, see Note 11 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. Federal funds sold and securities borrowed or purchased under agreements to resell , at their respective carrying values, consisted of the following: In millions of dollars March 31, December 31, 2017 Federal funds sold $ — $ — Securities purchased under agreements to resell 133,616 130,984 Deposits paid for securities borrowed 124,271 101,494 Total (1) $ 257,887 $ 232,478 Federal funds purchased and securities loaned or sold under agreements to repurchase , at their respective carrying values, consisted of the following: In millions of dollars March 31, December 31, 2017 Federal funds purchased $ 325 $ 326 Securities sold under agreements to repurchase 157,550 142,646 Deposits received for securities loaned 13,884 13,305 Total (1) $ 171,759 $ 156,277 (1) The above tables do not include securities-for-securities lending transactions of $15.6 billion and $14.0 billion at March 31, 2018 and December 31, 2017, 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 . 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. A substantial portion of the resale and repurchase agreements is recorded at fair value, as described in Notes 20 and 21 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. 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 21 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 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 March 31, 2018 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 220,159 $ 86,543 $ 133,616 $ 101,046 $ 32,570 Deposits paid for securities borrowed 124,271 — 124,271 24,560 99,711 Total $ 344,430 $ 86,543 $ 257,887 $ 125,606 $ 132,281 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 244,093 $ 86,543 $ 157,550 $ 79,626 $ 77,924 Deposits received for securities loaned 13,884 — 13,884 4,528 9,356 Total $ 257,977 $ 86,543 $ 171,434 $ 84,154 $ 87,280 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 (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 the Company 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 March 31, 2018 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 $ 96,155 $ 77,118 $ 26,587 $ 44,233 $ 244,093 Deposits received for securities loaned 9,369 397 2,197 1,921 13,884 Total $ 105,524 $ 77,515 $ 28,784 $ 46,154 $ 257,977 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 The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by class of underlying collateral: As of March 31, 2018 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 72,336 $ — $ 72,336 State and municipal securities 1,794 — 1,794 Foreign government securities 99,870 226 100,096 Corporate bonds 23,168 691 23,859 Equity securities 21,659 12,310 33,969 Mortgage-backed securities 15,930 — 15,930 Asset-backed securities 6,593 — 6,593 Other 2,743 657 3,400 Total $ 244,093 $ 13,884 $ 257,977 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

BROKERAGE RECEIVABLES AND BROKE

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES	BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES The Company has receivables and payables for financial instruments sold to and purchased from brokers, dealers and customers, which arise in the ordinary course of business. For additional information on these receivables and payables, see Note 12 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. Brokerage receivables and Brokerage payables consisted of the following: In millions of dollars March 31, December 31, 2017 Receivables from customers $ 19,186 $ 19,215 Receivables from brokers, dealers and clearing organizations 27,386 19,169 Total brokerage receivables (1) $ 46,572 $ 38,384 Payables to customers $ 43,122 $ 38,741 Payables to brokers, dealers and clearing organizations 26,563 22,601 Total brokerage payables (1) $ 69,685 $ 61,342 (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	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS For additional information regarding Citi’s investment portfolios, including evaluating investments for other-than-temporary impairment (OTTI), see Note 13 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. Overview Citi adopted ASU 2016-01 and ASU 2018-03 as of January 1, 2018. The ASUs require fair value changes on marketable equity securities to be recognized in earnings. The available-for-sale category is eliminated for equity securities. Also, non-marketable equity securities are required to be measured at fair value with changes in fair value recognized in earnings unless: (i) the measurement alternative is elected or (ii) the investment represents Federal Reserve Bank and Federal Home Loan Bank stock or certain exchange seats that continue to be carried at cost. See Note 1 to the Consolidated Financial Statements for additional details. The following tables present Citi’s investments by category: In millions of dollars March 31, Debt securities available-for-sale (AFS) $ 291,523 Debt securities held-to-maturity (HTM) (1) 52,492 Marketable equity securities carried at fair value (2) 277 Non-marketable equity securities carried at fair value (2) 1,292 Non-marketable equity securities measured using the measurement alternative (3) 401 Non-marketable equity securities carried at cost (4) 5,986 Total investments $ 351,971 In millions of dollars December 31, Securities available-for-sale (AFS) $ 290,914 Debt securities held-to-maturity (HTM) (1) 53,320 Non-marketable equity securities carried at fair value (2) 1,206 Non-marketable equity securities carried at cost (4) 6,850 Total investments $ 352,290 (1) Carried at adjusted amortized cost basis, net of any credit-related impairment. (2) Unrealized gains and losses are recognized in earnings. (3) Impairment losses and adjustments to the carrying value as a result of observable price changes are recognized in earnings. (4) Represents shares issued by the Federal Reserve Bank, Federal Home Loan Banks and various exchanges of which Citigroup is a member. The following table presents interest and dividend income on investments: Three Months Ended March 31, In millions of dollars 2018 2017 Taxable interest $ 2,042 $ 1,764 Interest exempt from U.S. federal income tax 130 142 Dividend income 62 54 Total interest and dividend income $ 2,234 $ 1,960 The following table presents realized gains and losses on the sales of investments, which excludes OTTI losses: Three Months Ended March 31, In millions of dollars 2018 2017 Gross realized investment gains $ 345 $ 288 Gross realized investment losses (175 ) (96 ) Net realized gains on sale of investments $ 170 $ 192 Securities Available-for-Sale The amortized cost and fair value of AFS securities were as follows: March 31, 2018 December 31, 2017 In millions of dollars Amortized cost Gross unrealized gains Gross unrealized losses Fair value Amortized cost Gross unrealized gains Gross unrealized losses Fair value Securities AFS Mortgage-backed securities (1) U.S. government-sponsored agency guaranteed $ 42,147 $ 134 $ 993 $ 41,288 $ 42,116 $ 125 $ 500 $ 41,741 Prime 6 3 — 9 11 6 — 17 Alt-A 9 88 — 97 26 90 — 116 Non-U.S. residential 2,645 10 2 2,653 2,744 13 6 2,751 Commercial 310 1 3 308 334 — 2 332 Total mortgage-backed securities $ 45,117 $ 236 $ 998 $ 44,355 $ 45,231 $ 234 $ 508 $ 44,957 U.S. Treasury and federal agency securities U.S. Treasury $ 108,335 $ 74 $ 1,611 $ 106,798 $ 108,344 $ 77 $ 971 $ 107,450 Agency obligations 10,689 5 178 10,516 10,813 7 124 10,696 Total U.S. Treasury and federal agency securities $ 119,024 $ 79 $ 1,789 $ 117,314 $ 119,157 $ 84 $ 1,095 $ 118,146 State and municipal (2) $ 9,980 $ 126 $ 269 $ 9,837 $ 8,870 $ 140 $ 245 $ 8,765 Foreign government 103,833 540 598 103,775 100,615 508 590 100,533 Corporate 13,068 43 115 12,996 14,144 51 86 14,109 Asset-backed securities (1) 3,075 53 47 3,081 3,906 14 2 3,918 Other debt securities 165 — — 165 297 — — 297 Total debt securities AFS $ 294,262 $ 1,077 $ 3,816 $ 291,523 $ 292,220 $ 1,031 $ 2,526 $ 290,725 Marketable equity securities AFS (3) $ — $ — $ — $ — $ 186 $ 4 $ 1 $ 189 Total securities AFS $ 294,262 $ 1,077 $ 3,816 $ 291,523 $ 292,406 $ 1,035 $ 2,527 $ 290,914 (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 18 to the Consolidated Financial Statements. (2) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, see Note 1 to the Consolidated Financial Statements. (3) Citi adopted ASU 2016-01 and ASU 2018-03 as of January 1, 2018, resulting in a cumulative effect adjustment from AOCI to retained earnings for net unrealized gains on marketable equity securities AFS. The available for sale category is eliminated for equity securities effective January 1, 2018. See Note 1 to the Consolidated Financial Statements for additional details. The following 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 March 31, 2018 Debt Securities AFS (1) Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 32,313 $ 900 $ 1,873 $ 93 $ 34,186 $ 993 Non-U.S. residential 891 2 — — 891 2 Commercial 241 2 41 1 282 3 Total mortgage-backed securities $ 33,445 $ 904 $ 1,914 $ 94 $ 35,359 $ 998 U.S. Treasury and federal agency securities U.S. Treasury $ 81,738 $ 1,417 $ 7,526 $ 194 $ 89,264 $ 1,611 Agency obligations 7,964 144 1,567 34 9,531 178 Total U.S. Treasury and federal agency securities $ 89,702 $ 1,561 $ 9,093 $ 228 $ 98,795 $ 1,789 State and municipal $ 2,250 $ 35 $ 1,116 $ 234 $ 3,366 $ 269 Foreign government 46,459 371 9,972 227 56,431 598 Corporate 5,831 101 890 14 6,721 115 Asset-backed securities 699 47 20 — 719 47 Other debt securities 22 — — — 22 — Total debt securities AFS $ 178,408 $ 3,019 $ 23,005 $ 797 $ 201,413 $ 3,816 December 31, 2017 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 30,994 $ 438 $ 2,206 $ 62 $ 33,200 $ 500 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 (1) 11 1 — — 11 1 Total securities AFS $ 181,216 $ 1,854 $ 21,920 $ 673 $ 203,136 $ 2,527 (1) Citi adopted ASU 2016-01 and ASU 2018-03 as of January 1, 2018, resulting in a cumulative effect adjustment from AOCI to retained earnings for net unrealized gains on marketable equity securities AFS. The available for sale category is eliminated for equity securities effective January 1, 2018. See Note 1 to the Consolidated Financial Statements for additional details. The following table presents the amortized cost and fair value of AFS debt securities by contractual maturity dates: March 31, 2018 December 31, 2017 In millions of dollars Amortized cost Fair value Amortized cost Fair value Mortgage-backed securities (1) Due within 1 year $ 92 $ 91 $ 45 $ 45 After 1 but within 5 years 1,331 1,327 1,306 1,304 After 5 but within 10 years 1,320 1,298 1,376 1,369 After 10 years (2) 42,374 41,639 42,504 42,239 Total $ 45,117 $ 44,355 $ 45,231 $ 44,957 U.S. Treasury and federal agency securities Due within 1 year $ 12,897 $ 12,906 $ 4,913 $ 4,907 After 1 but within 5 years 104,061 102,375 111,236 110,238 After 5 but within 10 years 2,066 2,033 3,008 3,001 After 10 years (2) — — — — Total $ 119,024 $ 117,314 $ 119,157 $ 118,146 State and municipal Due within 1 year $ 1,874 $ 1,873 $ 1,792 $ 1,792 After 1 but within 5 years 2,496 2,494 2,579 2,576 After 5 but within 10 years 591 607 514 528 After 10 years (2) 5,019 4,863 3,985 3,869 Total $ 9,980 $ 9,837 $ 8,870 $ 8,765 Foreign government Due within 1 year $ 32,899 $ 32,909 $ 32,130 $ 32,100 After 1 but within 5 years 55,910 55,571 53,034 53,165 After 5 but within 10 years 12,454 12,639 12,949 12,680 After 10 years (2) 2,570 2,656 2,502 2,588 Total $ 103,833 $ 103,775 $ 100,615 $ 100,533 All other (3) Due within 1 year $ 2,821 $ 2,818 $ 3,998 $ 3,991 After 1 but within 5 years 9,147 9,092 9,047 9,027 After 5 but within 10 years 2,905 2,907 3,415 3,431 After 10 years (2) 1,435 1,425 1,887 1,875 Total $ 16,308 $ 16,242 $ 18,347 $ 18,324 Total debt securities AFS $ 294,262 $ 291,523 $ 292,220 $ 290,725 (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 Amortized cost basis (1) Net unrealized gains (losses) recognized in AOCI Carrying value (2) Gross unrealized gains Gross unrealized (losses) Fair value March 31, 2018 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 23,968 $ (38 ) $ 23,930 $ 8 $ (553 ) $ 23,385 Alt-A — — — — — — Non-U.S. residential 1,492 — 1,492 25 — 1,517 Commercial 260 — 260 — — 260 Total mortgage-backed securities $ 25,720 $ (38 ) $ 25,682 $ 33 $ (553 ) $ 25,162 State and municipal $ 7,686 $ (33 ) $ 7,653 $ 185 $ (132 ) 7,706 Foreign government 1,354 — 1,354 3 (12 ) 1,345 Asset-backed securities (3) 17,803 — 17,803 87 (3 ) 17,887 Total debt securities held-to-maturity $ 52,563 $ (71 ) $ 52,492 $ 308 $ (700 ) $ 52,100 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 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 (1) For debt securities transferred to HTM from Trading account assets , 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 debt securities transferred to HTM from AFS, amortized cost 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 debt securities are carried on the Consolidated Balance Sheet at amortized cost basis, plus or minus any unamortized unrealized gains and losses and fair value hedge adjustments recognized in AOCI prior to reclassifying the debt 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 18 to the Consolidated Financial Statements. (4) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, see Note 1 to the Consolidated Financial Statements. 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 March 31, 2018 Debt securities held-to-maturity Mortgage-backed securities $ 6,889 $ 98 $ 15,108 $ 455 $ 21,997 $ 553 State and municipal 1,528 21 758 111 2,286 132 Foreign government 1,344 12 — — 1,344 12 Asset-backed securities 36 3 — — 36 3 Total debt securities held-to-maturity $ 9,797 $ 134 $ 15,866 $ 566 $ 25,663 $ 700 December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities $ 6,244 $ 50 $ 8,678 $ 107 $ 14,922 $ 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 $ 7,391 $ 76 $ 9,647 $ 194 $ 17,038 $ 270 Note: Excluded from the gross unrecognized losses presented in the table above are $(71) million and $(117) million of net unrealized losses recorded in AOCI as of March 31, 2018 and December 31, 2017 , respectively, primarily related to the difference between the amortized cost and carrying value of HTM debt 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 March 31, 2018 and December 31, 2017 . The following table presents the carrying value and fair value of HTM debt securities by contractual maturity dates: March 31, 2018 December 31, 2017 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 131 130 720 720 After 5 but within 10 years 166 165 148 149 After 10 years (1) 25,385 24,867 25,231 25,235 Total $ 25,682 $ 25,162 $ 26,099 $ 26,104 State and municipal Due within 1 year $ 234 $ 234 $ 407 $ 425 After 1 but within 5 years 380 398 259 270 After 5 but within 10 years 438 442 512 524 After 10 years (1) 6,601 6,632 7,719 7,983 Total $ 7,653 $ 7,706 $ 8,897 $ 9,202 Foreign government Due within 1 year $ 486 $ 486 $ 381 $ 381 After 1 but within 5 years 868 859 359 341 After 5 but within 10 years — — — — After 10 years (1) — — — — Total $ 1,354 $ 1,345 $ 740 $ 722 All other (2) Due within 1 year $ — $ — $ — $ — After 1 but within 5 years — — — — After 5 but within 10 years 1,989 1,994 1,669 1,680 After 10 years (1) 15,814 15,893 15,915 16,044 Total $ 17,803 $ 17,887 $ 17,584 $ 17,724 Total debt securities held-to-maturity $ 52,492 $ 52,100 $ 53,320 $ 53,752 (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 Overview The Company conducts periodic reviews of all securities with unrealized losses to evaluate whether the impairment is other-than-temporary. This review applies to all securities that are not measured at fair value with changes in fair value recognized in earnings. Effective January 1, 2018, the AFS category is eliminated for equity securities and, therefore, other-than-temporary impairment (OTTI) review is not required for those securities. See Note 1 to the Consolidated Financial Statements for additional details. An unrealized loss exists when the current fair value of an individual security is less than its 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 debt securities generally are not recorded, as these investments are carried at adjusted amortized cost basis. However, for HTM debt securities with credit-related impairment, 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. For debt securities transferred to HTM from Trading account assets , amortized cost is defined as the fair value of the securities at the date of transfer, plus any accretion income and less any impairment recognized in earnings subsequent to transfer. For debt securities transferred to HTM from AFS, amortized cost 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 impairment recognized in earnings. Regardless of the classification of 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 any anticipated recovery. The Company’s review for impairment generally entails: • identification and evaluation of impaired investments; • analysis of individual investments that have fair values less than 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 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 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 management does not expect to receive contractual principal and interest cash flows sufficient to recover the entire amortized cost basis of a security. AFS Equity Securities and Equity Method Investments For AFS 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 to cost 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. Effective January 1, 2018, the AFS category is eliminated for equity securities and, therefore, OTTI review is not required for those securities. See Note 1 to the Consolidated Financial Statements for additional details. Management 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 20 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 March 31, 2018. Mortgage-Backed Securities For U.S. mortgage-backed securities (and in particular for Alt-A and other mortgage-backed securities that have significant unrealized losses as a percentage of amortized cost), 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, the full impairment is recognized in earnings. Recognition and Measurement of OTTI The following tables present total OTTI recognized in earnings: OTTI on Investments Three Months Ended In millions of dollars AFS (1) HTM Total Impairment losses related to debt securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ — $ — $ — Less: portion of impairment loss recognized in AOCI (before taxes) — — — Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell $ — $ — $ — Impairment losses recognized in earnings for debt 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 27 — 27 Total OTTI losses recognized in earnings $ 27 $ — $ 27 (1) For the three months ended March 31, 2018, amounts represent AFS debt securities. Effective January 1, 2018, the AFS category is eliminated for equity securities. See Note 1 to the Consolidated Financial Statements for additional details. OTTI on Investments Three months ended In millions of dollars AFS (1) HTM 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 $ — $ — $ — 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 $ — $ — $ — 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 and FX losses 11 1 12 Total impairment losses recognized in earnings $ 11 $ 1 $ 12 (1) Includes OTTI on non-marketable equity securities. The following are three-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 debt securities still held In millions of dollars December 31, 2017 balance Credit Credit Changes due to (1) March 31, 2018 balance AFS debt securities Mortgage-backed securities (2) $ 38 $ — $ — $ (13 ) $ 25 State and municipal 4 — — (4 ) — Foreign government securities — — — — — Corporate 4 — — — 4 All other debt securities 2 — — — 2 Total OTTI credit losses recognized for AFS debt securities $ 48 $ — $ — $ (17 ) $ 31 HTM debt securities Mortgage-backed securities (3) $ 54 $ — $ — $ (54 ) $ — State and municipal 3 — — (3 ) — Total OTTI credit losses recognized for HTM debt securities $ 57 $ — $ — $ (57 ) $ — (1) Includes $18 million in cumulative OTTI reclassified from HTM to AFS due to the transfer of the related debt securities from HTM to AFS. Citi adopted ASU 2017-12, Targeted Improvements to Accounting for Hedge Activities , on January 1, 2018 and transferred approximately $4 billion of HTM debt securities into AFS classification as permitted as a one-time transfer under the standard. (2) Primarily consists of Prime securities. (3) Primarily consists of Alt-A securities. Cumulative OTTI credit losses recognized in earnings on debt securities still held In millions of dollars December 31, 2016 balance Credit Credit Reductions due to March 31, 2017 balance AFS debt securities Mortgage-backed securities $ — $ — $ — $ — $ — State and municipal 4 — — — 4 Foreign government securities — — — — — Corporate 5 — — (1 ) 4 All other debt securities 22 — — — 22 Total OTTI credit losses recognized for AFS debt securities $ 31 $ — $ — $ (1 ) $ 30 HTM debt securities Mortgage-backed securities (1) $ 101 $ — $ — $ (4 ) $ 97 State and municipal 3 — — — 3 Total OTTI credit losses recognized for HTM debt securities $ 104 $ — $ — $ (4 ) $ 100 (1) Primarily consists of Alt-A securities. Non-Marketable Equity Securities Not Carried at Fair Value Effective January 1, 2018, non-marketable equity securities are required to be measured at fair value with changes in fair value recognized in earnings unless: (i) the measurement alternative is elected or (ii) the investment represents Federal Reserve Bank and Federal Home Loan Bank stock or certain exchange seats that continue to be carried at cost. See Note 1 to the Consolidated Financial Statements for additional details. The election to measure a non-marketable equity security using the measurement alternative is made on an instrument-by-instrument basis. Under the measurement alternative, an equity security is carried at cost plus or minus changes resulting from observable prices in orderly transactions for the identical or a similar investment of the same issuer, less impairment (if any). The carrying value of the equity security is adjusted to fair value on the date of an observed transaction. Fair value may differ from the observed transaction price due to a number of factors, including marketability adjustments and differences in rights and obligations when the observed transaction is not for the identical investment held by Citi. On a quarterly basis, management qualitatively assesses whether each equity security under the measurement alternative is impaired. Impairment indicators that are considered include, but are not limited to the following: • A significant deterioration in the earnings performance, credit rating, asset quality, or business prospects of the investee • A significant adverse change in the regulatory, economic, or technological environment of the investee • A significant adverse change in the general market condition of either the geographical area or the industry in which the investee operates • A bona fide offer to purchase, an offer by the investee to sell, or a completed auction process for the same or similar investment for an amount less than the carrying amount of that investment • Factors that raise significant concerns about the investee’s ability to continue as a going concern, such as negative cash flows from operations, working capital deficiencies, or noncompliance with statutory capital requirements or debt covenants When the qualitative assessment indicates that impairment exists, the investment is written down to fair value, with the full difference between the fair value

LOANS

LOANS	3 Months Ended
	Mar. 31, 2018
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. For additional information regarding Citi’s consumer and corporate loans, including related accounting policies, see Note 14 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. 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: In millions of dollars March 31, December 31, 2017 In U.S. offices Mortgage and real estate (1) $ 63,412 $ 65,467 Installment, revolving credit and other 3,306 3,398 Cards 131,081 139,006 Commercial and industrial 7,493 7,840 $ 205,292 $ 215,711 In offices outside the U.S. Mortgage and real estate (1) $ 44,833 $ 44,081 Installment, revolving credit and other 27,651 26,556 Cards 25,993 26,257 Commercial and industrial 20,526 20,238 Lease financing 62 76 $ 119,065 $ 117,208 Total consumer loans $ 324,357 $ 332,919 Net unearned income $ 727 $ 737 Consumer loans, net of unearned income $ 325,084 $ 333,656 (1) Loans secured primarily by real estate. During the three months ended March 31, 2018 and 2017, the Company sold and/or reclassified to held-for-sale, $0.8 billion and $2.3 billion , respectively, of consumer loans. Consumer Loan Delinquency and Non-Accrual Details at March 31, 2018 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) $ 46,607 $ 364 $ 257 $ 1,010 $ 48,238 $ 636 $ 750 Home equity loans (6)(7) 13,476 160 315 — 13,951 691 — Credit cards 128,790 1,460 1,528 — 131,778 — 1,528 Installment and other 3,333 38 14 — 3,385 21 Commercial banking loans 9,011 14 44 — 9,069 152 13 Total $ 201,217 $ 2,036 $ 2,158 $ 1,010 $ 206,421 $ 1,500 $ 2,291 In offices outside North America Residential first mortgages (5) $ 37,447 $ 250 $ 147 $ — $ 37,844 $ 412 $ — Credit cards 24,702 437 373 — 25,512 323 256 Installment and other 26,243 311 116 — 26,670 161 — Commercial banking loans 28,504 69 63 — 28,636 179 — Total $ 116,896 $ 1,067 $ 699 $ — $ 118,662 $ 1,075 $ 256 Total GCB and Corporate/Other — Consumer $ 318,113 $ 3,103 $ 2,857 $ 1,010 $ 325,083 $ 2,575 $ 2,547 Other (8) 1 — — — 1 — — Total Citigroup $ 318,114 $ 3,103 $ 2,857 $ 1,010 $ 325,084 $ 2,575 $ 2,547 (1) Loans less than 30 days past due are presented as current. (2) Includes $23 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 $0.8 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, 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 banking 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 banking 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 Credit Scores (FICO) The following tables provide details on the FICO scores for Citi’s U.S. consumer loan portfolio based on end-of-period receivables (commercial banking 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) March 31, 2018 In millions of dollars Less than 620 ≥ 620 but less than 660 ≥ 660 but less than 720 Equal to or greater than 720 Residential first mortgages $ 1,750 $ 1,746 $ 6,655 $ 35,253 Home equity loans 1,075 937 3,138 8,409 Credit cards 9,169 11,285 37,275 70,598 Installment and other 146 229 681 1,710 Total $ 12,140 $ 14,197 $ 47,749 $ 115,970 FICO score distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than 620 ≥ 620 but less than 660 ≥ 660 but less Equal to or greater than 720 Residential first mortgages $ 2,100 $ 1,932 $ 6,931 $ 35,334 Home equity loans 1,379 1,081 3,446 8,530 Credit cards 9,079 11,651 37,916 77,661 Installment and other 276 250 667 1,818 Total $ 12,834 $ 14,914 $ 48,960 $ 123,343 (1) Excludes loans guaranteed by U.S. government entities, loans subject to long-term standby commitments (LTSC) 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 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) March 31, 2018 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 42,790 $ 2,536 $ 214 Home equity loans 10,788 1,954 737 Total $ 53,578 $ 4,490 $ 951 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 (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 The following tables present information about impaired consumer loans and interest income recognized on impaired consumer loans: Three Months Ended Balance at March 31, 2018 2018 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income (5) Interest income (5) Mortgage and real estate Residential first mortgages $ 3,020 $ 3,123 $ 250 $ 3,002 $ 21 $ 36 Home equity loans 673 893 211 1,044 7 8 Credit cards 1,846 1,879 626 1,809 30 38 Installment and other Individual installment and other 443 473 182 428 6 8 Commercial banking 287 500 26 374 3 6 Total $ 6,269 $ 6,868 $ 1,295 $ 6,657 $ 67 $ 96 (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) $526 million of residential first mortgages, $348 million of home equity loans and $9 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. Balance, December 31, 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Mortgage and real estate Residential first mortgages $ 2,877 $ 3,121 $ 278 $ 3,155 Home equity loans 1,151 1,590 216 1,181 Credit cards 1,787 1,819 614 1,803 Installment and other Individual installment and other 431 460 175 415 Commercial banking 334 541 51 429 Total $ 6,580 $ 7,531 $ 1,334 $ 6,983 (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. Consumer Troubled Debt Restructurings At and for the three months ended March 31, 2018 In millions of dollars except number of loans modified Number of Post- (1)(2) Deferred (3) Contingent (4) Principal (5) Average North America Residential first mortgages 588 $ 89 $ 1 $ — $ — — % Home equity loans 456 41 2 — — 1 Credit cards 63,203 244 — — — 18 Installment and other revolving 342 3 — — — 5 Commercial banking (6) 9 1 — — — — Total (8) 64,598 $ 378 $ 3 $ — $ — International Residential first mortgages 549 $ 18 $ — $ — $ — — % Credit cards 23,394 94 — — 2 15 Installment and other revolving 9,325 59 — — 2 10 Commercial banking (6) 145 28 — — — 2 Total (8) 33,413 $ 199 $ — $ — $ 4 At and for the three months ended March 31, 2017 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 966 $ 130 $ 3 $ — $ 1 1 % Home equity loans 679 56 3 — — 1 Credit cards 59,337 231 — — — 17 Installment and other revolving 221 2 — — — 5 Commercial banking (6) 26 5 — — — — Total (8) 61,229 $ 424 $ 6 $ — $ 1 International Residential first mortgages 613 $ 27 $ — $ — $ — — % Credit cards 25,237 85 — — 2 14 Installment and other revolving 11,307 60 — — 4 7 Commercial banking (6) 32 13 — — — 2 Total (8) 37,189 $ 185 $ — $ — $ 6 (1) Post-modification balances include past due amounts that are capitalized at the modification date. (2) Post-modification balances in North America include $11 million of residential first mortgages and $4 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the three months ended March 31, 2018 . These amounts include $8 million of residential first mortgages and $3 million of home equity loans that were newly classified as TDRs in the three months ended March 31, 2018 , 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 $ 15 million of residential first mortgages and $ 6 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the three months ended March 31, 2017 . These amounts include $ 9 million of residential first mortgages and $ 6 million of home equity loans that were newly classified as TDRs in the three months ended March 31, 2017 , 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. Three Months Ended March 31, In millions of dollars 2018 2017 North America Residential first mortgages $ 44 $ 51 Home equity loans 10 9 Credit cards 59 52 Installment and other revolving 1 — Commercial banking 8 2 Total $ 122 $ 114 International Residential first mortgages $ 2 $ 2 Credit cards 53 42 Installment and other revolving 24 23 Commercial banking — — Total $ 79 $ 67 Corporate Loans Corporate loans represent loans and leases managed by ICG . The following table presents information by corporate loan type: In millions of dollars March 31, December 31, In U.S. offices Commercial and industrial $ 54,005 $ 51,319 Financial institutions 40,472 39,128 Mortgage and real estate (1) 45,581 44,683 Installment, revolving credit and other 32,866 33,181 Lease financing 1,463 1,470 $ 174,387 $ 169,781 In offices outside the U.S. Commercial and industrial $ 101,368 $ 93,750 Financial institutions 35,659 35,273 Mortgage and real estate (1) 7,543 7,309 Installment, revolving credit and other 23,338 22,638 Lease financing 167 190 Governments and official institutions 6,170 5,200 $ 174,245 $ 164,360 Total corporate loans $ 348,632 $ 334,141 Net unearned income $ (778 ) $ (763 ) Corporate loans, net of unearned income $ 347,854 $ 333,378 (1) Loans secured primarily by real estate. The Company sold and/or reclassified to HFS $0.1 billion and $0.5 billion of corporate loans during the three months ended March 31, 2018 and 2017, respectively. The Company did not have significant purchases of corporate loans classified as held-for-investment for the three months ended March 31, 2018 or 2017 . Corporate Loan Delinquency and Non-Accrual Details at March 31, 2018 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 $ 478 $ 77 $ 555 $ 1,260 $ 149,912 $ 151,727 Financial institutions 63 22 85 87 74,840 75,012 Mortgage and real estate 131 14 145 192 52,772 53,109 Leases 22 — 22 43 1,564 1,629 Other 188 7 195 86 61,583 61,864 Loans at fair value 4,513 Purchased distressed loans — Total $ 882 $ 120 $ 1,002 $ 1,668 $ 340,671 $ 347,854 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 Purchased distressed loans — Total $ 627 $ 108 $ 735 $ 1,942 $ 326,352 $ 333,378 (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. Corporate Loans Credit Quality Indicators Recorded investment in loans (1) In millions of dollars March 31, December 31, Investment grade (2) Commercial and industrial $ 108,881 $ 101,313 Financial institutions 62,082 60,404 Mortgage and real estate 23,831 23,213 Leases 1,063 1,090 Other 57,863 56,306 Total investment grade $ 253,720 $ 242,326 Non-investment grade (2) Accrual Commercial and industrial $ 41,586 $ 38,503 Financial institutions 12,843 13,261 Mortgage and real estate 3,226 2,881 Leases 523 518 Other 3,915 3,924 Non-accrual Commercial and industrial 1,260 1,506 Financial institutions 87 92 Mortgage and real estate 192 195 Leases 43 46 Other 86 103 Total non-investment grade $ 63,761 $ 61,029 Non-rated private bank loans managed on a delinquency basis (2) $ 25,860 $ 25,674 Loans at fair value 4,513 4,349 Corporate loans, net of unearned income $ 347,854 $ 333,378 (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. Non-Accrual Corporate Loans The following tables present non-accrual loan information by corporate loan type and interest income recognized on non-accrual corporate loans: March 31, 2018 Three Months Ended 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 $ 1,260 $ 1,501 $ 227 $ 1,439 $ 3 Financial institutions 87 102 25 159 — Mortgage and real estate 192 349 10 186 1 Lease financing 43 43 4 53 — Other 86 195 5 105 — Total non-accrual corporate loans $ 1,668 $ 2,190 $ 271 $ 1,942 $ 4 December 31, 2017 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Non-accrual corporate loans Commercial and industrial $ 1,506 $ 1,775 $ 368 $ 1,547 Financial institutions 92 102 41 212 Mortgage and real estate 195 324 11 183 Lease financing 46 46 4 59 Other 103 212 2 108 Total non-accrual corporate loans $ 1,942 $ 2,459 $ 426 $ 2,109 March 31, 2018 December 31, 2017 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 $ 574 $ 227 $ 1,017 $ 368 Financial institutions 87 25 88 41 Mortgage and real estate 54 10 51 11 Lease financing 43 4 46 4 Other 16 5 13 2 Total non-accrual corporate loans with specific allowance $ 774 $ 271 $ 1,215 $ 426 Non-accrual corporate loans without specific allowance Commercial and industrial $ 686 $ 489 Financial institutions — 4 Mortgage and real estate 138 144 Lease financing — — Other 70 90 Total non-accrual corporate loans without specific allowance $ 894 N/A $ 727 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 three months ended March 31, 2017 was $2 million . N/A Not applicable Corporate Troubled Debt Restructurings At and for the three months ended March 31, 2018 : 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 $ 2 $ — $ — $ 2 Mortgage and real estate 1 — — 1 Total $ 3 $ — $ — $ 3 At and for the three months ended March 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 $ 55 $ — $ — $ 55 Financial institutions 15 — — 15 Mortgage and real estate 1 — — 1 Total $ 71 $ — $ — $ 71 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 March 31, 2018 TDR loans in payment default during the three months ended March 31, 2018 TDR balances at March 31, 2017 TDR loans in payment default during the three months ended March 31, 2017 Commercial and industrial $ 507 $ 59 $ 390 $ 9 Loans to financial institutions 40 — 24 3 Mortgage and real estate 98 — 84 — Other 41 — 177 — Total (1) $ 686 $ 59 $ 675 $ 12 (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	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
ALLOWANCE FOR CREDIT LOSSES	ALLOWANCE FOR CREDIT LOSSES Three Months Ended March 31, In millions of dollars 2018 2017 Allowance for loan losses at beginning of period $ 12,355 $ 12,060 Gross credit losses (2,296 ) (2,144 ) Gross recoveries (1) 429 435 Net credit losses (NCLs) $ (1,867 ) $ (1,709 ) NCLs $ 1,867 $ 1,709 Net reserve builds (releases) 102 (20 ) Net specific reserve releases (166 ) (14 ) Total provision for loan losses $ 1,803 $ 1,675 Other, net (see table below) 63 4 Allowance for loan losses at end of period $ 12,354 $ 12,030 Allowance for credit losses on unfunded lending commitments at beginning of period $ 1,258 $ 1,418 Provision (release) for unfunded lending commitments 28 (43 ) Other, net 4 2 Allowance for credit losses on unfunded lending commitments at end of period (2) $ 1,290 $ 1,377 Total allowance for loans, leases and unfunded lending commitments $ 13,644 $ 13,407 (1) Recoveries have been reduced by certain collection costs that are incurred only if collection efforts are successful. (2) 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 Three Months Ended March 31, In millions of dollars 2018 2017 Sales or transfers of various consumer loan portfolios to HFS Transfer of real estate loan portfolios $ (53 ) $ (37 ) Transfer of other loan portfolios (2 ) (124 ) Sales or transfers of various consumer loan portfolios to HFS $ (55 ) $ (161 ) FX translation, consumer 118 164 Other — 1 Other, net $ 63 $ 4 Allowance for Credit Losses and Investment in Loans Three Months Ended March 31, 2018 March 31, 2017 In millions of dollars Corporate Consumer Total Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,486 $ 9,869 $ 12,355 $ 2,702 $ 9,358 $ 12,060 Charge-offs (139 ) (2,157 ) (2,296 ) (103 ) (2,041 ) (2,144 ) Recoveries 43 386 429 66 369 435 Replenishment of net charge-offs 96 1,771 1,867 37 1,672 1,709 Net reserve builds (releases) (19 ) 121 102 (166 ) 146 (20 ) Net specific reserve builds (releases) (155 ) (11 ) (166 ) (12 ) (2 ) (14 ) Other 3 60 63 11 (7 ) 4 Ending balance $ 2,315 $ 10,039 $ 12,354 $ 2,535 $ 9,495 $ 12,030 March 31, 2018 December 31, 2017 In millions of dollars Corporate Consumer Total Corporate Consumer Total Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,045 $ 8,740 $ 10,785 $ 2,060 $ 8,531 $ 10,591 Individually evaluated in accordance with ASC 310-10-35 270 1,295 1,565 426 1,334 1,760 Purchased credit-impaired in accordance with ASC 310-30 — 4 4 — 4 4 Total allowance for loan losses $ 2,315 $ 10,039 $ 12,354 $ 2,486 $ 9,869 $ 12,355 Loans, net of unearned income Collectively evaluated in accordance with ASC 450 $ 341,676 $ 318,666 $ 660,342 $ 327,142 $ 326,884 $ 654,026 Individually evaluated in accordance with ASC 310-10-35 1,665 6,269 7,934 1,887 6,580 8,467 Purchased credit-impaired in accordance with ASC 310-30 — 126 126 — 167 167 Held at fair value 4,513 23 4,536 4,349 25 4,374 Total loans, net of unearned income $ 347,854 $ 325,084 $ 672,938 $ 333,378 $ 333,656 $ 667,034

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Goodwill impairment testing is performed at the level below each business segment (referred to as a reporting unit). See Note 3 for further information on business segments. For additional information regarding Citi’s goodwill impairment testing process, see Notes 1 and 16 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. There were no triggering events identified and no goodwill was impaired during the first quarter of 2018. Goodwill The changes in Goodwill were as follows: In millions of dollars Global Consumer Banking Institutional Clients Group Corporate/Other Total Balance, December 31, 2017 $ 12,784 $ 9,456 $ 16 $ 22,256 Foreign exchange translation and other $ 184 $ 235 $ — $ 419 Divestiture (1) — — (16 ) (16 ) Balance at March 31, 2018 $ 12,968 $ 9,691 $ — $ 22,659 (1) Goodwill allocated to the sale of Citi Colombia consumer business, the only remaining business in Citi Holdings—Consumer Latin America reporting unit reported as part of Corporate/Other , which is classified as HFS beginning the first quarter of 2018. Intangible Assets The components of intangible assets were as follows: March 31, 2018 December 31, 2017 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,308 $ 3,805 $ 1,503 $ 5,375 $ 3,836 $ 1,539 Credit card contract related intangibles (1) 5,044 2,542 $ 2,502 5,045 2,456 2,589 Core deposit intangibles 449 439 $ 10 639 628 11 Other customer relationships 486 294 $ 192 459 272 187 Present value of future profits 35 31 $ 4 32 28 4 Indefinite-lived intangible assets 231 — $ 231 244 — 244 Other 100 92 $ 8 100 86 14 Intangible assets (excluding MSRs) $ 11,653 $ 7,203 $ 4,450 $ 11,894 $ 7,306 $ 4,588 Mortgage servicing rights (MSRs) (2) 587 — 587 558 — 558 Total intangible assets $ 12,240 $ 7,203 $ 5,037 $ 12,452 $ 7,306 $ 5,146 The changes in intangible assets were as follows: Net carrying Net carrying amount at In millions of dollars December 31, Acquisitions/ divestitures Amortization FX translation and other March 31, Purchased credit card relationships $ 1,539 $ — $ (35 ) $ (1 ) $ 1,503 Credit card contract related intangibles (1) 2,589 — (86 ) (1 ) 2,502 Core deposit intangibles 11 — (2 ) 1 10 Other customer relationships 187 — (6 ) 11 192 Present value of future profits 4 — — — 4 Indefinite-lived intangible assets 244 — — (13 ) 231 Other 14 — (6 ) — 8 Intangible assets (excluding MSRs) $ 4,588 $ — $ (135 ) $ (3 ) $ 4,450 Mortgage servicing rights (MSRs) (2) 558 587 Total intangible assets $ 5,146 $ 5,037 (1) Primarily reflects contract-related intangibles associated with the American Airlines, The Home Depot, Costco, Sears and AT&T credit card program agreements, which represented 97% of the aggregate net carrying amount at March 31, 2018 and December 31, 2017. (2) For additional information on Citi’s MSRs, including the rollforward for the three months ended March 31, 2018 , see Note 18 to the Consolidated Financial Statements.

DEBT

DEBT	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
DEBT	DEBT For additional information regarding Citi’s short-term borrowings and long-term debt, see Note 17 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. Short-Term Borrowings In millions of dollars March 31, December 31, Commercial paper $ 10,022 $ 9,940 Other borrowings (1) 26,072 34,512 Total $ 36,094 $ 44,452 (1) Includes borrowings from Federal Home Loan Banks and other market participants. At March 31, 2018 and December 31, 2017 , collateralized short-term advances from the Federal Home Loan Banks were $15.3 billion and $23.8 billion , respectively. Long-Term Debt In millions of dollars March 31, December 31, 2017 Citigroup Inc. (1) $ 153,074 $ 152,163 Bank (2) 64,757 65,856 Broker-dealer and other (3) 20,107 18,690 Total $ 237,938 $ 236,709 (1) Represents the parent holding company. (2) Represents Citibank entities as well as other bank entities. At March 31, 2018 and December 31, 2017 , collateralized long-term advances from the Federal Home Loan Banks were $15.7 billion and $19.3 billion , respectively. (3) Represents broker-dealer and other non-bank subsidiaries that are consolidated into Citigroup Inc., the parent holding company. Long-term debt outstanding includes trust preferred securities with a balance sheet carrying value of $1.7 billion at both March 31, 2018 and December 31, 2017 . The following table summarizes Citi’s outstanding trust preferred securities at March 31, 2018 : 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 99,901 140 3 mo LIBOR + 88.75 bps 50 140 June 28, 2067 June 28, 2017 Total obligated $ 2,580 $ 2,586 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.

CHANGES IN ACCUMULATED OTHER CO

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI)	3 Months Ended
	Mar. 31, 2018
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) were as follows: Three Months Ended March 31, 2018 In millions of dollars Net Debt valuation adjustment (DVA) Cash flow hedges (1) Benefit plans (2) Foreign (3) Excluded Component of fair value hedges (4) Accumulated Balance, December 31, 2017 $ (1,158 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ — $ (34,668 ) Adjustment to opening balance, net of taxes (5) (3 ) — — — — — (3 ) Adjusted balance, beginning of period $ (1,161 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ — $ (34,671 ) Other comprehensive income before reclassifications (949 ) 101 (243 ) 41 1,120 (4 ) 70 Increase (decrease) due to amounts reclassified from AOCI (109 ) 27 21 47 — — (14 ) Change, net of taxes $ (1,058 ) $ 128 $ (222 ) $ 88 $ 1,120 $ (4 ) $ 52 Balance at March 31, 2018 $ (2,219 ) $ (793 ) $ (920 ) $ (6,095 ) $ (24,588 ) $ (4 ) $ (34,619 ) In millions of dollars Net Debt valuation adjustment (DVA) Cash flow hedges (1) Benefit plans (2) Foreign (3) Excluded Component of fair value hedges (4) Accumulated Balance, December 31, 2016 $ (799 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ — $ (32,381 ) Adjustment to opening balance, net of taxes (6) 504 — — — — — 504 Adjusted balance, beginning of period $ (295 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ — $ (31,877 ) Other comprehensive income before reclassifications 334 (55 ) 24 (49 ) 1,465 — 1,719 Increase (decrease) due to amounts reclassified from AOCI (114 ) (5 ) (26 ) 37 (147 ) — (255 ) Change, net of taxes $ 220 $ (60 ) $ (2 ) $ (12 ) $ 1,318 $ — $ 1,464 Balance, March 31, 2017 $ (75 ) $ (412 ) $ (562 ) $ (5,176 ) $ (24,188 ) $ — $ (30,413 ) (1) Primarily driven by Citigroup’s pay fixed/receive floating interest rate swap programs that hedge the floating rates on liabilities. (2) Primarily reflects adjustments based on the quarterly actuarial valuations of the Company’s Significant pension and postretirement plans, annual actuarial valuations of all other plans and amortization of amounts previously recognized in other comprehensive income. (3) Primarily reflects the movements in (by order of impact) the Mexican Peso, Japanese Yen, Euro, and Chinese Yuan against the U.S. dollar and changes in related tax effects and hedges for the quarter ended March 31, 2018 . Primarily reflects the movements in (by order of impact) the Mexican peso, Korean Won, Japanese Yen and Indian Rupee against the U.S. dollar and changes in related tax effects and hedges for the quarter ended March, 31, 2017. (4) Beginning in the first quarter of 2018, changes in the excluded component of fair value hedges are reflected as a component of AOCI, pursuant to the early adoption of ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities . See Note 1 to the Consolidated Financial Statements for further information regarding this change. (5) Citi adopted ASU 2016-01 and ASU 2018-03 on January 1, 2018. Upon adoption, a cumulative effect adjustment was recorded from AOCI to retained earnings for net unrealized gains on former AFS equity securities. For additional information, see Note 1 to the Consolidated Financial Statements. (6) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, see Note 1 to the Consolidated Financial Statements. The pretax and after-tax changes in each component of Accumulated other comprehensive income (loss) were as follows: Three Months Ended March 31, 2018 In millions of dollars Pretax Tax effect (1) After-tax Balance, December 31, 2017 (1) $ (41,228 ) $ 6,560 $ (34,668 ) Adjustment to opening balance (2) (4 ) 1 (3 ) Adjusted balance, beginning of period $ (41,232 ) $ 6,561 $ (34,671 ) Change in net unrealized gains (losses) on AFS debt securities (1,380 ) 322 (1,058 ) Debt valuation adjustment (DVA) 167 (39 ) 128 Cash flow hedges (290 ) 68 (222 ) Benefit plans 91 (3 ) 88 Foreign currency translation adjustment 1,130 (10 ) 1,120 Excluded component of fair value hedges (5 ) 1 (4 ) Change $ (287 ) $ 339 $ 52 Balance, March 31, 2018 $ (41,519 ) $ 6,900 $ (34,619 ) Three Months Ended March 31, 2017 In millions of dollars Pretax Tax effect After-tax 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 346 (126 ) 220 Debt valuation adjustment (DVA) (95 ) 35 (60 ) Cash flow hedges 1 (3 ) (2 ) Benefit plans (2 ) (10 ) (12 ) Foreign currency translation adjustment 1,468 (150 ) 1,318 Excluded component of fair value hedges — — — Change $ 1,718 $ (254 ) $ 1,464 Balance, March 31, 2017 $ (39,514 ) $ 9,101 $ (30,413 ) (1) Includes the impact of ASU 2018-02, which transferred amounts from AOCI to Retained Earnings . For additional information, see Note 19 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. (2) Citi adopted ASU 2016-01 and ASU 2018-03 on January 1, 2018. Upon adoption, a cumulative effect adjustment was recorded from AOCI to retained earnings for net unrealized gains on former AFS equity securities. For additional information, 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 to the Consolidated Statement of Income as follows: Increase (decrease) in AOCI due to amounts reclassified to Consolidated Statement of Income Three Months Ended March 31, In millions of dollars 2018 2017 Realized (gains) losses on sales of investments $ (170 ) $ (192 ) Gross impairment losses 27 12 Subtotal, pretax $ (143 ) $ (180 ) Tax effect 34 66 Net realized (gains) losses on investments after-tax (1) $ (109 ) $ (114 ) Realized DVA (gains) losses on fair value option liabilities $ 35 $ (8 ) Subtotal, pretax $ 35 $ (8 ) Tax effect (8 ) 3 Net realized debt valuation adjustment, after-tax $ 27 $ (5 ) Interest rate contracts $ 31 $ (44 ) Foreign exchange contracts (2 ) 3 Subtotal, pretax $ 29 $ (41 ) Tax effect (8 ) 15 Amortization of cash flow hedges, after-tax (2) $ 21 $ (26 ) Amortization of unrecognized Prior service cost (benefit) $ (11 ) $ (10 ) Net actuarial loss 69 67 Curtailment/settlement impact (3) 4 — Subtotal, pretax $ 62 $ 57 Tax effect (15 ) (20 ) Amortization of benefit plans, after-tax (3) $ 47 $ 37 Foreign currency translation adjustment $ — $ (232 ) Tax effect — 85 Foreign currency translation adjustment $ — $ (147 ) Total amounts reclassified out of AOCI, pretax $ (17 ) $ (404 ) Total tax effect 3 149 Total amounts reclassified out of AOCI, after-tax $ (14 ) $ (255 ) (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 12 to the Consolidated Financial Statements for additional details. (2) See Note 19 to the Consolidated Financial Statements for additional details. (3) See Note 8 to the Consolidated Financial Statements for additional details.

SECURITIZATIONS AND VARIABLE IN

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES	3 Months Ended
	Mar. 31, 2018
Securitizations and Variable Interest Entities [Abstract]
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES	SECURITIZATIONS AND VARIABLE INTEREST ENTITIES For additional information regarding Citi’s use of special purpose entities (SPEs) and variable interest entities (VIEs), see Note 21 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. 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 March 31, 2018 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 $ 46,540 $ 46,540 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored 111,980 — 111,980 2,690 — — 87 2,777 Non-agency-sponsored 20,660 1,891 18,769 335 — — 1 336 Citi-administered asset-backed commercial paper conduits (ABCP) 18,962 18,962 — — — — — — Collateralized loan obligations (CLOs) 16,491 — 16,491 5,362 — — 9 5,371 Asset-based financing 63,019 637 62,382 19,190 571 6,904 — 26,665 Municipal securities tender option bond trusts (TOBs) 7,105 2,165 4,940 18 — 3,344 — 3,362 Municipal investments 19,265 5 19,260 2,769 3,632 2,129 — 8,530 Client intermediation 1,414 1,279 135 37 — — 7 44 Investment funds 1,874 603 1,271 10 7 13 — 30 Other 693 34 659 28 8 33 49 118 Total $ 308,003 $ 72,116 $ 235,887 $ 30,439 $ 4,218 $ 12,423 $ 153 $ 47,233 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 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 (1) The definition of maximum exposure to loss is included in the text that follows this table. (2) Included on Citigroup’s March 31, 2018 and December 31, 2017 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. The previous tables do not include: • 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 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 12 and 20 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 $8 billion and $9 billion at March 31, 2018 and December 31, 2017 , respectively; • certain representations and warranties exposures in Citigroup residential mortgage securitizations, where 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: March 31, 2018 December 31, 2017 In millions of dollars Liquidity facilities Loan/equity commitments Liquidity facilities Loan/equity commitments Asset-based financing $ — $ 6,904 $ — $ 5,878 Municipal securities tender option bond trusts (TOBs) 3,344 — 3,035 — Municipal investments — 2,129 — 2,344 Investment funds — 13 — 13 Other — 33 — 34 Total funding commitments $ 3,344 $ 9,079 $ 3,035 $ 8,269 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 March 31, 2018 December 31, 2017 Cash $ — $ — Trading account assets 7.7 8.5 Investments 4.4 4.4 Total loans, net of allowance 21.9 22.2 Other 0.5 0.5 Total assets $ 34.5 $ 35.6 Credit Card Securitizations Substantially all of the Company’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. The following table reflects amounts related to the Company’s securitized credit card receivables: In billions of dollars March 31, 2018 December 31, 2017 Ownership interests in principal amount of trust credit card receivables Sold to investors via trust-issued securities $ 28.8 $ 28.8 Retained by Citigroup as trust-issued securities 7.7 7.6 Retained by Citigroup via non-certificated interests 10.1 14.4 Total $ 46.6 $ 50.8 The following tables summarize selected cash flow information related to Citigroup’s credit card securitizations: Three Months Ended March 31, In billions of dollars 2018 2017 Proceeds from new securitizations $ 2.8 $ 2.5 Pay down of maturing notes (2.8 ) (2.0 ) Master Trust Liabilities (at Par Value) The weighted average maturity of the third-party term notes issued by the Master Trust was 2.7 years as of March 31, 2018 and 2.6 years as of December 31, 2017 . In billions of dollars Mar. 31, 2018 Dec. 31, 2017 Term notes issued to third parties $ 27.8 $ 27.8 Term notes retained by Citigroup affiliates 5.8 5.7 Total Master Trust liabilities $ 33.6 $ 33.5 Omni Trust Liabilities (at Par Value) The weighted average maturity of the third-party term notes issued by the Omni Trust was 1.6 years as of March 31, 2018 and 1.9 years as of December 31, 2017 . In billions of dollars Mar. 31, 2018 Dec. 31, 2017 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 The following table summarizes selected cash flow information related to Citigroup mortgage securitizations: 2018 2017 In billions of dollars U.S. agency- Non-agency- U.S. agency- Non-agency- Proceeds from new securitizations $ 8.0 $ 3.4 $ 7.2 $ 1.4 Contractual servicing fees received — — 0.1 — During the first quarter of 2018 , gains recognized on the securitization of U.S. agency-sponsored mortgages and non-agency sponsored mortgages were $5 million and $18 million , respectively. Agency and non-agency securitizations for the quarter ended March 31, 2017 were $29 million and $20 million , respectively. Key assumptions used in measuring the fair value of retained interests at the date of sale or securitization of mortgage receivables were as follows: March 31, 2018 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 3.0% to 11.4% — — Weighted average discount rate 6.4 % — — Constant prepayment rate 4.2% to 16.0% — — Weighted average constant prepayment rate 8.5 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 7.7 to 18.0 years — — March 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 2.4% to 19.9% — — Weighted average discount rate 13.0 % — — Constant prepayment rate 3.8% to 10.5% — — Weighted average constant prepayment rate 6.2 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 6.5 to 12.2 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 the Company 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. March 31, 2018 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 0.8% to 41.3% 6.5 % 4.0% to 11.2% Weighted average discount rate 6.2 % 6.5 % 7.3 % Constant prepayment rate 4.3% to 18.4% 8.9 % 9.1% to 13.1% Weighted average constant prepayment rate 10.3 % 8.9 % 10.7 % Anticipated net credit losses (2) NM 46.9 % 35.1% to 52.1% Weighted average anticipated net credit losses NM 46.9 % 44.5 % Weighted average life 0.1 to 27.5 years 5.4 years 2.1 to 18.3 years December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated 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 (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. March 31, 2018 Non-agency-sponsored mortgages (1) In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests $ 1,767 $ 245 $ 138 Discount rates Adverse change of 10% $ (47 ) $ — $ (2 ) Adverse change of 20% (91 ) — (4 ) Constant prepayment rate Adverse change of 10% (37 ) — (1 ) Adverse change of 20% (75 ) — (2 ) Anticipated net credit losses Adverse change of 10% NM — — Adverse change of 20% NM — (1 ) December 31, 2017 Non-agency-sponsored mortgages (1) In millions of dollars U.S. agency- Senior Subordinated Carrying value of retained interests $ 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 ) — (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 (MSRs) The fair value of Citi’s capitalized MSRs was $587 million and $567 million at March 31, 2018 and 2017 , respectively. The MSRs correspond to principal loan balances of $64 billion and $71 billion as of March 31, 2018 and 2017 , respectively. The following table summarizes the changes in capitalized MSRs: In millions of dollars 2018 2017 Balance, beginning of year $ 558 $ 1,564 Originations 17 35 Changes in fair value of MSRs due to changes in inputs and assumptions 46 67 Other changes (1) (17 ) (53 ) Sale of MSRs (2) (17 ) (1,046 ) Balance, as of March 31 $ 587 $ 567 (1) Represents changes due to customer payments and passage of time. (2) See Note 2 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs in 2017 . The Company receives fees during the course of servicing previously securitized mortgages. The amounts of these fees were as follows: In millions of dollars 2018 2017 Servicing fees $ 46 $ 106 Late fees 1 3 Ancillary fees 3 4 Total MSR fees $ 50 $ 113 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 . Re-securitizations The Company 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 quarters ended March 31, 2018 and 2017 . These securities are backed by either residential or commercial mortgages and are often structured on behalf of clients. As of March 31, 2018 , the fair value of Citi-retained interests in private-label re-securitization transactions structured by Citi totaled approximately $74 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, 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). 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 March 31, 2018 and December 31, 2017 was approximately $668 million and $887 million , respectively. The Company also re-securitizes U.S. government-agency guaranteed mortgage-backed (agency) securities. During the quarters ended March 31, 2018 and 2017 , Citi transferred agency securities with a fair value of approximately $7.0 billion and $4.5 billion , respectively. As of March 31, 2018 , the fair value of Citi-retained interests in agency re-securitization transactions structured by Citi totaled approximately $2.1 billion (including $744 million related to re-securitization transactions executed in 2018 ) compared to $2.1 billion as of December 31, 2017 (including $854 million related to re-securitization transactions executed in 2017 ), 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 March 31, 2018 and December 31, 2017 was approximately $65.2 billion and $68.3 billion , respectively. As of March 31, 2018 and December 31, 2017 , the Company did not consolidate any private-label or agency re-securitization entities. Citi-Administered Asset-Backed Commercial Paper Conduits At March 31, 2018 and December 31, 2017 , the commercial paper conduits administered by Citi had approximately $19.0 billion and $19.3 billion of purchased assets outstanding, respectively, and had incremental funding commitments with clients of approximately $15.2 billion and $14.5 billion , respectively. Substantially all of the funding of the conduits is in the form of short-term commercial paper. At March 31, 2018 and December 31, 2017 , the weighted average remaining lives of the commercial paper issued by the conduits were approximately 43 and 51 days , respectively. The primary credit enhancement provided to the conduit investors is in the form of transaction-specific credit enhancements described above. In addition to the transaction-specific credit enhancements, the conduits, other than the government guaranteed loan conduit, have obtained a letter of credit from the Company, which is equal to at least 8% to 10% of the conduit’s assets with a minimum of $200 million . The letters of credit provided by the Company to the conduits total approximately $1.7 billion as of March 31, 2018 and December 31, 2017 . The net result across multi-seller conduits administered by the Company is that, in the event defaulted assets exceed the transaction-specific credit enhancements described above, any losses in each conduit are allocated first to the Company and then the commercial paper investors. At March 31, 2018 and December 31, 2017 , the Company owned $9.0 billion and $9.3 billion , respectively, of the commercial paper issued by its administered conduits. The Company's investments were not driven by market illiquidity and the Company is not obligated under any agreement to purchase the commercial paper issued by the conduits. Collateralized Loan Obligations The following table summarizes selected cash flow information related to Citigroup CLOs: Three Months Ended March 31, In billions of dollars 2018 2017 Proceeds from new securitizations $ 1.4 $ 0.3 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: Mar. 31, 2018 Dec. 31, 2017 Discount rate 1.1% to 1.6% 1.1% to 1.6% In millions of dollars Mar. 31, 2018 Dec. 31, 2017 Carrying value of retained interests $ 3,713 $ 3,607 Discount rates Adverse change of 10% $ (25 ) $ (24 ) Adverse change of 20% (49 ) (47 ) 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. March 31, 2018 In millions of dollars Total unconsolidated VIE assets Maximum exposure to unconsolidated VIEs Type Commercial and other real estate $ 15,152 $ 4,815 Corporate loans 6,862 5,731 Hedge funds and equities 449 58 Airplanes, ships and other assets 39,919 16,061 Total $ 62,382 $ 26,665 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 Municipal Securities Tender Option Bond (TOB) Trusts At March 31, 2018 and December 31, 2017 , none of the municipal bonds owned by non-customer TOB trusts were subject to a credit guarantee provided by the Company. At March 31, 2018 and December 31, 2017 , liquidity agreements provided with respect to customer TOB trusts totaled $3.4 billion and $3.2 billion , respectively, of which $2.0 billion and $2.0 billion , respectively, were offset by reimbursement agreements. For the remaining exposure related to TOB transactions, where the residual owned by the customer was at least 25% of the bond value at the inception of the transaction, no reimbursement agreement was executed. The Company also provides other liquidity agreements or letters of credit to customer-sponsored municipal investment funds, which are not variable interest entities, and municipality-related issuers that totaled $6.2 billion and $6.1 billion as of March 31, 2018 and December 31, 2017 , respectively. These liquidity agreements and letters of credit are offset by reimbursement agreements with various term-out provisions. Client Intermediation The proceeds from new securitizations related to the Company’s client intermediation transactions for the quarters ended March 31, 2018 and 2017 totaled approximately $0.2 billion and $0.5 billion , respectively.

DERIVATIVES ACTIVITIES

DERIVATIVES ACTIVITIES	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES ACTIVITIES	DERIVATIVES ACTIVITIES As of January 1, 2018, Citigroup early adopted ASU 2017-12, Targeted Improvements to Accounting for Hedge Activities . This standard primarily impacts Citi’s accounting for derivatives designated as cash flow hedges and fair value hedges. Refer to the respective sections below for details. In the ordinary course of business, Citigroup enters into various types of derivative transactions. All derivatives are recorded in Trading account assets/Trading account liabilities on the Consolidated Balance Sheet. For additional information regarding Citi’s use of and accounting for derivatives, see Note 22 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. 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) Other derivative instruments Trading derivatives In millions of dollars March 31, December 31, March 31, December 31, Interest rate contracts Swaps $ 197,328 $ 189,779 $ 21,321,930 $ 18,754,219 Futures and forwards 500 — 8,245,034 6,460,539 Written options — — 4,578,837 3,516,131 Purchased options — — 3,710,550 3,234,025 Total interest rate contract notionals $ 197,828 $ 189,779 $ 37,856,351 $ 31,964,914 Foreign exchange contracts Swaps $ 40,063 $ 37,162 $ 6,940,579 $ 5,576,357 Futures, forwards and spot 39,102 33,103 4,465,416 3,097,700 Written options 1,151 3,951 1,460,614 1,127,728 Purchased options 1,405 6,427 1,450,534 1,148,686 Total foreign exchange contract notionals $ 81,721 $ 80,643 $ 14,317,143 $ 10,950,471 Equity contracts Swaps $ — $ — $ 243,567 $ 215,834 Futures and forwards — — 67,910 72,616 Written options — — 427,798 389,961 Purchased options — — 366,219 328,154 Total equity contract notionals $ — $ — $ 1,105,494 $ 1,006,565 Commodity and other contracts Swaps $ — $ — $ 92,552 $ 82,039 Futures and forwards 91 23 176,174 153,248 Written options — — 71,136 62,045 Purchased options — — 66,092 60,526 Total commodity and other contract notionals $ 91 $ 23 $ 405,954 $ 357,858 Credit derivatives (2) Protection sold $ — $ — $ 741,700 $ 735,142 Protection purchased — — 790,134 777,713 Total credit derivatives $ — $ — $ 1,531,834 $ 1,512,855 Total derivative notionals $ 279,640 $ 270,445 $ 55,216,776 $ 45,792,663 (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 $2 million and $63 million at March 31, 2018 and December 31, 2017 , respectively. (2) 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 March 31, 2018 and December 31, 2017 . 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 following tables reflect 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 reflects a reduction of approximately $110 billion and $100 billion as of March 31, 2018 and December 31, 2017, respectively, 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 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 that 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 March 31, 2018 Derivatives classified (1)(2) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Over-the-counter $ 1,896 $ 92 Cleared 62 125 Interest rate contracts $ 1,958 $ 217 Over-the-counter $ 1,011 $ 1,199 Foreign exchange contracts $ 1,011 $ 1,199 Total derivatives instruments designated as ASC 815 hedges $ 2,969 $ 1,416 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 184,682 $ 163,259 Cleared 8,972 11,926 Exchange traded 217 184 Interest rate contracts $ 193,871 $ 175,369 Over-the-counter $ 125,761 $ 119,004 Cleared 3,426 3,343 Exchange traded 19 8 Foreign exchange contracts $ 129,206 $ 122,355 Over-the-counter $ 18,737 $ 23,424 Cleared 12 17 Exchange traded 10,686 10,674 Equity contracts $ 29,435 $ 34,115 Over-the-counter $ 15,189 $ 18,134 Exchange traded 642 717 Commodity and other contracts $ 15,831 $ 18,851 Over-the-counter $ 12,059 $ 11,633 Cleared 6,968 7,976 Credit derivatives $ 19,027 $ 19,609 Total derivatives instruments not designated as ASC 815 hedges $ 387,370 $ 370,299 Total derivatives $ 390,339 $ 371,715 Cash collateral paid/received (3) $ 8,676 $ 14,971 Less: Netting agreements (4) (303,169 ) (303,169 ) Less: Netting cash collateral received/paid (5) (40,951 ) (33,800 ) Net receivables/payables included on the Consolidated Balance Sheet (6) $ 54,895 $ 49,717 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (924 ) $ (113 ) Less: Non-cash collateral received/paid (13,525 ) (20,260 ) Total net receivables/payables (6) $ 40,446 $ 29,344 (1) The trading derivatives fair values are also presented in Note 20 to the Consolidated Financial Statements. (2) 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. (3) Reflects the net amount of the $42,476 million and $55,922 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $33,800 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $40,951 million was used to offset trading derivative assets. (4) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $163 billion , $129 billion and $11 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange-traded derivatives, respectively. (5) 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. (6) The net receivables/payables include approximately $5 billion of derivative asset and $7 billion of derivative liability fair values not subject to enforceable master netting agreements, respectively. In millions of dollars at December 31, 2017 Derivatives classified in Trading (1)(2) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Over-the-counter $ 1,969 $ 134 Cleared 110 92 Interest rate contracts $ 2,079 $ 226 Over-the-counter $ 1,143 $ 1,150 Foreign exchange contracts $ 1,143 $ 1,150 Total derivatives instruments designated as ASC 815 hedges $ 3,222 $ 1,376 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 195,677 $ 173,937 Cleared 7,129 10,381 Exchange traded 102 95 Interest rate contracts $ 202,908 $ 184,413 Over-the-counter $ 119,092 $ 117,473 Cleared 1,690 2,028 Exchange traded 34 121 Foreign exchange contracts $ 120,816 $ 119,622 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 $ 12,972 $ 12,958 Cleared 7,562 8,575 Credit derivatives $ 20,534 $ 21,533 Total derivatives instruments not designated as ASC 815 hedges $ 385,339 $ 373,968 Total derivatives $ 388,561 $ 375,344 Cash collateral paid/received (3) $ 7,541 $ 14,308 Less: Netting agreements (4) (306,401 ) (306,401 ) Less: Netting cash collateral received/paid (5) (38,532 ) (35,666 ) Net receivables/payables included on the Consolidated Balance Sheet (6) $ 51,169 $ 47,585 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 (12,739 ) (6,929 ) Total net receivables/payables (6) $ 37,558 $ 40,535 (1) The trading derivatives fair values are presented in Note 20 to the Consolidated Financial Statements. Derivative mark-to-market receivables/payables previously reported within Other assets/Other liabilities have been reclassified to Trading account assets/Trading account liabilities to conform with the current period presentation. (2) 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. (3) Reflects the net amount of the $43,207 million and $52,840 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $35,666 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $38,532 million was used to offset trading derivative assets. (4) 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. (5) 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. (6) 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. For the three months ended March 31, 2018 and 2017 , 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 how 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 Three Months Ended March 31, In millions of dollars 2018 2017 Interest rate contracts $ (28 ) $ (53 ) Foreign exchange 527 225 Credit derivatives (46 ) (279 ) Total Citigroup $ 453 $ (107 ) Fair Value Hedge 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 or loans. For qualifying fair value hedges of interest rate risk, the changes in the fair value of the derivative and the change in the fair value of the hedged item attributable to the hedged risk, either total cash flows or benchmark only cash flows are presented within Interest revenue or Interest expense based on whether the hedged item is an asset or a liability. Prior to the adoption of ASU 2017-12, the fair value of the derivative was presented in Other revenue or Principal transactions and the difference between the changes in the hedged item and the derivative was defined as ineffectiveness. Hedging of Foreign Exchange Risk Citigroup hedges the change in fair value attributable to foreign exchange rate movements in available-for-sale securities and long-term debt that are denominated in currencies other than the functional currency of the entity holding the securities or issuing the debt, which may be within or outside the U.S. The hedging instrument may be a forward foreign exchange contract or a cross currency swap contract. Citigroup considers the premium associated with forward contracts (i.e., the differential between the 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. Beginning January 1, 2018, Citi excludes changes in cross-currency basis associated with cross-currency swaps from the assessment of hedge effectiveness and records it in Other-comprehensive-income. 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 and amortizes directly into earnings over the life of the hedge. The following table summarizes the gains (losses) on the Company’s fair value hedges: Gains (losses) on fair value hedges (1) Three Months Ended March 31, 2018 2017 (3) In millions of dollars Other Revenue Net interest revenue Other Revenue Gain (loss) on the derivatives in designated and qualifying fair value hedges Interest rate hedges $ — $ 878 $ (305 ) Foreign exchange hedges 179 — (82 ) Commodity hedges (2 ) — 2 Total gain (loss) on the derivatives in designated and qualifying fair value hedges $ 177 $ 878 $ (385 ) Gain (loss) on the hedged item in designated and qualifying fair value hedges Interest rate hedges $ — $ (866 ) $ 296 Foreign exchange hedges (249 ) — 196 Commodity hedges 1 — (1 ) Total gain (loss) on the hedged item in designated and qualifying fair value hedges $ (248 ) $ (866 ) $ 491 Net gain (loss) excluded from assessment of the effectiveness of fair value hedges Interest rate hedges $ — $ — $ 1 Foreign exchange hedges (2) 23 — 52 Commodity hedges 1 — 1 Total net gain (loss) excluded from assessment of the effectiveness of fair value hedges $ 24 $ — $ 54 (1) Beginning January 1, 2018, gain (loss) amounts for interest rate risk hedges are included in Interest income/expense while the remaining amounts including the amounts for interest rate hedges prior to January 1, 2018 are included in Other revenue or Principal transactions on the Consolidated Statement of Income. The accrued interest income on fair value hedges both prior to and after January 1, 2018 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. After January 1, 2018, amounts include cross-currency basis which is recognized in accumulated other comprehensive income. The amount of cross currency basis that was included in accumulated other comprehensive income was $5 million , none of which was recognized in earnings. (3) Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges for the three months ended March 31, 2017 was $(10) million for interest rate hedges and $62 million for foreign exchange hedges, for a total of $52 million . Cumulative Basis Adjustment Upon electing to apply ASC 815 fair value hedge accounting, the carrying value of the hedged item is adjusted to reflect the cumulative impact of changes in the hedged risk. The hedge basis adjustment, whether arising from an active or de-designated hedge relationship, remains with the hedged item until the hedged item is de-recognized from the balance sheet. The table below presents the carrying amount of Citi’s hedged assets and liabilities under qualifying fair value hedges at March 31, 2018, along with the cumulative hedge basis adjustments included within the carrying value of those hedged assets and liabilities. In millions of dollars Balance sheet line item in which hedged item is recorded Carrying amount of hedged asset/ liability Cumulative fair value hedging adjustment included in the carrying amount Active De-Designated Long-term debt $ 139,786 $ (24 ) $ 1,921 Investments available for sale 73,717 259 69 Cash Flow Hedges Citigroup hedges the variability of forecasted cash flows associated with floating-rate assets/liabilities and other forecasted transactions. Variable cash flows from those liabilities are synthetically converted to fixed-rate cash flows by entering into receive variable, pay-fixed interest rate swaps and receive-variable, pay-fixed forward-starting interest rate swaps. Variable cash flows associated with certain assets are synthetically converted to fixed-rate cash flows by entering into receive-fixed, pay-variable interest rate swaps. These cash flow hedging relationships use either regression analysis or dollar-offset ratio analysis to assess whether the hedging relationships are highly effective at inception and on an ongoing basis. Prior to the adoption of ASU 2017-12, Citigroup designated the risk being hedged as the risk of overall variability in the hedged cash flows for certain items. With the adoption of ASU 2017-12, Citigroup hedges the variability from changes in a contractually specified rate and recognizes the entire change in fair value of the cash flow hedging instruments in AOCI. Prior to the adoption of ASU 2017-12, to the extent these derivatives were not fully effective, changes in their fair values in excess of changes in the value of the hedged transactions were immediately included in Other revenue . The adoption of ASU 2017-12 no longer requires such amounts to be immediately recognized in income, but instead requires the full change in the value of the hedging instrument to be recognized in AOCI, and then recognized in earnings in the same period that the cash flows impact earnings. The pretax change in AOCI from cash flow hedges is presented below: Three Months Ended March 31, In millions of dollars 2018 2017 Amount of gain (loss) recognized in AOCI on derivative Interest rate contracts (1) $ (322 ) $ 41 Foreign exchange contracts 6 — Total gain (loss) recognized in AOCI $ (316 ) $ 41 Amount of gain (loss) reclassified from AOCI to earnings Other revenue Net interest revenue Interest rate contracts (1) $ — $ (31 ) $ 44 Foreign exchange contracts 2 — (3 ) Total gain (loss) reclassified from AOCI into earnings $ 2 $ (31 ) $ 41 (1) After January 1, 2018, all amounts reclassified into earnings for interest rate contracts are included in Interest income Interest expense . For all other hedges, including interest rate hedges prior to January 1, 2018, the amounts reclassified to earnings are included primarily in Other revenue and Net interest revenue on the Consolidated Income Statement. For cash flow hedges, the changes in the fair value of the hedging derivative remain in AOCI on the Consolidated Balance Sheet and will be included in the earnings of future periods to offset the variability of the hedged cash flows when such cash flows affect earnings. The net gain (loss) associated with cash flow hedges expected to be reclassified from AOCI within 12 months of March 31, 2018 is approximately $142 million . The maximum length of time over which forecasted cash flows are hedged is 10 years . The after-tax impact of cash flow hedges on AOCI is shown in Note 17 to the Consolidated Financial Statements. Net Investment Hedges The pretax gain (loss) recorded in the Foreign currency translation adjustment account within AOCI, related to net investment hedges, is $(491) million and $(1,716) million for the three months ended March 31, 2018 and March 31, 2017, respectively. Credit Derivatives 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 March 31, 2018 Receivable (1) Payable (2) Protection Protection By industry/counterparty Banks $ 6,782 $ 6,120 $ 263,672 $ 272,815 Broker-dealers 2,155 2,060 72,862 83,585 Non-financial 75 75 1,240 2,313 Insurance and other financial institutions 10,015 11,354 452,360 382,987 Total by industry/counterparty $ 19,027 $ 19,609 $ 790,134 $ 741,700 By instrument Credit default swaps and options $ 18,591 $ 18,787 $ 766,018 $ 729,303 Total return swaps and other 436 822 24,116 12,397 Total by instrument $ 19,027 $ 19,609 $ 790,134 $ 741,700 By rating Investment grade $ 9,496 $ 9,594 $ 597,093 $ 559,526 Non-investment grade 9,531 10,015 193,041 182,174 Total by rating $ 19,027 $ 19,609 $ 790,134 $ 741,700 By maturity Within 1 year $ 2,337 $ 2,517 $ 228,396 $ 212,661 From 1 to 5 years 14,152 14,223 477,627 454,001 After 5 years 2,538 2,869 84,111 75,038 Total by maturity $ 19,027 $ 19,609 $ 790,134 $ 741,700 (1) The fair value amount receivable is composed of $3,016 million under protection purchased and $16,011 million under protection sold. (2) The fair value amount payable is composed of $16,793 million under protection purchased and $2,816 million under protection sold. 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 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. Credit Risk-Related Contingent Features in Derivatives Certain derivative instruments contain provisions that require the Company to either post additional collateral or immediately settle any outstanding liability balances upon the occurrence of a specified event related to the credit risk of the Company. These events, which are defined by the existing derivative contracts, are primarily downgrades in the credit ratings of the Company and its affiliates. The fair value (excluding CVA) of all derivative instruments with credit risk-related contingent features that were in a net liability position at both March 31, 2018 and December 31, 2017 was $29 billion . The Company posted $26 billion and $28 billion as collateral for this exposure in the normal course of business as of March 31, 2018 and December 31, 2017, respectively. A downgrade could trigger additional collateral or cash settlement requirements for the Company and certain affiliates. In the event that Citigroup and Citibank were downgraded a single notch by all three major rating agencies as of March 31, 2018, the Company could be required to post an additional $0.7 billion as either collateral or settlement of the derivative transactions. Additionally, the Company could be required to segregate with third-party custodians collateral previously received from existing derivative counterparties in the amount of $0.2 billion upon the single notch downgrade, resulting in aggregate cash obligations and collateral requirements of approximately $0.9 billion . Derivatives Accompanied by Financial Asset Transfers For transfers of financial assets accounted for as a sale by the Company and the Company has retained substantially all of the economic exposure to the transferred asset through a total return swap executed with the same counterparty in contemplation of the initial sale (and still outstanding) both the asset amounts derecognized and the gross cash proceeds received as of the date of derecognition were $3.4 billion and $3.0 billion as of March 31, 2018 and December 31, 2017, respectively. At March 31, 2018 , the fair value of these previously derecognized assets was $3.4 billion . The fair value of the total return swaps as of March 31, 2018 was $79 million recorded as gross derivative assets and $52 million recorded as gross derivative liabilities. At December 31, 2017, the fair value of these previously derecognized assets was $3.1 billion and the fair value of the total return swaps was $89 million , recorded as gross derivative assets, and $15 million recorded as gross derivative liabilities. The balances for the total return swaps are on a gross basis, before the application of counterparty and cash collateral netting, and are included primarily as equity derivatives in the tabular disclosures in this Note.

FAIR VALUE MEASUREMENT

FAIR VALUE MEASUREMENT	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENT	FAIR VALUE MEASUREMENT For additional information regarding fair value measurement at Citi, see Note 24 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. Market Valuation Adjustments The table below summarizes the credit valuation adjustments (CVA) and funding valuation adjustments (FVA) applied to the fair value of derivative instruments at March 31, 2018 and December 31, 2017 : Credit and funding valuation adjustments contra-liability (contra-asset) In millions of dollars March 31, December 31, Counterparty CVA $ (841 ) $ (970 ) Asset FVA (438 ) (447 ) Citigroup (own-credit) CVA 364 287 Liability FVA 40 47 Total CVA—derivative instruments (1) $ (875 ) $ (1,083 ) (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 periods indicated: Credit/funding/debt valuation adjustments gain (loss) Three Months Ended March 31, In millions of dollars 2018 2017 Counterparty CVA $ 23 $ 90 Asset FVA 9 92 Own-credit CVA 75 (72 ) Liability FVA (7 ) (10 ) Total CVA—derivative instruments $ 100 $ 100 DVA related to own FVO liabilities (1) $ 167 $ (95 ) Total CVA and DVA (2) $ 267 $ 5 (1) See Note 1 and Note 17 to the Consolidated Financial Statements. (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 March 31, 2018 and December 31, 2017 . 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 March 31, 2018 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 $ — $ 222,936 $ 16 $ 222,952 $ (61,415 ) $ 161,537 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,317 206 22,523 — 22,523 Residential — 1,084 143 1,227 — 1,227 Commercial — 1,440 35 1,475 — 1,475 Total trading mortgage-backed securities $ — $ 24,841 $ 384 $ 25,225 $ — $ 25,225 U.S. Treasury and federal agency securities $ 20,812 $ 3,898 $ — $ 24,710 $ — $ 24,710 State and municipal — 3,671 211 3,882 — 3,882 Foreign government 46,617 24,918 21 71,556 — 71,556 Corporate 274 18,826 252 19,352 — 19,352 Equity securities 47,797 6,253 237 54,287 — 54,287 Asset-backed securities — 1,586 1,597 3,183 — 3,183 Other trading assets (3) 2 11,000 716 11,718 — 11,718 Total trading non-derivative assets $ 115,502 $ 94,993 $ 3,418 $ 213,913 $ — $ 213,913 Trading derivatives Interest rate contracts $ 276 $ 193,319 $ 2,234 $ 195,829 Foreign exchange contracts 5 129,691 521 130,217 Equity contracts 2,212 26,664 559 29,435 Commodity contracts 169 15,100 562 15,831 Credit derivatives — 18,153 874 19,027 Total trading derivatives $ 2,662 $ 382,927 $ 4,750 $ 390,339 Cash collateral paid (4) $ 8,676 Netting agreements $ (303,169 ) Netting of cash collateral received (40,951 ) Total trading derivatives $ 2,662 $ 382,927 $ 4,750 $ 399,015 $ (344,120 ) $ 54,895 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 41,265 $ 23 $ 41,288 $ — $ 41,288 Residential — 2,759 — 2,759 — 2,759 Commercial — 303 5 308 — 308 Total investment mortgage-backed securities $ — $ 44,327 $ 28 $ 44,355 $ — $ 44,355 U.S. Treasury and federal agency securities $ 106,239 $ 11,075 $ — $ 117,314 $ — $ 117,314 State and municipal — 9,155 682 9,837 — 9,837 Foreign government 61,312 42,393 70 103,775 — 103,775 Corporate 3,756 9,164 76 12,996 — 12,996 Equity securities 233 43 1 277 — 277 Asset-backed securities — 2,584 497 3,081 — 3,081 Other debt securities — 165 — 165 — 165 Non-marketable equity securities (5) — 125 734 859 — 859 Total investments $ 171,540 $ 119,031 $ 2,088 $ 292,659 $ — $ 292,659 Table continues on the next page. In millions of dollars at March 31, 2018 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Loans $ — $ 3,982 $ 554 $ 4,536 $ — $ 4,536 Mortgage servicing rights — — 587 587 — 587 Non-trading derivatives and other financial assets measured on a recurring basis $ 15,549 $ 4,881 $ 13 $ 20,443 $ — $ 20,443 Total assets $ 305,253 $ 828,750 $ 11,426 $ 1,154,105 $ (405,535 ) $ 748,570 Total as a percentage of gross assets (6) 26.6 % 72.4 % 1.0 % Liabilities Interest-bearing deposits $ — $ 1,394 $ 292 $ 1,686 $ — $ 1,686 Federal funds purchased and securities loaned or sold under agreements to repurchase — 106,398 857 107,255 (61,415 ) 45,840 Trading account liabilities Securities sold, not yet purchased 80,995 10,911 48 91,954 — 91,954 Other trading liabilities — 2,290 — 2,290 — 2,290 Total trading liabilities $ 80,995 $ 13,201 $ 48 $ 94,244 $ — $ 94,244 Trading derivatives Interest rate contracts $ 218 $ 173,128 $ 2,240 $ 175,586 Foreign exchange contracts 4 123,117 433 123,554 Equity contracts 2,126 29,689 2,300 34,115 Commodity contracts 138 16,242 2,471 18,851 Credit derivatives 2 17,874 1,733 19,609 Total trading derivatives $ 2,488 $ 360,050 $ 9,177 $ 371,715 Cash collateral received (7) $ 14,971 Netting agreements $ (303,169 ) Netting of cash collateral paid (33,800 ) Total trading derivatives $ 2,488 $ 360,050 $ 9,177 $ 386,686 $ (336,969 ) $ 49,717 Short-term borrowings $ — $ 4,386 $ 81 $ 4,467 $ — $ 4,467 Long-term debt — 20,087 13,484 33,571 — 33,571 Total non-trading derivatives and other financial liabilities measured on a recurring basis $ 15,549 $ — $ 3 $ 15,552 $ — $ 15,552 Total liabilities $ 99,032 $ 505,516 $ 23,942 $ 643,461 $ (398,384 ) $ 245,077 Total as a percentage of gross liabilities (6) 15.8 % 80.4 % 3.8 % (1) For the three months ended March 31, 2018 , the Company transferred assets of approximately $0.7 billion from Level 1 to Level 2, primarily related to foreign government securities and equity securities not traded in active markets. During the three months ended March 31, 2018 , the Company transferred assets of approximately $4.0 billion from Level 2 to Level 1, primarily related to foreign government bonds, foreign corporate securities, and equity securities traded with sufficient frequency to constitute an active market. For the three months ended March 31, 2018 , there were no material transfers of liabilities from Level 1 to Level 2. During the three months ended March 31, 2018 , the Company transferred liabilities of approximately $0.2 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 21 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 $42,476 million gross cash collateral paid, of which $33,800 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 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). (6) 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. (7) Reflects the net amount $55,922 million of gross cash collateral received, of which $40,951 million was used to offset trading derivative assets. 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 $ 203,134 $ 1,708 $ 204,987 Foreign exchange contracts 19 121,363 577 121,959 Equity contracts 2,364 24,170 444 26,978 Commodity contracts 282 13,252 569 14,103 Credit derivatives — 19,624 910 20,534 Total trading derivatives $ 2,810 $ 381,543 $ 4,208 $ 388,561 Cash collateral paid (4) $ 7,541 Netting agreements $ (306,401 ) Netting of cash collateral received (38,532 ) Total trading derivatives $ 2,810 $ 381,543 $ 4,208 $ 396,102 $ (344,933 ) $ 51,169 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. 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 $ 13,903 $ 4,640 $ 16 $ 18,559 $ — $ 18,559 Total assets $ 292,700 $ 790,217 $ 11,059 $ 1,101,517 $ (400,571 ) $ 700,946 Total as a percentage of gross assets (6) 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 account derivatives Interest rate contracts $ 137 $ 182,372 $ 2,130 $ 184,639 Foreign exchange contracts 9 120,316 447 120,772 Equity contracts 2,430 26,472 2,471 31,373 Commodity contracts 115 14,482 2,430 17,027 Credit derivatives — 19,824 1,709 21,533 Total trading derivatives $ 2,691 $ 363,466 $ 9,187 $ 375,344 Cash collateral received (7) $ 14,308 Netting agreements $ (306,401 ) Netting of cash collateral paid (35,666 ) Total trading derivatives $ 2,691 $ 363,466 $ 9,187 $ 389,652 $ (342,067 ) $ 47,585 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 $ 13,903 $ 50 $ 8 $ 13,961 $ — $ 13,961 Total liabilities $ 82,437 $ 494,879 $ 23,334 $ 614,958 $ (397,705 ) $ 217,253 Total as a percentage of gross liabilities (6) 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, respectively. 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 21 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 $43,207 million of gross cash collateral paid, of which $35,666 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) 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. (7) Reflects the net amount of $52,840 million of gross cash collateral received, of which $38,532 million was used to offset trading derivative assets. Changes in Level 3 Fair Value Category The following tables present the changes in the Level 3 fair value category for the three months ended March 31, 2018 and 2017 . The gains and losses presented below include changes in the fair value related to both observable and unobservable inputs. The Company often hedges positions with offsetting positions that are classified in a different level. For example, the gains and losses for assets and liabilities in the Level 3 category presented in the tables below do not reflect the effect of offsetting losses and gains on hedging instruments that may be classified in the Level 1 or Level 2 categories. In addition, the Company hedges items classified in the Level 3 category with instruments also classified in Level 3 of the fair value hierarchy. 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, 2017 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2018 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 16 $ 18 $ — $ — $ — $ — $ — $ — $ (18 ) $ 16 $ 3 Trading non-derivative assets Trading mortgage- backed securities U.S. government-sponsored agency guaranteed 163 1 — 86 (49 ) 116 — (111 ) — 206 — Residential 164 22 — 35 (77 ) 46 — (47 ) — 143 3 Commercial 57 1 — 4 (35 ) 15 — (7 ) — 35 3 Total trading mortgage- backed securities $ 384 $ 24 $ — $ 125 $ (161 ) $ 177 $ — $ (165 ) $ — $ 384 $ 6 U.S. Treasury and federal agency securities $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — State and municipal 274 6 — — (44 ) — — (25 ) — 211 (1 ) Foreign government 16 — — 2 — 14 — (11 ) — 21 — Corporate 275 43 — 49 (72 ) 34 — (77 ) — 252 84 Equity securities 120 75 — 1 (15 ) 168 — (112 ) — 237 (3 ) Asset-backed securities 1,590 58 — 18 (15 ) 316 — (370 ) — 1,597 73 Other trading assets 615 135 — 58 (10 ) 112 5 (194 ) (5 ) 716 6 Total trading non- derivative assets $ 3,274 $ 341 $ — $ 253 $ (317 ) $ 821 $ 5 $ (954 ) $ (5 ) $ 3,418 $ 165 Trading derivatives, net (4) Interest rate contracts $ (422 ) $ 381 $ — $ 5 $ 37 $ 7 $ — $ (16 ) $ 2 $ (6 ) $ (94 ) Foreign exchange contracts 130 (62 ) — (1 ) 8 1 — — 12 88 (155 ) Equity contracts (2,027 ) (136 ) — (57 ) 472 13 — (7 ) 1 (1,741 ) 156 Commodity contracts (1,861 ) (33 ) — (47 ) 8 20 — — 4 (1,909 ) (42 ) Credit derivatives (799 ) (62 ) — 1 (2 ) 2 — 1 — (859 ) (203 ) Total trading derivatives, net (4) $ (4,979 ) $ 88 $ — $ (99 ) $ 523 $ 43 $ — $ (22 ) $ 19 $ (4,427 ) $ (338 ) Table continues on the next page. Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31 2017 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2018 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 24 $ — $ (1 ) $ — $ — $ — $ — $ — $ — $ 23 $ 2 Residential — — — — — — — — — — — Commercial 3 — 2 — — — — — — 5 — Total investment mortgage-backed securities $ 27 $ — $ 1 $ — $ — $ — $ — $ — $ — $ 28 $ 2 U.S. Treasury and federal agency securities $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — State and municipal 737 — (16 ) — (9 ) 29 — (59 ) — 682 (33 ) Foreign government 92 — (1 ) — (2 ) 57 — (76 ) — 70 — Corporate 71 — (1 ) 3 — 3 — — — 76 — Equity securities 2 — — — — — — (1 ) — 1 — Asset-backed securities 827 — 10 2 (342 ) — — — — 497 7 Other debt securities — — — — — — — — — — — Non-marketable equity securities 681 — 24 30 — 15 — — (16 ) 734 22 Total investments $ 2,437 $ — $ 17 $ 35 $ (353 ) $ 104 $ — $ (136 ) $ (16 ) $ 2,088 $ (2 ) Loans $ 550 $ — $ 19 $ — $ (1 ) $ 4 $ — $ (16 ) $ (2 ) $ 554 $ 26 Mortgage servicing rights 558 — 46 — — — 17 (17 ) (17 ) 587 46 Other financial assets measured on a recurring basis 16 — 8 — — 4 12 — (27 ) 13 18 Liabilities Interest-bearing deposits $ 286 $ — $ 26 $ 12 $ — $ — $ 20 $ — $ — $ 292 $ 29 Federal funds purchased and securities loaned or sold under agreements to repurchase 726 14 — — — — 147 — (2 ) 857 14 Trading account liabilities Securities sold, not yet purchased 22 (105 ) — 3 (19 ) — — 3 (66 ) 48 (7 ) Other trading liabilities 5 5 — — — — — — — — (5 ) Short-term borrowings 18 7 — 45 — — 25 — — 81 (2 ) Long-term debt 13,082 (236 ) — 940 (764 ) 36 3 (44 ) (5 ) 13,484 254 Other financial liabilities measured on a recurring basis 8 — — — (5 ) — 2 — (2 ) 3 (1 ) (1) Changes in fair value for available-for-sale debt securities 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 debt securities), attributable to the change in fair value relating to assets and liabilities classified as Level 3 that are still held at March 31, 2018 . (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, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2017 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 1,496 $ (56 ) $ — $ — $ (252 ) $ — $ — $ — $ (1 ) $ 1,187 $ 4 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed 176 5 — 50 (17 ) 161 — (104 ) — 271 — Residential 399 15 — 17 (29 ) 50 — (84 ) — 368 10 Commercial 206 (8 ) — 17 (13 ) 190 — (126 ) — 266 (4 ) Total trading mortgage-backed securities $ 781 $ 12 $ — $ 84 $ (59 ) $ 401 $ — $ (314 ) $ — $ 905 $ 6 U.S. Treasury and federal agency securities $ 1 $ — $ — $ — $ — $ — $ — $ — $ — $ 1 $ — State and municipal 296 2 — 2 (47 ) 81 — (64 ) — 270 2 Foreign government 40 4 — 78 (13 ) 44 — (27 ) — 126 6 Corporate 324 91 — 27 (52 ) 118 — (197 ) (15 ) 296 12 Equity securities 127 15 — 2 (12 ) 7 — (29 ) — 110 2 Asset-backed securities 1,868 160 — 20 (16 ) 391 — (482 ) — 1,941 81 Other trading assets 2,814 (7 ) — 210 (531 ) 287 1 (875 ) (11 ) 1,888 (55 ) Total trading non-derivative assets $ 6,251 $ 277 $ — $ 423 $ (730 ) $ 1,329 $ 1 $ (1,988 ) $ (26 ) $ 5,537 $ 54 Trading derivatives, net (4) Interest rate contracts $ (663 ) $ (37 ) $ — $ (38 ) $ 19 $ 6 $ — $ (113 ) $ 53 $ (773 ) $ (23 ) Foreign exchange contracts 413 (390 ) — 55 (20 ) 34 — (32 ) (12 ) 48 (341 ) Equity contracts (1,557 ) (2 ) — — (16 ) 85 — (24 ) (10 ) (1,524 ) 202 Commodity contracts (1,945 ) (175 ) — 46 (2 ) — — — 2 (2,074 ) (170 ) Credit derivatives (1,001 ) (92 ) — (24 ) (8 ) — — — 2 (1,123 ) (108 ) Total trading derivatives, net (4) $ (4,753 ) $ (696 ) $ — $ 39 $ (27 ) $ 125 $ — $ (169 ) $ 35 $ (5,446 ) $ (440 ) Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 101 $ — $ 2 $ 1 $ (49 ) $ — $ — $ — $ — $ 55 $ 2 Residential 50 — 2 — (47 ) — — (5 ) — — — Commercial — — — — — 8 — (8 ) — — — Total investment mortgage-backed securities $ 151 $ — $ 4 $ 1 $ (96 ) $ 8 $ — $ (13 ) $ — $ 55 $ 2 U.S. Treasury and federal agency securities $ 2 $ — $ — $ — $ — $ — $ — $ (1 ) $ — $ 1 $ — State and municipal 1,211 — 12 37 (30 ) 54 — (51 ) — 1,233 6 Foreign government 186 — 1 2 (18 ) 142 — (78 ) — 235 1 Corporate 311 — 2 59 (4 ) 91 — (120 ) — 339 2 Equity securities 9 — — — — — — — — 9 — Asset-backed securities 660 — 9 17 — 26 — — — 712 3 Other debt securities — — — — — 11 — (11 ) — — — Non-marketable equity securities 1,331 — (94 ) — — 8 — (73 ) (90 ) 1,082 (2 ) Total investments $ 3,861 $ — $ (66 ) $ 116 $ (148 ) $ 340 $ — $ (347 ) $ (90 ) $ 3,666 $ 12 Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2017 Loans $ 568 $ — $ (4 ) $ 65 $ (16 ) $ 12 $ — $ (43 ) $ (2 ) $ 580 $ 74 Mortgage servicing rights 1,564 — 67 — — — 35 (1,046 ) (53 ) 567 83 Other financial assets measured on a recurring basis 34 — (189 ) 3 (1 ) — 29 204 (53 ) 27 (191 ) Liabilities Interest-bearing deposits $ 293 $ — $ 11 $ 20 $ — $ — $ — $ — $ — $ 302 $ 25 Federal funds purchased and securities loaned or sold under agreements to repurchase 849 6 — — — — — — (34 ) 809 6 Trading account liabilities Securities sold, not yet purchased 1,177 54 — 11 (14 ) — — 101 (70 ) 1,151 2 Other trading liabilities 1 — — — — — — — (1 ) — — Short-term borrowings 42 (9 ) — — — — 11 — (2 ) 60 22 Long-term debt 9,744 17 — 200 (409 ) — 929 — (271 ) 10,176 116 Other financial liabilities measured on a recurring basis 8 — (2 ) — — (1 ) 1 — (6 ) 4 (2 ) (1) Changes in fair value for available-for-sale debt securities 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 debt securities), 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. Level 3 Fair Value Rollforward The following were the significant Level 3 transfers for the period December 31, 2017 to March 31, 2018 : • Transfers of Long-term debt of $0.9 billion from Level 2 to Level 3, and of $0.8 billion from Level 3 to Level 2, mainly related to structured debt, reflecting changes in the significance of unobservable inputs as well as certain underlying market inputs becoming less or more observable. The were no significant Level 3 transfers for the period from December 31, 2016 to March 31, 2017 . Valuation Techniques and Inputs for 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. As of March 31, 2018 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 1.74 % 2.41 % 2.40 % Mortgage-backed securities $ 220 Yield analysis Yield 2.18 % 8.14 % 3.89 % 147 Price-based Price $ 6.00 $ 102.26 $ 74.57 State and municipal, foreign government, corporate and other debt securities $ 943 Model-based Price $ 3.47 $ 110.39 $ 88.85 883 Price-based Credit spread 35bps 500bps 252bps Yield 2.00 % 14.88 % 6.54 % Equity securities (5) $ 206 Price-based Price $ 0.01 $ 18,320.07 $ 654.81 30 Model-based Asset-backed securities $ 1,983 Price-based Price $ 2.33 $ 100.76 $ 69.28 Non-marketable equities $ 431 Comparables analysis EBITDA multiples 7.00 x 10.90 x 8.56 x 265 Price-based Discount to price — % 100.00 % 13.24 % Price to book ratio 5.00 x 100.00 x 68.86 x Derivatives—gross (6) Interest rate contracts (gross) $ 4,440 Model-based Mean reversion 1.00 % 20.00 % 10.50 % Inflation volatility 0.25 % 2.70 % 0.82 % IR Normal Volatility 0.12 % 78.91 % 50.71 % Foreign exchange contracts (gross) $ 877 Model-based FX volatility 6.41 % 20.25 % 12.75 % IR basis (0.74 )% 2.01 % (0.01 )% Credit spread 23bps 7,823bps 166bps IR-IR correlation 40.00 % 40.00 % 40.00 % IR-FX correlation 40.00 % 60.00 % 50.00 % Equity contracts (gross) $ 2,835 Model-based Equity volatility 1.16 % 70.22 % 25.72 % Forward price 63.73 % 153.71 % 101.21 % Commodity and other contracts (gross) $ 2,940 Model-based Forward price 35.75 % 478.26 % 114.73 % Commodity volatility 9.14 % 41.03 % 22.87 % Commodity correlation (51.36 )% 91.85 % 19.83 % Credit derivatives (gross) $ 1,833 Model-based Credit correlation 25.00 % 85.00 % 43.30 % 774 Price-based Upfront points 3.84 % 97.33 % 59.81 % Credit spread 6bps 1,200bps 115bps Price $ 7.54 $ 100.00 $ 64.58 As of March 31, 2018 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) $ 19 Model-based Recovery rate 25.00 % 46.00 % 38.21 % Credit spread 21bps 129bps 77bps Redemption rate 5.14 % 99.50 % 72.69 % Upfront points 54.00 % 54.00 % 54.00 % Loans and leases $ 520 Model-based Credit spread 17bps 500bps 92bps Yield 2.70 % 4.06 % 3.71 % Mortgage servicing rights $ 500 Cash flow Yield 4.26 % 12.60 % 8.36 % 87 Model-based WAL 4.08 years 7.63 years 6.53 years Liabilities Interest-bearing deposits $ 292 Model-based Mean reversion — % 20.00 % 7.85 % Federal funds purchased and securities loaned or sold under agreement to repurchase $ 857 Model-based Interest rate 1.74 % 2.41 % 2.40 % Trading account liabilities Securities sold, not yet purchased $ 31 Model-based Equity volatility 3.00 % 70.22 % 31.84 % 18 Price-based Equity-equity correlation (99.00 )% 100.00 % 59.65 % Equity-FX correlation (80.37 )% 56.00 % (29.86 )% Forward Price 63.73 % 153.71 % 100.14 % Price $ — $ 100.00 $ 24.84 Short-term borrowings and long-term debt $ 13,559 Model-based Equity volatility 3.00 % 70.22 % 18.48 % Forward price 63.73 % 167.94 % 103.12 % 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 35bps 500bps 249bps 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) As of December 31, 2017 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) 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 11bps 717bps 173bps 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 1,636bps 173bps Price $ 1.00 $ 100.24 $ 57.63 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 38bps 275bps 127bps Upfront points 61.00 % 61.00 % 61.00 % Loans $ 391 Model-based Equity Volatility 3.00 % 68.93 % 22.52 % 148 Price-based Credit spread 134bps 500bps 173bps 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 % (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 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 on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis and therefore are not included in the tables above. These include assets measured at cost that have been written down to fair value during the periods as a result of an impairment. These also include non-marketable equity investments that have been measured using the measurement alternative and are either (i) written down to fair value during the periods as a result of an impairment or (ii) adjusted upward or downward to fair value as a result of a transaction observed during the periods for the identical or similar i

FAIR VALUE ELECTIONS

FAIR VALUE ELECTIONS	3 Months Ended
	Mar. 31, 2018
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 20 to the Consolidated Financial Statements The Company has elected fair value accounting for its mortgage servicing rights. See Note 18 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) Three Months Ended March 31, In millions of dollars 2018 2017 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ (16 ) $ (33 ) Trading account assets (16 ) 430 Investments — — Loans Certain corporate loans (123 ) 24 Certain consumer loans — — Total loans $ (123 ) $ 24 Other assets MSRs $ 46 $ 67 Certain mortgage loans held-for-sale (1) 2 37 Total other assets $ 48 $ 104 Total assets $ (107 ) $ 525 Liabilities Interest-bearing deposits $ 28 $ (14 ) Federal funds purchased and securities loaned or sold under agreements to repurchase (111 ) 613 Trading account liabilities (6 ) 26 Short-term borrowings 177 19 Long-term debt 618 (332 ) Total liabilities $ 706 $ 312 (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) was a gain of $167 million and a loss of $95 million for the three months ended March 31, 2018 and 2017 , 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 Interest 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: March 31, 2018 December 31, 2017 In millions of dollars Trading assets Loans Trading assets Loans Carrying amount reported on the Consolidated Balance Sheet $ 9,194 $ 4,536 $ 8,851 $ 4,374 Aggregate unpaid principal balance in excess of (less than) fair value 475 870 623 682 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 In addition to the amounts reported above, $ 408 million and $ 508 million of unfunded commitments related to certain credit products selected for fair value accounting were outstanding as of March 31, 2018 and December 31, 2017 , 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 three months ended March 31, 2018 and 2017 due to instrument-specific credit risk totaled to gains of $ 19 million and $ 26 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 $ 0.7 billion and $ 0.9 billion at March 31, 2018 and December 31, 2017 , 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 March 31, 2018 , there were approximately $ 12.0 billion and $ 10.1 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 elected 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 . Effective January 1, 2018, under ASU 2016-01 and ASU 2018-03, a fair value option election is no longer required to measure these non-marketable equity securities at fair value through earnings. See Note 1 to the Consolidated Financial Statements for additional details. 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 March 31, December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 333 $ 426 Aggregate fair value in excess of (less than) unpaid principal balance 7 14 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 three months ended March 31, 2018 and 2017 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 March 31, 2018 December 31, 2017 Interest rate linked $ 15.9 $ 13.9 Foreign exchange linked 0.3 0.3 Equity linked 12.8 13.0 Commodity linked 0.4 0.2 Credit linked 1.9 1.9 Total $ 31.3 $ 29.3 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) is 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 March 31, 2018 December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 33,571 $ 31,392 Aggregate unpaid principal balance in excess of (less than) fair value (93 ) (579 ) The following table provides information about short-term borrowings carried at fair value: In millions of dollars March 31, 2018 December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 4,467 $ 4,627 Aggregate unpaid principal balance in excess of fair value 463 74

GUARANTEES AND COMMITMENTS

GUARANTEES AND COMMITMENTS	3 Months Ended
	Mar. 31, 2018
Pledged Assets, Collateral, Guarantees and Commitments [Abstract]
GUARANTEES AND COMMITMENTS	GUARANTEES AND COMMITMENTS 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. For additional information regarding Citi’s guarantees and indemnifications included in the tables below, as well as its other guarantees and indemnifications excluded from the tables below, see Note 26 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. The following tables present information about Citi’s guarantees at March 31, 2018 and December 31, 2017 : Maximum potential amount of future payments In billions of dollars at March 31, 2018 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 $ 30.4 $ 63.0 $ 93.4 $ 131 Performance guarantees 7.5 4.1 11.6 31 Derivative instruments considered to be guarantees 17.0 85.6 102.6 432 Loans sold with recourse — 0.2 0.2 8 Securities lending indemnifications (1) 126.9 — 126.9 — Credit card merchant processing (1)(2) 82.5 — 82.5 — Credit card arrangements with partners 0.2 1.1 1.3 162 Custody indemnifications and other — 38.5 38.5 82 Total $ 264.5 $ 192.5 $ 457.0 $ 846 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 (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 March 31, 2018 and December 31, 2017 , this maximum potential exposure was estimated to be $83 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. 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 at March 31, 2018 and December 31, 2017 , and these amounts are included in Other liabilities on the Consolidated Balance Sheet. 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 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. 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 March 31, 2018 and December 31, 2017, the actual and estimated losses incurred and the carrying value of Citi’s obligations related to these programs were immaterial. 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 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 March 31, 2018 or December 31, 2017 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 $7.4 billion as of March 31, 2018, compared to $7.5 billion at December 31, 2017. 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 March 31, 2018 and December 31, 2017 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 (CCP) for clients that need to clear exchange-traded and over-the-counter (OTC) derivatives contracts with CCPs. 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 19 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 $11.6 billion and $10.7 billion as of March 31, 2018 and December 31, 2017 , 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 nonperformance 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 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 March 31, 2018 and December 31, 2017 , 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 $0.8 billion . 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 $52 billion and $46 billion at March 31, 2018 and December 31, 2017 , respectively. Securities and other marketable assets held as collateral amounted to $88 billion and $70 billion at March 31, 2018 and December 31, 2017 , 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 $3.9 billion and $3.7 billion at both March 31, 2018 and December 31, 2017 . 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 Presented in the tables below are the maximum potential amounts of future payments that are classified based upon internal and external credit ratings. 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 March 31, 2018 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 68.1 $ 10.3 $ 15.0 $ 93.4 Performance guarantees 8.2 2.3 1.1 11.6 Derivative instruments deemed to be guarantees — — 102.6 102.6 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 126.9 126.9 Credit card merchant processing — — 82.5 82.5 Credit card arrangements with partners — — 1.3 1.3 Custody indemnifications and other 25.8 12.7 — 38.5 Total $ 102.1 $ 25.3 $ 329.6 $ 457.0 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 Credit Commitments and Lines of Credit The table below summarizes Citigroup’s credit commitments: In millions of dollars U.S. Outside of U.S. March 31, December 31, 2017 Commercial and similar letters of credit $ 821 $ 4,675 $ 5,496 $ 5,000 One- to four-family residential mortgages 1,385 1,610 2,995 2,674 Revolving open-end loans secured by one- to four-family residential properties 10,703 1,510 12,213 12,323 Commercial real estate, construction and land development 8,955 2,146 11,101 11,151 Credit card lines 583,477 102,158 685,635 678,300 Commercial and other consumer loan commitments 188,945 111,770 300,715 272,655 Other commitments and contingencies 2,145 716 2,861 3,071 Total $ 796,431 $ 224,585 $ 1,021,016 $ 985,174 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. Other commitments and contingencies Other commitments and contingencies include 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 March 31, 2018, and December 31, 2017, Citigroup had $78.7 billion and $35.0 billion of unsettled reverse repurchase and securities borrowing agreements, respectively, and $33.7 billion and $19.1 billion of unsettled repurchase and securities lending agreements, respectively. 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 10 to the Consolidated Financial Statements.

CONTINGENCIES

CONTINGENCIES	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES The following information supplements and amends, as applicable, the disclosures in Note 27 to the Consolidated Financial Statements of Citigroup’s 2017 Annual Report on Form 10-K. For purposes of this Note, Citigroup, its affiliates and subsidiaries and current and former officers, directors and employees, are sometimes collectively referred to as Citigroup and Related Parties. 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. 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. If Citigroup has not accrued for a matter because the matter does not meet the criteria for accrual (as set forth above), or Citigroup believes an exposure to loss exists in excess of the amount accrued for a particular matter, in each case assuming a material loss is reasonably possible, Citigroup discloses the matter. In addition, for such matters, Citigroup discloses an estimate of the aggregate reasonably possible loss or range of loss in excess of the amounts accrued for those matters as to which an estimate can be made. At March 31, 2018, Citigroup’s estimate of the reasonably possible unaccrued loss for these matters was materially unchanged from the estimate of approximately $1.0 billion in the aggregate as of December 31, 2017. 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, Citigroup may have only preliminary, incomplete or inaccurate information about the facts underlying the claim; 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 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 estimates because it had deemed such an outcome to be remote. For all 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. 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. For further information on ASC 450 and Citigroup's accounting and disclosure framework for contingencies, including for litigation and regulatory matters disclosed herein, see Note 27 to the Consolidated Financial Statements of Citigroup’s 2017 Annual Report on Form 10-K. Credit Crisis-Related Litigation and Other Matters Mortgage-Backed Securities Trustee Actions: On March 22, 2018, the United States District Court for the Southern District of New York granted Citibank’s motion for summary judgment and denied plaintiffs’ motion for class certification in FIXED INCOME SHARES: SERIES M ET AL. v. CITIBANK N.A. 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 March 13, 2018, Citibank filed a motion to dismiss the amended complaint filed by the Federal Deposit Insurance Corporation in FEDERAL DEPOSIT INSURANCE CORPORATION AS RECEIVER FOR GUARANTY BANK v. CITIBANK N.A. Additional information concerning this action is publicly available in court filings under the docket number 15-cv-6574 (S.D.N.Y.) (Carter, J.). Tribune Company Bankruptcy On April 3, 2018, the United States Supreme Court issued an order deferring consideration of the noteholders’ petition for a writ of certiorari appealing the dismissal of their claims from KIRSCHNER v. FITZSIMONS, ET AL. 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.). Depositary Receipts Conversion Litigation On March 23, 2018, the court granted in part and denied in part plaintiffs’ motion for class certification, certifying only a class of holders of Citi-sponsored American depositary receipts that plaintiffs own. 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 Antitrust and Other Litigation : On March 12, 2018, the court in NYPL v. JPMORGAN CHASE & CO., ET AL. granted the motion of defendants to dismiss claims based on conduct after 2013, but denied the motion in other respects. On March 7, 2018, the plaintiffs asked the court to expand the case to include additional types of transactions, which the defendants opposed. 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 March 15, 2018, the court in CONTANT, ET AL. v. BANK OF AMERICA CORPORATION, ET AL. granted the motion of defendants to dismiss the complaint for failure to state a claim. On April 5, 2018, plaintiffs filed a motion for leave to file a second consolidated class action complaint. 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 Antitrust and Other Litigation : In IN RE LIBOR-BASED FINANCIAL INSTRUMENTS ANTITRUST LITIGATION, on February 28, 2018, the court denied certification of two classes (investors who transacted in Eurodollar futures or options on exchanges and lending institutions with interests in loans tied to USD LIBOR) and certified the largest plaintiffs’ class (investors who purchased over-the-counter (OTC) derivatives from USD LIBOR panel banks) with respect to the antitrust claims against certain remaining defendants. On March 24, 2018, the parties filed petitions in the United States Court of Appeals for the Second Circuit seeking review of the court’s class-certification rulings. On February 23, 2018, the Second Circuit vacated the portion of the judgment entered by the district court on April 11, 2016, that dismissed non-antitrust claims of various Schwab entities on personal jurisdiction grounds, and remanded the case to the district court. 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 16-1189 (2d Cir.). Parmalat Litigation On March 2, 2018, Parmalat filed an appeal to the Milan Court of Appeal against the January 25, 2018 decision of the Milan civil court dismissing Parmalat’s claim for €1.8 billion against Citigroup and Related Parties. Shareholder Derivative Litigation On March 12, 2018, the Delaware Chancery Court denied plaintiffs’ motion to reopen the judgment and for leave to amend the complaint in OKLAHOMA FIREFIGHTERS PENSION & RETIREMENT SYSTEM, ET AL. v. CORBAT, ET AL. Additional information concerning this action is publicly available in court filings under the docket numbers C.A. No. 12151-VCG (Del. Ch.) (Glasscock, Ch.) and No. 32, 2018 (Del.). Sovereign Securities Matters Antitrust and Other Litigation: In IN RE TREASURY SECURITIES AUCTION ANTITRUST LITIGATION, Citigroup Global Markets Inc. (CGMI) and the other defendants filed motions to dismiss the amended consolidated complaint on February 23, 2018. Additional information relating to this action is publicly available in court filings under the docket number 15 MD 2673 (S.D.N.Y.) (Gardephe, J.). On March 30, 2018, a new putative class action captioned OKLAHOMA FIREFIGHTERS PENSION & RETIREMENT SYSTEM AND ELECTRICAL WORKERS PENSION FUND LOCAL 103 v. BANCO SANTANDER S.A., ET AL. was filed against numerous defendants, including Citigroup, CGMI, Citigroup Financial Products Inc., Citigroup Global Markets Holdings Inc., and Citibanamex in the United States District Court for the Southern District of New York. The complaint alleges a conspiracy to fix prices in the Mexican sovereign bond market from 2006 to 2017, and asserts antitrust and unjust enrichment claims against the Citi defendants, as well as a number of other banks. Plaintiffs seek treble damages, restitution, and injunctive relief. Additional information relating to this action is publicly available in court filings under the docket number 18 Civ. 2830 (S.D.N.Y.) (Oetken, J.). Settlement Payments Payments required in settlement agreements described above have been made or are covered by existing litigation accruals.

CONDENSED CONSOLIDATING FINANCI

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS	3 Months Ended
	Mar. 31, 2018
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 three months ended March 31, 2018 and 2017 , Condensed Consolidating Balance Sheet as of March 31, 2018 and December 31, 2017 and Condensed Consolidating Statement of Cash Flows for the three months ended March 31, 2018 and 2017 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 Three Months Ended March 31, 2018 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 5,585 $ — $ — $ (5,585 ) $ — Interest revenue 52 1,655 14,625 — 16,332 Interest revenue—intercompany 1,130 383 (1,513 ) — — Interest expense 910 1,013 3,237 — 5,160 Interest expense—intercompany 587 772 (1,359 ) — — Net interest revenue $ (315 ) $ 253 $ 11,234 $ — $ 11,172 Commissions and fees $ — $ 1,252 $ 1,778 $ — $ 3,030 Commissions and fees—intercompany — — — — — Principal transactions 1,031 921 1,337 — 3,289 Principal transactions—intercompany (386 ) 192 194 — — Other income (928 ) 153 2,156 — 1,381 Other income—intercompany 55 50 (105 ) — — Total non-interest revenues $ (228 ) $ 2,568 $ 5,360 $ — $ 7,700 Total revenues, net of interest expense $ 5,042 $ 2,821 $ 16,594 $ (5,585 ) $ 18,872 Provisions for credit losses and for benefits and claims $ — $ — $ 1,857 $ — $ 1,857 Operating expenses Compensation and benefits $ 134 $ 1,265 $ 4,408 $ — $ 5,807 Compensation and benefits—intercompany 34 — (34 ) — — Other operating 44 548 4,526 — 5,118 Other operating—intercompany 12 578 (590 ) — — Total operating expenses $ 224 $ 2,391 $ 8,310 $ — $ 10,925 Equity in undistributed income of subsidiaries $ (445 ) $ — $ — $ 445 $ — Income (loss) from continuing operations before income taxes $ 4,373 $ 430 $ 6,427 $ (5,140 ) $ 6,090 Provision (benefit) for income taxes (247 ) 65 1,623 — 1,441 Income (loss) from continuing operations $ 4,620 $ 365 $ 4,804 $ (5,140 ) $ 4,649 Loss from discontinued operations, net of taxes — — (7 ) — (7 ) Net income before attribution of noncontrolling interests $ 4,620 $ 365 $ 4,797 $ (5,140 ) $ 4,642 Noncontrolling interests — — 22 — 22 Net income (loss) $ 4,620 $ 365 $ 4,775 $ (5,140 ) $ 4,620 Comprehensive income Add: Other comprehensive income (loss) $ 52 $ 82 $ (3,156 ) $ 3,074 $ 52 Total Citigroup comprehensive income (loss) $ 4,672 $ 447 $ 1,619 $ (2,066 ) $ 4,672 Add: Other comprehensive income attributable to noncontrolling interests $ — $ — $ 14 $ — $ 14 Add: Net income attributable to noncontrolling interests — — 22 — 22 Total comprehensive income (loss) $ 4,672 $ 447 $ 1,655 $ (2,066 ) $ 4,708 Condensed Consolidating Statements of Income and Comprehensive Income Three Months Ended March 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 3,750 $ — $ — $ (3,750 ) $ — Interest revenue 1 1,027 13,493 — 14,521 Interest revenue—intercompany 793 157 (950 ) — — Interest expense 1,218 393 1,955 — 3,566 Interest expense—intercompany 90 428 (518 ) — — Net interest revenue $ (514 ) $ 363 $ 11,106 $ — $ 10,955 Commissions and fees $ — $ 1,323 $ 1,732 $ — $ 3,055 Commissions and fees—intercompany — 2 (2 ) — — Principal transactions (163 ) 1,658 1,599 — 3,094 Principal transactions—intercompany 204 (695 ) 491 — — Other income (39 ) 65 1,236 — 1,262 Other income—intercompany (123 ) 110 13 — — Total non-interest revenues $ (121 ) $ 2,463 $ 5,069 $ — $ — $ 7,411 Total revenues, net of interest expense $ 3,115 $ 2,826 $ 16,175 $ (3,750 ) $ 18,366 Provisions for credit losses and for benefits and claims $ — $ — $ 1,662 $ — $ 1,662 Operating expenses Compensation and benefits $ (14 ) $ 1,262 $ 4,286 $ — $ 5,534 Compensation and benefits—intercompany 31 — (31 ) — — Other operating 28 509 4,652 — 5,189 Other operating—intercompany (59 ) 540 (481 ) — — Total operating expenses $ (14 ) $ 2,311 $ 8,426 $ — $ 10,723 Equity in undistributed income of subsidiaries $ 587 $ — $ — $ (587 ) $ — Income (loss) from continuing operations before income taxes $ 3,716 $ 515 $ 6,087 $ (4,337 ) $ 5,981 Provision (benefit) for income taxes (374 ) 215 2,022 — 1,863 Income (loss) from continuing operations $ 4,090 $ 300 $ 4,065 $ (4,337 ) $ 4,118 Loss from discontinued operations, net of taxes — — (18 ) — (18 ) Net income (loss) before attribution of noncontrolling interests $ 4,090 $ 300 $ 4,047 $ (4,337 ) $ 4,100 Noncontrolling interests — — 10 — 10 Net income (loss) $ 4,090 $ 300 $ 4,037 $ (4,337 ) $ 4,090 Comprehensive income Add: Other comprehensive income (loss) $ 1,464 $ (20 ) $ (3,721 ) $ 3,741 $ 1,464 Total Citigroup comprehensive income (loss) $ 5,554 $ 280 $ 316 $ (596 ) $ 5,554 Add: Other comprehensive income attributable to noncontrolling interests $ — $ — — $ 31 $ — $ 31 Add: Net income attributable to noncontrolling interests — — — 10 — 10 Total comprehensive income (loss) $ 5,554 $ 280 $ 357 $ (596 ) $ 5,595 Condensed Consolidating Balance Sheet March 31, 2018 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ 2 $ 423 $ 21,425 $ — $ 21,850 Cash and due from banks—intercompany 14 5,225 (5,239 ) — — Deposits with banks — 3,005 177,849 — 180,854 Deposits with banks - intercompany 3,000 5,492 (8,492 ) — — Federal funds sold and resale agreements — 206,659 51,228 — 257,887 Federal funds sold and resale agreements—intercompany — 14,284 (14,284 ) — — Trading account assets 298 150,249 118,261 — 268,808 Trading account assets—intercompany 483 2,079 (2,562 ) — — Investments 7,755 249 343,967 — 351,971 Loans, net of unearned income — 875 672,063 — 672,938 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,354 ) — (12,354 ) Total loans, net $ — $ 875 $ 659,709 $ — $ 660,584 Advances to subsidiaries $ 141,977 $ — $ (141,977 ) $ — $ — Investments in subsidiaries 209,808 — — (209,808 ) — Other assets (1) 10,784 66,723 102,643 — 180,150 Other assets—intercompany 3,667 47,051 (50,718 ) — — Total assets $ 377,788 $ 502,314 $ 1,251,810 $ (209,808 ) $ 1,922,104 Liabilities and equity Deposits $ — $ — $ 1,001,219 $ — $ 1,001,219 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 144,400 27,359 — 171,759 Federal funds purchased and securities loaned or sold—intercompany — 20,444 (20,444 ) — — Trading account liabilities 2 98,287 45,672 — 143,961 Trading account liabilities—intercompany 241 1,904 (2,145 ) — — Short-term borrowings 235 3,159 32,700 — 36,094 Short-term borrowings—intercompany — 41,097 (41,097 ) — — Long-term debt 153,074 19,907 64,957 — 237,938 Long-term debt—intercompany — 60,351 (60,351 ) — — Advances from subsidiaries 19,151 — (19,151 ) — — Other liabilities 2,832 69,516 55,919 — 128,267 Other liabilities—intercompany 338 10,336 (10,674 ) — — Stockholders’ equity 201,915 32,913 177,846 (209,808 ) 202,866 Total liabilities and equity $ 377,788 $ 502,314 $ 1,251,810 $ (209,808 ) $ 1,922,104 (1) Other assets for Citigroup parent company at March 31, 2018 included $ 24.8 billion of placements to Citibank and its branches, of which $ 20.3 billion had a remaining term of less than 30 days. 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 ) — — Deposits with banks — 3,348 153,393 — 156,741 Deposits with banks - intercompany 11,000 5,219 (16,219 ) — — 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 — 139,462 113,328 — 252,790 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 58,299 100,569 — 169,712 Other assets—intercompany 3,428 43,613 (47,041 ) — — 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 44,369 — 125,170 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 53,577 — 118,363 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 Statement of Cash Flows Three Months Ended March 31, 2018 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 $ 5,268 $ 7,046 $ (5,358 ) $ — $ 6,956 Cash flows from investing activities of continuing operations Purchases of investments $ (7,955 ) $ — $ (33,075 ) $ — $ (41,030 ) Proceeds from sales of investments — — 20,688 — 20,688 Proceeds from maturities of investments — — 21,509 — 21,509 Change in loans — — (8,717 ) — (8,717 ) Proceeds from sales and securitizations of loans — — 1,654 — 1,654 Change in federal funds sold and resales — (22,167 ) (3,242 ) — (25,409 ) Changes in investments and advances—intercompany (1,463 ) (3,603 ) 5,066 — — Other investing activities (729 ) (9 ) (81 ) — (819 ) Net cash provided by (used in) investing activities of continuing operations $ (10,147 ) $ (25,779 ) $ 3,802 $ — $ (32,124 ) Cash flows from financing activities of continuing operations Dividends paid $ (1,095 ) $ — $ — $ — $ (1,095 ) Redemption of preferred stock (97 ) — — — (97 ) Treasury stock acquired (2,378 ) — — — (2,378 ) Proceeds from issuance of long-term debt, net 699 2,004 184 — 2,887 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (412 ) 412 — — Change in deposits — — 41,397 — 41,397 Change in federal funds purchased and repos — 11,359 4,123 — 15,482 Change in short-term borrowings — (409 ) (7,949 ) — (8,358 ) Net change in short-term borrowings and other advances—intercompany 14 8,226 (8,240 ) — — Capital contributions from (to) parent — (585 ) 585 — — Other financing activities (261 ) — (214 ) — (475 ) Net cash provided by (used in) financing activities of continuing operations $ (3,118 ) $ 20,183 $ 30,298 $ — $ 47,363 Effect of exchange rate changes on cash and due from banks $ — $ — $ (7 ) $ — $ (7 ) Change in cash, due from banks and deposits with banks $ (7,997 ) $ 1,450 $ 28,735 $ — $ 22,188 Cash, due from banks and deposits with banks at beginning of period 11,013 12,695 156,808 — 180,516 Cash, due from banks and deposits with banks at end of period $ 3,016 $ 14,145 $ 185,543 $ — $ 202,704 Cash and due from banks $ 16 $ 5,648 $ 16,186 $ — $ 21,850 Deposits with banks 3,000 8,497 169,357 — 180,854 Cash, due from banks and deposits with banks at end of period $ 3,016 $ 14,145 $ 185,543 $ — $ 202,704 Supplemental disclosure of cash flow information for continuing operations Cash paid (received) during the year for income taxes $ (266 ) $ 29 $ 975 $ — $ 738 Cash paid during the year for interest 883 1,627 2,076 — 4,586 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 900 $ — $ 900 Transfers to OREO and other repossessed assets — — 26 — 26 Condensed Consolidating Statement of Cash Flows Three Months Ended March 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 $ (652 ) $ (3,404 ) $ 1,004 $ — $ (3,052 ) Cash flows from investing activities of continuing operations Purchases of investments $ — $ — $ (41,584 ) $ — $ (41,584 ) Proceeds from sales of investments 116 — 29,340 — 29,456 Proceeds from maturities of investments — — 24,006 — 24,006 Change in loans — — (7,953 ) — (7,953 ) Proceeds from sales and securitizations of loans — — 3,191 — 3,191 Proceeds from significant disposals — — 2,732 — 2,732 Change in federal funds sold and resales — (2,623 ) (3,493 ) — (6,116 ) Changes in investments and advances—intercompany (569 ) (5,007 ) 5,576 — — Other investing activities — — (607 ) — (607 ) Net cash provided by (used in) investing activities of continuing operations $ (453 ) $ (7,630 ) $ 11,208 $ — $ 3,125 Cash flows from financing activities of continuing operations Dividends paid $ (744 ) $ — $ — $ — $ (744 ) Treasury stock acquired (1,858 ) — — — (1,858 ) Proceeds (repayments) from issuance of long-term debt, net (1,454 ) 5,175 (4,003 ) — (282 ) Proceeds (repayments) from issuance of long-term debt—intercompany, net — (12,506 ) 12,506 — — Change in deposits — — 20,584 — 20,584 Change in federal funds purchased and repos — 1,266 5,143 — 6,409 Change in short-term borrowings — 605 (5,179 ) — (4,574 ) Net change in short-term borrowings and other advances—intercompany (14,901 ) 8,938 5,963 — — Other financing activities (397 ) — — — (397 ) Net cash provided by (used in) financing activities of continuing operations $ (19,354 ) $ 3,478 $ 35,014 $ — $ 19,138 Effect of exchange rate changes on cash and due from banks $ — $ — $ 340 $ — $ 340 Change in cash and due from banks $ (20,459 ) $ (7,556 ) $ 47,566 $ — $ 19,551 Cash and due from banks at beginning of period 20,811 25,118 114,565 — 160,494 Cash and due from banks at end of period $ 352 $ 17,562 $ 162,131 $ — $ 180,045 Cash and due from banks $ 352 $ 3,647 $ 18,273 $ — $ 22,272 Deposits with banks — 13,915 143,858 — 157,773 Cash, due from banks and deposits with banks at end of period $ 352 $ 17,562 $ 162,131 $ — $ 180,045 Supplemental disclosure of cash flow information for continuing operations Cash paid (refund) during the year for income taxes $ (139 ) $ 64 $ 988 $ — $ 913 Cash paid during the year for interest 1,153 822 1,275 — 3,250 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 2,800 $ — $ 2,800 Transfers to OREO and other repossessed assets — — 30 — 30

BASIS OF PRESENTATION AND ACC33

BASIS OF PRESENTATION AND ACCOUNTING CHANGES (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Accounting Changes	ACCOUNTING CHANGES Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers (Revenue Recognition), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU defines the promised good or service as the performance obligation under the contract. While the guidance replaces most existing revenue recognition guidance in GAAP, the ASU is not applicable to financial instruments and, therefore, does not impact a majority of the Company’s revenues, including net interest income, loan fees, gains on sales and mark-to-market accounting. In accordance with the new revenue recognition standard, Citi has identified the specific performance obligation (promised services) associated with the contract with the customer and has determined when that specific performance obligation has been satisfied, which may be at a point in time or over time depending on how the performance obligation is defined. The contracts with customers also contain the transaction price, which consists of fixed consideration and/or consideration that may vary (variable consideration), and is defined as the amount of consideration an entity expects to be entitled to when or as the performance obligation is satisfied, excluding amounts collected on behalf of third parties (including transaction taxes). The amounts recognized at the point in time the performance obligation is satisfied may differ from the ultimate transaction price associated with that performance obligation when a portion of it is based on variable consideration. For example some consideration is based on the client’s month-end balance or market values which are unknown at the time the contract is executed. The remaining transaction price amount, if any, will be recognized as the variable consideration becomes determinable. In certain transactions, the performance obligation is considered satisfied at a point in time in the future. In this instance, Citi defers revenue on the balance sheet that will only be recognized upon completion of the performance obligation. The new revenue recognition standard further clarified the guidance related to reporting revenue gross as principal versus net as an agent. In many cases, Citi outsources a component of its performance obligations to third parties. The Company has determined that it acts as principal in the majority of these transactions and therefore presents the amounts paid to these third parties gross within operating expenses. The Company has retrospectively adopted this standard as of January 1, 2018 and as a result was required to report amounts paid to third parties where Citi is principal to the contract within Operating expenses. The adoption resulted in an increase in both revenue and expenses of approximately $250 million for the three-month periods ended March 31, 2018 and March 31, 2017, respectively, while increasing approximately $1 billion for the year ended December 31, 2017 with similar amounts for prior periods. Prior to adoption, these expense amounts were reported as contra revenue primarily within Commissions and fees and Administration and other fiduciary fees revenue. Accordingly, prior periods have been reclassified to conform to the new presentation. See Note 5 to the Consolidated Financial Statements for a description of the Company’s revenue recognition policies for Commissions and fees and Administration and other fiduciary fees . Income Tax Impact of Intra-Entity Transfers of Assets In October 2016, the FASB issued ASU No. 2016-16, Income Taxes—Intra-Entity Transfers of Assets Other Than Inventory , which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The ASU was effective January 1, 2018 and was adopted as of that date. The impact of this standard was an increase of DTAs by approximately $300 million , a decrease of retained earnings by approximately $80 million and a decrease of prepaid tax assets by approximately $380 million . Clarifying the Definition of a Business In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The definition of a business directly and indirectly affects many areas of accounting (e.g., acquisitions, disposals, goodwill and consolidation). The ASU narrows the definition of a business by introducing a quantitative screen as the first step, such that if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the set of transferred assets and activities is not a business. If the set is not scoped out from the quantitative screen, the entity then evaluates whether the set meets the requirement that a business include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs. The ASU was effective for public entities, including Citi, as of January 1, 2018 with prospective application. The impact of the ASU will depend upon the acquisition and disposal activities of Citi. If fewer transactions qualify as a business, there could be less initial recognition of goodwill, but also less goodwill allocated to disposals. Changes in Accounting for Pension and Postretirement (Benefit) Expense In March 2017, the FASB issued ASU No. 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost , which changes the income statement presentation of net benefit expense and requires restating the Company’s financial statements for each of the earlier periods presented in Citi’s annual and interim financial statements. The change in presentation was effective for annual and interim periods starting January 1, 2018. The ASU requires that only the service cost component of net benefit expense be included in Compensation and benefits on the income statement. The other components of net benefit expense will be required to be presented outside of Compensation and benefits and will be presented in Other operating expense . Since both of these income statement line items are part of Operating expenses , total Operating expenses will not change, nor will there be any change in Net income . This change in presentation did not have a material effect on Compensation and benefits and Other operating expenses and is applied prospectively. The components of the net benefit expense are currently disclosed in Note 7 to the Consolidated Financial Statements. The new standard also changes the components of net benefit expense that are eligible for capitalization when employee costs are capitalized in connection with various activities, such as internally developed software, construction-in-progress, and loan origination costs. Prospectively from January 1, 2018, only the service cost component of net benefit expense may be capitalized. Existing capitalized balances are not affected. This change in amounts eligible for capitalization does not have a material effect on the Company’s Consolidated Financial Statements and related disclosures. Hedging In August 2017, the FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities , which better aligns an entity’s risk management activities and financial reporting for hedging relationships through changes to the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The ASU requires the change in the fair value of the hedging instrument to be presented in the same income statement line as the hedged item and also requires expanded disclosures. Citi adopted this standard on January 1, 2018 and transferred approximately $4 billion of pre-payable mortgage backed securities and municipal bonds held-to-maturity (HTM) securities into available-for-sale (AFS) classification as permitted as a one-time transfer under the standard as these assets were deemed to be eligible to be hedged under the last of layer hedge strategy. The impact to opening retained earnings was immaterial. See Note 19 to the Consolidated Financial Statements for more information. 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. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments—Overall (Subtopic 825-10) , to clarify certain provisions in ASU 2016-01. The ASUs require 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 the AFS category for equity investments. However, Federal Reserve Bank and Federal Home Loan Bank stock, as well as certain exchange seats, will continue to be presented at cost. The ASUs also provide an instrument-by-instrument election to measure non-marketable equity investments using a measurement alternative. Under the measurement alternative, the investment is carried at cost plus or minus changes resulting from observable prices in orderly transactions for the identical or a similar investment of the same issuer, less impairment (if any). Finally, the ASUs require that fair value disclosures for financial instruments not measured at fair value on the balance sheet be presented at their exit prices (e.g., held-for-investment loans). Citi early adopted the provisions of ASU 2016-01 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 Accumulated other comprehensive income (loss) (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 17, 20 and 21 to the Consolidated Financial Statements. The other provisions of ASU 2016-01 are effective January 1, 2018. The provisions of ASU 2018-03 are effective July 1, 2018 for interim financial statements, but may be early adopted in any interim period starting January 1, 2018 as long as ASU 2016-01 is also adopted. Citi has adopted both ASU 2016-01 and ASU 2018-03 as of January 1, 2018. Accordingly, as of the first quarter of 2018, the changes to accounting for equity securities and fair value disclosures have been reflected in Citigroup’s financial statements. The impact of adopting the change to AFS equity securities resulted in a cumulative catch-up reclassification from AOCI to retained earnings of an accumulated after-tax gain of approximately $3 million at January 1, 2018. Citi elected the measurement alternative for all non-marketable equity investments that no longer qualify for cost measurement under the ASUs. This provision in the ASUs was adopted prospectively. Financial statements for periods prior to 2018 were not subject to restatement under the provisions of the ASUs. For additional information, see Notes 12, 17 and 20 to the Consolidated Financial Statements. Statement of Cash Flows In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , which requires that companies present cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents (restricted cash) when reconciling beginning-of-period and end-of-period totals on the Statement of Cash Flows. In connection with the adoption of the ASU, Citigroup also changed its definition of cash and cash equivalents to include all of Cash and due from banks and predominately all of Deposits with banks. The Company has retrospectively adopted this ASU as of January 1, 2018 and as a result Net cash provided by investing activities of continuing operations on the Statement of Cash Flows increased by $20.3 billion for the three months ended March 31, 2017. Citigroup defines restricted cash (as cash subject to withdrawal restrictions) to include cash deposited with central banks that must be maintained to meet minimum regulatory requirements, and cash set aside for the benefit of customers or for other purposes such as compensating balance arrangements or debt retirement. Restricted cash includes minimum reserve requirements with the Federal Reserve Bank and certain other central banks and cash segregated to satisfy rules regarding the protection of customer assets as required by Citigroup broker-dealers’ primary regulators, including the Securities and Exchange Commission, the Commodities Futures Trading Commission and the United Kingdom’s Prudential Regulation Authority. Cash and due from banks includes restricted cash of $84 million and $39 million at March 31, 2018 and December 31, 2017, respectively. Deposits with banks includes restricted cash of $29.0 billion and $36.7 billion at March 31, 2018 and December 31, 2017, respectively. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments , which provides guidance on the classification and presentation of certain cash receipts and payments on the Statement of Cash Flows. The Company has retrospectively adopted this ASU as of January 1, 2018 which resulted in immaterial changes to Citi’s Consolidated Statement of Cash Flows. Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued Accounting Standards Update (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. For calendar-year-end entities, 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 AFS and HTM portfolios of callable state and municipal debt 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 debt securities.

DISCONTINUED OPERATIONS AND S34

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS (Tables)	3 Months Ended
	Mar. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
Summarized financial information disposal groups including discontinued operations	The following summarizes financial information for all discontinued operations: Three Months Ended March 31, In millions of dollars 2018 2017 Total revenues, net of interest expense $ — $ — Loss from discontinued operations $ (7 ) $ (28 ) Benefit for income taxes — (10 ) Loss from discontinued operations, net of taxes $ (7 ) $ (18 )

BUSINESS SEGMENTS (Tables)

BUSINESS SEGMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
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: Three Months Ended March 31, Revenues, (1) Provision (benefits) Income (loss) from (2) Identifiable assets In millions of dollars, except identifiable assets in billions 2018 2017 2018 2017 2018 2017 March 31, December 31, 2017 Global Consumer Banking $ 8,433 $ 7,846 $ 453 $ 582 $ 1,394 $ 998 $ 423 $ 428 Institutional Clients Group 9,848 9,319 1,057 1,375 3,329 3,011 1,407 1,336 Corporate/Other 591 1,201 (69 ) (94 ) (74 ) 109 92 78 Total $ 18,872 $ 18,366 $ 1,441 $ 1,863 $ 4,649 $ 4,118 $ 1,922 $ 1,842 (1) Includes total revenues, net of interest expense (excluding Corporate/Other ), in North America of $8.4 billion and $8.5 billion ; in EMEA of $3.2 billion and $2.9 billion ; in Latin America of $2.6 billion and $2.3 billion ; and in Asia of $4.1 billion and $3.5 billion for the three months ended March 31, 2018 and 2017 , respectively. These regional numbers exclude Corporate/Other , which largely operates within the U.S. (2) Includes pretax provisions for credit losses and for benefits and claims in the GCB results of $1.9 billion and $1.8 billion ; in the ICG results of $(41) million and $(205) million ; and in the Corporate/Other results of $(7) million and $52 million for the three months ended March 31, 2018 and 2017 , respectively.

INTEREST REVENUE AND EXPENSE (T

INTEREST REVENUE AND EXPENSE (Tables)	3 Months Ended
	Mar. 31, 2018
Banking and Thrift, Interest [Abstract]
Interest revenue and interest expense	Interest revenue and Interest expense consisted of the following: Three Months Ended March 31, In millions of dollars 2018 2017 Interest revenue Loan interest, including fees $ 10,892 $ 10,045 Deposits with banks 432 295 Federal funds sold and securities borrowed or purchased under agreements to resell 1,039 661 Investments, including dividends 2,234 1,960 Trading account assets (1) 1,371 1,266 Other interest 364 294 Total interest revenue $ 16,332 $ 14,521 Interest expense Deposits (2) $ 1,997 $ 1,415 Federal funds purchased and securities loaned or sold under agreements to repurchase 949 493 Trading account liabilities (1) 215 147 Short-term borrowings 471 199 Long-term debt 1,528 1,312 Total interest expense $ 5,160 $ 3,566 Net interest revenue $ 11,172 $ 10,955 Provision for loan losses 1,803 1,675 Net interest revenue after provision for loan losses $ 9,369 $ 9,280 (1) Interest expense on Trading account liabilities is reported as a reduction of interest revenue from Trading account assets . (2) Includes deposit insurance fees and charges of $376 million and $305 million for the three months ended March 31, 2018 and 2017 , respectively.

COMMISSIONS AND FEES; ADMINIS37

COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES (Tables)	3 Months Ended
	Mar. 31, 2018
Fees and Commissions [Abstract]
Commissions and fees revenues	The following tables present Commissions and fees revenue: Three Months Ended March 31, 2018 In millions of dollars ICG GCB Corporate/Other Total Investment banking $ 822 $ — $ — $ 822 Brokerage commissions 566 248 — 814 Credit- and bank-card income Interchange fees 260 1,875 5 2,140 Card-related loan fees 14 155 6 175 Card rewards and partner payments (124 ) (1,874 ) (5 ) (2,003 ) Deposit-related fees (1) 236 183 1 420 Transactional service fees 190 21 2 213 Corporate finance (2) 142 1 — 143 Insurance distribution revenue (3) 5 143 5 153 Insurance premiums (3) — 33 (1 ) 32 Loan servicing 38 22 12 72 Other 15 32 2 49 Total commissions and fees (4) $ 2,164 $ 839 $ 27 $ 3,030 Three Months Ended March 31, 2017 In millions of dollars ICG GCB Corporate/Other Total Investment banking $ 904 $ — $ — $ 904 Brokerage commissions 482 193 1 676 Credit- and bank-card income Interchange fees 222 1,703 40 1,965 Card-related loan fees 12 167 16 195 Card rewards and partner payments (103 ) (1,685 ) (27 ) (1,815 ) Deposit-related fees (1) 208 185 4 397 Transactional service fees 174 27 24 225 Corporate finance (2) 184 1 — 185 Insurance distribution revenue (3) 2 144 25 171 Insurance premiums (3) — 33 (1 ) 32 Loan servicing 35 26 31 92 Other (20 ) 25 23 28 Total commissions and fees (4) $ 2,100 $ 819 $ 136 $ 3,055 (1) Includes $32 million and $33 million of overdraft fees in the first quarter of 2018 and the first quarter of 2017, respectively. Overdraft fees are accounted for under ASC 310. (2) Consists primarily of fees earned from structuring and underwriting loan syndications or related financing activity. This activity is accounted for under ASC 310. (3) Previously reported as insurance premiums on the Consolidated Statement of Income. (4) Commissions and fees includes $(1,545) million and $(1,278) million not accounted for under ASC 606, Revenue from Contracts with Customers , for the first quarters of 2018 and 2017, respectively. Amounts reported in Commissions and fees accounted for under other guidance primarily include card-related loan fees, card reward programs and certain partner payments, corporate finance fees, insurance premiums, and loan servicing fees. The following table presents Administration and other fiduciary fees : Three Months Ended March 31, 2018 In millions of dollars ICG GCB Corp/Other Total Custody fees $ 368 $ 47 $ 16 $ 431 Fiduciary fees 167 147 7 321 Guarantee fees 137 14 2 153 Total administration and other fiduciary fees (1) $ 672 $ 208 $ 25 $ 905 Three Months Ended March 31, 2017 In millions of dollars ICG GCB Corp/Other Total Custody fees $ 355 $ 38 $ 13 $ 406 Fiduciary fees 141 133 11 285 Guarantee fees 128 13 2 143 Total administration and other fiduciary fees (1) $ 624 $ 184 $ 26 $ 834 (1) Administration and other fiduciary fees includes $153 million and $143 million for the first quarters of 2018 and 2017, respectively, that are not accounted for under ASC 606, Revenue from Contracts with Customers. These amounts include guarantee fees.

PRINCIPAL TRANSACTIONS (Tables)

PRINCIPAL TRANSACTIONS (Tables)	3 Months Ended
	Mar. 31, 2018
Principal Transactions Revenue, Net [Abstract]
Principal transactions revenue	The following table presents Principal transactions revenue: Three Months Ended March 31, In millions of dollars 2018 2017 Global Consumer Banking (1) $ 150 $ 155 Institutional Clients Group 2,884 2,731 Corporate/Other (1) 255 208 Total Citigroup $ 3,289 $ 3,094 Interest rate risks (2) $ 1,622 $ 1,746 Foreign exchange risks (3) 745 579 Equity risks (4) 566 212 Commodity and other risks (5) 92 153 Credit products and risks (6) 264 404 Total $ 3,289 $ 3,094 (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.

RETIREMENT BENEFITS (Tables)

RETIREMENT BENEFITS (Tables)	3 Months Ended
	Mar. 31, 2018
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: Three Months Ended March 31, Pension plans Postretirement benefit plans U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2018 2017 2018 2017 2018 2017 Benefits earned during the period $ 1 $ 1 $ 38 $ 36 $ — $ — $ 2 $ 2 Interest cost on benefit obligation 123 139 75 71 6 6 26 24 Expected return on plan assets (213 ) (216 ) (78 ) (70 ) (3 ) (1 ) (23 ) (21 ) Amortization of unrecognized Prior service benefit — — (1 ) (1 ) — — (2 ) (2 ) Net actuarial loss (gain) 47 44 13 16 — (1 ) 7 8 Settlement loss (1) — — 4 — — — — — Total net (benefit) expense $ (42 ) $ (32 ) $ 51 $ 52 $ 3 $ 4 $ 10 $ 11 (1) Losses due to settlement relate to repositioning and divestiture activities. 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: Three Months Ended March 31, In millions of dollars 2018 2017 Service-related expense $ — $ — Interest cost on benefit obligation — — Amortization of unrecognized Prior service benefit (8 ) (8 ) Net actuarial loss 1 1 Total service-related benefit $ (7 ) $ (7 ) Non-service-related expense $ 6 $ 8 Total net (benefit) expense $ (1 ) $ 1
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 Significant Plans. Three Months Ended March 31, 2018 Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans Change in projected benefit obligation Projected benefit obligation at beginning of year $ 14,040 $ 7,433 $ 699 $ 1,261 Plans measured annually (28 ) (1,987 ) — (334 ) Projected benefit obligation at beginning of year—Significant Plans $ 14,012 $ 5,446 $ 699 $ 927 Benefits earned during the period 1 22 — 2 Interest cost on benefit obligation 123 63 6 23 Actuarial (gain) loss (495 ) (6 ) (21 ) 5 Benefits paid, net of participants’ contributions and government subsidy (205 ) (68 ) (17 ) (12 ) Foreign exchange impact and other — 140 — 71 Projected benefit obligation at period end—Significant Plans $ 13,436 $ 5,597 $ 667 $ 1,016 Three Months Ended March 31, 2018 Pension plans Postretirement benefit plans In millions of dollars U.S. plans Non-U.S. plans U.S. plans Non-U.S. plans Change in plan assets Plan assets at fair value at beginning of year $ 12,725 $ 7,128 $ 262 $ 1,119 Plans measured annually — (1,305 ) — (10 ) Plan assets at fair value at beginning of year—Significant Plans $ 12,725 $ 5,823 $ 262 $ 1,109 Actual return on plan assets (157 ) 26 — (14 ) Company contributions, net of reimbursements 13 11 (4 ) — Benefits paid, net of participants’ contributions and government subsidy (205 ) (68 ) (17 ) (12 ) Foreign exchange impact and other — 146 — 84 Plan assets at fair value at period end—Significant Plans $ 12,376 $ 5,938 $ 241 $ 1,167 Funded status of the Significant Plans Qualified plans (1) $ (365 ) $ 341 $ (426 ) $ 151 Nonqualified plans (695 ) — — — Funded status of the plans at period end—Significant Plans $ (1,060 ) $ 341 $ (426 ) $ 151 Net amount recognized at period end Benefit asset $ — $ 829 $ — $ 151 Benefit liability (1,060 ) (488 ) (426 ) — Net amount recognized on the balance sheet—Significant Plans $ (1,060 ) $ 341 $ (426 ) $ 151 Amounts recognized in AOCI at period end Prior service benefit $ — $ 27 $ — $ 86 Net actuarial (loss) gain (6,644 ) (882 ) 89 (364 ) Net amount recognized in equity (pretax)—Significant Plans $ (6,644 ) $ (855 ) $ 89 $ (278 ) Accumulated benefit obligation at period end—Significant Plans $ 13,430 $ 5,329 $ 667 $ 1,016 (1) The U.S. qualified pension plan is fully funded pursuant to the Employee Retirement Income Security Act of 1974, as amended (ERISA), funding rules as of January 1, 2018 and no minimum required funding is expected for 2018 .
Change in accumulated other comprehensive income (loss)	The following table shows the change in AOCI related to the Company’s pension, postretirement and post employment plans: In millions of dollars Three Months Ended For Year Ended December 31, 2017 Beginning of period balance, net of tax (1)(2) $ (6,183 ) $ (5,164 ) Actuarial assumptions changes and plan experience 516 (760 ) Net asset (loss) gain due to difference between actual and expected returns (451 ) 625 Net amortization 58 229 Prior service cost — (4 ) Curtailment/settlement gain (3) 4 17 Foreign exchange impact and other (36 ) (93 ) Impact of Tax Reform (4) — (1,020 ) Change in deferred taxes, net (3 ) (13 ) Change, net of tax $ 88 $ (1,019 ) End of period balance, net of tax (1)(2) $ (6,095 ) $ (6,183 ) (1) See Note 17 to the Consolidated Financial Statements for further discussion of net AOCI balance. (2) Includes net-of-tax amounts for certain profit sharing plans outside the U.S. (3) Gains due to curtailment and settlement relate to repositioning and divestiture activities. (4) In the fourth quarter of 2017, the Company adopted ASU 2018-02, which transferred these amounts from AOCI to Retained earnings. See Note 1 to the 2017 Consolidated Financial Statements.
Assumptions used in determining benefit obligations and net benefit expense	The discount rates utilized during the period in determining the pension and postretirement net (benefit) expense for the Significant Plans are as follows: Net (benefit) expense assumed discount rates during the period Three Months Ended Mar. 31, 2018 Dec. 31, 2017 Mar. 31, 2017 U.S. plans Qualified pension 3.60% 3.75% 4.10% Nonqualified pension 3.60 3.65 4.00 Postretirement 3.50 3.55 3.90 Non-U.S. plans Pension 0.6-10.20 0.65-10.35 0.60-11.00 Weighted average 4.75 4.86 5.08 Postretirement 9.55 8.95 9.65 The discount rates utilized at period-end in determining the pension and postretirement benefit obligations for the Significant Plans are as follows: Plan obligations assumed discount rates at period ended Mar. 31, 2018 Dec. 31, 2017 U.S. plans Qualified pension 3.95% 3.60% Nonqualified pension 3.95 3.60 Postretirement 3.90 3.50 Non-U.S. plans Pension 0.75 -9.90 0.6-10.20 Weighted average 4.88 4.75 Postretirement 9.50 9.55
Effect of one-percentage-point change in the discount rates on pension expense	The following table summarizes the estimated effect on the Company’s Significant Plans quarterly expense of a one-percentage-point change in the discount rate: Three Months Ended March 31, 2018 In millions of dollars One-percentage-point increase One-percentage-point decrease Pension U.S. plans $ 8 $ (12 ) Non-U.S. plans (3 ) 6 Postretirement U.S. plans — (1 ) Non-U.S. plans (2 ) 3
Schedule of company contributions	The following table summarizes the Company’s actual contributions for the three months ended March 31, 2018 and 2017 , as well as estimated expected Company contributions for the remainder of 2018 and the actual contributions made for the remainder of 2017 . Pension plans Postretirement plans U.S. plans (1) Non-U.S. plans U.S. plans Non-U.S. plans In millions of dollars 2018 2017 2018 2017 2018 2017 2018 2017 Company contributions (2) for the three months ended March 31 $ 14 $ 13 $ 29 $ 34 $ — $ 12 $ 3 $ 2 Company contributions made or expected to be made during the remainder of the year 45 92 99 101 — 164 8 7 (1) The U.S. pension plans include benefits paid directly by the Company for the nonqualified pension plans. (2) Company contributions are composed of cash contributions made to the plans and benefits paid directly by the Company.
Defined contribution plans	The following table summarizes the Company’s contributions for the defined contribution plans: Three Months Ended March 31, In millions of dollars 2018 2017 U.S. plans $ 104 $ 98 Non-U.S. plans 76 69

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2018
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: Three Months Ended March 31, In millions, except per-share amounts 2018 2017 Income from continuing operations before attribution of noncontrolling interests $ 4,649 $ 4,118 Less: Noncontrolling interests from continuing operations 22 10 Net income from continuing operations (for EPS purposes) $ 4,627 $ 4,108 Income (loss) from discontinued operations, net of taxes (7 ) (18 ) Citigroup's net income $ 4,620 $ 4,090 Less: Preferred dividends (1) 272 301 Net income available to common shareholders $ 4,348 $ 3,789 Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS 51 55 Net income allocated to common shareholders for basic EPS $ 4,297 $ 3,734 Net income allocated to common shareholders for diluted EPS 4,297 3,734 Weighted-average common shares outstanding applicable to basic EPS 2,561.6 2,765.3 Effect of dilutive securities (2) Options (3) 0.1 0.2 Other employee plans 1.3 — Adjusted weighted-average common shares outstanding applicable to diluted EPS (4) 2,563.0 2,765.5 Basic earnings per share (5) Income from continuing operations $ 1.68 $ 1.36 Discontinued operations — (0.01 ) Net income $ 1.68 $ 1.35 Diluted earnings per share (5) Income from continuing operations $ 1.68 $ 1.36 Discontinued operations — (0.01 ) Net income $ 1.68 $ 1.35 (1) As of March 31, 2018 , Citi estimates it will distribute preferred dividends of approximately $902 million during the remainder of 2018, assuming such dividends are declared by the Citi Board of Directors. During the first quarter of 2018, Citi redeemed all of its 3.8 million Series AA preferred shares for $96.8 million at par value. Citi redeemed its Series E preferred stock in April 2018. (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 $104.67 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 the three months ended March 31, 2018 and 2017 because they were anti-dilutive. (3) During the first quarters of 2018 and 2017 , weighted-average options to purchase 0.5 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 $149.41 and $201.01 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 BOR41

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
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: In millions of dollars March 31, December 31, 2017 Federal funds sold $ — $ — Securities purchased under agreements to resell 133,616 130,984 Deposits paid for securities borrowed 124,271 101,494 Total (1) $ 257,887 $ 232,478
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: In millions of dollars March 31, December 31, 2017 Federal funds purchased $ 325 $ 326 Securities sold under agreements to repurchase 157,550 142,646 Deposits received for securities loaned 13,884 13,305 Total (1) $ 171,759 $ 156,277 (1) The above tables do not include securities-for-securities lending transactions of $15.6 billion and $14.0 billion at March 31, 2018 and December 31, 2017, 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 March 31, 2018 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 220,159 $ 86,543 $ 133,616 $ 101,046 $ 32,570 Deposits paid for securities borrowed 124,271 — 124,271 24,560 99,711 Total $ 344,430 $ 86,543 $ 257,887 $ 125,606 $ 132,281 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 244,093 $ 86,543 $ 157,550 $ 79,626 $ 77,924 Deposits received for securities loaned 13,884 — 13,884 4,528 9,356 Total $ 257,977 $ 86,543 $ 171,434 $ 84,154 $ 87,280 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 (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 the Company 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 March 31, 2018 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities purchased under agreements to resell $ 220,159 $ 86,543 $ 133,616 $ 101,046 $ 32,570 Deposits paid for securities borrowed 124,271 — 124,271 24,560 99,711 Total $ 344,430 $ 86,543 $ 257,887 $ 125,606 $ 132,281 In millions of dollars Gross amounts Gross amounts (1) Net amounts of (2) Amounts (3) Net (4) Securities sold under agreements to repurchase $ 244,093 $ 86,543 $ 157,550 $ 79,626 $ 77,924 Deposits received for securities loaned 13,884 — 13,884 4,528 9,356 Total $ 257,977 $ 86,543 $ 171,434 $ 84,154 $ 87,280 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 (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 the Company 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 March 31, 2018 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 $ 96,155 $ 77,118 $ 26,587 $ 44,233 $ 244,093 Deposits received for securities loaned 9,369 397 2,197 1,921 13,884 Total $ 105,524 $ 77,515 $ 28,784 $ 46,154 $ 257,977 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 The following tables present the gross amount of liabilities associated with repurchase agreements and securities lending agreements, by class of underlying collateral: As of March 31, 2018 In millions of dollars Repurchase agreements Securities lending agreements Total U.S. Treasury and federal agency securities $ 72,336 $ — $ 72,336 State and municipal securities 1,794 — 1,794 Foreign government securities 99,870 226 100,096 Corporate bonds 23,168 691 23,859 Equity securities 21,659 12,310 33,969 Mortgage-backed securities 15,930 — 15,930 Asset-backed securities 6,593 — 6,593 Other 2,743 657 3,400 Total $ 244,093 $ 13,884 $ 257,977 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

BROKERAGE RECEIVABLES AND BRO42

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES (Tables)	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Brokerage receivables and brokerage payables	Brokerage receivables and Brokerage payables consisted of the following: In millions of dollars March 31, December 31, 2017 Receivables from customers $ 19,186 $ 19,215 Receivables from brokers, dealers and clearing organizations 27,386 19,169 Total brokerage receivables (1) $ 46,572 $ 38,384 Payables to customers $ 43,122 $ 38,741 Payables to brokers, dealers and clearing organizations 26,563 22,601 Total brokerage payables (1) $ 69,685 $ 61,342 (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)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of investments by category	The following tables present Citi’s investments by category: In millions of dollars March 31, Debt securities available-for-sale (AFS) $ 291,523 Debt securities held-to-maturity (HTM) (1) 52,492 Marketable equity securities carried at fair value (2) 277 Non-marketable equity securities carried at fair value (2) 1,292 Non-marketable equity securities measured using the measurement alternative (3) 401 Non-marketable equity securities carried at cost (4) 5,986 Total investments $ 351,971 In millions of dollars December 31, Securities available-for-sale (AFS) $ 290,914 Debt securities held-to-maturity (HTM) (1) 53,320 Non-marketable equity securities carried at fair value (2) 1,206 Non-marketable equity securities carried at cost (4) 6,850 Total investments $ 352,290 (1) Carried at adjusted amortized cost basis, net of any credit-related impairment. (2) Unrealized gains and losses are recognized in earnings. (3) Impairment losses and adjustments to the carrying value as a result of observable price changes are recognized in earnings. (4) Represents shares issued by the Federal Reserve Bank, Federal Home Loan Banks and various exchanges of which Citigroup is a member.
Interest and dividends on investments	The following table presents interest and dividend income on investments: Three Months Ended March 31, In millions of dollars 2018 2017 Taxable interest $ 2,042 $ 1,764 Interest exempt from U.S. federal income tax 130 142 Dividend income 62 54 Total interest and dividend income $ 2,234 $ 1,960
Realized gains and losses on investments excluding other-than-temporary impairment	The following table presents realized gains and losses on the sales of investments, which excludes OTTI losses: Three Months Ended March 31, In millions of dollars 2018 2017 Gross realized investment gains $ 345 $ 288 Gross realized investment losses (175 ) (96 ) Net realized gains on sale of investments $ 170 $ 192
Amortized cost and fair value of AFS	The amortized cost and fair value of AFS securities were as follows: March 31, 2018 December 31, 2017 In millions of dollars Amortized cost Gross unrealized gains Gross unrealized losses Fair value Amortized cost Gross unrealized gains Gross unrealized losses Fair value Securities AFS Mortgage-backed securities (1) U.S. government-sponsored agency guaranteed $ 42,147 $ 134 $ 993 $ 41,288 $ 42,116 $ 125 $ 500 $ 41,741 Prime 6 3 — 9 11 6 — 17 Alt-A 9 88 — 97 26 90 — 116 Non-U.S. residential 2,645 10 2 2,653 2,744 13 6 2,751 Commercial 310 1 3 308 334 — 2 332 Total mortgage-backed securities $ 45,117 $ 236 $ 998 $ 44,355 $ 45,231 $ 234 $ 508 $ 44,957 U.S. Treasury and federal agency securities U.S. Treasury $ 108,335 $ 74 $ 1,611 $ 106,798 $ 108,344 $ 77 $ 971 $ 107,450 Agency obligations 10,689 5 178 10,516 10,813 7 124 10,696 Total U.S. Treasury and federal agency securities $ 119,024 $ 79 $ 1,789 $ 117,314 $ 119,157 $ 84 $ 1,095 $ 118,146 State and municipal (2) $ 9,980 $ 126 $ 269 $ 9,837 $ 8,870 $ 140 $ 245 $ 8,765 Foreign government 103,833 540 598 103,775 100,615 508 590 100,533 Corporate 13,068 43 115 12,996 14,144 51 86 14,109 Asset-backed securities (1) 3,075 53 47 3,081 3,906 14 2 3,918 Other debt securities 165 — — 165 297 — — 297 Total debt securities AFS $ 294,262 $ 1,077 $ 3,816 $ 291,523 $ 292,220 $ 1,031 $ 2,526 $ 290,725 Marketable equity securities AFS (3) $ — $ — $ — $ — $ 186 $ 4 $ 1 $ 189 Total securities AFS $ 294,262 $ 1,077 $ 3,816 $ 291,523 $ 292,406 $ 1,035 $ 2,527 $ 290,914 (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 18 to the Consolidated Financial Statements. (2) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, see Note 1 to the Consolidated Financial Statements. (3) Citi adopted ASU 2016-01 and ASU 2018-03 as of January 1, 2018, resulting in a cumulative effect adjustment from AOCI to retained earnings for net unrealized gains on marketable equity securities AFS. The available for sale category is eliminated for equity securities effective January 1, 2018. See Note 1 to the Consolidated Financial Statements for additional details.
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 March 31, 2018 Debt securities held-to-maturity Mortgage-backed securities $ 6,889 $ 98 $ 15,108 $ 455 $ 21,997 $ 553 State and municipal 1,528 21 758 111 2,286 132 Foreign government 1,344 12 — — 1,344 12 Asset-backed securities 36 3 — — 36 3 Total debt securities held-to-maturity $ 9,797 $ 134 $ 15,866 $ 566 $ 25,663 $ 700 December 31, 2017 Debt securities held-to-maturity Mortgage-backed securities $ 6,244 $ 50 $ 8,678 $ 107 $ 14,922 $ 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 $ 7,391 $ 76 $ 9,647 $ 194 $ 17,038 $ 270 Note: Excluded from the gross unrecognized losses presented in the table above are $(71) million and $(117) million of net unrealized losses recorded in AOCI as of March 31, 2018 and December 31, 2017 , respectively, primarily related to the difference between the amortized cost and carrying value of HTM debt 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 March 31, 2018 and December 31, 2017 . The following 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 March 31, 2018 Debt Securities AFS (1) Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 32,313 $ 900 $ 1,873 $ 93 $ 34,186 $ 993 Non-U.S. residential 891 2 — — 891 2 Commercial 241 2 41 1 282 3 Total mortgage-backed securities $ 33,445 $ 904 $ 1,914 $ 94 $ 35,359 $ 998 U.S. Treasury and federal agency securities U.S. Treasury $ 81,738 $ 1,417 $ 7,526 $ 194 $ 89,264 $ 1,611 Agency obligations 7,964 144 1,567 34 9,531 178 Total U.S. Treasury and federal agency securities $ 89,702 $ 1,561 $ 9,093 $ 228 $ 98,795 $ 1,789 State and municipal $ 2,250 $ 35 $ 1,116 $ 234 $ 3,366 $ 269 Foreign government 46,459 371 9,972 227 56,431 598 Corporate 5,831 101 890 14 6,721 115 Asset-backed securities 699 47 20 — 719 47 Other debt securities 22 — — — 22 — Total debt securities AFS $ 178,408 $ 3,019 $ 23,005 $ 797 $ 201,413 $ 3,816 December 31, 2017 Securities AFS Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 30,994 $ 438 $ 2,206 $ 62 $ 33,200 $ 500 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 (1) 11 1 — — 11 1 Total securities AFS $ 181,216 $ 1,854 $ 21,920 $ 673 $ 203,136 $ 2,527 (1) Citi adopted ASU 2016-01 and ASU 2018-03 as of January 1, 2018, resulting in a cumulative effect adjustment from AOCI to retained earnings for net unrealized gains on marketable equity securities AFS. The available for sale category is eliminated for equity securities effective January 1, 2018. See Note 1 to the Consolidated Financial Statements for additional details.
Amortized cost and fair value of debt securities by contractual maturity dates	The following table presents the amortized cost and fair value of AFS debt securities by contractual maturity dates: March 31, 2018 December 31, 2017 In millions of dollars Amortized cost Fair value Amortized cost Fair value Mortgage-backed securities (1) Due within 1 year $ 92 $ 91 $ 45 $ 45 After 1 but within 5 years 1,331 1,327 1,306 1,304 After 5 but within 10 years 1,320 1,298 1,376 1,369 After 10 years (2) 42,374 41,639 42,504 42,239 Total $ 45,117 $ 44,355 $ 45,231 $ 44,957 U.S. Treasury and federal agency securities Due within 1 year $ 12,897 $ 12,906 $ 4,913 $ 4,907 After 1 but within 5 years 104,061 102,375 111,236 110,238 After 5 but within 10 years 2,066 2,033 3,008 3,001 After 10 years (2) — — — — Total $ 119,024 $ 117,314 $ 119,157 $ 118,146 State and municipal Due within 1 year $ 1,874 $ 1,873 $ 1,792 $ 1,792 After 1 but within 5 years 2,496 2,494 2,579 2,576 After 5 but within 10 years 591 607 514 528 After 10 years (2) 5,019 4,863 3,985 3,869 Total $ 9,980 $ 9,837 $ 8,870 $ 8,765 Foreign government Due within 1 year $ 32,899 $ 32,909 $ 32,130 $ 32,100 After 1 but within 5 years 55,910 55,571 53,034 53,165 After 5 but within 10 years 12,454 12,639 12,949 12,680 After 10 years (2) 2,570 2,656 2,502 2,588 Total $ 103,833 $ 103,775 $ 100,615 $ 100,533 All other (3) Due within 1 year $ 2,821 $ 2,818 $ 3,998 $ 3,991 After 1 but within 5 years 9,147 9,092 9,047 9,027 After 5 but within 10 years 2,905 2,907 3,415 3,431 After 10 years (2) 1,435 1,425 1,887 1,875 Total $ 16,308 $ 16,242 $ 18,347 $ 18,324 Total debt securities AFS $ 294,262 $ 291,523 $ 292,220 $ 290,725 (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. The following table presents the carrying value and fair value of HTM debt securities by contractual maturity dates: March 31, 2018 December 31, 2017 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 131 130 720 720 After 5 but within 10 years 166 165 148 149 After 10 years (1) 25,385 24,867 25,231 25,235 Total $ 25,682 $ 25,162 $ 26,099 $ 26,104 State and municipal Due within 1 year $ 234 $ 234 $ 407 $ 425 After 1 but within 5 years 380 398 259 270 After 5 but within 10 years 438 442 512 524 After 10 years (1) 6,601 6,632 7,719 7,983 Total $ 7,653 $ 7,706 $ 8,897 $ 9,202 Foreign government Due within 1 year $ 486 $ 486 $ 381 $ 381 After 1 but within 5 years 868 859 359 341 After 5 but within 10 years — — — — After 10 years (1) — — — — Total $ 1,354 $ 1,345 $ 740 $ 722 All other (2) Due within 1 year $ — $ — $ — $ — After 1 but within 5 years — — — — After 5 but within 10 years 1,989 1,994 1,669 1,680 After 10 years (1) 15,814 15,893 15,915 16,044 Total $ 17,803 $ 17,887 $ 17,584 $ 17,724 Total debt securities held-to-maturity $ 52,492 $ 52,100 $ 53,320 $ 53,752 (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.
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 Amortized cost basis (1) Net unrealized gains (losses) recognized in AOCI Carrying value (2) Gross unrealized gains Gross unrealized (losses) Fair value March 31, 2018 Debt securities held-to-maturity Mortgage-backed securities (3) U.S. government agency guaranteed $ 23,968 $ (38 ) $ 23,930 $ 8 $ (553 ) $ 23,385 Alt-A — — — — — — Non-U.S. residential 1,492 — 1,492 25 — 1,517 Commercial 260 — 260 — — 260 Total mortgage-backed securities $ 25,720 $ (38 ) $ 25,682 $ 33 $ (553 ) $ 25,162 State and municipal $ 7,686 $ (33 ) $ 7,653 $ 185 $ (132 ) 7,706 Foreign government 1,354 — 1,354 3 (12 ) 1,345 Asset-backed securities (3) 17,803 — 17,803 87 (3 ) 17,887 Total debt securities held-to-maturity $ 52,563 $ (71 ) $ 52,492 $ 308 $ (700 ) $ 52,100 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 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 (1) For debt securities transferred to HTM from Trading account assets , 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 debt securities transferred to HTM from AFS, amortized cost 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 debt securities are carried on the Consolidated Balance Sheet at amortized cost basis, plus or minus any unamortized unrealized gains and losses and fair value hedge adjustments recognized in AOCI prior to reclassifying the debt 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 18 to the Consolidated Financial Statements. (4) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, see Note 1 to the Consolidated Financial Statements.
Total other-than-temporary impairments recognized	The following tables present total OTTI recognized in earnings: OTTI on Investments Three Months Ended In millions of dollars AFS (1) HTM Total Impairment losses related to debt securities that the Company does not intend to sell nor will likely be required to sell: Total OTTI losses recognized during the period $ — $ — $ — Less: portion of impairment loss recognized in AOCI (before taxes) — — — Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell $ — $ — $ — Impairment losses recognized in earnings for debt 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 27 — 27 Total OTTI losses recognized in earnings $ 27 $ — $ 27 (1) For the three months ended March 31, 2018, amounts represent AFS debt securities. Effective January 1, 2018, the AFS category is eliminated for equity securities. See Note 1 to the Consolidated Financial Statements for additional details. OTTI on Investments Three months ended In millions of dollars AFS (1) HTM 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 $ — $ — $ — 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 $ — $ — $ — 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 and FX losses 11 1 12 Total impairment losses recognized in earnings $ 11 $ 1 $ 12 (1) Includes OTTI on non-marketable equity securities.
Cumulative other-than-temporary impairment credit losses recognized in earnings	The following are three-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 debt securities still held In millions of dollars December 31, 2017 balance Credit Credit Changes due to (1) March 31, 2018 balance AFS debt securities Mortgage-backed securities (2) $ 38 $ — $ — $ (13 ) $ 25 State and municipal 4 — — (4 ) — Foreign government securities — — — — — Corporate 4 — — — 4 All other debt securities 2 — — — 2 Total OTTI credit losses recognized for AFS debt securities $ 48 $ — $ — $ (17 ) $ 31 HTM debt securities Mortgage-backed securities (3) $ 54 $ — $ — $ (54 ) $ — State and municipal 3 — — (3 ) — Total OTTI credit losses recognized for HTM debt securities $ 57 $ — $ — $ (57 ) $ — (1) Includes $18 million in cumulative OTTI reclassified from HTM to AFS due to the transfer of the related debt securities from HTM to AFS. Citi adopted ASU 2017-12, Targeted Improvements to Accounting for Hedge Activities , on January 1, 2018 and transferred approximately $4 billion of HTM debt securities into AFS classification as permitted as a one-time transfer under the standard. (2) Primarily consists of Prime securities. (3) Primarily consists of Alt-A securities. Cumulative OTTI credit losses recognized in earnings on debt securities still held In millions of dollars December 31, 2016 balance Credit Credit Reductions due to March 31, 2017 balance AFS debt securities Mortgage-backed securities $ — $ — $ — $ — $ — State and municipal 4 — — — 4 Foreign government securities — — — — — Corporate 5 — — (1 ) 4 All other debt securities 22 — — — 22 Total OTTI credit losses recognized for AFS debt securities $ 31 $ — $ — $ (1 ) $ 30 HTM debt securities Mortgage-backed securities (1) $ 101 $ — $ — $ (4 ) $ 97 State and municipal 3 — — — 3 Total OTTI credit losses recognized for HTM debt securities $ 104 $ — $ — $ (4 ) $ 100 (1) Primarily consists of Alt-A securities.
Carrying value of non-marketable equity securities measured using the measurement alternative	Below is the carrying value of non-marketable equity securities measured using the measurement alternative at March 31, 2018, and amounts recognized in earnings for the three months ended March 31, 2018: In millions of dollars Three Months Ended March 31, 2018 Measurement alternative, balance at March 31, 2018 $ 401 Measurement alternative—impairment losses (1) 1 Measurement alternative—downward changes for observable prices (1) 2 Measurement alternative—upward changes for observable prices (1) 123 (1) See Note 20 to the Consolidated Financial Statements for additional information on these nonrecurring fair value measurements.
Investments in alternative investment funds	Fair value Unfunded Redemption frequency (if currently eligible) monthly, quarterly, annually Redemption notice period In millions of dollars March 31, December 31, 2017 March 31, December 31, 2017 Hedge funds $ — $ 1 $ — $ — Generally quarterly 10–95 days Private equity funds (1)(2) 413 372 62 62 — — Real estate funds (2)(3) 20 31 19 20 — — Total $ 433 $ 404 $ 81 $ 82 — — (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)	3 Months Ended
	Mar. 31, 2018
Consumer
Loans receivable
Schedule of loans	The following table provides Citi’s consumer loans by loan type: In millions of dollars March 31, December 31, 2017 In U.S. offices Mortgage and real estate (1) $ 63,412 $ 65,467 Installment, revolving credit and other 3,306 3,398 Cards 131,081 139,006 Commercial and industrial 7,493 7,840 $ 205,292 $ 215,711 In offices outside the U.S. Mortgage and real estate (1) $ 44,833 $ 44,081 Installment, revolving credit and other 27,651 26,556 Cards 25,993 26,257 Commercial and industrial 20,526 20,238 Lease financing 62 76 $ 119,065 $ 117,208 Total consumer loans $ 324,357 $ 332,919 Net unearned income $ 727 $ 737 Consumer loans, net of unearned income $ 325,084 $ 333,656 (1) Loans secured primarily by real estate.
Schedule of loan delinquency and non-accrual details	Consumer Loan Delinquency and Non-Accrual Details at March 31, 2018 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) $ 46,607 $ 364 $ 257 $ 1,010 $ 48,238 $ 636 $ 750 Home equity loans (6)(7) 13,476 160 315 — 13,951 691 — Credit cards 128,790 1,460 1,528 — 131,778 — 1,528 Installment and other 3,333 38 14 — 3,385 21 Commercial banking loans 9,011 14 44 — 9,069 152 13 Total $ 201,217 $ 2,036 $ 2,158 $ 1,010 $ 206,421 $ 1,500 $ 2,291 In offices outside North America Residential first mortgages (5) $ 37,447 $ 250 $ 147 $ — $ 37,844 $ 412 $ — Credit cards 24,702 437 373 — 25,512 323 256 Installment and other 26,243 311 116 — 26,670 161 — Commercial banking loans 28,504 69 63 — 28,636 179 — Total $ 116,896 $ 1,067 $ 699 $ — $ 118,662 $ 1,075 $ 256 Total GCB and Corporate/Other — Consumer $ 318,113 $ 3,103 $ 2,857 $ 1,010 $ 325,083 $ 2,575 $ 2,547 Other (8) 1 — — — 1 — — Total Citigroup $ 318,114 $ 3,103 $ 2,857 $ 1,010 $ 325,084 $ 2,575 $ 2,547 (1) Loans less than 30 days past due are presented as current. (2) Includes $23 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 $0.8 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, 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 banking 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 banking 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.
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) March 31, 2018 In millions of dollars Less than or equal to 80% > 80% but less than or equal to 100% Greater than 100% Residential first mortgages $ 42,790 $ 2,536 $ 214 Home equity loans 10,788 1,954 737 Total $ 53,578 $ 4,490 $ 951 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 (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 banking 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) March 31, 2018 In millions of dollars Less than 620 ≥ 620 but less than 660 ≥ 660 but less than 720 Equal to or greater than 720 Residential first mortgages $ 1,750 $ 1,746 $ 6,655 $ 35,253 Home equity loans 1,075 937 3,138 8,409 Credit cards 9,169 11,285 37,275 70,598 Installment and other 146 229 681 1,710 Total $ 12,140 $ 14,197 $ 47,749 $ 115,970 FICO score distribution in U.S. portfolio (1)(2) December 31, 2017 In millions of dollars Less than 620 ≥ 620 but less than 660 ≥ 660 but less Equal to or greater than 720 Residential first mortgages $ 2,100 $ 1,932 $ 6,931 $ 35,334 Home equity loans 1,379 1,081 3,446 8,530 Credit cards 9,079 11,651 37,916 77,661 Installment and other 276 250 667 1,818 Total $ 12,834 $ 14,914 $ 48,960 $ 123,343 (1) Excludes loans guaranteed by U.S. government entities, loans subject to long-term standby commitments (LTSC) 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: Three Months Ended Balance at March 31, 2018 2018 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Interest income (5) Interest income (5) Mortgage and real estate Residential first mortgages $ 3,020 $ 3,123 $ 250 $ 3,002 $ 21 $ 36 Home equity loans 673 893 211 1,044 7 8 Credit cards 1,846 1,879 626 1,809 30 38 Installment and other Individual installment and other 443 473 182 428 6 8 Commercial banking 287 500 26 374 3 6 Total $ 6,269 $ 6,868 $ 1,295 $ 6,657 $ 67 $ 96 (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) $526 million of residential first mortgages, $348 million of home equity loans and $9 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. Balance, December 31, 2017 In millions of dollars Recorded investment (1)(2) Unpaid principal balance Related specific allowance (3) Average carrying value (4) Mortgage and real estate Residential first mortgages $ 2,877 $ 3,121 $ 278 $ 3,155 Home equity loans 1,151 1,590 216 1,181 Credit cards 1,787 1,819 614 1,803 Installment and other Individual installment and other 431 460 175 415 Commercial banking 334 541 51 429 Total $ 6,580 $ 7,531 $ 1,334 $ 6,983 (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.
Schedule of troubled debt restructurings	Consumer Troubled Debt Restructurings At and for the three months ended March 31, 2018 In millions of dollars except number of loans modified Number of Post- (1)(2) Deferred (3) Contingent (4) Principal (5) Average North America Residential first mortgages 588 $ 89 $ 1 $ — $ — — % Home equity loans 456 41 2 — — 1 Credit cards 63,203 244 — — — 18 Installment and other revolving 342 3 — — — 5 Commercial banking (6) 9 1 — — — — Total (8) 64,598 $ 378 $ 3 $ — $ — International Residential first mortgages 549 $ 18 $ — $ — $ — — % Credit cards 23,394 94 — — 2 15 Installment and other revolving 9,325 59 — — 2 10 Commercial banking (6) 145 28 — — — 2 Total (8) 33,413 $ 199 $ — $ — $ 4 At and for the three months ended March 31, 2017 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 966 $ 130 $ 3 $ — $ 1 1 % Home equity loans 679 56 3 — — 1 Credit cards 59,337 231 — — — 17 Installment and other revolving 221 2 — — — 5 Commercial banking (6) 26 5 — — — — Total (8) 61,229 $ 424 $ 6 $ — $ 1 International Residential first mortgages 613 $ 27 $ — $ — $ — — % Credit cards 25,237 85 — — 2 14 Installment and other revolving 11,307 60 — — 4 7 Commercial banking (6) 32 13 — — — 2 Total (8) 37,189 $ 185 $ — $ — $ 6 (1) Post-modification balances include past due amounts that are capitalized at the modification date. (2) Post-modification balances in North America include $11 million of residential first mortgages and $4 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the three months ended March 31, 2018 . These amounts include $8 million of residential first mortgages and $3 million of home equity loans that were newly classified as TDRs in the three months ended March 31, 2018 , 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 $ 15 million of residential first mortgages and $ 6 million of home equity loans to borrowers who have gone through Chapter 7 bankruptcy in the three months ended March 31, 2017 . These amounts include $ 9 million of residential first mortgages and $ 6 million of home equity loans that were newly classified as TDRs in the three months ended March 31, 2017 , 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. Three Months Ended March 31, In millions of dollars 2018 2017 North America Residential first mortgages $ 44 $ 51 Home equity loans 10 9 Credit cards 59 52 Installment and other revolving 1 — Commercial banking 8 2 Total $ 122 $ 114 International Residential first mortgages $ 2 $ 2 Credit cards 53 42 Installment and other revolving 24 23 Commercial banking — — Total $ 79 $ 67
Corporate
Loans receivable
Schedule of loans	The following table presents information by corporate loan type: In millions of dollars March 31, December 31, In U.S. offices Commercial and industrial $ 54,005 $ 51,319 Financial institutions 40,472 39,128 Mortgage and real estate (1) 45,581 44,683 Installment, revolving credit and other 32,866 33,181 Lease financing 1,463 1,470 $ 174,387 $ 169,781 In offices outside the U.S. Commercial and industrial $ 101,368 $ 93,750 Financial institutions 35,659 35,273 Mortgage and real estate (1) 7,543 7,309 Installment, revolving credit and other 23,338 22,638 Lease financing 167 190 Governments and official institutions 6,170 5,200 $ 174,245 $ 164,360 Total corporate loans $ 348,632 $ 334,141 Net unearned income $ (778 ) $ (763 ) Corporate loans, net of unearned income $ 347,854 $ 333,378 (1) Loans secured primarily by real estate.
Schedule of loan delinquency and non-accrual details	Corporate Loan Delinquency and Non-Accrual Details at March 31, 2018 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 $ 478 $ 77 $ 555 $ 1,260 $ 149,912 $ 151,727 Financial institutions 63 22 85 87 74,840 75,012 Mortgage and real estate 131 14 145 192 52,772 53,109 Leases 22 — 22 43 1,564 1,629 Other 188 7 195 86 61,583 61,864 Loans at fair value 4,513 Purchased distressed loans — Total $ 882 $ 120 $ 1,002 $ 1,668 $ 340,671 $ 347,854 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 Purchased distressed loans — Total $ 627 $ 108 $ 735 $ 1,942 $ 326,352 $ 333,378 (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 March 31, December 31, Investment grade (2) Commercial and industrial $ 108,881 $ 101,313 Financial institutions 62,082 60,404 Mortgage and real estate 23,831 23,213 Leases 1,063 1,090 Other 57,863 56,306 Total investment grade $ 253,720 $ 242,326 Non-investment grade (2) Accrual Commercial and industrial $ 41,586 $ 38,503 Financial institutions 12,843 13,261 Mortgage and real estate 3,226 2,881 Leases 523 518 Other 3,915 3,924 Non-accrual Commercial and industrial 1,260 1,506 Financial institutions 87 92 Mortgage and real estate 192 195 Leases 43 46 Other 86 103 Total non-investment grade $ 63,761 $ 61,029 Non-rated private bank loans managed on a delinquency basis (2) $ 25,860 $ 25,674 Loans at fair value 4,513 4,349 Corporate loans, net of unearned income $ 347,854 $ 333,378 (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: March 31, 2018 Three Months Ended 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 $ 1,260 $ 1,501 $ 227 $ 1,439 $ 3 Financial institutions 87 102 25 159 — Mortgage and real estate 192 349 10 186 1 Lease financing 43 43 4 53 — Other 86 195 5 105 — Total non-accrual corporate loans $ 1,668 $ 2,190 $ 271 $ 1,942 $ 4 December 31, 2017 In millions of dollars Recorded investment (1) Unpaid principal balance Related specific allowance Average carrying value (2) Non-accrual corporate loans Commercial and industrial $ 1,506 $ 1,775 $ 368 $ 1,547 Financial institutions 92 102 41 212 Mortgage and real estate 195 324 11 183 Lease financing 46 46 4 59 Other 103 212 2 108 Total non-accrual corporate loans $ 1,942 $ 2,459 $ 426 $ 2,109 March 31, 2018 December 31, 2017 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 $ 574 $ 227 $ 1,017 $ 368 Financial institutions 87 25 88 41 Mortgage and real estate 54 10 51 11 Lease financing 43 4 46 4 Other 16 5 13 2 Total non-accrual corporate loans with specific allowance $ 774 $ 271 $ 1,215 $ 426 Non-accrual corporate loans without specific allowance Commercial and industrial $ 686 $ 489 Financial institutions — 4 Mortgage and real estate 138 144 Lease financing — — Other 70 90 Total non-accrual corporate loans without specific allowance $ 894 N/A $ 727 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 three months ended March 31, 2017 was $2 million . N/A Not applicable
Schedule of troubled debt restructurings	At and for the three months ended March 31, 2018 : 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 $ 2 $ — $ — $ 2 Mortgage and real estate 1 — — 1 Total $ 3 $ — $ — $ 3 At and for the three months ended March 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 $ 55 $ — $ — $ 55 Financial institutions 15 — — 15 Mortgage and real estate 1 — — 1 Total $ 71 $ — $ — $ 71
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 March 31, 2018 TDR loans in payment default during the three months ended March 31, 2018 TDR balances at March 31, 2017 TDR loans in payment default during the three months ended March 31, 2017 Commercial and industrial $ 507 $ 59 $ 390 $ 9 Loans to financial institutions 40 — 24 3 Mortgage and real estate 98 — 84 — Other 41 — 177 — Total (1) $ 686 $ 59 $ 675 $ 12 (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)	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Allowance for credit losses	Three Months Ended March 31, In millions of dollars 2018 2017 Allowance for loan losses at beginning of period $ 12,355 $ 12,060 Gross credit losses (2,296 ) (2,144 ) Gross recoveries (1) 429 435 Net credit losses (NCLs) $ (1,867 ) $ (1,709 ) NCLs $ 1,867 $ 1,709 Net reserve builds (releases) 102 (20 ) Net specific reserve releases (166 ) (14 ) Total provision for loan losses $ 1,803 $ 1,675 Other, net (see table below) 63 4 Allowance for loan losses at end of period $ 12,354 $ 12,030 Allowance for credit losses on unfunded lending commitments at beginning of period $ 1,258 $ 1,418 Provision (release) for unfunded lending commitments 28 (43 ) Other, net 4 2 Allowance for credit losses on unfunded lending commitments at end of period (2) $ 1,290 $ 1,377 Total allowance for loans, leases and unfunded lending commitments $ 13,644 $ 13,407 (1) Recoveries have been reduced by certain collection costs that are incurred only if collection efforts are successful. (2) 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 Three Months Ended March 31, In millions of dollars 2018 2017 Sales or transfers of various consumer loan portfolios to HFS Transfer of real estate loan portfolios $ (53 ) $ (37 ) Transfer of other loan portfolios (2 ) (124 ) Sales or transfers of various consumer loan portfolios to HFS $ (55 ) $ (161 ) FX translation, consumer 118 164 Other — 1 Other, net $ 63 $ 4
Schedule of allowance for credit losses and investment in loans by portfolio segment	Three Months Ended March 31, 2018 March 31, 2017 In millions of dollars Corporate Consumer Total Corporate Consumer Total Allowance for loan losses at beginning of period $ 2,486 $ 9,869 $ 12,355 $ 2,702 $ 9,358 $ 12,060 Charge-offs (139 ) (2,157 ) (2,296 ) (103 ) (2,041 ) (2,144 ) Recoveries 43 386 429 66 369 435 Replenishment of net charge-offs 96 1,771 1,867 37 1,672 1,709 Net reserve builds (releases) (19 ) 121 102 (166 ) 146 (20 ) Net specific reserve builds (releases) (155 ) (11 ) (166 ) (12 ) (2 ) (14 ) Other 3 60 63 11 (7 ) 4 Ending balance $ 2,315 $ 10,039 $ 12,354 $ 2,535 $ 9,495 $ 12,030 March 31, 2018 December 31, 2017 In millions of dollars Corporate Consumer Total Corporate Consumer Total Allowance for loan losses Collectively evaluated in accordance with ASC 450 $ 2,045 $ 8,740 $ 10,785 $ 2,060 $ 8,531 $ 10,591 Individually evaluated in accordance with ASC 310-10-35 270 1,295 1,565 426 1,334 1,760 Purchased credit-impaired in accordance with ASC 310-30 — 4 4 — 4 4 Total allowance for loan losses $ 2,315 $ 10,039 $ 12,354 $ 2,486 $ 9,869 $ 12,355 Loans, net of unearned income Collectively evaluated in accordance with ASC 450 $ 341,676 $ 318,666 $ 660,342 $ 327,142 $ 326,884 $ 654,026 Individually evaluated in accordance with ASC 310-10-35 1,665 6,269 7,934 1,887 6,580 8,467 Purchased credit-impaired in accordance with ASC 310-30 — 126 126 — 167 167 Held at fair value 4,513 23 4,536 4,349 25 4,374 Total loans, net of unearned income $ 347,854 $ 325,084 $ 672,938 $ 333,378 $ 333,656 $ 667,034

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The changes in Goodwill were as follows: In millions of dollars Global Consumer Banking Institutional Clients Group Corporate/Other Total Balance, December 31, 2017 $ 12,784 $ 9,456 $ 16 $ 22,256 Foreign exchange translation and other $ 184 $ 235 $ — $ 419 Divestiture (1) — — (16 ) (16 ) Balance at March 31, 2018 $ 12,968 $ 9,691 $ — $ 22,659 (1) Goodwill allocated to the sale of Citi Colombia consumer business, the only remaining business in Citi Holdings—Consumer Latin America reporting unit reported as part of Corporate/Other , which is classified as HFS beginning the first quarter of 2018.
Components of intangible assets, finite-lived	The components of intangible assets were as follows: March 31, 2018 December 31, 2017 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,308 $ 3,805 $ 1,503 $ 5,375 $ 3,836 $ 1,539 Credit card contract related intangibles (1) 5,044 2,542 $ 2,502 5,045 2,456 2,589 Core deposit intangibles 449 439 $ 10 639 628 11 Other customer relationships 486 294 $ 192 459 272 187 Present value of future profits 35 31 $ 4 32 28 4 Indefinite-lived intangible assets 231 — $ 231 244 — 244 Other 100 92 $ 8 100 86 14 Intangible assets (excluding MSRs) $ 11,653 $ 7,203 $ 4,450 $ 11,894 $ 7,306 $ 4,588 Mortgage servicing rights (MSRs) (2) 587 — 587 558 — 558 Total intangible assets $ 12,240 $ 7,203 $ 5,037 $ 12,452 $ 7,306 $ 5,146
Components of intangible assets, indefinite-lived	The components of intangible assets were as follows: March 31, 2018 December 31, 2017 In millions of dollars Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Purchased credit card relationships $ 5,308 $ 3,805 $ 1,503 $ 5,375 $ 3,836 $ 1,539 Credit card contract related intangibles (1) 5,044 2,542 $ 2,502 5,045 2,456 2,589 Core deposit intangibles 449 439 $ 10 639 628 11 Other customer relationships 486 294 $ 192 459 272 187 Present value of future profits 35 31 $ 4 32 28 4 Indefinite-lived intangible assets 231 — $ 231 244 — 244 Other 100 92 $ 8 100 86 14 Intangible assets (excluding MSRs) $ 11,653 $ 7,203 $ 4,450 $ 11,894 $ 7,306 $ 4,588 Mortgage servicing rights (MSRs) (2) 587 — 587 558 — 558 Total intangible assets $ 12,240 $ 7,203 $ 5,037 $ 12,452 $ 7,306 $ 5,146
Changes in intangible assets	The changes in intangible assets were as follows: Net carrying Net carrying amount at In millions of dollars December 31, Acquisitions/ divestitures Amortization FX translation and other March 31, Purchased credit card relationships $ 1,539 $ — $ (35 ) $ (1 ) $ 1,503 Credit card contract related intangibles (1) 2,589 — (86 ) (1 ) 2,502 Core deposit intangibles 11 — (2 ) 1 10 Other customer relationships 187 — (6 ) 11 192 Present value of future profits 4 — — — 4 Indefinite-lived intangible assets 244 — — (13 ) 231 Other 14 — (6 ) — 8 Intangible assets (excluding MSRs) $ 4,588 $ — $ (135 ) $ (3 ) $ 4,450 Mortgage servicing rights (MSRs) (2) 558 587 Total intangible assets $ 5,146 $ 5,037 (1) Primarily reflects contract-related intangibles associated with the American Airlines, The Home Depot, Costco, Sears and AT&T credit card program agreements, which represented 97% of the aggregate net carrying amount at March 31, 2018 and December 31, 2017. (2) For additional information on Citi’s MSRs, including the rollforward for the three months ended March 31, 2018 , see Note 18 to the Consolidated Financial Statements.

DEBT (Tables)

DEBT (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of short-term borrowings	In millions of dollars March 31, December 31, Commercial paper $ 10,022 $ 9,940 Other borrowings (1) 26,072 34,512 Total $ 36,094 $ 44,452 (1) Includes borrowings from Federal Home Loan Banks and other market participants. At March 31, 2018 and December 31, 2017 , collateralized short-term advances from the Federal Home Loan Banks were $15.3 billion and $23.8 billion , respectively.
Schedule of long-term debt	In millions of dollars March 31, December 31, 2017 Citigroup Inc. (1) $ 153,074 $ 152,163 Bank (2) 64,757 65,856 Broker-dealer and other (3) 20,107 18,690 Total $ 237,938 $ 236,709 (1) Represents the parent holding company. (2) Represents Citibank entities as well as other bank entities. At March 31, 2018 and December 31, 2017 , collateralized long-term advances from the Federal Home Loan Banks were $15.7 billion and $19.3 billion , respectively. (3) Represents broker-dealer and other non-bank subsidiaries that are consolidated into Citigroup Inc., the parent holding company.
Summary of outstanding trust preferred securities	The following table summarizes Citi’s outstanding trust preferred securities at March 31, 2018 : 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 99,901 140 3 mo LIBOR + 88.75 bps 50 140 June 28, 2067 June 28, 2017 Total obligated $ 2,580 $ 2,586 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.

CHANGES IN ACCUMULATED OTHER 48

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) (Tables)	3 Months Ended
	Mar. 31, 2018
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) were as follows: Three Months Ended March 31, 2018 In millions of dollars Net Debt valuation adjustment (DVA) Cash flow hedges (1) Benefit plans (2) Foreign (3) Excluded Component of fair value hedges (4) Accumulated Balance, December 31, 2017 $ (1,158 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ — $ (34,668 ) Adjustment to opening balance, net of taxes (5) (3 ) — — — — — (3 ) Adjusted balance, beginning of period $ (1,161 ) $ (921 ) $ (698 ) $ (6,183 ) $ (25,708 ) $ — $ (34,671 ) Other comprehensive income before reclassifications (949 ) 101 (243 ) 41 1,120 (4 ) 70 Increase (decrease) due to amounts reclassified from AOCI (109 ) 27 21 47 — — (14 ) Change, net of taxes $ (1,058 ) $ 128 $ (222 ) $ 88 $ 1,120 $ (4 ) $ 52 Balance at March 31, 2018 $ (2,219 ) $ (793 ) $ (920 ) $ (6,095 ) $ (24,588 ) $ (4 ) $ (34,619 ) In millions of dollars Net Debt valuation adjustment (DVA) Cash flow hedges (1) Benefit plans (2) Foreign (3) Excluded Component of fair value hedges (4) Accumulated Balance, December 31, 2016 $ (799 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ — $ (32,381 ) Adjustment to opening balance, net of taxes (6) 504 — — — — — 504 Adjusted balance, beginning of period $ (295 ) $ (352 ) $ (560 ) $ (5,164 ) $ (25,506 ) $ — $ (31,877 ) Other comprehensive income before reclassifications 334 (55 ) 24 (49 ) 1,465 — 1,719 Increase (decrease) due to amounts reclassified from AOCI (114 ) (5 ) (26 ) 37 (147 ) — (255 ) Change, net of taxes $ 220 $ (60 ) $ (2 ) $ (12 ) $ 1,318 $ — $ 1,464 Balance, March 31, 2017 $ (75 ) $ (412 ) $ (562 ) $ (5,176 ) $ (24,188 ) $ — $ (30,413 ) (1) Primarily driven by Citigroup’s pay fixed/receive floating interest rate swap programs that hedge the floating rates on liabilities. (2) Primarily reflects adjustments based on the quarterly actuarial valuations of the Company’s Significant pension and postretirement plans, annual actuarial valuations of all other plans and amortization of amounts previously recognized in other comprehensive income. (3) Primarily reflects the movements in (by order of impact) the Mexican Peso, Japanese Yen, Euro, and Chinese Yuan against the U.S. dollar and changes in related tax effects and hedges for the quarter ended March 31, 2018 . Primarily reflects the movements in (by order of impact) the Mexican peso, Korean Won, Japanese Yen and Indian Rupee against the U.S. dollar and changes in related tax effects and hedges for the quarter ended March, 31, 2017. (4) Beginning in the first quarter of 2018, changes in the excluded component of fair value hedges are reflected as a component of AOCI, pursuant to the early adoption of ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities . See Note 1 to the Consolidated Financial Statements for further information regarding this change. (5) Citi adopted ASU 2016-01 and ASU 2018-03 on January 1, 2018. Upon adoption, a cumulative effect adjustment was recorded from AOCI to retained earnings for net unrealized gains on former AFS equity securities. For additional information, see Note 1 to the Consolidated Financial Statements. (6) In the second quarter of 2017, Citi early adopted ASU 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. 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. For additional information, 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) were as follows: Three Months Ended March 31, 2018 In millions of dollars Pretax Tax effect (1) After-tax Balance, December 31, 2017 (1) $ (41,228 ) $ 6,560 $ (34,668 ) Adjustment to opening balance (2) (4 ) 1 (3 ) Adjusted balance, beginning of period $ (41,232 ) $ 6,561 $ (34,671 ) Change in net unrealized gains (losses) on AFS debt securities (1,380 ) 322 (1,058 ) Debt valuation adjustment (DVA) 167 (39 ) 128 Cash flow hedges (290 ) 68 (222 ) Benefit plans 91 (3 ) 88 Foreign currency translation adjustment 1,130 (10 ) 1,120 Excluded component of fair value hedges (5 ) 1 (4 ) Change $ (287 ) $ 339 $ 52 Balance, March 31, 2018 $ (41,519 ) $ 6,900 $ (34,619 ) Three Months Ended March 31, 2017 In millions of dollars Pretax Tax effect After-tax 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 346 (126 ) 220 Debt valuation adjustment (DVA) (95 ) 35 (60 ) Cash flow hedges 1 (3 ) (2 ) Benefit plans (2 ) (10 ) (12 ) Foreign currency translation adjustment 1,468 (150 ) 1,318 Excluded component of fair value hedges — — — Change $ 1,718 $ (254 ) $ 1,464 Balance, March 31, 2017 $ (39,514 ) $ 9,101 $ (30,413 ) (1) Includes the impact of ASU 2018-02, which transferred amounts from AOCI to Retained Earnings . For additional information, see Note 19 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K. (2) Citi adopted ASU 2016-01 and ASU 2018-03 on January 1, 2018. Upon adoption, a cumulative effect adjustment was recorded from AOCI to retained earnings for net unrealized gains on former AFS equity securities. For additional information, 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 to the Consolidated Statement of Income as follows: Increase (decrease) in AOCI due to amounts reclassified to Consolidated Statement of Income Three Months Ended March 31, In millions of dollars 2018 2017 Realized (gains) losses on sales of investments $ (170 ) $ (192 ) Gross impairment losses 27 12 Subtotal, pretax $ (143 ) $ (180 ) Tax effect 34 66 Net realized (gains) losses on investments after-tax (1) $ (109 ) $ (114 ) Realized DVA (gains) losses on fair value option liabilities $ 35 $ (8 ) Subtotal, pretax $ 35 $ (8 ) Tax effect (8 ) 3 Net realized debt valuation adjustment, after-tax $ 27 $ (5 ) Interest rate contracts $ 31 $ (44 ) Foreign exchange contracts (2 ) 3 Subtotal, pretax $ 29 $ (41 ) Tax effect (8 ) 15 Amortization of cash flow hedges, after-tax (2) $ 21 $ (26 ) Amortization of unrecognized Prior service cost (benefit) $ (11 ) $ (10 ) Net actuarial loss 69 67 Curtailment/settlement impact (3) 4 — Subtotal, pretax $ 62 $ 57 Tax effect (15 ) (20 ) Amortization of benefit plans, after-tax (3) $ 47 $ 37 Foreign currency translation adjustment $ — $ (232 ) Tax effect — 85 Foreign currency translation adjustment $ — $ (147 ) Total amounts reclassified out of AOCI, pretax $ (17 ) $ (404 ) Total tax effect 3 149 Total amounts reclassified out of AOCI, after-tax $ (14 ) $ (255 ) (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 12 to the Consolidated Financial Statements for additional details. (2) See Note 19 to the Consolidated Financial Statements for additional details. (3) See Note 8 to the Consolidated Financial Statements for additional details.

SECURITIZATIONS AND VARIABLE 49

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Tables)	3 Months Ended
	Mar. 31, 2018
Securitizations and Variable Interest Entities [Abstract]
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 March 31, 2018 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 $ 46,540 $ 46,540 $ — $ — $ — $ — $ — $ — Mortgage securitizations (4) U.S. agency-sponsored 111,980 — 111,980 2,690 — — 87 2,777 Non-agency-sponsored 20,660 1,891 18,769 335 — — 1 336 Citi-administered asset-backed commercial paper conduits (ABCP) 18,962 18,962 — — — — — — Collateralized loan obligations (CLOs) 16,491 — 16,491 5,362 — — 9 5,371 Asset-based financing 63,019 637 62,382 19,190 571 6,904 — 26,665 Municipal securities tender option bond trusts (TOBs) 7,105 2,165 4,940 18 — 3,344 — 3,362 Municipal investments 19,265 5 19,260 2,769 3,632 2,129 — 8,530 Client intermediation 1,414 1,279 135 37 — — 7 44 Investment funds 1,874 603 1,271 10 7 13 — 30 Other 693 34 659 28 8 33 49 118 Total $ 308,003 $ 72,116 $ 235,887 $ 30,439 $ 4,218 $ 12,423 $ 153 $ 47,233 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 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 (1) The definition of maximum exposure to loss is included in the text that follows this table. (2) Included on Citigroup’s March 31, 2018 and December 31, 2017 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.
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: March 31, 2018 December 31, 2017 In millions of dollars Liquidity facilities Loan/equity commitments Liquidity facilities Loan/equity commitments Asset-based financing $ — $ 6,904 $ — $ 5,878 Municipal securities tender option bond trusts (TOBs) 3,344 — 3,035 — Municipal investments — 2,129 — 2,344 Investment funds — 13 — 13 Other — 33 — 34 Total funding commitments $ 3,344 $ 9,079 $ 3,035 $ 8,269
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 March 31, 2018 December 31, 2017 Cash $ — $ — Trading account assets 7.7 8.5 Investments 4.4 4.4 Total loans, net of allowance 21.9 22.2 Other 0.5 0.5 Total assets $ 34.5 $ 35.6
Schedule of securitized credit card receivables	The following table reflects amounts related to the Company’s securitized credit card receivables: In billions of dollars March 31, 2018 December 31, 2017 Ownership interests in principal amount of trust credit card receivables Sold to investors via trust-issued securities $ 28.8 $ 28.8 Retained by Citigroup as trust-issued securities 7.7 7.6 Retained by Citigroup via non-certificated interests 10.1 14.4 Total $ 46.6 $ 50.8 The following tables summarize selected cash flow information related to Citigroup’s credit card securitizations: Three Months Ended March 31, In billions of dollars 2018 2017 Proceeds from new securitizations $ 2.8 $ 2.5 Pay down of maturing notes (2.8 ) (2.0 )
Schedule of Master Trust liabilities (at par value)	In billions of dollars Mar. 31, 2018 Dec. 31, 2017 Term notes issued to third parties $ 27.8 $ 27.8 Term notes retained by Citigroup affiliates 5.8 5.7 Total Master Trust liabilities $ 33.6 $ 33.5
Schedule of Omni Trust liabilities (at par value)	In billions of dollars Mar. 31, 2018 Dec. 31, 2017 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: 2018 2017 In billions of dollars U.S. agency- Non-agency- U.S. agency- Non-agency- Proceeds from new securitizations $ 8.0 $ 3.4 $ 7.2 $ 1.4 Contractual servicing fees received — — 0.1 —
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: March 31, 2018 Non-agency-sponsored mortgages (1) U.S. agency- sponsored mortgages Senior interests Subordinated interests Discount rate 3.0% to 11.4% — — Weighted average discount rate 6.4 % — — Constant prepayment rate 4.2% to 16.0% — — Weighted average constant prepayment rate 8.5 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 7.7 to 18.0 years — — March 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 2.4% to 19.9% — — Weighted average discount rate 13.0 % — — Constant prepayment rate 3.8% to 10.5% — — Weighted average constant prepayment rate 6.2 % — — Anticipated net credit losses (2) NM — — Weighted average anticipated net credit losses NM — — Weighted average life 6.5 to 12.2 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 the Company 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. March 31, 2018 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated Discount rate 0.8% to 41.3% 6.5 % 4.0% to 11.2% Weighted average discount rate 6.2 % 6.5 % 7.3 % Constant prepayment rate 4.3% to 18.4% 8.9 % 9.1% to 13.1% Weighted average constant prepayment rate 10.3 % 8.9 % 10.7 % Anticipated net credit losses (2) NM 46.9 % 35.1% to 52.1% Weighted average anticipated net credit losses NM 46.9 % 44.5 % Weighted average life 0.1 to 27.5 years 5.4 years 2.1 to 18.3 years December 31, 2017 Non-agency-sponsored mortgages (1) U.S. agency- Senior Subordinated 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 (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	March 31, 2018 Non-agency-sponsored mortgages (1) In millions of dollars U.S. agency- sponsored mortgages Senior interests Subordinated interests Carrying value of retained interests $ 1,767 $ 245 $ 138 Discount rates Adverse change of 10% $ (47 ) $ — $ (2 ) Adverse change of 20% (91 ) — (4 ) Constant prepayment rate Adverse change of 10% (37 ) — (1 ) Adverse change of 20% (75 ) — (2 ) Anticipated net credit losses Adverse change of 10% NM — — Adverse change of 20% NM — (1 ) December 31, 2017 Non-agency-sponsored mortgages (1) In millions of dollars U.S. agency- Senior Subordinated Carrying value of retained interests $ 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 ) — (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 2018 2017 Balance, beginning of year $ 558 $ 1,564 Originations 17 35 Changes in fair value of MSRs due to changes in inputs and assumptions 46 67 Other changes (1) (17 ) (53 ) Sale of MSRs (2) (17 ) (1,046 ) Balance, as of March 31 $ 587 $ 567 (1) Represents changes due to customer payments and passage of time. (2) See Note 2 to the Consolidated Financial Statements in Citi’s 2017 Annual Report on Form 10-K for more information on the exit of the U.S. mortgage servicing operations and sale of MSRs in 2017 .
Schedule of fees received on servicing previously securitized mortgages	The amounts of these fees were as follows: In millions of dollars 2018 2017 Servicing fees $ 46 $ 106 Late fees 1 3 Ancillary fees 3 4 Total MSR fees $ 50 $ 113
Schedule of cash flow information, collateralized loan obligations	The following table summarizes selected cash flow information related to Citigroup CLOs: Three Months Ended March 31, In billions of dollars 2018 2017 Proceeds from new securitizations $ 1.4 $ 0.3
Schedule of key assumptions for measuring fair value of retained interests at the date of sale or securitization of CDOs and CLOs	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: Mar. 31, 2018 Dec. 31, 2017 Discount rate 1.1% to 1.6% 1.1% to 1.6%
Schedule of sensitivity of adverse changes of 10% and 20% to discount rate, CDOs and CLOs	In millions of dollars Mar. 31, 2018 Dec. 31, 2017 Carrying value of retained interests $ 3,713 $ 3,607 Discount rates Adverse change of 10% $ (25 ) $ (24 ) Adverse change of 20% (49 ) (47 )
Schedule of asset-based financing	March 31, 2018 In millions of dollars Total unconsolidated VIE assets Maximum exposure to unconsolidated VIEs Type Commercial and other real estate $ 15,152 $ 4,815 Corporate loans 6,862 5,731 Hedge funds and equities 449 58 Airplanes, ships and other assets 39,919 16,061 Total $ 62,382 $ 26,665 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

DERIVATIVES ACTIVITIES (Tables)

DERIVATIVES ACTIVITIES (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative notionals	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) Other derivative instruments Trading derivatives In millions of dollars March 31, December 31, March 31, December 31, Interest rate contracts Swaps $ 197,328 $ 189,779 $ 21,321,930 $ 18,754,219 Futures and forwards 500 — 8,245,034 6,460,539 Written options — — 4,578,837 3,516,131 Purchased options — — 3,710,550 3,234,025 Total interest rate contract notionals $ 197,828 $ 189,779 $ 37,856,351 $ 31,964,914 Foreign exchange contracts Swaps $ 40,063 $ 37,162 $ 6,940,579 $ 5,576,357 Futures, forwards and spot 39,102 33,103 4,465,416 3,097,700 Written options 1,151 3,951 1,460,614 1,127,728 Purchased options 1,405 6,427 1,450,534 1,148,686 Total foreign exchange contract notionals $ 81,721 $ 80,643 $ 14,317,143 $ 10,950,471 Equity contracts Swaps $ — $ — $ 243,567 $ 215,834 Futures and forwards — — 67,910 72,616 Written options — — 427,798 389,961 Purchased options — — 366,219 328,154 Total equity contract notionals $ — $ — $ 1,105,494 $ 1,006,565 Commodity and other contracts Swaps $ — $ — $ 92,552 $ 82,039 Futures and forwards 91 23 176,174 153,248 Written options — — 71,136 62,045 Purchased options — — 66,092 60,526 Total commodity and other contract notionals $ 91 $ 23 $ 405,954 $ 357,858 Credit derivatives (2) Protection sold $ — $ — $ 741,700 $ 735,142 Protection purchased — — 790,134 777,713 Total credit derivatives $ — $ — $ 1,531,834 $ 1,512,855 Total derivative notionals $ 279,640 $ 270,445 $ 55,216,776 $ 45,792,663 (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 $2 million and $63 million at March 31, 2018 and December 31, 2017 , respectively. (2) 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	The following tables present the gross and net fair values of the Company’s derivative transactions and the related offsetting amounts as of March 31, 2018 and December 31, 2017 . 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 following tables reflect 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 reflects a reduction of approximately $110 billion and $100 billion as of March 31, 2018 and December 31, 2017, respectively, 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 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 that 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 March 31, 2018 Derivatives classified (1)(2) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Over-the-counter $ 1,896 $ 92 Cleared 62 125 Interest rate contracts $ 1,958 $ 217 Over-the-counter $ 1,011 $ 1,199 Foreign exchange contracts $ 1,011 $ 1,199 Total derivatives instruments designated as ASC 815 hedges $ 2,969 $ 1,416 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 184,682 $ 163,259 Cleared 8,972 11,926 Exchange traded 217 184 Interest rate contracts $ 193,871 $ 175,369 Over-the-counter $ 125,761 $ 119,004 Cleared 3,426 3,343 Exchange traded 19 8 Foreign exchange contracts $ 129,206 $ 122,355 Over-the-counter $ 18,737 $ 23,424 Cleared 12 17 Exchange traded 10,686 10,674 Equity contracts $ 29,435 $ 34,115 Over-the-counter $ 15,189 $ 18,134 Exchange traded 642 717 Commodity and other contracts $ 15,831 $ 18,851 Over-the-counter $ 12,059 $ 11,633 Cleared 6,968 7,976 Credit derivatives $ 19,027 $ 19,609 Total derivatives instruments not designated as ASC 815 hedges $ 387,370 $ 370,299 Total derivatives $ 390,339 $ 371,715 Cash collateral paid/received (3) $ 8,676 $ 14,971 Less: Netting agreements (4) (303,169 ) (303,169 ) Less: Netting cash collateral received/paid (5) (40,951 ) (33,800 ) Net receivables/payables included on the Consolidated Balance Sheet (6) $ 54,895 $ 49,717 Additional amounts subject to an enforceable master netting agreement, but not offset on the Consolidated Balance Sheet Less: Cash collateral received/paid $ (924 ) $ (113 ) Less: Non-cash collateral received/paid (13,525 ) (20,260 ) Total net receivables/payables (6) $ 40,446 $ 29,344 (1) The trading derivatives fair values are also presented in Note 20 to the Consolidated Financial Statements. (2) 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. (3) Reflects the net amount of the $42,476 million and $55,922 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $33,800 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $40,951 million was used to offset trading derivative assets. (4) Represents the netting of derivative receivable and payable balances with the same counterparty under enforceable netting agreements. Approximately $163 billion , $129 billion and $11 billion of the netting against trading account asset/liability balances is attributable to each of the OTC, cleared and exchange-traded derivatives, respectively. (5) 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. (6) The net receivables/payables include approximately $5 billion of derivative asset and $7 billion of derivative liability fair values not subject to enforceable master netting agreements, respectively. In millions of dollars at December 31, 2017 Derivatives classified in Trading (1)(2) Derivatives instruments designated as ASC 815 hedges Assets Liabilities Over-the-counter $ 1,969 $ 134 Cleared 110 92 Interest rate contracts $ 2,079 $ 226 Over-the-counter $ 1,143 $ 1,150 Foreign exchange contracts $ 1,143 $ 1,150 Total derivatives instruments designated as ASC 815 hedges $ 3,222 $ 1,376 Derivatives instruments not designated as ASC 815 hedges Over-the-counter $ 195,677 $ 173,937 Cleared 7,129 10,381 Exchange traded 102 95 Interest rate contracts $ 202,908 $ 184,413 Over-the-counter $ 119,092 $ 117,473 Cleared 1,690 2,028 Exchange traded 34 121 Foreign exchange contracts $ 120,816 $ 119,622 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 $ 12,972 $ 12,958 Cleared 7,562 8,575 Credit derivatives $ 20,534 $ 21,533 Total derivatives instruments not designated as ASC 815 hedges $ 385,339 $ 373,968 Total derivatives $ 388,561 $ 375,344 Cash collateral paid/received (3) $ 7,541 $ 14,308 Less: Netting agreements (4) (306,401 ) (306,401 ) Less: Netting cash collateral received/paid (5) (38,532 ) (35,666 ) Net receivables/payables included on the Consolidated Balance Sheet (6) $ 51,169 $ 47,585 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 (12,739 ) (6,929 ) Total net receivables/payables (6) $ 37,558 $ 40,535 (1) The trading derivatives fair values are presented in Note 20 to the Consolidated Financial Statements. Derivative mark-to-market receivables/payables previously reported within Other assets/Other liabilities have been reclassified to Trading account assets/Trading account liabilities to conform with the current period presentation. (2) 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. (3) Reflects the net amount of the $43,207 million and $52,840 million of gross cash collateral paid and received, respectively. Of the gross cash collateral paid, $35,666 million was used to offset trading derivative liabilities and, of the gross cash collateral received, $38,532 million was used to offset trading derivative assets. (4) 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. (5) 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. (6) 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.
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 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 Three Months Ended March 31, In millions of dollars 2018 2017 Interest rate contracts $ (28 ) $ (53 ) Foreign exchange 527 225 Credit derivatives (46 ) (279 ) Total Citigroup $ 453 $ (107 ) The following table summarizes the gains (losses) on the Company’s fair value hedges: Gains (losses) on fair value hedges (1) Three Months Ended March 31, 2018 2017 (3) In millions of dollars Other Revenue Net interest revenue Other Revenue Gain (loss) on the derivatives in designated and qualifying fair value hedges Interest rate hedges $ — $ 878 $ (305 ) Foreign exchange hedges 179 — (82 ) Commodity hedges (2 ) — 2 Total gain (loss) on the derivatives in designated and qualifying fair value hedges $ 177 $ 878 $ (385 ) Gain (loss) on the hedged item in designated and qualifying fair value hedges Interest rate hedges $ — $ (866 ) $ 296 Foreign exchange hedges (249 ) — 196 Commodity hedges 1 — (1 ) Total gain (loss) on the hedged item in designated and qualifying fair value hedges $ (248 ) $ (866 ) $ 491 Net gain (loss) excluded from assessment of the effectiveness of fair value hedges Interest rate hedges $ — $ — $ 1 Foreign exchange hedges (2) 23 — 52 Commodity hedges 1 — 1 Total net gain (loss) excluded from assessment of the effectiveness of fair value hedges $ 24 $ — $ 54 (1) Beginning January 1, 2018, gain (loss) amounts for interest rate risk hedges are included in Interest income/expense while the remaining amounts including the amounts for interest rate hedges prior to January 1, 2018 are included in Other revenue or Principal transactions on the Consolidated Statement of Income. The accrued interest income on fair value hedges both prior to and after January 1, 2018 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. After January 1, 2018, amounts include cross-currency basis which is recognized in accumulated other comprehensive income. The amount of cross currency basis that was included in accumulated other comprehensive income was $5 million , none of which was recognized in earnings. (3) Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges for the three months ended March 31, 2017 was $(10) million for interest rate hedges and $62 million for foreign exchange hedges, for a total of $52 million .
Schedule of amounts recorded on the Balance Sheet related to cumulative basis adjustments for fair value hedges	In millions of dollars Balance sheet line item in which hedged item is recorded Carrying amount of hedged asset/ liability Cumulative fair value hedging adjustment included in the carrying amount Active De-Designated Long-term debt $ 139,786 $ (24 ) $ 1,921 Investments available for sale 73,717 259 69
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 below: Three Months Ended March 31, In millions of dollars 2018 2017 Amount of gain (loss) recognized in AOCI on derivative Interest rate contracts (1) $ (322 ) $ 41 Foreign exchange contracts 6 — Total gain (loss) recognized in AOCI $ (316 ) $ 41 Amount of gain (loss) reclassified from AOCI to earnings Other revenue Net interest revenue Interest rate contracts (1) $ — $ (31 ) $ 44 Foreign exchange contracts 2 — (3 ) Total gain (loss) reclassified from AOCI into earnings $ 2 $ (31 ) $ 41 (1) After January 1, 2018, all amounts reclassified into earnings for interest rate contracts are included in Interest income Interest expense . For all other hedges, including interest rate hedges prior to January 1, 2018, the amounts reclassified to earnings are included primarily in Other revenue and Net interest revenue on the Consolidated Income Statement.
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 March 31, 2018 Receivable (1) Payable (2) Protection Protection By industry/counterparty Banks $ 6,782 $ 6,120 $ 263,672 $ 272,815 Broker-dealers 2,155 2,060 72,862 83,585 Non-financial 75 75 1,240 2,313 Insurance and other financial institutions 10,015 11,354 452,360 382,987 Total by industry/counterparty $ 19,027 $ 19,609 $ 790,134 $ 741,700 By instrument Credit default swaps and options $ 18,591 $ 18,787 $ 766,018 $ 729,303 Total return swaps and other 436 822 24,116 12,397 Total by instrument $ 19,027 $ 19,609 $ 790,134 $ 741,700 By rating Investment grade $ 9,496 $ 9,594 $ 597,093 $ 559,526 Non-investment grade 9,531 10,015 193,041 182,174 Total by rating $ 19,027 $ 19,609 $ 790,134 $ 741,700 By maturity Within 1 year $ 2,337 $ 2,517 $ 228,396 $ 212,661 From 1 to 5 years 14,152 14,223 477,627 454,001 After 5 years 2,538 2,869 84,111 75,038 Total by maturity $ 19,027 $ 19,609 $ 790,134 $ 741,700 (1) The fair value amount receivable is composed of $3,016 million under protection purchased and $16,011 million under protection sold. (2) The fair value amount payable is composed of $16,793 million under protection purchased and $2,816 million under protection sold. 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 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 VALUE MEASUREMENT (Tables)

FAIR VALUE MEASUREMENT (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of CVA and FVA applied to fair value of derivative instruments	The table below summarizes the credit valuation adjustments (CVA) and funding valuation adjustments (FVA) applied to the fair value of derivative instruments at March 31, 2018 and December 31, 2017 : Credit and funding valuation adjustments contra-liability (contra-asset) In millions of dollars March 31, December 31, Counterparty CVA $ (841 ) $ (970 ) Asset FVA (438 ) (447 ) Citigroup (own-credit) CVA 364 287 Liability FVA 40 47 Total CVA—derivative instruments (1) $ (875 ) $ (1,083 ) (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 periods indicated: Credit/funding/debt valuation adjustments gain (loss) Three Months Ended March 31, In millions of dollars 2018 2017 Counterparty CVA $ 23 $ 90 Asset FVA 9 92 Own-credit CVA 75 (72 ) Liability FVA (7 ) (10 ) Total CVA—derivative instruments $ 100 $ 100 DVA related to own FVO liabilities (1) $ 167 $ (95 ) Total CVA and DVA (2) $ 267 $ 5 (1) See Note 1 and Note 17 to the Consolidated Financial Statements. (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 March 31, 2018 and December 31, 2017 . 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 March 31, 2018 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 $ — $ 222,936 $ 16 $ 222,952 $ (61,415 ) $ 161,537 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed — 22,317 206 22,523 — 22,523 Residential — 1,084 143 1,227 — 1,227 Commercial — 1,440 35 1,475 — 1,475 Total trading mortgage-backed securities $ — $ 24,841 $ 384 $ 25,225 $ — $ 25,225 U.S. Treasury and federal agency securities $ 20,812 $ 3,898 $ — $ 24,710 $ — $ 24,710 State and municipal — 3,671 211 3,882 — 3,882 Foreign government 46,617 24,918 21 71,556 — 71,556 Corporate 274 18,826 252 19,352 — 19,352 Equity securities 47,797 6,253 237 54,287 — 54,287 Asset-backed securities — 1,586 1,597 3,183 — 3,183 Other trading assets (3) 2 11,000 716 11,718 — 11,718 Total trading non-derivative assets $ 115,502 $ 94,993 $ 3,418 $ 213,913 $ — $ 213,913 Trading derivatives Interest rate contracts $ 276 $ 193,319 $ 2,234 $ 195,829 Foreign exchange contracts 5 129,691 521 130,217 Equity contracts 2,212 26,664 559 29,435 Commodity contracts 169 15,100 562 15,831 Credit derivatives — 18,153 874 19,027 Total trading derivatives $ 2,662 $ 382,927 $ 4,750 $ 390,339 Cash collateral paid (4) $ 8,676 Netting agreements $ (303,169 ) Netting of cash collateral received (40,951 ) Total trading derivatives $ 2,662 $ 382,927 $ 4,750 $ 399,015 $ (344,120 ) $ 54,895 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ — $ 41,265 $ 23 $ 41,288 $ — $ 41,288 Residential — 2,759 — 2,759 — 2,759 Commercial — 303 5 308 — 308 Total investment mortgage-backed securities $ — $ 44,327 $ 28 $ 44,355 $ — $ 44,355 U.S. Treasury and federal agency securities $ 106,239 $ 11,075 $ — $ 117,314 $ — $ 117,314 State and municipal — 9,155 682 9,837 — 9,837 Foreign government 61,312 42,393 70 103,775 — 103,775 Corporate 3,756 9,164 76 12,996 — 12,996 Equity securities 233 43 1 277 — 277 Asset-backed securities — 2,584 497 3,081 — 3,081 Other debt securities — 165 — 165 — 165 Non-marketable equity securities (5) — 125 734 859 — 859 Total investments $ 171,540 $ 119,031 $ 2,088 $ 292,659 $ — $ 292,659 Table continues on the next page. In millions of dollars at March 31, 2018 Level 1 (1) Level 2 (1) Level 3 Gross Netting (2) Net Loans $ — $ 3,982 $ 554 $ 4,536 $ — $ 4,536 Mortgage servicing rights — — 587 587 — 587 Non-trading derivatives and other financial assets measured on a recurring basis $ 15,549 $ 4,881 $ 13 $ 20,443 $ — $ 20,443 Total assets $ 305,253 $ 828,750 $ 11,426 $ 1,154,105 $ (405,535 ) $ 748,570 Total as a percentage of gross assets (6) 26.6 % 72.4 % 1.0 % Liabilities Interest-bearing deposits $ — $ 1,394 $ 292 $ 1,686 $ — $ 1,686 Federal funds purchased and securities loaned or sold under agreements to repurchase — 106,398 857 107,255 (61,415 ) 45,840 Trading account liabilities Securities sold, not yet purchased 80,995 10,911 48 91,954 — 91,954 Other trading liabilities — 2,290 — 2,290 — 2,290 Total trading liabilities $ 80,995 $ 13,201 $ 48 $ 94,244 $ — $ 94,244 Trading derivatives Interest rate contracts $ 218 $ 173,128 $ 2,240 $ 175,586 Foreign exchange contracts 4 123,117 433 123,554 Equity contracts 2,126 29,689 2,300 34,115 Commodity contracts 138 16,242 2,471 18,851 Credit derivatives 2 17,874 1,733 19,609 Total trading derivatives $ 2,488 $ 360,050 $ 9,177 $ 371,715 Cash collateral received (7) $ 14,971 Netting agreements $ (303,169 ) Netting of cash collateral paid (33,800 ) Total trading derivatives $ 2,488 $ 360,050 $ 9,177 $ 386,686 $ (336,969 ) $ 49,717 Short-term borrowings $ — $ 4,386 $ 81 $ 4,467 $ — $ 4,467 Long-term debt — 20,087 13,484 33,571 — 33,571 Total non-trading derivatives and other financial liabilities measured on a recurring basis $ 15,549 $ — $ 3 $ 15,552 $ — $ 15,552 Total liabilities $ 99,032 $ 505,516 $ 23,942 $ 643,461 $ (398,384 ) $ 245,077 Total as a percentage of gross liabilities (6) 15.8 % 80.4 % 3.8 % (1) For the three months ended March 31, 2018 , the Company transferred assets of approximately $0.7 billion from Level 1 to Level 2, primarily related to foreign government securities and equity securities not traded in active markets. During the three months ended March 31, 2018 , the Company transferred assets of approximately $4.0 billion from Level 2 to Level 1, primarily related to foreign government bonds, foreign corporate securities, and equity securities traded with sufficient frequency to constitute an active market. For the three months ended March 31, 2018 , there were no material transfers of liabilities from Level 1 to Level 2. During the three months ended March 31, 2018 , the Company transferred liabilities of approximately $0.2 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 21 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 $42,476 million gross cash collateral paid, of which $33,800 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 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). (6) 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. (7) Reflects the net amount $55,922 million of gross cash collateral received, of which $40,951 million was used to offset trading derivative assets. 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 $ 203,134 $ 1,708 $ 204,987 Foreign exchange contracts 19 121,363 577 121,959 Equity contracts 2,364 24,170 444 26,978 Commodity contracts 282 13,252 569 14,103 Credit derivatives — 19,624 910 20,534 Total trading derivatives $ 2,810 $ 381,543 $ 4,208 $ 388,561 Cash collateral paid (4) $ 7,541 Netting agreements $ (306,401 ) Netting of cash collateral received (38,532 ) Total trading derivatives $ 2,810 $ 381,543 $ 4,208 $ 396,102 $ (344,933 ) $ 51,169 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. 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 $ 13,903 $ 4,640 $ 16 $ 18,559 $ — $ 18,559 Total assets $ 292,700 $ 790,217 $ 11,059 $ 1,101,517 $ (400,571 ) $ 700,946 Total as a percentage of gross assets (6) 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 account derivatives Interest rate contracts $ 137 $ 182,372 $ 2,130 $ 184,639 Foreign exchange contracts 9 120,316 447 120,772 Equity contracts 2,430 26,472 2,471 31,373 Commodity contracts 115 14,482 2,430 17,027 Credit derivatives — 19,824 1,709 21,533 Total trading derivatives $ 2,691 $ 363,466 $ 9,187 $ 375,344 Cash collateral received (7) $ 14,308 Netting agreements $ (306,401 ) Netting of cash collateral paid (35,666 ) Total trading derivatives $ 2,691 $ 363,466 $ 9,187 $ 389,652 $ (342,067 ) $ 47,585 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 $ 13,903 $ 50 $ 8 $ 13,961 $ — $ 13,961 Total liabilities $ 82,437 $ 494,879 $ 23,334 $ 614,958 $ (397,705 ) $ 217,253 Total as a percentage of gross liabilities (6) 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, respectively. 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 21 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 $43,207 million of gross cash collateral paid, of which $35,666 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) 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. (7) Reflects the net amount of $52,840 million of gross cash collateral received, of which $38,532 million was used to offset 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, 2017 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2018 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 16 $ 18 $ — $ — $ — $ — $ — $ — $ (18 ) $ 16 $ 3 Trading non-derivative assets Trading mortgage- backed securities U.S. government-sponsored agency guaranteed 163 1 — 86 (49 ) 116 — (111 ) — 206 — Residential 164 22 — 35 (77 ) 46 — (47 ) — 143 3 Commercial 57 1 — 4 (35 ) 15 — (7 ) — 35 3 Total trading mortgage- backed securities $ 384 $ 24 $ — $ 125 $ (161 ) $ 177 $ — $ (165 ) $ — $ 384 $ 6 U.S. Treasury and federal agency securities $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — State and municipal 274 6 — — (44 ) — — (25 ) — 211 (1 ) Foreign government 16 — — 2 — 14 — (11 ) — 21 — Corporate 275 43 — 49 (72 ) 34 — (77 ) — 252 84 Equity securities 120 75 — 1 (15 ) 168 — (112 ) — 237 (3 ) Asset-backed securities 1,590 58 — 18 (15 ) 316 — (370 ) — 1,597 73 Other trading assets 615 135 — 58 (10 ) 112 5 (194 ) (5 ) 716 6 Total trading non- derivative assets $ 3,274 $ 341 $ — $ 253 $ (317 ) $ 821 $ 5 $ (954 ) $ (5 ) $ 3,418 $ 165 Trading derivatives, net (4) Interest rate contracts $ (422 ) $ 381 $ — $ 5 $ 37 $ 7 $ — $ (16 ) $ 2 $ (6 ) $ (94 ) Foreign exchange contracts 130 (62 ) — (1 ) 8 1 — — 12 88 (155 ) Equity contracts (2,027 ) (136 ) — (57 ) 472 13 — (7 ) 1 (1,741 ) 156 Commodity contracts (1,861 ) (33 ) — (47 ) 8 20 — — 4 (1,909 ) (42 ) Credit derivatives (799 ) (62 ) — 1 (2 ) 2 — 1 — (859 ) (203 ) Total trading derivatives, net (4) $ (4,979 ) $ 88 $ — $ (99 ) $ 523 $ 43 $ — $ (22 ) $ 19 $ (4,427 ) $ (338 ) Table continues on the next page. Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31 2017 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2018 Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 24 $ — $ (1 ) $ — $ — $ — $ — $ — $ — $ 23 $ 2 Residential — — — — — — — — — — — Commercial 3 — 2 — — — — — — 5 — Total investment mortgage-backed securities $ 27 $ — $ 1 $ — $ — $ — $ — $ — $ — $ 28 $ 2 U.S. Treasury and federal agency securities $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — State and municipal 737 — (16 ) — (9 ) 29 — (59 ) — 682 (33 ) Foreign government 92 — (1 ) — (2 ) 57 — (76 ) — 70 — Corporate 71 — (1 ) 3 — 3 — — — 76 — Equity securities 2 — — — — — — (1 ) — 1 — Asset-backed securities 827 — 10 2 (342 ) — — — — 497 7 Other debt securities — — — — — — — — — — — Non-marketable equity securities 681 — 24 30 — 15 — — (16 ) 734 22 Total investments $ 2,437 $ — $ 17 $ 35 $ (353 ) $ 104 $ — $ (136 ) $ (16 ) $ 2,088 $ (2 ) Loans $ 550 $ — $ 19 $ — $ (1 ) $ 4 $ — $ (16 ) $ (2 ) $ 554 $ 26 Mortgage servicing rights 558 — 46 — — — 17 (17 ) (17 ) 587 46 Other financial assets measured on a recurring basis 16 — 8 — — 4 12 — (27 ) 13 18 Liabilities Interest-bearing deposits $ 286 $ — $ 26 $ 12 $ — $ — $ 20 $ — $ — $ 292 $ 29 Federal funds purchased and securities loaned or sold under agreements to repurchase 726 14 — — — — 147 — (2 ) 857 14 Trading account liabilities Securities sold, not yet purchased 22 (105 ) — 3 (19 ) — — 3 (66 ) 48 (7 ) Other trading liabilities 5 5 — — — — — — — — (5 ) Short-term borrowings 18 7 — 45 — — 25 — — 81 (2 ) Long-term debt 13,082 (236 ) — 940 (764 ) 36 3 (44 ) (5 ) 13,484 254 Other financial liabilities measured on a recurring basis 8 — — — (5 ) — 2 — (2 ) 3 (1 ) (1) Changes in fair value for available-for-sale debt securities 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 debt securities), attributable to the change in fair value relating to assets and liabilities classified as Level 3 that are still held at March 31, 2018 . (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, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2017 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ 1,496 $ (56 ) $ — $ — $ (252 ) $ — $ — $ — $ (1 ) $ 1,187 $ 4 Trading non-derivative assets Trading mortgage-backed securities U.S. government-sponsored agency guaranteed 176 5 — 50 (17 ) 161 — (104 ) — 271 — Residential 399 15 — 17 (29 ) 50 — (84 ) — 368 10 Commercial 206 (8 ) — 17 (13 ) 190 — (126 ) — 266 (4 ) Total trading mortgage-backed securities $ 781 $ 12 $ — $ 84 $ (59 ) $ 401 $ — $ (314 ) $ — $ 905 $ 6 U.S. Treasury and federal agency securities $ 1 $ — $ — $ — $ — $ — $ — $ — $ — $ 1 $ — State and municipal 296 2 — 2 (47 ) 81 — (64 ) — 270 2 Foreign government 40 4 — 78 (13 ) 44 — (27 ) — 126 6 Corporate 324 91 — 27 (52 ) 118 — (197 ) (15 ) 296 12 Equity securities 127 15 — 2 (12 ) 7 — (29 ) — 110 2 Asset-backed securities 1,868 160 — 20 (16 ) 391 — (482 ) — 1,941 81 Other trading assets 2,814 (7 ) — 210 (531 ) 287 1 (875 ) (11 ) 1,888 (55 ) Total trading non-derivative assets $ 6,251 $ 277 $ — $ 423 $ (730 ) $ 1,329 $ 1 $ (1,988 ) $ (26 ) $ 5,537 $ 54 Trading derivatives, net (4) Interest rate contracts $ (663 ) $ (37 ) $ — $ (38 ) $ 19 $ 6 $ — $ (113 ) $ 53 $ (773 ) $ (23 ) Foreign exchange contracts 413 (390 ) — 55 (20 ) 34 — (32 ) (12 ) 48 (341 ) Equity contracts (1,557 ) (2 ) — — (16 ) 85 — (24 ) (10 ) (1,524 ) 202 Commodity contracts (1,945 ) (175 ) — 46 (2 ) — — — 2 (2,074 ) (170 ) Credit derivatives (1,001 ) (92 ) — (24 ) (8 ) — — — 2 (1,123 ) (108 ) Total trading derivatives, net (4) $ (4,753 ) $ (696 ) $ — $ 39 $ (27 ) $ 125 $ — $ (169 ) $ 35 $ (5,446 ) $ (440 ) Investments Mortgage-backed securities U.S. government-sponsored agency guaranteed $ 101 $ — $ 2 $ 1 $ (49 ) $ — $ — $ — $ — $ 55 $ 2 Residential 50 — 2 — (47 ) — — (5 ) — — — Commercial — — — — — 8 — (8 ) — — — Total investment mortgage-backed securities $ 151 $ — $ 4 $ 1 $ (96 ) $ 8 $ — $ (13 ) $ — $ 55 $ 2 U.S. Treasury and federal agency securities $ 2 $ — $ — $ — $ — $ — $ — $ (1 ) $ — $ 1 $ — State and municipal 1,211 — 12 37 (30 ) 54 — (51 ) — 1,233 6 Foreign government 186 — 1 2 (18 ) 142 — (78 ) — 235 1 Corporate 311 — 2 59 (4 ) 91 — (120 ) — 339 2 Equity securities 9 — — — — — — — — 9 — Asset-backed securities 660 — 9 17 — 26 — — — 712 3 Other debt securities — — — — — 11 — (11 ) — — — Non-marketable equity securities 1,331 — (94 ) — — 8 — (73 ) (90 ) 1,082 (2 ) Total investments $ 3,861 $ — $ (66 ) $ 116 $ (148 ) $ 340 $ — $ (347 ) $ (90 ) $ 3,666 $ 12 Net realized/unrealized Transfers Unrealized (3) In millions of dollars Dec. 31, 2016 Principal Other (1)(2) into out of Purchases Issuances Sales Settlements Mar. 31, 2017 Loans $ 568 $ — $ (4 ) $ 65 $ (16 ) $ 12 $ — $ (43 ) $ (2 ) $ 580 $ 74 Mortgage servicing rights 1,564 — 67 — — — 35 (1,046 ) (53 ) 567 83 Other financial assets measured on a recurring basis 34 — (189 ) 3 (1 ) — 29 204 (53 ) 27 (191 ) Liabilities Interest-bearing deposits $ 293 $ — $ 11 $ 20 $ — $ — $ — $ — $ — $ 302 $ 25 Federal funds purchased and securities loaned or sold under agreements to repurchase 849 6 — — — — — — (34 ) 809 6 Trading account liabilities Securities sold, not yet purchased 1,177 54 — 11 (14 ) — — 101 (70 ) 1,151 2 Other trading liabilities 1 — — — — — — — (1 ) — — Short-term borrowings 42 (9 ) — — — — 11 — (2 ) 60 22 Long-term debt 9,744 17 — 200 (409 ) — 929 — (271 ) 10,176 116 Other financial liabilities measured on a recurring basis 8 — (2 ) — — (1 ) 1 — (6 ) 4 (2 ) (1) Changes in fair value for available-for-sale debt securities 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 debt securities), 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.
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. As of March 31, 2018 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 1.74 % 2.41 % 2.40 % Mortgage-backed securities $ 220 Yield analysis Yield 2.18 % 8.14 % 3.89 % 147 Price-based Price $ 6.00 $ 102.26 $ 74.57 State and municipal, foreign government, corporate and other debt securities $ 943 Model-based Price $ 3.47 $ 110.39 $ 88.85 883 Price-based Credit spread 35bps 500bps 252bps Yield 2.00 % 14.88 % 6.54 % Equity securities (5) $ 206 Price-based Price $ 0.01 $ 18,320.07 $ 654.81 30 Model-based Asset-backed securities $ 1,983 Price-based Price $ 2.33 $ 100.76 $ 69.28 Non-marketable equities $ 431 Comparables analysis EBITDA multiples 7.00 x 10.90 x 8.56 x 265 Price-based Discount to price — % 100.00 % 13.24 % Price to book ratio 5.00 x 100.00 x 68.86 x Derivatives—gross (6) Interest rate contracts (gross) $ 4,440 Model-based Mean reversion 1.00 % 20.00 % 10.50 % Inflation volatility 0.25 % 2.70 % 0.82 % IR Normal Volatility 0.12 % 78.91 % 50.71 % Foreign exchange contracts (gross) $ 877 Model-based FX volatility 6.41 % 20.25 % 12.75 % IR basis (0.74 )% 2.01 % (0.01 )% Credit spread 23bps 7,823bps 166bps IR-IR correlation 40.00 % 40.00 % 40.00 % IR-FX correlation 40.00 % 60.00 % 50.00 % Equity contracts (gross) $ 2,835 Model-based Equity volatility 1.16 % 70.22 % 25.72 % Forward price 63.73 % 153.71 % 101.21 % Commodity and other contracts (gross) $ 2,940 Model-based Forward price 35.75 % 478.26 % 114.73 % Commodity volatility 9.14 % 41.03 % 22.87 % Commodity correlation (51.36 )% 91.85 % 19.83 % Credit derivatives (gross) $ 1,833 Model-based Credit correlation 25.00 % 85.00 % 43.30 % 774 Price-based Upfront points 3.84 % 97.33 % 59.81 % Credit spread 6bps 1,200bps 115bps Price $ 7.54 $ 100.00 $ 64.58 As of March 31, 2018 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) $ 19 Model-based Recovery rate 25.00 % 46.00 % 38.21 % Credit spread 21bps 129bps 77bps Redemption rate 5.14 % 99.50 % 72.69 % Upfront points 54.00 % 54.00 % 54.00 % Loans and leases $ 520 Model-based Credit spread 17bps 500bps 92bps Yield 2.70 % 4.06 % 3.71 % Mortgage servicing rights $ 500 Cash flow Yield 4.26 % 12.60 % 8.36 % 87 Model-based WAL 4.08 years 7.63 years 6.53 years Liabilities Interest-bearing deposits $ 292 Model-based Mean reversion — % 20.00 % 7.85 % Federal funds purchased and securities loaned or sold under agreement to repurchase $ 857 Model-based Interest rate 1.74 % 2.41 % 2.40 % Trading account liabilities Securities sold, not yet purchased $ 31 Model-based Equity volatility 3.00 % 70.22 % 31.84 % 18 Price-based Equity-equity correlation (99.00 )% 100.00 % 59.65 % Equity-FX correlation (80.37 )% 56.00 % (29.86 )% Forward Price 63.73 % 153.71 % 100.14 % Price $ — $ 100.00 $ 24.84 Short-term borrowings and long-term debt $ 13,559 Model-based Equity volatility 3.00 % 70.22 % 18.48 % Forward price 63.73 % 167.94 % 103.12 % 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 35bps 500bps 249bps 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) As of December 31, 2017 Fair value (1) (in millions) Methodology Input Low (2)(3) High (2)(3) Weighted average (4) 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 11bps 717bps 173bps 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 1,636bps 173bps Price $ 1.00 $ 100.24 $ 57.63 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 38bps 275bps 127bps Upfront points 61.00 % 61.00 % 61.00 % Loans $ 391 Model-based Equity Volatility 3.00 % 68.93 % 22.52 % 148 Price-based Credit spread 134bps 500bps 173bps 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 % (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 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 March 31, 2018 Loans HFS (1) $ 3,481 $ 1,430 $ 2,051 Other real estate owned 70 41 29 Loans (2) 545 179 366 Non-marketable equity investments measured using the measurement alternative $ 188 $ 133 $ 55 Total assets at fair value on a nonrecurring basis $ 4,284 $ 1,783 $ 2,501 In millions of dollars Fair value Level 2 Level 3 December 31, 2017 Loans HFS (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 (1) Net of fair value amounts on the unfunded portion of loans HFS recognized as 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 less costs to sell, primarily real estate.
Valuation techniques and inputs for Level 3 nonrecurring fair value measurements	The following table presents 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 March 31, 2018 Fair value (1) (in millions) Methodology Input Low (2) High Weighted average (3) Loans held-for-sale $ 2,015 Price-based Price $ 0.88 $ 100.00 $ 95.86 Other real estate owned $ 26 Price-based Appraised value (4) $ 20,290 $ 8,423,945 $ 4,273,507 Price $ — $ 53.47 $ 50.08 Loans (5) $ 125 Recovery analysis Recovery rate 9.00 % 91.53 % 31.51 % 106 Cash flow Price $ 2.80 $ 100.00 $ 81.82 102 Price-based Appraised value $ 35,490,000 $ 465,594,643 $ 74,229,249 Non-marketable equity investments measured using the measurement alternative $ 55 Price-based Discount to price 25 % 25 % 25 % 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 (6) 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 (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) Represents impaired loans held for investment whose carrying amounts are based on the fair value of the underlying collateral, primarily real estate secured loans. (6) Includes estimated costs to sell.
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: Three Months Ended March 31, In millions of dollars 2018 Loans HFS $ (35 ) Other real estate owned (3 ) Loans (1) (32 ) Non-marketable equity investments measured using the measurement alternative 120 Total nonrecurring fair value gains (losses) $ 50 (1) Represents loans held for investment whose carrying amount is based on the fair value of the underlying collateral, primarily real estate. Three Months Ended March 31, In millions of dollars 2017 Loans HFS $ (22 ) Other real estate owned (2 ) Loans (1) (28 ) Total nonrecurring fair value gains (losses) $ (52 ) (1) Represents loans held for investment whose carrying amount is based on the fair value of the underlying collateral, primarily real estate.
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. March 31, 2018 Estimated fair value Carrying value Estimated fair value In billions of dollars Level 1 Level 2 Level 3 Assets Investments $ 58.5 $ 58.1 $ 1.1 $ 54.8 $ 2.2 Federal funds sold and securities borrowed or purchased under agreements to resell 96.4 96.4 — 91.4 5.0 Loans (1)(2) 654.4 653.4 — 4.3 649.1 Other financial assets (2)(3) 274.2 274.6 188.3 14.4 71.9 Liabilities Deposits $ 999.5 $ 997.7 $ — $ 850.2 $ 147.5 Federal funds purchased and securities loaned or sold under agreements to repurchase 125.9 125.9 — 125.8 0.1 Long-term debt (4) 204.4 209.7 — 189.5 20.2 Other financial liabilities (5) 116.5 116.5 — 15.3 101.2 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) 115.9 115.9 — 15.5 100.4 (1) The carrying value of loans is net of the Allowance for loan losses of $12.4 billion for March 31, 2018 and $12.4 billion for December 31, 2017 . In addition, the carrying values exclude $1.7 billion and $1.7 billion of lease finance receivables at March 31, 2018 and December 31, 2017 , 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 recoverables 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, separate and variable accounts, 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)	3 Months Ended
	Mar. 31, 2018
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) Three Months Ended March 31, In millions of dollars 2018 2017 Assets Federal funds sold and securities borrowed or purchased under agreements to resell $ (16 ) $ (33 ) Trading account assets (16 ) 430 Investments — — Loans Certain corporate loans (123 ) 24 Certain consumer loans — — Total loans $ (123 ) $ 24 Other assets MSRs $ 46 $ 67 Certain mortgage loans held-for-sale (1) 2 37 Total other assets $ 48 $ 104 Total assets $ (107 ) $ 525 Liabilities Interest-bearing deposits $ 28 $ (14 ) Federal funds purchased and securities loaned or sold under agreements to repurchase (111 ) 613 Trading account liabilities (6 ) 26 Short-term borrowings 177 19 Long-term debt 618 (332 ) Total liabilities $ 706 $ 312 (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: March 31, 2018 December 31, 2017 In millions of dollars Trading assets Loans Trading assets Loans Carrying amount reported on the Consolidated Balance Sheet $ 9,194 $ 4,536 $ 8,851 $ 4,374 Aggregate unpaid principal balance in excess of (less than) fair value 475 870 623 682 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
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 March 31, December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 333 $ 426 Aggregate fair value in excess of (less than) unpaid principal balance 7 14 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 March 31, 2018 December 31, 2017 Interest rate linked $ 15.9 $ 13.9 Foreign exchange linked 0.3 0.3 Equity linked 12.8 13.0 Commodity linked 0.4 0.2 Credit linked 1.9 1.9 Total $ 31.3 $ 29.3
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 March 31, 2018 December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 33,571 $ 31,392 Aggregate unpaid principal balance in excess of (less than) fair value (93 ) (579 )
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 March 31, 2018 December 31, 2017 Carrying amount reported on the Consolidated Balance Sheet $ 4,467 $ 4,627 Aggregate unpaid principal balance in excess of fair value 463 74

GUARANTEES AND COMMITMENTS (Tab

GUARANTEES AND COMMITMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
Pledged Assets, Collateral, Guarantees and Commitments [Abstract]
Schedule of guarantor obligations	The following tables present information about Citi’s guarantees at March 31, 2018 and December 31, 2017 : Maximum potential amount of future payments In billions of dollars at March 31, 2018 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 $ 30.4 $ 63.0 $ 93.4 $ 131 Performance guarantees 7.5 4.1 11.6 31 Derivative instruments considered to be guarantees 17.0 85.6 102.6 432 Loans sold with recourse — 0.2 0.2 8 Securities lending indemnifications (1) 126.9 — 126.9 — Credit card merchant processing (1)(2) 82.5 — 82.5 — Credit card arrangements with partners 0.2 1.1 1.3 162 Custody indemnifications and other — 38.5 38.5 82 Total $ 264.5 $ 192.5 $ 457.0 $ 846 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 (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 March 31, 2018 and December 31, 2017 , this maximum potential exposure was estimated to be $83 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. 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 March 31, 2018 Investment grade Non-investment grade Not rated Total Financial standby letters of credit $ 68.1 $ 10.3 $ 15.0 $ 93.4 Performance guarantees 8.2 2.3 1.1 11.6 Derivative instruments deemed to be guarantees — — 102.6 102.6 Loans sold with recourse — — 0.2 0.2 Securities lending indemnifications — — 126.9 126.9 Credit card merchant processing — — 82.5 82.5 Credit card arrangements with partners — — 1.3 1.3 Custody indemnifications and other 25.8 12.7 — 38.5 Total $ 102.1 $ 25.3 $ 329.6 $ 457.0 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
Schedule of credit commitments	The table below summarizes Citigroup’s credit commitments: In millions of dollars U.S. Outside of U.S. March 31, December 31, 2017 Commercial and similar letters of credit $ 821 $ 4,675 $ 5,496 $ 5,000 One- to four-family residential mortgages 1,385 1,610 2,995 2,674 Revolving open-end loans secured by one- to four-family residential properties 10,703 1,510 12,213 12,323 Commercial real estate, construction and land development 8,955 2,146 11,101 11,151 Credit card lines 583,477 102,158 685,635 678,300 Commercial and other consumer loan commitments 188,945 111,770 300,715 272,655 Other commitments and contingencies 2,145 716 2,861 3,071 Total $ 796,431 $ 224,585 $ 1,021,016 $ 985,174

CONDENSED CONSOLIDATING FINAN54

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Statements of Income and Comprehensive Income	Condensed Consolidating Statements of Income and Comprehensive Income Three Months Ended March 31, 2018 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 5,585 $ — $ — $ (5,585 ) $ — Interest revenue 52 1,655 14,625 — 16,332 Interest revenue—intercompany 1,130 383 (1,513 ) — — Interest expense 910 1,013 3,237 — 5,160 Interest expense—intercompany 587 772 (1,359 ) — — Net interest revenue $ (315 ) $ 253 $ 11,234 $ — $ 11,172 Commissions and fees $ — $ 1,252 $ 1,778 $ — $ 3,030 Commissions and fees—intercompany — — — — — Principal transactions 1,031 921 1,337 — 3,289 Principal transactions—intercompany (386 ) 192 194 — — Other income (928 ) 153 2,156 — 1,381 Other income—intercompany 55 50 (105 ) — — Total non-interest revenues $ (228 ) $ 2,568 $ 5,360 $ — $ 7,700 Total revenues, net of interest expense $ 5,042 $ 2,821 $ 16,594 $ (5,585 ) $ 18,872 Provisions for credit losses and for benefits and claims $ — $ — $ 1,857 $ — $ 1,857 Operating expenses Compensation and benefits $ 134 $ 1,265 $ 4,408 $ — $ 5,807 Compensation and benefits—intercompany 34 — (34 ) — — Other operating 44 548 4,526 — 5,118 Other operating—intercompany 12 578 (590 ) — — Total operating expenses $ 224 $ 2,391 $ 8,310 $ — $ 10,925 Equity in undistributed income of subsidiaries $ (445 ) $ — $ — $ 445 $ — Income (loss) from continuing operations before income taxes $ 4,373 $ 430 $ 6,427 $ (5,140 ) $ 6,090 Provision (benefit) for income taxes (247 ) 65 1,623 — 1,441 Income (loss) from continuing operations $ 4,620 $ 365 $ 4,804 $ (5,140 ) $ 4,649 Loss from discontinued operations, net of taxes — — (7 ) — (7 ) Net income before attribution of noncontrolling interests $ 4,620 $ 365 $ 4,797 $ (5,140 ) $ 4,642 Noncontrolling interests — — 22 — 22 Net income (loss) $ 4,620 $ 365 $ 4,775 $ (5,140 ) $ 4,620 Comprehensive income Add: Other comprehensive income (loss) $ 52 $ 82 $ (3,156 ) $ 3,074 $ 52 Total Citigroup comprehensive income (loss) $ 4,672 $ 447 $ 1,619 $ (2,066 ) $ 4,672 Add: Other comprehensive income attributable to noncontrolling interests $ — $ — $ 14 $ — $ 14 Add: Net income attributable to noncontrolling interests — — 22 — 22 Total comprehensive income (loss) $ 4,672 $ 447 $ 1,655 $ (2,066 ) $ 4,708 Condensed Consolidating Statements of Income and Comprehensive Income Three Months Ended March 31, 2017 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Revenues Dividends from subsidiaries $ 3,750 $ — $ — $ (3,750 ) $ — Interest revenue 1 1,027 13,493 — 14,521 Interest revenue—intercompany 793 157 (950 ) — — Interest expense 1,218 393 1,955 — 3,566 Interest expense—intercompany 90 428 (518 ) — — Net interest revenue $ (514 ) $ 363 $ 11,106 $ — $ 10,955 Commissions and fees $ — $ 1,323 $ 1,732 $ — $ 3,055 Commissions and fees—intercompany — 2 (2 ) — — Principal transactions (163 ) 1,658 1,599 — 3,094 Principal transactions—intercompany 204 (695 ) 491 — — Other income (39 ) 65 1,236 — 1,262 Other income—intercompany (123 ) 110 13 — — Total non-interest revenues $ (121 ) $ 2,463 $ 5,069 $ — $ — $ 7,411 Total revenues, net of interest expense $ 3,115 $ 2,826 $ 16,175 $ (3,750 ) $ 18,366 Provisions for credit losses and for benefits and claims $ — $ — $ 1,662 $ — $ 1,662 Operating expenses Compensation and benefits $ (14 ) $ 1,262 $ 4,286 $ — $ 5,534 Compensation and benefits—intercompany 31 — (31 ) — — Other operating 28 509 4,652 — 5,189 Other operating—intercompany (59 ) 540 (481 ) — — Total operating expenses $ (14 ) $ 2,311 $ 8,426 $ — $ 10,723 Equity in undistributed income of subsidiaries $ 587 $ — $ — $ (587 ) $ — Income (loss) from continuing operations before income taxes $ 3,716 $ 515 $ 6,087 $ (4,337 ) $ 5,981 Provision (benefit) for income taxes (374 ) 215 2,022 — 1,863 Income (loss) from continuing operations $ 4,090 $ 300 $ 4,065 $ (4,337 ) $ 4,118 Loss from discontinued operations, net of taxes — — (18 ) — (18 ) Net income (loss) before attribution of noncontrolling interests $ 4,090 $ 300 $ 4,047 $ (4,337 ) $ 4,100 Noncontrolling interests — — 10 — 10 Net income (loss) $ 4,090 $ 300 $ 4,037 $ (4,337 ) $ 4,090 Comprehensive income Add: Other comprehensive income (loss) $ 1,464 $ (20 ) $ (3,721 ) $ 3,741 $ 1,464 Total Citigroup comprehensive income (loss) $ 5,554 $ 280 $ 316 $ (596 ) $ 5,554 Add: Other comprehensive income attributable to noncontrolling interests $ — $ — — $ 31 $ — $ 31 Add: Net income attributable to noncontrolling interests — — — 10 — 10 Total comprehensive income (loss) $ 5,554 $ 280 $ 357 $ (596 ) $ 5,595
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet March 31, 2018 In millions of dollars Citigroup parent company CGMHI Other Citigroup subsidiaries and eliminations Consolidating adjustments Citigroup consolidated Assets Cash and due from banks $ 2 $ 423 $ 21,425 $ — $ 21,850 Cash and due from banks—intercompany 14 5,225 (5,239 ) — — Deposits with banks — 3,005 177,849 — 180,854 Deposits with banks - intercompany 3,000 5,492 (8,492 ) — — Federal funds sold and resale agreements — 206,659 51,228 — 257,887 Federal funds sold and resale agreements—intercompany — 14,284 (14,284 ) — — Trading account assets 298 150,249 118,261 — 268,808 Trading account assets—intercompany 483 2,079 (2,562 ) — — Investments 7,755 249 343,967 — 351,971 Loans, net of unearned income — 875 672,063 — 672,938 Loans, net of unearned income—intercompany — — — — — Allowance for loan losses — — (12,354 ) — (12,354 ) Total loans, net $ — $ 875 $ 659,709 $ — $ 660,584 Advances to subsidiaries $ 141,977 $ — $ (141,977 ) $ — $ — Investments in subsidiaries 209,808 — — (209,808 ) — Other assets (1) 10,784 66,723 102,643 — 180,150 Other assets—intercompany 3,667 47,051 (50,718 ) — — Total assets $ 377,788 $ 502,314 $ 1,251,810 $ (209,808 ) $ 1,922,104 Liabilities and equity Deposits $ — $ — $ 1,001,219 $ — $ 1,001,219 Deposits—intercompany — — — — — Federal funds purchased and securities loaned or sold — 144,400 27,359 — 171,759 Federal funds purchased and securities loaned or sold—intercompany — 20,444 (20,444 ) — — Trading account liabilities 2 98,287 45,672 — 143,961 Trading account liabilities—intercompany 241 1,904 (2,145 ) — — Short-term borrowings 235 3,159 32,700 — 36,094 Short-term borrowings—intercompany — 41,097 (41,097 ) — — Long-term debt 153,074 19,907 64,957 — 237,938 Long-term debt—intercompany — 60,351 (60,351 ) — — Advances from subsidiaries 19,151 — (19,151 ) — — Other liabilities 2,832 69,516 55,919 — 128,267 Other liabilities—intercompany 338 10,336 (10,674 ) — — Stockholders’ equity 201,915 32,913 177,846 (209,808 ) 202,866 Total liabilities and equity $ 377,788 $ 502,314 $ 1,251,810 $ (209,808 ) $ 1,922,104 (1) Other assets for Citigroup parent company at March 31, 2018 included $ 24.8 billion of placements to Citibank and its branches, of which $ 20.3 billion had a remaining term of less than 30 days. 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 ) — — Deposits with banks — 3,348 153,393 — 156,741 Deposits with banks - intercompany 11,000 5,219 (16,219 ) — — 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 — 139,462 113,328 — 252,790 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 58,299 100,569 — 169,712 Other assets—intercompany 3,428 43,613 (47,041 ) — — 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 44,369 — 125,170 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 53,577 — 118,363 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 Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows Three Months Ended March 31, 2018 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 $ 5,268 $ 7,046 $ (5,358 ) $ — $ 6,956 Cash flows from investing activities of continuing operations Purchases of investments $ (7,955 ) $ — $ (33,075 ) $ — $ (41,030 ) Proceeds from sales of investments — — 20,688 — 20,688 Proceeds from maturities of investments — — 21,509 — 21,509 Change in loans — — (8,717 ) — (8,717 ) Proceeds from sales and securitizations of loans — — 1,654 — 1,654 Change in federal funds sold and resales — (22,167 ) (3,242 ) — (25,409 ) Changes in investments and advances—intercompany (1,463 ) (3,603 ) 5,066 — — Other investing activities (729 ) (9 ) (81 ) — (819 ) Net cash provided by (used in) investing activities of continuing operations $ (10,147 ) $ (25,779 ) $ 3,802 $ — $ (32,124 ) Cash flows from financing activities of continuing operations Dividends paid $ (1,095 ) $ — $ — $ — $ (1,095 ) Redemption of preferred stock (97 ) — — — (97 ) Treasury stock acquired (2,378 ) — — — (2,378 ) Proceeds from issuance of long-term debt, net 699 2,004 184 — 2,887 Proceeds (repayments) from issuance of long-term debt—intercompany, net — (412 ) 412 — — Change in deposits — — 41,397 — 41,397 Change in federal funds purchased and repos — 11,359 4,123 — 15,482 Change in short-term borrowings — (409 ) (7,949 ) — (8,358 ) Net change in short-term borrowings and other advances—intercompany 14 8,226 (8,240 ) — — Capital contributions from (to) parent — (585 ) 585 — — Other financing activities (261 ) — (214 ) — (475 ) Net cash provided by (used in) financing activities of continuing operations $ (3,118 ) $ 20,183 $ 30,298 $ — $ 47,363 Effect of exchange rate changes on cash and due from banks $ — $ — $ (7 ) $ — $ (7 ) Change in cash, due from banks and deposits with banks $ (7,997 ) $ 1,450 $ 28,735 $ — $ 22,188 Cash, due from banks and deposits with banks at beginning of period 11,013 12,695 156,808 — 180,516 Cash, due from banks and deposits with banks at end of period $ 3,016 $ 14,145 $ 185,543 $ — $ 202,704 Cash and due from banks $ 16 $ 5,648 $ 16,186 $ — $ 21,850 Deposits with banks 3,000 8,497 169,357 — 180,854 Cash, due from banks and deposits with banks at end of period $ 3,016 $ 14,145 $ 185,543 $ — $ 202,704 Supplemental disclosure of cash flow information for continuing operations Cash paid (received) during the year for income taxes $ (266 ) $ 29 $ 975 $ — $ 738 Cash paid during the year for interest 883 1,627 2,076 — 4,586 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 900 $ — $ 900 Transfers to OREO and other repossessed assets — — 26 — 26 Condensed Consolidating Statement of Cash Flows Three Months Ended March 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 $ (652 ) $ (3,404 ) $ 1,004 $ — $ (3,052 ) Cash flows from investing activities of continuing operations Purchases of investments $ — $ — $ (41,584 ) $ — $ (41,584 ) Proceeds from sales of investments 116 — 29,340 — 29,456 Proceeds from maturities of investments — — 24,006 — 24,006 Change in loans — — (7,953 ) — (7,953 ) Proceeds from sales and securitizations of loans — — 3,191 — 3,191 Proceeds from significant disposals — — 2,732 — 2,732 Change in federal funds sold and resales — (2,623 ) (3,493 ) — (6,116 ) Changes in investments and advances—intercompany (569 ) (5,007 ) 5,576 — — Other investing activities — — (607 ) — (607 ) Net cash provided by (used in) investing activities of continuing operations $ (453 ) $ (7,630 ) $ 11,208 $ — $ 3,125 Cash flows from financing activities of continuing operations Dividends paid $ (744 ) $ — $ — $ — $ (744 ) Treasury stock acquired (1,858 ) — — — (1,858 ) Proceeds (repayments) from issuance of long-term debt, net (1,454 ) 5,175 (4,003 ) — (282 ) Proceeds (repayments) from issuance of long-term debt—intercompany, net — (12,506 ) 12,506 — — Change in deposits — — 20,584 — 20,584 Change in federal funds purchased and repos — 1,266 5,143 — 6,409 Change in short-term borrowings — 605 (5,179 ) — (4,574 ) Net change in short-term borrowings and other advances—intercompany (14,901 ) 8,938 5,963 — — Other financing activities (397 ) — — — (397 ) Net cash provided by (used in) financing activities of continuing operations $ (19,354 ) $ 3,478 $ 35,014 $ — $ 19,138 Effect of exchange rate changes on cash and due from banks $ — $ — $ 340 $ — $ 340 Change in cash and due from banks $ (20,459 ) $ (7,556 ) $ 47,566 $ — $ 19,551 Cash and due from banks at beginning of period 20,811 25,118 114,565 — 160,494 Cash and due from banks at end of period $ 352 $ 17,562 $ 162,131 $ — $ 180,045 Cash and due from banks $ 352 $ 3,647 $ 18,273 $ — $ 22,272 Deposits with banks — 13,915 143,858 — 157,773 Cash, due from banks and deposits with banks at end of period $ 352 $ 17,562 $ 162,131 $ — $ 180,045 Supplemental disclosure of cash flow information for continuing operations Cash paid (refund) during the year for income taxes $ (139 ) $ 64 $ 988 $ — $ 913 Cash paid during the year for interest 1,153 822 1,275 — 3,250 Non-cash investing activities Transfers to loans HFS from loans $ — $ — $ 2,800 $ — $ 2,800 Transfers to OREO and other repossessed assets — — 30 — 30

BASIS OF PRESENTATION AND ACC55

BASIS OF PRESENTATION AND ACCOUNTING CHANGES - Accounting Changes (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jan. 01, 2018	Jan. 01, 2017	Dec. 31, 2016	Jan. 01, 2016
New Accounting Pronouncements or Change in Accounting Principle
Revenue		$ 18,872	$ 18,366
Operating expenses		10,925	10,723
Decrease in retained earnings		(141,863)		$ (138,425)
Available for sale debt securities		291,523		290,725
Held-to-maturity Securities		52,492		53,320
Reclassification from AOCI		34,619		34,668
Net cash used in investing activities of continuing operations		(32,124)	3,125
Net reduction to total stockholders' equity		(202,866)	(228,997)	(201,672)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle
Increase in DTAs					$ 300
Decrease in retained earnings					80
Decrease in prepaid taxes					380
Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle
Available for sale debt securities					4,000
Held-to-maturity Securities					(4,000)
Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle
Decrease in retained earnings								$ (15)
Reclassification from AOCI								$ 15
Accounting Standards Update 2016-01 And 2018-03
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment after tax					$ 3
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle
Net cash used in investing activities of continuing operations			20,300
Early adoption | Accounting Standards Update 2017-08
New Accounting Pronouncements or Change in Accounting Principle
Net reduction to total stockholders' equity						$ 156
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment after tax	[1]			(84)			$ (660)
Net reduction to total stockholders' equity		(141,863)	(149,071)	(138,425)			(146,477)
Retained earnings | Early adoption | Accounting Standards Update 2017-08
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment after tax						(660)
Accumulated other comprehensive income (loss)
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment after tax	[1]			(3)			504
Net reduction to total stockholders' equity		34,619	30,413	34,668			$ 32,381
Accumulated other comprehensive income (loss) | Early adoption | Accounting Standards Update 2017-08
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment after tax						$ 504
Cash and due from banks
New Accounting Pronouncements or Change in Accounting Principle
Restricted cash		84		39
Deposits with banks
New Accounting Pronouncements or Change in Accounting Principle
Restricted cash		29,000		36,700
Restatement Adjustment | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle
Revenue		250	250	1,000
Operating expenses		$ 250	$ 250	$ 1,000
[1]	See Note 1 to the Consolidated Financial Statements for additional details.

DISCONTINUED OPERATIONS AND S56

DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS - Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Results of Discontinued Operations
Total revenues, net of interest expense	$ 0	$ 0
Loss from discontinued operations	(7)	(28)
Provision (benefit) for income taxes on discontinued operations	0	(10)
Loss from discontinued operations, net of taxes	$ (7)	$ (18)

BUSINESS SEGMENTS (Details)

BUSINESS SEGMENTS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment reporting information
Revenues, net of interest expense	$ 18,872	$ 18,366
Provision (benefits) for income taxes	1,441	1,863
Income (loss) from continuing operations	4,649	4,118
Identifiable assets	1,922,104		$ 1,842,465
Provisions for credit losses and for benefits and claims	1,857	1,662
Corporate/Other
Segment reporting information
Revenues, net of interest expense	591	1,201
Provision (benefits) for income taxes	(69)	(94)
Income (loss) from continuing operations	(74)	109
Identifiable assets	92,000		78,000
Provisions for credit losses and for benefits and claims	(7)	52
Operating Segments | Citicorp | North America
Segment reporting information
Revenues, net of interest expense	8,400	8,500
Operating Segments | Citicorp | EMEA
Segment reporting information
Revenues, net of interest expense	3,200	2,900
Operating Segments | Citicorp | Latin America
Segment reporting information
Revenues, net of interest expense	2,600	2,300
Operating Segments | Citicorp | Asia
Segment reporting information
Revenues, net of interest expense	4,100	3,500
Operating Segments | Global Consumer Banking
Segment reporting information
Revenues, net of interest expense	8,433	7,846
Provision (benefits) for income taxes	453	582
Income (loss) from continuing operations	1,394	998
Identifiable assets	423,000		428,000
Provisions for credit losses and for benefits and claims	1,900	1,800
Operating Segments | Institutional Clients Group
Segment reporting information
Revenues, net of interest expense	9,848	9,319
Provision (benefits) for income taxes	1,057	1,375
Income (loss) from continuing operations	3,329	3,011
Identifiable assets	1,407,000		$ 1,336,000
Provisions for credit losses and for benefits and claims	$ (41)	$ (205)

INTEREST REVENUE AND EXPENSE (D

INTEREST REVENUE AND EXPENSE (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest revenue
Loan interest, including fees	$ 10,892	$ 10,045
Deposits with banks	432	295
Federal funds sold and securities borrowed or purchased under agreements to resell	1,039	661
Investments, including dividends	2,234	1,960
Trading account assets	1,371	1,266
Other interest	364	294
Total interest revenue	16,332	14,521
Interest expense
Deposits	1,997	1,415
Federal funds purchased and securities loaned or sold under agreements to repurchase	949	493
Trading account liabilities	215	147
Short-term borrowings	471	199
Long-term debt	1,528	1,312
Total interest expense	5,160	3,566
Net interest revenue	11,172	10,955
Provision for loan losses	1,803	1,675
Net interest revenue after provision for loan losses	9,369	9,280
Insurance fees and charges	$ 376	$ 305

COMMISSIONS AND FEES; ADMINIS59

COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Brokerage commissions
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 148	$ 96
Insurance distribution revenue
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 103	$ 120

COMMISSIONS AND FEES; ADMINIS60

COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Commissions and Fees Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commissions and fees
Total commissions and fees	$ 3,030	$ 3,055
Revenue not accounted for under ASC 606, Revenue from Contracts with Customers	(153)	(143)
Investment banking
Commissions and fees
Total commissions and fees	822	904
Brokerage commissions
Commissions and fees
Total commissions and fees	814	676
Interchange fees
Commissions and fees
Total commissions and fees	2,140	1,965
Card-related loan fees
Commissions and fees
Total commissions and fees	175	195
Card rewards and partner payments
Commissions and fees
Total commissions and fees	(2,003)	(1,815)
Deposit-related fees
Commissions and fees
Total commissions and fees	420	397
Transactional service fees
Commissions and fees
Total commissions and fees	213	225
Corporate finance
Commissions and fees
Total commissions and fees	143	185
Insurance distribution revenue
Commissions and fees
Total commissions and fees	153	171
Insurance premiums
Commissions and fees
Total commissions and fees	32	32
Loan servicing
Commissions and fees
Total commissions and fees	72	92
Other
Commissions and fees
Total commissions and fees	49	28
Overdraft fees
Commissions and fees
Total commissions and fees	32	33
Commissions and fees
Commissions and fees
Revenue not accounted for under ASC 606, Revenue from Contracts with Customers	(1,545)	(1,278)
Institutional Clients Group
Commissions and fees
Total commissions and fees	2,164	2,100
Institutional Clients Group | Investment banking
Commissions and fees
Total commissions and fees	822	904
Institutional Clients Group | Brokerage commissions
Commissions and fees
Total commissions and fees	566	482
Institutional Clients Group | Interchange fees
Commissions and fees
Total commissions and fees	260	222
Institutional Clients Group | Card-related loan fees
Commissions and fees
Total commissions and fees	14	12
Institutional Clients Group | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(124)	(103)
Institutional Clients Group | Deposit-related fees
Commissions and fees
Total commissions and fees	236	208
Institutional Clients Group | Transactional service fees
Commissions and fees
Total commissions and fees	190	174
Institutional Clients Group | Corporate finance
Commissions and fees
Total commissions and fees	142	184
Institutional Clients Group | Insurance distribution revenue
Commissions and fees
Total commissions and fees	5	2
Institutional Clients Group | Insurance premiums
Commissions and fees
Total commissions and fees	0	0
Institutional Clients Group | Loan servicing
Commissions and fees
Total commissions and fees	38	35
Institutional Clients Group | Other
Commissions and fees
Total commissions and fees	15	(20)
Global Consumer Banking
Commissions and fees
Total commissions and fees	839	819
Global Consumer Banking | Investment banking
Commissions and fees
Total commissions and fees	0	0
Global Consumer Banking | Brokerage commissions
Commissions and fees
Total commissions and fees	248	193
Global Consumer Banking | Interchange fees
Commissions and fees
Total commissions and fees	1,875	1,703
Global Consumer Banking | Card-related loan fees
Commissions and fees
Total commissions and fees	155	167
Global Consumer Banking | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(1,874)	(1,685)
Global Consumer Banking | Deposit-related fees
Commissions and fees
Total commissions and fees	183	185
Global Consumer Banking | Transactional service fees
Commissions and fees
Total commissions and fees	21	27
Global Consumer Banking | Corporate finance
Commissions and fees
Total commissions and fees	1	1
Global Consumer Banking | Insurance distribution revenue
Commissions and fees
Total commissions and fees	143	144
Global Consumer Banking | Insurance premiums
Commissions and fees
Total commissions and fees	33	33
Global Consumer Banking | Loan servicing
Commissions and fees
Total commissions and fees	22	26
Global Consumer Banking | Other
Commissions and fees
Total commissions and fees	32	25
Corporate/Other
Commissions and fees
Total commissions and fees	27	136
Corporate/Other | Investment banking
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Brokerage commissions
Commissions and fees
Total commissions and fees	0	1
Corporate/Other | Interchange fees
Commissions and fees
Total commissions and fees	5	40
Corporate/Other | Card-related loan fees
Commissions and fees
Total commissions and fees	6	16
Corporate/Other | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(5)	(27)
Corporate/Other | Deposit-related fees
Commissions and fees
Total commissions and fees	1	4
Corporate/Other | Transactional service fees
Commissions and fees
Total commissions and fees	2	24
Corporate/Other | Corporate finance
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Insurance distribution revenue
Commissions and fees
Total commissions and fees	5	25
Corporate/Other | Insurance premiums
Commissions and fees
Total commissions and fees	(1)	(1)
Corporate/Other | Loan servicing
Commissions and fees
Total commissions and fees	12	31
Corporate/Other | Other
Commissions and fees
Total commissions and fees	$ 2	$ 23

COMMISSIONS AND FEES; ADMINIS61

COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Administration and Other Fiduciary Fees (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commissions and fees
Administration and other fiduciary fees	$ 905	$ 834
Revenue not accounted for under ASC 606, Revenue from Contracts with Customers	153	143
Institutional Clients Group
Commissions and fees
Administration and other fiduciary fees	672	624
Global Consumer Banking
Commissions and fees
Administration and other fiduciary fees	208	184
Corporate/Other
Commissions and fees
Administration and other fiduciary fees	25	26
Custody fees
Commissions and fees
Administration and other fiduciary fees	431	406
Custody fees | Institutional Clients Group
Commissions and fees
Administration and other fiduciary fees	368	355
Custody fees | Global Consumer Banking
Commissions and fees
Administration and other fiduciary fees	47	38
Custody fees | Corporate/Other
Commissions and fees
Administration and other fiduciary fees	16	13
Fiduciary fees
Commissions and fees
Administration and other fiduciary fees	321	285
Fiduciary fees | Institutional Clients Group
Commissions and fees
Administration and other fiduciary fees	167	141
Fiduciary fees | Global Consumer Banking
Commissions and fees
Administration and other fiduciary fees	147	133
Fiduciary fees | Corporate/Other
Commissions and fees
Administration and other fiduciary fees	7	11
Guarantee fees
Commissions and fees
Administration and other fiduciary fees	153	143
Guarantee fees | Institutional Clients Group
Commissions and fees
Administration and other fiduciary fees	137	128
Guarantee fees | Global Consumer Banking
Commissions and fees
Administration and other fiduciary fees	14	13
Guarantee fees | Corporate/Other
Commissions and fees
Administration and other fiduciary fees	$ 2	$ 2

PRINCIPAL TRANSACTIONS (Details

PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Principal transactions revenue
Principal transactions revenue	$ 3,289	$ 3,094
Interest rate risks
Principal transactions revenue
Principal transactions revenue	1,622	1,746
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	745	579
Equity risks
Principal transactions revenue
Principal transactions revenue	566	212
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	92	153
Credit products and risks
Principal transactions revenue
Principal transactions revenue	264	404
Citicorp
Principal transactions revenue
Principal transactions revenue	3,289	3,094
Global Consumer Banking | Operating Segments
Principal transactions revenue
Principal transactions revenue	150	155
Institutional Clients Group | Operating Segments
Principal transactions revenue
Principal transactions revenue	2,884	2,731
Corporate/Other
Principal transactions revenue
Principal transactions revenue	$ 255	$ 208

RETIREMENT BENEFITS - Net (Bene

RETIREMENT BENEFITS - Net (Benefit) Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
U.S. | Pension Plans
Service-related expense
Benefits earned during the period	$ 1	$ 1
Interest cost on benefit obligation	123	139
Expected return on plan assets	(213)	(216)
Amortization of unrecognized
Prior service benefit	0	0
Net actuarial loss (gain)	47	44
Settlement loss	0	0
Total net (benefit) expense	(42)	(32)
U.S. | Postretirement Benefit Plans
Service-related expense
Benefits earned during the period	0	0
Interest cost on benefit obligation	6	6
Expected return on plan assets	(3)	(1)
Amortization of unrecognized
Prior service benefit	0	0
Net actuarial loss (gain)	0	(1)
Settlement loss	0	0
Total net (benefit) expense	3	4
Non-U.S. plans | Pension Plans
Service-related expense
Benefits earned during the period	38	36
Interest cost on benefit obligation	75	71
Expected return on plan assets	(78)	(70)
Amortization of unrecognized
Prior service benefit	(1)	(1)
Net actuarial loss (gain)	13	16
Settlement loss	4	0
Total net (benefit) expense	51	52
Non-U.S. plans | Postretirement Benefit Plans
Service-related expense
Benefits earned during the period	2	2
Interest cost on benefit obligation	26	24
Expected return on plan assets	(23)	(21)
Amortization of unrecognized
Prior service benefit	(2)	(2)
Net actuarial loss (gain)	7	8
Settlement loss	0	0
Total net (benefit) expense	$ 10	$ 11

RETIREMENT BENEFITS - Funded St

RETIREMENT BENEFITS - Funded Status and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
U.S. | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	$ 14,040
Benefits earned during the period	1	$ 1
Interest cost on benefit obligation	123	139
Projected benefit obligation at period end—Significant Plans	13,436
Change in plan assets
Plan assets at fair value at beginning of year	12,725
Plan assets at fair value at period end—Significant Plans	12,376
Funded status of the Significant Plans	(1,060)
Net amount recognized at period end
Benefit asset	0
Benefit liability	(1,060)
Net amount recognized on the balance sheet—Significant Plans	(1,060)
Amounts recognized in AOCI at period end
Prior service benefit	0
Net actuarial (loss) gain	(6,644)
Net amount recognized in equity-pretax	(6,644)
Accumulated benefit obligation at period end—Significant Plans	13,430
U.S. | Pension Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year	28
Change in plan assets
Plan assets at fair value at beginning of year	0
U.S. | Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	14,012
Benefits earned during the period	1
Interest cost on benefit obligation	123
Actuarial (gain) loss	(495)
Benefits paid, net of participants’ contributions and government subsidy	(205)
Foreign exchange impact and other	0
Change in plan assets
Plan assets at fair value at beginning of year	12,725
Actual return on plan assets	(157)
Company contributions, net of reimbursements	13
Benefits paid, net of participants’ contributions and government subsidy	(205)
Foreign exchange impact and other	0
U.S. | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	699
Benefits earned during the period	0	0
Interest cost on benefit obligation	6	6
Projected benefit obligation at period end—Significant Plans	667
Change in plan assets
Plan assets at fair value at beginning of year	262
Plan assets at fair value at period end—Significant Plans	241
Funded status of the Significant Plans	(426)
Net amount recognized at period end
Benefit asset	0
Benefit liability	(426)
Net amount recognized on the balance sheet—Significant Plans	(426)
Amounts recognized in AOCI at period end
Prior service benefit	0
Net actuarial (loss) gain	89
Net amount recognized in equity-pretax	89
Accumulated benefit obligation at period end—Significant Plans	667
U.S. | Postretirement Benefit Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year	0
Change in plan assets
Plan assets at fair value at beginning of year	0
U.S. | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	699
Benefits earned during the period	0
Interest cost on benefit obligation	6
Actuarial (gain) loss	(21)
Benefits paid, net of participants’ contributions and government subsidy	(17)
Foreign exchange impact and other	0
Change in plan assets
Plan assets at fair value at beginning of year	262
Actual return on plan assets	0
Company contributions, net of reimbursements	(4)
Benefits paid, net of participants’ contributions and government subsidy	(17)
Foreign exchange impact and other	0
Non-U.S. plans | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	7,433
Benefits earned during the period	38	36
Interest cost on benefit obligation	75	71
Projected benefit obligation at period end—Significant Plans	5,597
Change in plan assets
Plan assets at fair value at beginning of year	7,128
Plan assets at fair value at period end—Significant Plans	5,938
Funded status of the Significant Plans	341
Net amount recognized at period end
Benefit asset	829
Benefit liability	(488)
Net amount recognized on the balance sheet—Significant Plans	341
Amounts recognized in AOCI at period end
Prior service benefit	27
Net actuarial (loss) gain	(882)
Net amount recognized in equity-pretax	(855)
Accumulated benefit obligation at period end—Significant Plans	5,329
Non-U.S. plans | Pension Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,987
Change in plan assets
Plan assets at fair value at beginning of year	1,305
Non-U.S. plans | Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	5,446
Benefits earned during the period	22
Interest cost on benefit obligation	63
Actuarial (gain) loss	(6)
Benefits paid, net of participants’ contributions and government subsidy	(68)
Foreign exchange impact and other	140
Change in plan assets
Plan assets at fair value at beginning of year	5,823
Actual return on plan assets	26
Company contributions, net of reimbursements	11
Benefits paid, net of participants’ contributions and government subsidy	(68)
Foreign exchange impact and other	146
Non-U.S. plans | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,261
Benefits earned during the period	2	2
Interest cost on benefit obligation	26	$ 24
Projected benefit obligation at period end—Significant Plans	1,016
Change in plan assets
Plan assets at fair value at beginning of year	1,119
Plan assets at fair value at period end—Significant Plans	1,167
Funded status of the Significant Plans	151
Net amount recognized at period end
Benefit asset	151
Benefit liability	0
Net amount recognized on the balance sheet—Significant Plans	151
Amounts recognized in AOCI at period end
Prior service benefit	86
Net actuarial (loss) gain	(364)
Net amount recognized in equity-pretax	(278)
Accumulated benefit obligation at period end—Significant Plans	1,016
Non-U.S. plans | Postretirement Benefit Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year	334
Change in plan assets
Plan assets at fair value at beginning of year	10
Non-U.S. plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	927
Benefits earned during the period	2
Interest cost on benefit obligation	23
Actuarial (gain) loss	5
Benefits paid, net of participants’ contributions and government subsidy	(12)
Foreign exchange impact and other	71
Change in plan assets
Plan assets at fair value at beginning of year	1,109
Actual return on plan assets	(14)
Company contributions, net of reimbursements	0
Benefits paid, net of participants’ contributions and government subsidy	(12)
Foreign exchange impact and other	84
Qualified plans | U.S. | Pension Plans
Change in plan assets
Funded status of the Significant Plans	(365)
Qualified plans | U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the Significant Plans	(426)
Qualified plans | Non-U.S. plans | Pension Plans
Change in plan assets
Funded status of the Significant Plans	341
Qualified plans | Non-U.S. plans | Postretirement Benefit Plans
Change in plan assets
Funded status of the Significant Plans	151
Nonqualified plans | U.S. | Pension Plans
Change in plan assets
Funded status of the Significant Plans	(695)
Nonqualified plans | U.S. | Postretirement Benefit Plans
Change in plan assets
Funded status of the Significant Plans	0
Nonqualified plans | Non-U.S. plans | Pension Plans
Change in plan assets
Funded status of the Significant Plans	0
Nonqualified plans | Non-U.S. plans | Postretirement Benefit Plans
Change in plan assets
Funded status of the Significant Plans	$ 0

RETIREMENT BENEFITS - Accumulat

RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	$ 201,672
Actuarial assumptions changes and plan experience	516		$ (760)
Net asset (loss) gain due to difference between actual and expected returns	(451)		625
Net amortization	58		229
Prior service cost	0		(4)
Curtailment/settlement gain	4		17
Foreign exchange impact and other	(36)		(93)
Impact of Tax Reform	0		(1,020)
Change in deferred taxes, net	(3)		(13)
Change, net of tax	88	$ (12)	(1,019)
Balance, end of period	202,866	228,997	201,672
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(6,183)	(5,164)	(5,164)
Balance, end of period	$ (6,095)	$ (5,176)	$ (6,183)

RETIREMENT BENEFITS - Assumptio

RETIREMENT BENEFITS - Assumptions Used (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
U.S. | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	3.50%	3.90%	3.55%
Plan Assumptions - At year end
Discount rate	3.90%		3.50%
Non-U.S. plans | Pension Plans | Weighted Average
Plan Assumptions - During the year
Discount rate	4.75%	5.08%	4.86%
Plan Assumptions - At year end
Discount rate	4.88%		4.75%
Non-U.S. plans | Pension Plans | Minimum
Plan Assumptions - During the year
Discount rate	0.60%	0.60%	0.65%
Plan Assumptions - At year end
Discount rate	0.75%		0.60%
Non-U.S. plans | Pension Plans | Maximum
Plan Assumptions - During the year
Discount rate	10.20%	11.00%	10.35%
Plan Assumptions - At year end
Discount rate	9.90%		10.20%
Non-U.S. plans | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	9.55%	9.65%	8.95%
Plan Assumptions - At year end
Discount rate	9.50%		9.55%
Qualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.60%	4.10%	3.75%
Plan Assumptions - At year end
Discount rate	3.95%		3.60%
Nonqualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.60%	4.00%	3.65%
Plan Assumptions - At year end
Discount rate	3.95%		3.60%

RETIREMENT BENEFITS - Sensitivi

RETIREMENT BENEFITS - Sensitivities of Certain Key Assumptions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
U.S. | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	$ 8
Effect of one-percentage-point decrease in discount rates	(12)
U.S. | Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	0
Effect of one-percentage-point decrease in discount rates	(1)
Non-U.S. plans | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	(3)
Effect of one-percentage-point decrease in discount rates	6
Non-U.S. plans | Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Effect of one-percentage-point increase in discount rates	(2)
Effect of one-percentage-point decrease in discount rates	$ 3

RETIREMENT BENEFITS - Contribut

RETIREMENT BENEFITS - Contributions (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
U.S. | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Company contributions for the three months ended March 31	$ 14	$ 13
Company contributions made or expected to be made during the remainder of the year	45	92
U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Company contributions for the three months ended March 31	0	12
Company contributions made or expected to be made during the remainder of the year	0	164
Non-U.S. plans | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Company contributions for the three months ended March 31	29	34
Company contributions made or expected to be made during the remainder of the year	99	101
Non-U.S. plans | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Company contributions for the three months ended March 31	3	2
Company contributions made or expected to be made during the remainder of the year	$ 8	$ 7

RETIREMENT BENEFITS - Defined C

RETIREMENT BENEFITS - Defined Contribution Plans and Postemployment Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Postemployment Retirement Benefits
Service-related expense
Service-related expense	$ 0	$ 0
Interest cost on benefit obligation	0	0
Amortization of unrecognized
Prior service benefit	(8)	(8)
Net actuarial loss	1	1
Total service-related benefit	(7)	(7)
Non-service-related expense (benefit)	6	8
Total net (benefit) expense	(1)	1
U.S. | Postretirement Benefit Plans
Defined Contribution Plans
Company's contributions for defined contribution plans	104	98
Service-related expense
Service-related expense	0	0
Interest cost on benefit obligation	6	6
Amortization of unrecognized
Prior service benefit	0	0
Total net (benefit) expense	3	4
Non-U.S. plans | Postretirement Benefit Plans
Defined Contribution Plans
Company's contributions for defined contribution plans	76	69
Service-related expense
Service-related expense	2	2
Interest cost on benefit obligation	26	24
Amortization of unrecognized
Prior service benefit	(2)	(2)
Total net (benefit) expense	$ 10	$ 11

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2018
Earnings Per Share [Abstract]
Income from continuing operations before attribution of noncontrolling interests		$ 4,649	$ 4,118
Less: Noncontrolling interests from continuing operations		22	10
Net income from continuing operations (for EPS purposes)		4,627	4,108
Income (loss) from discontinued operations, net of taxes		(7)	(18)
Citigroup’s net income		4,620	4,090
Less: Preferred dividends		272	301
Net income available to common shareholders		4,348	3,789
Less: Dividends and undistributed earnings allocated to employee restricted and deferred shares with nonforfeitable rights to dividends, applicable to basic EPS		51	55
Net income allocated to common shareholders for basic EPS		4,297	3,734
Net income allocated to common shareholders for diluted EPS		$ 4,297	$ 3,734
Weighted-average common shares outstanding applicable to basic EPS (in shares)		2,561.6	2,765.3
Effect of dilutive securities
Options (in shares)		0.1	0.2
Other employee plans (in shares)		1.3	0
Adjusted weighted-average common shares outstanding applicable to diluted EPS (in shares)		2,563	2,765.5
Basic earnings per share
Income from continuing operations (in dollars per share)	[1]	$ 1.68	$ 1.36
Discontinued operations (in dollars per share)	[1]	0	(0.01)
Net income (in dollars per share)	[1]	1.68	1.35
Diluted earnings per share
Income from continuing operations (in dollars per share)	[1]	1.68	1.36
Discontinued operations (in dollars per share)	[1]	0	(0.01)
Net income (in dollars per share)	[1]	1.68	1.35
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)		$ 178.50	$ 178.50
Antidilutive securities excluded from computation of earnings per common share (in shares)		21	21
Warrants issued to U.S. Treasury as part of TARP and loss-sharing agreement | Warrant with the exercise price of $104.67
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities exercise price (in dollars per share)		$ 104.67	$ 104.67
Antidilutive securities excluded from computation of earnings per common share (in shares)		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)		$ 149.41	$ 201.01
Antidilutive securities excluded from computation of earnings per common share (in shares)		0.5	0.9
Forecast
Antidilutive Securities Excluded from Computation of Earnings Per Share
Distribution of preferred dividends				$ 902
Preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share
Treasury stock acquired		$ 97	$ 0
Preferred stock | Series AA
Antidilutive Securities Excluded from Computation of Earnings Per Share
Number of shares redeemed		3.8
Treasury stock acquired		$ 96.8
[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 BOR71

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Federal Funds, Securities, and Deposits (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal funds sold	$ 0	$ 0
Securities purchased under agreements to resell	133,616	130,984
Deposits paid for securities borrowed	124,271	101,494
Total	257,887	232,478
Federal funds purchased	325	326
Securities sold under agreements to repurchase	157,550	142,646
Deposits received for securities loaned	13,884	13,305
Total	171,759	156,277
Securities-for-securities lending transactions	$ 15,600	$ 14,000

FEDERAL FUNDS, SECURITIES BOR72

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 220,159	$ 204,460
Gross amounts offset on the Consolidated Balance Sheet	86,543	73,476
Net amounts of assets included on the Consolidated Balance Sheet	133,616	130,984
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	101,046	103,022
Net amounts	32,570	27,962
Deposits paid for securities borrowed
Gross amounts of recognized assets	124,271	101,494
Net amounts of assets included on the Consolidated Balance Sheet	124,271	101,494
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	24,560	22,271
Net amounts	99,711	79,223
Total
Gross amounts of recognized assets	344,430	305,954
Gross amounts offset on the Consolidated Balance Sheet	86,543	73,476
Net amounts of assets included on the Consolidated Balance Sheet	257,887	232,478
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	125,606	125,293
Net amounts	132,281	107,185
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	244,093	216,122
Gross amounts offset on the Consolidated Balance Sheet	86,543	73,476
Net amounts of liabilities included on the Consolidated Balance Sheet	157,550	142,646
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	79,626	73,716
Net amounts	77,924	68,930
Deposits received for securities loaned
Gross amounts of recognized liabilities	13,884	13,305
Net amounts of liabilities included on the Consolidated Balance Sheet	13,884	13,305
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	4,528	4,079
Net amounts	9,356	9,226
Total
Gross amounts of recognized liabilities	257,977	229,427
Gross amounts offset on the Consolidated Balance Sheet	86,543	73,476
Net amounts of liabilities included on the Consolidated Balance Sheet	171,434	155,951
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	84,154	77,795
Net amounts	$ 87,280	$ 78,156

FEDERAL FUNDS, SECURITIES BOR73

FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Repurchase Agreements (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	$ 244,093	$ 216,122
Deposits received for securities loaned	13,884	13,305
Total	257,977	229,427
U.S. Treasury and federal agency securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	72,336	58,774
Deposits received for securities loaned	0	0
Total	72,336	58,774
State and municipal securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	1,794	1,605
Deposits received for securities loaned	0	0
Total	1,794	1,605
Foreign government
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	99,870	89,576
Deposits received for securities loaned	226	105
Total	100,096	89,681
Corporate bonds
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	23,168	20,194
Deposits received for securities loaned	691	657
Total	23,859	20,851
Equity securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	21,659	20,724
Deposits received for securities loaned	12,310	11,907
Total	33,969	32,631
Mortgage-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	15,930	17,791
Deposits received for securities loaned	0	0
Total	15,930	17,791
Asset-backed securities
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	6,593	5,479
Deposits received for securities loaned	0	0
Total	6,593	5,479
Other
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	2,743	1,979
Deposits received for securities loaned	657	636
Total	3,400	2,615
Open and overnight
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	96,155	82,073
Deposits received for securities loaned	9,369	9,946
Total	105,524	92,019
Up to 30 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	77,118	68,372
Deposits received for securities loaned	397	266
Total	77,515	68,638
31–90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	26,587	33,846
Deposits received for securities loaned	2,197	1,912
Total	28,784	35,758
Greater than 90 days
Assets Sold under Agreements to Repurchase
Securities sold under agreements to repurchase	44,233	31,831
Deposits received for securities loaned	1,921	1,181
Total	$ 46,154	$ 33,012

BROKERAGE RECEIVABLES AND BRO74

BROKERAGE RECEIVABLES AND BROKERAGE PAYABLES (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Brokers and Dealers [Abstract]
Receivables from customers	$ 19,186	$ 19,215
Receivables from brokers, dealers and clearing organizations	27,386	19,169
Total brokerage receivables	46,572	38,384
Payables to customers	43,122	38,741
Payables to brokers, dealers and clearing organizations	26,563	22,601
Total brokerage payables	$ 69,685	$ 61,342

INVESTMENTS - Overview (Details

INVESTMENTS - Overview (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investment Holdings
Investments	$ 351,971		$ 352,290
Interest and dividends on investments
Taxable interest	2,042	$ 1,764
Interest exempt from U.S. federal income tax	130	142
Dividend income	62	54
Total interest and dividend income	2,234	1,960
Gross realized investments losses, excluding losses from other-than-temporary impairment
Gross realized investment gains	345	288
Gross realized investment losses	(175)	(96)
Net realized gains on sale of investments	170	$ 192
Securities AFS
Amortized cost	294,262		292,220
Gross unrealized gains	1,077
Gross unrealized losses	3,816
Fair value	291,523		290,725
Amortized cost			292,406
Gross unrealized gains			1,035
Gross unrealized losses			2,527
Fair value			290,914
Mortgage-backed securities - U.S. agency-sponsored
Securities AFS
Amortized cost	42,147
Gross unrealized gains	134
Gross unrealized losses	993
Fair value	41,288
Amortized cost			42,116
Gross unrealized gains			125
Gross unrealized losses			500
Fair value			41,741
Mortgage-backed securities - Prime
Securities AFS
Amortized cost	6
Gross unrealized gains	3
Gross unrealized losses	0
Fair value	9
Amortized cost			11
Gross unrealized gains			6
Gross unrealized losses			0
Fair value			17
Mortgage-backed securities - Alt-A
Securities AFS
Amortized cost	9
Gross unrealized gains	88
Gross unrealized losses	0
Fair value	97
Amortized cost			26
Gross unrealized gains			90
Gross unrealized losses			0
Fair value			116
Mortgage-backed securities - Non-U.S. residential
Securities AFS
Amortized cost	2,645
Gross unrealized gains	10
Gross unrealized losses	2
Fair value	2,653
Amortized cost			2,744
Gross unrealized gains			13
Gross unrealized losses			6
Fair value			2,751
Mortgage-backed securities - Commercial
Securities AFS
Amortized cost	310
Gross unrealized gains	1
Gross unrealized losses	3
Fair value	308
Amortized cost			334
Gross unrealized gains			0
Gross unrealized losses			2
Fair value			332
Mortgage-backed securities
Securities AFS
Amortized cost	45,117		45,231
Gross unrealized gains	236
Gross unrealized losses	998
Fair value	44,355		44,957
Amortized cost			45,231
Gross unrealized gains			234
Gross unrealized losses			508
Fair value			44,957
U.S. Treasury
Securities AFS
Amortized cost	108,335
Gross unrealized gains	74
Gross unrealized losses	1,611
Fair value	106,798
Amortized cost			108,344
Gross unrealized gains			77
Gross unrealized losses			971
Fair value			107,450
Agency obligations
Securities AFS
Amortized cost	10,689
Gross unrealized gains	5
Gross unrealized losses	178
Fair value	10,516
Amortized cost			10,813
Gross unrealized gains			7
Gross unrealized losses			124
Fair value			10,696
U.S. Treasury and federal agency securities
Securities AFS
Amortized cost	119,024		119,157
Gross unrealized gains	79
Gross unrealized losses	1,789
Fair value	117,314		118,146
Amortized cost			119,157
Gross unrealized gains			84
Gross unrealized losses			1,095
Fair value			118,146
State and municipal securities
Securities AFS
Amortized cost	9,980		8,870
Gross unrealized gains	126
Gross unrealized losses	269
Fair value	9,837		8,765
Amortized cost			8,870
Gross unrealized gains			140
Gross unrealized losses			245
Fair value			8,765
Foreign government
Securities AFS
Amortized cost	103,833		100,615
Gross unrealized gains	540
Gross unrealized losses	598
Fair value	103,775		100,533
Amortized cost			100,615
Gross unrealized gains			508
Gross unrealized losses			590
Fair value			100,533
Corporate
Securities AFS
Amortized cost	13,068
Gross unrealized gains	43
Gross unrealized losses	115
Fair value	12,996
Amortized cost			14,144
Gross unrealized gains			51
Gross unrealized losses			86
Fair value			14,109
Asset-backed securities
Securities AFS
Amortized cost	3,075
Gross unrealized gains	53
Gross unrealized losses	47
Fair value	3,081
Amortized cost			3,906
Gross unrealized gains			14
Gross unrealized losses			2
Fair value			3,918
Other debt securities
Securities AFS
Amortized cost	165
Gross unrealized gains	0
Gross unrealized losses	0
Fair value	165
Amortized cost			297
Gross unrealized gains			0
Gross unrealized losses			0
Fair value			297
Debt securities
Securities AFS
Amortized cost	294,262
Gross unrealized gains	1,077
Gross unrealized losses	3,816
Fair value	291,523
Amortized cost			292,220
Gross unrealized gains			1,031
Gross unrealized losses			2,526
Fair value			290,725
Equity securities
Securities AFS
Amortized cost			186
Gross unrealized gains			4
Gross unrealized losses			1
Fair value			189
Securities available-for-sale (AFS)
Investment Holdings
Investments	291,523		290,914
Held-to-maturity securities
Investment Holdings
Investments	52,492		53,320
Marketable equity securities | Fair value
Investment Holdings
Investments	277
Non-marketable equity securities | Fair value
Investment Holdings
Investments	1,292		1,206
Non-marketable equity securities | Carried at cost
Investment Holdings
Investments	5,986		$ 6,850
Non-marketable securities, measured using measurement alternative
Investment Holdings
Investments	$ 401

INVESTMENTS - Fair Value of AFS

INVESTMENTS - Fair Value of AFS Securities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair value
Less than 12 months	$ 178,408
Less than 12 months		$ 181,216
12 months or longer	23,005
12 months or longer		21,920
Total	201,413
Total		203,136
Gross unrealized losses
Less than 12 months	3,019
Less than 12 months		1,854
12 months or longer	797
12 months or longer		673
Total	3,816
Total		2,527
Mortgage-backed securities - U.S. agency-sponsored
Fair value
Less than 12 months	32,313
Less than 12 months		30,994
12 months or longer	1,873
12 months or longer		2,206
Total	34,186
Total		33,200
Gross unrealized losses
Less than 12 months	900
Less than 12 months		438
12 months or longer	93
12 months or longer		62
Total	993
Total		500
Mortgage-backed securities - Non-U.S. residential
Fair value
Less than 12 months	891
Less than 12 months		753
12 months or longer	0
12 months or longer		0
Total	891
Total		753
Gross unrealized losses
Less than 12 months	2
Less than 12 months		6
12 months or longer	0
12 months or longer		0
Total	2
Total		6
Mortgage-backed securities - Commercial
Fair value
Less than 12 months	241
Less than 12 months		150
12 months or longer	41
12 months or longer		57
Total	282
Total		207
Gross unrealized losses
Less than 12 months	2
Less than 12 months		1
12 months or longer	1
12 months or longer		1
Total	3
Total		2
Mortgage-backed securities
Fair value
Less than 12 months	33,445
Less than 12 months		31,897
12 months or longer	1,914
12 months or longer		2,263
Total	35,359
Total		34,160
Gross unrealized losses
Less than 12 months	904
Less than 12 months		445
12 months or longer	94
12 months or longer		63
Total	998
Total		508
U.S. Treasury
Fair value
Less than 12 months	81,738
Less than 12 months		79,050
12 months or longer	7,526
12 months or longer		7,404
Total	89,264
Total		86,454
Gross unrealized losses
Less than 12 months	1,417
Less than 12 months		856
12 months or longer	194
12 months or longer		115
Total	1,611
Total		971
Agency obligations
Fair value
Less than 12 months	7,964
Less than 12 months		8,857
12 months or longer	1,567
12 months or longer		1,163
Total	9,531
Total		10,020
Gross unrealized losses
Less than 12 months	144
Less than 12 months		110
12 months or longer	34
12 months or longer		14
Total	178
Total		124
U.S. Treasury and federal agency securities
Fair value
Less than 12 months	89,702
Less than 12 months		87,907
12 months or longer	9,093
12 months or longer		8,567
Total	98,795
Total		96,474
Gross unrealized losses
Less than 12 months	1,561
Less than 12 months		966
12 months or longer	228
12 months or longer		129
Total	1,789
Total		1,095
State and municipal securities
Fair value
Less than 12 months	2,250
Less than 12 months		1,009
12 months or longer	1,116
12 months or longer		1,155
Total	3,366
Total		2,164
Gross unrealized losses
Less than 12 months	35
Less than 12 months		11
12 months or longer	234
12 months or longer		234
Total	269
Total		245
Foreign government
Fair value
Less than 12 months	46,459
Less than 12 months		53,206
12 months or longer	9,972
12 months or longer		9,051
Total	56,431
Total		62,257
Gross unrealized losses
Less than 12 months	371
Less than 12 months		356
12 months or longer	227
12 months or longer		234
Total	598
Total		590
Corporate
Fair value
Less than 12 months	5,831
Less than 12 months		6,737
12 months or longer	890
12 months or longer		859
Total	6,721
Total		7,596
Gross unrealized losses
Less than 12 months	101
Less than 12 months		74
12 months or longer	14
12 months or longer		12
Total	115
Total		86
Asset-backed securities
Fair value
Less than 12 months	699
Less than 12 months		449
12 months or longer	20
12 months or longer		25
Total	719
Total		474
Gross unrealized losses
Less than 12 months	47
Less than 12 months		1
12 months or longer	0
12 months or longer		1
Total	47
Total		2
Other debt securities
Fair value
Less than 12 months	22
Less than 12 months		0
12 months or longer	0
12 months or longer		0
Total	22
Total		0
Gross unrealized losses
Less than 12 months	0
Less than 12 months		0
12 months or longer	0
12 months or longer		0
Total	$ 0
Total		0
Equity securities
Fair value
Less than 12 months		11
12 months or longer		0
Total		11
Gross unrealized losses
Less than 12 months		1
12 months or longer		0
Total		$ 1

INVESTMENTS - Fair Value of A77

INVESTMENTS - Fair Value of AFS Debt Securities by Contractual Maturity Date (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Amortized cost
Amortized cost	$ 294,262	$ 292,220
Fair value
Total fair value	291,523	290,725
Mortgage-backed securities
Amortized cost
Due within 1 year, amortized cost	92	45
After 1 but within 5 years, amortized cost	1,331	1,306
After 5 but within 10 years, amortized cost	1,320	1,376
After 10 years, amortized cost	42,374	42,504
Amortized cost	45,117	45,231
Fair value
Fair value, due within 1 year	91	45
Fair value, after 1 but within 5 years	1,327	1,304
Fair value, after 5 but within 10 years	1,298	1,369
Fair value, after 10 years	41,639	42,239
Total fair value	44,355	44,957
U.S. Treasury and federal agency securities
Amortized cost
Due within 1 year, amortized cost	12,897	4,913
After 1 but within 5 years, amortized cost	104,061	111,236
After 5 but within 10 years, amortized cost	2,066	3,008
After 10 years, amortized cost	0	0
Amortized cost	119,024	119,157
Fair value
Fair value, due within 1 year	12,906	4,907
Fair value, after 1 but within 5 years	102,375	110,238
Fair value, after 5 but within 10 years	2,033	3,001
Fair value, after 10 years	0	0
Total fair value	117,314	118,146
State and municipal securities
Amortized cost
Due within 1 year, amortized cost	1,874	1,792
After 1 but within 5 years, amortized cost	2,496	2,579
After 5 but within 10 years, amortized cost	591	514
After 10 years, amortized cost	5,019	3,985
Amortized cost	9,980	8,870
Fair value
Fair value, due within 1 year	1,873	1,792
Fair value, after 1 but within 5 years	2,494	2,576
Fair value, after 5 but within 10 years	607	528
Fair value, after 10 years	4,863	3,869
Total fair value	9,837	8,765
Foreign government
Amortized cost
Due within 1 year, amortized cost	32,899	32,130
After 1 but within 5 years, amortized cost	55,910	53,034
After 5 but within 10 years, amortized cost	12,454	12,949
After 10 years, amortized cost	2,570	2,502
Amortized cost	103,833	100,615
Fair value
Fair value, due within 1 year	32,909	32,100
Fair value, after 1 but within 5 years	55,571	53,165
Fair value, after 5 but within 10 years	12,639	12,680
Fair value, after 10 years	2,656	2,588
Total fair value	103,775	100,533
All other
Amortized cost
Due within 1 year, amortized cost	2,821	3,998
After 1 but within 5 years, amortized cost	9,147	9,047
After 5 but within 10 years, amortized cost	2,905	3,415
After 10 years, amortized cost	1,435	1,887
Amortized cost	16,308	18,347
Fair value
Fair value, due within 1 year	2,818	3,991
Fair value, after 1 but within 5 years	9,092	9,027
Fair value, after 5 but within 10 years	2,907	3,431
Fair value, after 10 years	1,425	1,875
Total fair value	$ 16,242	$ 18,324

INVESTMENTS - Debt Securities H

INVESTMENTS - Debt Securities Held-to-Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Securities Held-to-maturity
Amortized cost basis	$ 52,563	$ 53,437
Net unrealized gains (losses) recognized in AOCI	(71)	(117)
Carrying value	52,492	53,320
Gross unrealized gains	308	702
Gross unrealized (losses)	(700)	(270)
Fair value	52,100	53,752
Mortgage-backed securities - U.S. agency-sponsored
Debt Securities Held-to-maturity
Amortized cost basis	23,968	23,854
Net unrealized gains (losses) recognized in AOCI	(38)	26
Carrying value	23,930	23,880
Gross unrealized gains	8	40
Gross unrealized (losses)	(553)	(157)
Fair value	23,385	23,763
Mortgage-backed securities - Alt-A
Debt Securities Held-to-maturity
Amortized cost basis	0	206
Net unrealized gains (losses) recognized in AOCI	0	(65)
Carrying value	0	141
Gross unrealized gains	0	57
Gross unrealized (losses)	0	0
Fair value	0	198
Mortgage-backed securities - Non-U.S. residential
Debt Securities Held-to-maturity
Amortized cost basis	1,492	1,887
Net unrealized gains (losses) recognized in AOCI	0	(46)
Carrying value	1,492	1,841
Gross unrealized gains	25	65
Gross unrealized (losses)	0	0
Fair value	1,517	1,906
Mortgage-backed securities - Commercial
Debt Securities Held-to-maturity
Amortized cost basis	260	237
Net unrealized gains (losses) recognized in AOCI	0	0
Carrying value	260	237
Gross unrealized gains	0	0
Gross unrealized (losses)	0	0
Fair value	260	237
Mortgage-backed securities
Debt Securities Held-to-maturity
Amortized cost basis	25,720	26,184
Net unrealized gains (losses) recognized in AOCI	(38)	(85)
Carrying value	25,682	26,099
Gross unrealized gains	33	162
Gross unrealized (losses)	(553)	(157)
Fair value	25,162	26,104
State and municipal securities
Debt Securities Held-to-maturity
Amortized cost basis	7,686	8,925
Net unrealized gains (losses) recognized in AOCI	(33)	(28)
Carrying value	7,653	8,897
Gross unrealized gains	185	378
Gross unrealized (losses)	(132)	(73)
Fair value	7,706	9,202
Foreign government
Debt Securities Held-to-maturity
Amortized cost basis	1,354	740
Net unrealized gains (losses) recognized in AOCI	0	0
Carrying value	1,354	740
Gross unrealized gains	3	0
Gross unrealized (losses)	(12)	(18)
Fair value	1,345	722
Asset-backed securities
Debt Securities Held-to-maturity
Amortized cost basis	17,803	17,588
Net unrealized gains (losses) recognized in AOCI	0	(4)
Carrying value	17,803	17,584
Gross unrealized gains	87	162
Gross unrealized (losses)	(3)	(22)
Fair value	$ 17,887	$ 17,724

INVESTMENTS - Debt Securities i

INVESTMENTS - Debt Securities in HTM in Unrecognized Loss Position (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value
Less than 12 months	$ 9,797	$ 7,391
12 months or longer	15,866	9,647
Total	25,663	17,038
Held-to-maturity Securities, Continuous Unrealized Loss Position, Gross Recognized Losses
Less than 12 months	134	76
12 months or longer	566	194
Total	700	270
Unrealized (loss), other than temporary impairment, not credit loss, recorded in AOCI	(71)	(117)
Mortgage-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value
Less than 12 months	6,889	6,244
12 months or longer	15,108	8,678
Total	21,997	14,922
Held-to-maturity Securities, Continuous Unrealized Loss Position, Gross Recognized Losses
Less than 12 months	98	50
12 months or longer	455	107
Total	553	157
State and municipal securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value
Less than 12 months	1,528	353
12 months or longer	758	835
Total	2,286	1,188
Held-to-maturity Securities, Continuous Unrealized Loss Position, Gross Recognized Losses
Less than 12 months	21	5
12 months or longer	111	68
Total	132	73
Foreign government
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value
Less than 12 months	1,344	723
12 months or longer	0	0
Total	1,344	723
Held-to-maturity Securities, Continuous Unrealized Loss Position, Gross Recognized Losses
Less than 12 months	12	18
12 months or longer	0	0
Total	12	18
Asset-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value
Less than 12 months	36	71
12 months or longer	0	134
Total	36	205
Held-to-maturity Securities, Continuous Unrealized Loss Position, Gross Recognized Losses
Less than 12 months	3	3
12 months or longer	0	19
Total	$ 3	$ 22

INVESTMENTS - Carrying Value an

INVESTMENTS - Carrying Value and Fair Value of HTM Debt Securities by Contractual Maturity Dates (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Carrying value	$ 52,492	$ 53,320
Held-to-maturity Securities, Debt Maturities, Fair Value;
Fair value	52,100	53,752
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	131	720
After 5 but within 10 years, carrying value	166	148
After 10 years, carrying value	25,385	25,231
Carrying value	25,682	26,099
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	0	0
After 1 but within 5 years, fair value	130	720
After 5 but within 10 years, fair value	165	149
After 10 years, fair value	24,867	25,235
Fair value	25,162	26,104
State and municipal securities
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	234	407
After 1 but within 5 years, carrying value	380	259
After 5 but within 10 years, carrying value	438	512
After 10 years, carrying value	6,601	7,719
Carrying value	7,653	8,897
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	234	425
After 1 but within 5 years, fair value	398	270
After 5 but within 10 years, fair value	442	524
After 10 years, fair value	6,632	7,983
Fair value	7,706	9,202
Foreign government
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value	486	381
After 1 but within 5 years, carrying value	868	359
After 5 but within 10 years, carrying value	0	0
After 10 years, carrying value	0	0
Carrying value	1,354	740
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value	486	381
After 1 but within 5 years, fair value	859	341
After 5 but within 10 years, fair value	0	0
After 10 years, fair value	0	0
Fair value	1,345	722
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	1,989	1,669
After 10 years, carrying value	15,814	15,915
Carrying value	17,803	17,584
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	1,994	1,680
After 10 years, fair value	15,893	16,044
Fair value	$ 17,887	$ 17,724

INVESTMENTS - Recognition and M

INVESTMENTS - Recognition and Measurement of OTTI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OTTI on Investments disclosures
Total OTTI losses recognized during the period	$ 0	$ 0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	0	0
Impairment losses recognized in earnings for debt 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	27	12
Total OTTI losses recognized in earnings	27	12
Securities available-for-sale (AFS)
OTTI on Investments disclosures
Total OTTI losses recognized during the period	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	0	0
Impairment losses recognized in earnings for debt 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	27	11
Total OTTI losses recognized in earnings	27	11
Held-to-maturity securities
OTTI on Investments disclosures
Total OTTI losses recognized during the period	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	0	0
Impairment losses recognized in earnings for debt 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	1
Total OTTI losses recognized in earnings	$ 0	$ 1

INVESTMENTS - Cumulative OTTI C

INVESTMENTS - Cumulative OTTI Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities	$ 291,523			$ 290,725
Held-to-maturity Securities	52,492			53,320
Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Cumulative OTTI reclassified	(18)
Available for sale debt securities	44,355			44,957
Held-to-maturity Securities	25,682			26,099
State and municipal securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities	9,837			8,765
Held-to-maturity Securities	7,653			8,897
Foreign government securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities	103,775			100,533
Held-to-maturity Securities	1,354			$ 740
Corporate
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities	12,996
Other debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities	165
AFS debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	48	$ 31
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
Changes due to credit-impaired securities sold, transferred or matured	(17)	(1)
Ending balance	31	30
AFS debt securities | Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	38	0
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
Changes due to credit-impaired securities sold, transferred or matured	(13)	0
Ending balance	25	0
AFS debt securities | State and municipal securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	4	4
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
Changes due to credit-impaired securities sold, transferred or matured	(4)	0
Ending balance	0	4
AFS debt securities | Foreign government securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	0	0
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
Changes due to credit-impaired securities sold, transferred or matured	0	0
Ending balance	0	0
AFS debt securities | Corporate
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	4	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
Changes due to credit-impaired securities sold, transferred or matured	0	(1)
Ending balance	4	4
AFS debt securities | Other debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	2	22
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
Changes due to credit-impaired securities sold, transferred or matured	0	0
Ending balance	2	22
HTM debt securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	57	104
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
Changes due to credit-impaired securities sold, transferred or matured	(57)	(4)
Ending balance	0	100
HTM debt securities | Mortgage-backed securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	54	101
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
Changes due to credit-impaired securities sold, transferred or matured	(54)	(4)
Ending balance	0	97
HTM debt securities | State and municipal securities
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Beginning balance	3	3
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
Changes due to credit-impaired securities sold, transferred or matured	(3)	0
Ending balance	$ 0	$ 3
Accounting Standards Update 2017-12
Schedule of other-than-temporary impairment, credit losses recognized in earnings, roll forward
Available for sale debt securities			$ 4,000
Held-to-maturity Securities			$ (4,000)

INVESTMENTS - Carrying Value of

INVESTMENTS - Carrying Value of Non-marketable Equity Securities Measured Using the Measurement Alternative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Investments, Debt and Equity Securities [Abstract]
Measurement alternative, balance at March 31, 2018	$ 401
Measurement alternative—impairment losses	1
Measurement alternative—downward changes for observable prices	2
Measurement alternative—upward changes for observable prices	$ 123

INVESTMENTS - Alternative Inves

INVESTMENTS - Alternative Investment Funds (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Investments in Alternative Investment Funds
Alternative investment funds, fair value	$ 433	$ 404
Alternative investment funds, unfunded commitments	81	82
Hedge funds
Investments in Alternative Investment Funds
Alternative investment funds, fair value	0	1
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	10 days	10 days
Hedge funds | Maximum
Investments in Alternative Investment Funds
Alternative investment funds, redemption notice period	95 days	95 days
Private equity
Investments in Alternative Investment Funds
Alternative investment funds, fair value	$ 413	$ 372
Alternative investment funds, unfunded commitments	62	62
Real estate funds
Investments in Alternative Investment Funds
Alternative investment funds, fair value	20	31
Alternative investment funds, unfunded commitments	$ 19	$ 20

LOANS - Consumer Loans (Details

LOANS - Consumer Loans (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)category	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Loans
Number of loan categories | category	2
Loans, net of unearned income	$ 672,938		$ 667,034
Consumer
Loans
Total loans	324,357		332,919
Net unearned income	727		737
Loans, net of unearned income	325,084		333,656
Loans sold and/or reclassified to held-for-sale	800	$ 2,300
In U.S. offices | Consumer
Loans
Total loans	205,292		215,711
In U.S. offices | Consumer | Mortgage and real estate
Loans
Total loans	63,412		65,467
In U.S. offices | Consumer | Installment, revolving credit and other
Loans
Total loans	3,306		3,398
In U.S. offices | Consumer | Cards
Loans
Total loans	131,081		139,006
In U.S. offices | Consumer | Commercial and industrial
Loans
Total loans	7,493		7,840
In offices outside the U.S. | Consumer
Loans
Total loans	119,065		117,208
In offices outside the U.S. | Consumer | Mortgage and real estate
Loans
Total loans	44,833		44,081
In offices outside the U.S. | Consumer | Installment, revolving credit and other
Loans
Total loans	27,651		26,556
In offices outside the U.S. | Consumer | Cards
Loans
Total loans	25,993		26,257
In offices outside the U.S. | Consumer | Commercial and industrial
Loans
Total loans	20,526		20,238
In offices outside the U.S. | Consumer | Lease financing
Loans
Total loans	$ 62		$ 76

LOANS - Consumer Loan Delinquen

LOANS - Consumer Loan Delinquency (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Non-Accrual Details
Loans, net of unearned income	$ 672,938	$ 667,034
Loans at fair value	4,536	4,374
Consumer
Non-Accrual Details
Loans, current	318,114	326,092
Loans, net of unearned income	325,084	333,656
Total non-accrual	2,575	2,690
90 days past due and accruing	$ 2,547	$ 2,812
Loans less than this number of days past due are considered current	30 days	30 days
Loans at fair value	$ 23	$ 25
Number of days past due, non-accrual status	60 days
Consumer | Less than or equal to 80%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	$ 53,578	55,029
Consumer | 80% but less than or equal to 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	4,490	4,725
Consumer | Greater than 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	951	1,047
Consumer | Less than 620
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	12,140	12,834
Consumer | ≥ 620 but less than 660
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	14,197	14,914
Consumer | ≥ 660 but less than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	47,749	48,960
Consumer | Equal to or greater than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	115,970	123,343
Consumer | Government-guaranteed
Non-Accrual Details
Loans, past due	1,010	1,225
Consumer | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	3,103	3,304
Consumer | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	2,857	3,035
Consumer | Residential first mortgages
Non-Accrual Details
Loans at fair value	$ 23	$ 25
Number of days past due, non-accrual status	90 days	90 days
Consumer | Residential first mortgages | Less than or equal to 80%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	$ 42,790	$ 43,626
Consumer | Residential first mortgages | 80% but less than or equal to 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	2,536	2,578
Consumer | Residential first mortgages | Greater than 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	214	247
Consumer | Residential first mortgages | Less than 620
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	1,750	2,100
Consumer | Residential first mortgages | ≥ 620 but less than 660
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	1,746	1,932
Consumer | Residential first mortgages | ≥ 660 but less than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	6,655	6,931
Consumer | Residential first mortgages | Equal to or greater than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	35,253	35,334
Consumer | Home equity loans | Less than or equal to 80%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	10,788	11,403
Consumer | Home equity loans | 80% but less than or equal to 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	1,954	2,147
Consumer | Home equity loans | Greater than 100%
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	737	800
Consumer | Home equity loans | Less than 620
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	1,075	1,379
Consumer | Home equity loans | ≥ 620 but less than 660
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	937	1,081
Consumer | Home equity loans | ≥ 660 but less than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	3,138	3,446
Consumer | Home equity loans | Equal to or greater than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	8,409	8,530
Consumer | Credit cards | Less than 620
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	9,169	9,079
Consumer | Credit cards | ≥ 620 but less than 660
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	11,285	11,651
Consumer | Credit cards | ≥ 660 but less than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	37,275	37,916
Consumer | Credit cards | Equal to or greater than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	70,598	77,661
Consumer | Installment and other revolving | Less than 620
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	146	276
Consumer | Installment and other revolving | ≥ 620 but less than 660
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	229	250
Consumer | Installment and other revolving | ≥ 660 but less than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	681	667
Consumer | Installment and other revolving | Equal to or greater than 720
Financing Receivable
Purchased credit-impaired in accordance with ASC 310-30	$ 1,710	1,818
Consumer | Commercial banking loans
Non-Accrual Details
Number of days past due, non-accrual status	90 days
Consumer | Total GCB and Corporate/Other— Consumer
Non-Accrual Details
Loans, current	$ 318,113	326,091
Loans, net of unearned income	325,083	333,655
Total non-accrual	2,575	2,690
90 days past due and accruing	2,547	2,812
Consumer | Total GCB and Corporate/Other— Consumer | Government-guaranteed
Non-Accrual Details
Loans, past due	1,010	1,225
Consumer | Total GCB and Corporate/Other— Consumer | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	3,103	3,304
Consumer | Total GCB and Corporate/Other— Consumer | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	2,857	3,035
Consumer | Other
Non-Accrual Details
Loans, current	1	1
Loans, net of unearned income	1	1
Total non-accrual	0	0
90 days past due and accruing	0	0
Consumer | Other | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | Other | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	0	0
Consumer | Other | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	0	0
Consumer | In North America offices
Non-Accrual Details
Loans, current	201,217	211,012
Loans, net of unearned income	206,421	216,899
Total non-accrual	1,500	1,650
90 days past due and accruing	2,291	2,553
Consumer | In North America offices | Government-guaranteed
Non-Accrual Details
Loans, past due	1,010	1,225
Consumer | In North America offices | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	2,036	2,336
Consumer | In North America offices | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	2,158	2,326
Consumer | In North America offices | Residential first mortgages
Non-Accrual Details
Loans, current	46,607	47,366
Loans, net of unearned income	48,238	49,376
Total non-accrual	636	665
90 days past due and accruing	750	941
Mortgage loans in process of foreclosure	100	100
Consumer | In North America offices | Residential first mortgages | Government-guaranteed
Non-Accrual Details
Loans, past due	1,010	1,225
Consumer | In North America offices | Residential first mortgages | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	364	505
Consumer | In North America offices | Residential first mortgages | 30 to 89 Days Past Due | Government-guaranteed
Non-Accrual Details
Loans, past due	200	200
Consumer | In North America offices | Residential first mortgages | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	257	280
Consumer | In North America offices | Residential first mortgages | Equal to greater than 90 days past due | Government-guaranteed
Non-Accrual Details
Loans, past due	800	1,000
Consumer | In North America offices | Home equity loans
Non-Accrual Details
Loans, current	13,476	14,268
Loans, net of unearned income	13,951	14,827
Total non-accrual	691	750
90 days 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
Non-Accrual Details
Loans, past due	0	0
Consumer | In North America offices | Home equity loans | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	160	207
Consumer | In North America offices | Home equity loans | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	315	352
Consumer | In North America offices | Credit cards
Non-Accrual Details
Loans, current	128,790	136,588
Loans, net of unearned income	131,778	139,729
Total non-accrual	0	0
90 days past due and accruing	1,528	1,596
Consumer | In North America offices | Credit cards | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In North America offices | Credit cards | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	1,460	1,528
Consumer | In North America offices | Credit cards | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	1,528	1,613
Consumer | In North America offices | Installment and other revolving
Non-Accrual Details
Loans, current	3,333	3,395
Loans, net of unearned income	3,385	3,456
Total non-accrual	21	22
90 days past due and accruing		1
Consumer | In North America offices | Installment and other revolving | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In North America offices | Installment and other revolving | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	38	45
Consumer | In North America offices | Installment and other revolving | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	14	16
Consumer | In North America offices | Commercial banking loans
Non-Accrual Details
Loans, current	9,011	9,395
Loans, net of unearned income	9,069	9,511
Total non-accrual	152	213
90 days past due and accruing	13	15
Consumer | In North America offices | Commercial banking loans | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In North America offices | Commercial banking loans | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	14	51
Consumer | In North America offices | Commercial banking loans | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	44	65
Consumer | In offices outside North America
Non-Accrual Details
Loans, current	116,896	115,079
Loans, net of unearned income	118,662	116,756
Total non-accrual	1,075	1,040
90 days past due and accruing	256	259
Consumer | In offices outside North America | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In offices outside North America | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	1,067	968
Consumer | In offices outside North America | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	699	709
Consumer | In offices outside North America | Residential first mortgages
Non-Accrual Details
Loans, current	37,447	37,062
Loans, net of unearned income	37,844	37,419
Total non-accrual	412	400
90 days past due and accruing	0	0
Consumer | In offices outside North America | Residential first mortgages | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In offices outside North America | Residential first mortgages | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	250	209
Consumer | In offices outside North America | Residential first mortgages | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	147	148
Consumer | In offices outside North America | Credit cards
Non-Accrual Details
Loans, current	24,702	24,934
Loans, net of unearned income	25,512	25,727
Total non-accrual	323	323
90 days past due and accruing	256	259
Consumer | In offices outside North America | Credit cards | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In offices outside North America | Credit cards | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	437	427
Consumer | In offices outside North America | Credit cards | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	373	366
Consumer | In offices outside North America | Installment and other revolving
Non-Accrual Details
Loans, current	26,243	25,634
Loans, net of unearned income	26,670	26,032
Total non-accrual	161	157
90 days past due and accruing	0	0
Consumer | In offices outside North America | Installment and other revolving | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In offices outside North America | Installment and other revolving | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	311	275
Consumer | In offices outside North America | Installment and other revolving | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	116	123
Consumer | In offices outside North America | Commercial banking loans
Non-Accrual Details
Loans, current	28,504	27,449
Loans, net of unearned income	28,636	27,578
Total non-accrual	179	160
90 days past due and accruing	0	0
Consumer | In offices outside North America | Commercial banking loans | Government-guaranteed
Non-Accrual Details
Loans, past due	0	0
Consumer | In offices outside North America | Commercial banking loans | 30 to 89 Days Past Due
Non-Accrual Details
Loans, past due	69	57
Consumer | In offices outside North America | Commercial banking loans | Equal to greater than 90 days past due
Non-Accrual Details
Loans, past due	$ 63	$ 72

LOANS - Impaired Consumer Loans

LOANS - Impaired Consumer Loans (Details) - Consumer $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)Q	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)Q
Financing receivable impaired
Recorded investment			$ 6,580
Unpaid principal balance	$ 6,868		7,531
Related specific allowance	1,295		1,334
Average carrying value	6,657		$ 6,983
Interest income recognized	$ 67	$ 96
Number of quarters used to calculate the average recorded investment balance | Q	4		4
Residential first mortgages
Financing receivable impaired
Recorded investment	$ 3,020		$ 2,877
Unpaid principal balance	3,123		3,121
Related specific allowance	250		278
Average carrying value	3,002		3,155
Interest income recognized	21	36
Impaired financing receivable without specific allowance	526		607
Home equity loans
Financing receivable impaired
Recorded investment	673		1,151
Unpaid principal balance	893		1,590
Related specific allowance	211		216
Average carrying value	1,044		1,181
Interest income recognized	7	8
Impaired financing receivable without specific allowance	348		370
Credit cards
Financing receivable impaired
Recorded investment	1,846		1,787
Unpaid principal balance	1,879		1,819
Related specific allowance	626		614
Average carrying value	1,809		1,803
Interest income recognized	30	38
Individual installment and other
Financing receivable impaired
Recorded investment	443		431
Unpaid principal balance	473		460
Related specific allowance	182		175
Average carrying value	428		415
Interest income recognized	6	8
Commercial banking loans
Financing receivable impaired
Recorded investment	287		334
Unpaid principal balance	500		541
Related specific allowance	26		51
Average carrying value	374		429
Interest income recognized	3	$ 6
Impaired financing receivable without specific allowance	$ 9		$ 10

LOANS - Consumer Troubled Debt

LOANS - Consumer Troubled Debt Restructurings (Details) - Consumer $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan	Dec. 31, 2017
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
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	64,598	61,229
Post-modification recorded investment	$ 378	$ 424
TDR in payment default	$ 122	$ 114
In North America offices | Residential first mortgages
Loans receivable
Number of loans modified | loan	588	966
Post-modification recorded investment	$ 89	$ 130
Average interest rate reduction	0.00%	1.00%
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 11	$ 15
TDR in payment default	44	51
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	$ 8	$ 9
In North America offices | Home equity loans
Loans receivable
Number of loans modified | loan	456	679
Post-modification recorded investment	$ 41	$ 56
Average interest rate reduction	1.00%	1.00%
Post-modification recorded investment for borrowers that have gone through Chapter 7 bankruptcy	$ 4	$ 6
TDR in payment default	10	9
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	$ 3	$ 6
In North America offices | Credit cards
Loans receivable
Number of loans modified | loan	63,203	59,337
Post-modification recorded investment	$ 244	$ 231
Average interest rate reduction	18.00%	17.00%
TDR in payment default	$ 59	$ 52
In North America offices | Installment and other revolving
Loans receivable
Number of loans modified | loan	342	221
Post-modification recorded investment	$ 3	$ 2
Average interest rate reduction	5.00%	5.00%
TDR in payment default	$ 1	$ 0
In North America offices | Commercial banking
Loans receivable
Number of loans modified | loan	9	26
Post-modification recorded investment	$ 1	$ 5
Average interest rate reduction	0.00%	0.00%
TDR in payment default	$ 8	$ 2
In offices outside the U.S.
Loans receivable
Number of loans modified | loan	33,413	37,189
Post-modification recorded investment	$ 199	$ 185
TDR in payment default	$ 79	$ 67
In offices outside the U.S. | Residential first mortgages
Loans receivable
Number of loans modified | loan	549	613
Post-modification recorded investment	$ 18	$ 27
Average interest rate reduction	0.00%	0.00%
TDR in payment default	$ 2	$ 2
In offices outside the U.S. | Credit cards
Loans receivable
Number of loans modified | loan	23,394	25,237
Post-modification recorded investment	$ 94	$ 85
Average interest rate reduction	15.00%	14.00%
TDR in payment default	$ 53	$ 42
In offices outside the U.S. | Installment and other revolving
Loans receivable
Number of loans modified | loan	9,325	11,307
Post-modification recorded investment	$ 59	$ 60
Average interest rate reduction	10.00%	7.00%
TDR in payment default	$ 24	$ 23
In offices outside the U.S. | Commercial banking
Loans receivable
Number of loans modified | loan	145	32
Post-modification recorded investment	$ 28	$ 13
Average interest rate reduction	2000000.00%	2.00%
TDR in payment default	$ 0	$ 0
Deferred principal | In North America offices
Loans receivable
Post-modification recorded investment	3	6
Deferred principal | In North America offices | Residential first mortgages
Loans receivable
Post-modification recorded investment	1	3
Deferred principal | In North America offices | Home equity loans
Loans receivable
Post-modification recorded investment	2	3
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 revolving
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 revolving
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 revolving
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 revolving
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	0	1
Principal forgiveness | In North America offices | Residential first mortgages
Loans receivable
Post-modification recorded investment	0	1
Principal forgiveness | In North America offices | Home equity loans
Loans receivable
Post-modification recorded investment	0	0
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 revolving
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	4	6
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	2	2
Principal forgiveness | In offices outside the U.S. | Installment and other revolving
Loans receivable
Post-modification recorded investment	2	4
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	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Loans
Loans, net of unearned income	$ 672,938		$ 667,034
Corporate
Loans
Total loans	348,632		334,141
Net unearned income	(778)		(763)
Loans, net of unearned income	347,854		333,378
Loans sold and/or reclassified to held-for-sale	100	$ 500
Corporate | Commercial and industrial
Loans
Loans, net of unearned income	151,727		141,322
Corporate | Financial institutions
Loans
Loans, net of unearned income	75,012		73,757
Corporate | Mortgage and real estate
Loans
Loans, net of unearned income	53,109		51,964
Corporate | Lease financing
Loans
Loans, net of unearned income	1,629		1,655
Corporate | In U.S. offices
Loans
Total loans	174,387		169,781
Corporate | In U.S. offices | Commercial and industrial
Loans
Total loans	54,005		51,319
Corporate | In U.S. offices | Financial institutions
Loans
Total loans	40,472		39,128
Corporate | In U.S. offices | Mortgage and real estate
Loans
Total loans	45,581		44,683
Corporate | In U.S. offices | Installment, revolving credit and other
Loans
Total loans	32,866		33,181
Corporate | In U.S. offices | Lease financing
Loans
Total loans	1,463		1,470
Corporate | In offices outside the U.S.
Loans
Total loans	174,245		164,360
Corporate | In offices outside the U.S. | Commercial and industrial
Loans
Total loans	101,368		93,750
Corporate | In offices outside the U.S. | Financial institutions
Loans
Total loans	35,659		35,273
Corporate | In offices outside the U.S. | Mortgage and real estate
Loans
Total loans	7,543		7,309
Corporate | In offices outside the U.S. | Installment, revolving credit and other
Loans
Total loans	23,338		22,638
Corporate | In offices outside the U.S. | Lease financing
Loans
Total loans	167		190
Corporate | In offices outside the U.S. | Government and official institutions
Loans
Total loans	$ 6,170		$ 5,200

LOANS - Corporate Loan Delinque

LOANS - Corporate Loan Delinquency (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Non-Accrual Details
Loans, net of unearned income	$ 672,938	$ 667,034
Loans at fair value	4,536	4,374
Corporate
Non-Accrual Details
Past due and accruing	1,002	735
Total non-accrual	1,668	1,942
Total current	340,671	326,352
Loans, net of unearned income	347,854	333,378
Loans at fair value	4,513	4,349
Purchased distressed loans	$ 0	0
Number of days past due, non-accrual status	90 days
Loans less than this number of days past due are considered current	30 days
Corporate | Commercial and industrial
Non-Accrual Details
Past due and accruing	$ 555	262
Total non-accrual	1,260	1,506
Total current	149,912	139,554
Loans, net of unearned income	151,727	141,322
Corporate | Financial institutions
Non-Accrual Details
Past due and accruing	85	108
Total non-accrual	87	92
Total current	74,840	73,557
Loans, net of unearned income	75,012	73,757
Corporate | Mortgage and real estate
Non-Accrual Details
Past due and accruing	145	206
Total non-accrual	192	195
Total current	52,772	51,563
Loans, net of unearned income	53,109	51,964
Corporate | Leases
Non-Accrual Details
Past due and accruing	22	76
Total non-accrual	43	46
Total current	1,564	1,533
Loans, net of unearned income	1,629	1,655
Corporate | Other
Non-Accrual Details
Past due and accruing	195	83
Total non-accrual	86	103
Total current	61,583	60,145
Loans, net of unearned income	61,864	60,331
Corporate | 30 to 89 Days Past Due
Non-Accrual Details
Past due and accruing	882	627
Corporate | 30 to 89 Days Past Due | Commercial and industrial
Non-Accrual Details
Past due and accruing	478	249
Corporate | 30 to 89 Days Past Due | Financial institutions
Non-Accrual Details
Past due and accruing	63	93
Corporate | 30 to 89 Days Past Due | Mortgage and real estate
Non-Accrual Details
Past due and accruing	131	147
Corporate | 30 to 89 Days Past Due | Leases
Non-Accrual Details
Past due and accruing	22	68
Corporate | 30 to 89 Days Past Due | Other
Non-Accrual Details
Past due and accruing	188	70
Corporate | Equal to greater than 90 days past due and accruing
Non-Accrual Details
Past due and accruing	120	108
Corporate | Equal to greater than 90 days past due and accruing | Commercial and industrial
Non-Accrual Details
Past due and accruing	77	13
Corporate | Equal to greater than 90 days past due and accruing | Financial institutions
Non-Accrual Details
Past due and accruing	22	15
Corporate | Equal to greater than 90 days past due and accruing | Mortgage and real estate
Non-Accrual Details
Past due and accruing	14	59
Corporate | Equal to greater than 90 days past due and accruing | Leases
Non-Accrual Details
Past due and accruing	0	8
Corporate | Equal to greater than 90 days past due and accruing | Other
Non-Accrual Details
Past due and accruing	$ 7	$ 13

LOANS - Corporate Loans Credit

LOANS - Corporate Loans Credit Quality Indicators (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Loans receivable
Loans, net of unearned income	$ 672,938	$ 667,034
Loans at fair value	4,536	4,374
Corporate
Loans receivable
Loans, net of unearned income	347,854	333,378
Total non-accrual	1,668	1,942
Loans at fair value	4,513	4,349
Corporate | Commercial and industrial
Loans receivable
Loans, net of unearned income	151,727	141,322
Total non-accrual	1,260	1,506
Corporate | Financial institutions
Loans receivable
Loans, net of unearned income	75,012	73,757
Total non-accrual	87	92
Corporate | Mortgage and real estate
Loans receivable
Loans, net of unearned income	53,109	51,964
Total non-accrual	192	195
Corporate | Lease financing
Loans receivable
Loans, net of unearned income	1,629	1,655
Total non-accrual	43	46
Corporate | Other
Loans receivable
Loans, net of unearned income	61,864	60,331
Total non-accrual	86	103
Corporate | Private bank loans managed on a delinquency basis
Loans receivable
Loans, net of unearned income	25,860	25,674
Corporate | Investment grade
Loans receivable
Loans, net of unearned income	253,720	242,326
Corporate | Investment grade | Commercial and industrial
Loans receivable
Loans, net of unearned income	108,881	101,313
Corporate | Investment grade | Financial institutions
Loans receivable
Loans, net of unearned income	62,082	60,404
Corporate | Investment grade | Mortgage and real estate
Loans receivable
Loans, net of unearned income	23,831	23,213
Corporate | Investment grade | Lease financing
Loans receivable
Loans, net of unearned income	1,063	1,090
Corporate | Investment grade | Other
Loans receivable
Loans, net of unearned income	57,863	56,306
Corporate | Non-investment grade
Loans receivable
Loans, net of unearned income	63,761	61,029
Corporate | Non-investment grade | Commercial and industrial
Loans receivable
Loans, net of unearned income	41,586	38,503
Total non-accrual	1,260	1,506
Corporate | Non-investment grade | Financial institutions
Loans receivable
Loans, net of unearned income	12,843	13,261
Total non-accrual	87	92
Corporate | Non-investment grade | Mortgage and real estate
Loans receivable
Loans, net of unearned income	3,226	2,881
Total non-accrual	192	195
Corporate | Non-investment grade | Lease financing
Loans receivable
Loans, net of unearned income	523	518
Total non-accrual	43	46
Corporate | Non-investment grade | Other
Loans receivable
Loans, net of unearned income	3,915	3,924
Total non-accrual	$ 86	$ 103

LOANS - Non-accrual Corporate L

LOANS - Non-accrual Corporate Loans (Details) - Corporate - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing receivable impaired
Recorded investment	$ 1,668		$ 1,942
Unpaid principal balance	2,190		2,459
Related specific allowance	271		426
Average carrying value	1,942		2,109
Interest income recognized	4	$ 2
Impaired financing receivable with specific allowance	774		1,215
Impaired financing receivable without specific allowance	894		727
Commercial and industrial
Financing receivable impaired
Recorded investment	1,260		1,506
Unpaid principal balance	1,501		1,775
Related specific allowance	227		368
Average carrying value	1,439		1,547
Interest income recognized	3
Impaired financing receivable with specific allowance	574		1,017
Impaired financing receivable without specific allowance	686		489
Financial institutions
Financing receivable impaired
Recorded investment	87		92
Unpaid principal balance	102		102
Related specific allowance	25		41
Average carrying value	159		212
Interest income recognized	0
Impaired financing receivable with specific allowance	87		88
Impaired financing receivable without specific allowance	0		4
Mortgage and real estate
Financing receivable impaired
Recorded investment	192		195
Unpaid principal balance	349		324
Related specific allowance	10		11
Average carrying value	186		183
Interest income recognized	1
Impaired financing receivable with specific allowance	54		51
Impaired financing receivable without specific allowance	138		144
Lease financing
Financing receivable impaired
Recorded investment	43		46
Unpaid principal balance	43		46
Related specific allowance	4		4
Average carrying value	53		59
Interest income recognized	0
Impaired financing receivable with specific allowance	43		46
Impaired financing receivable without specific allowance	0		0
Other
Financing receivable impaired
Recorded investment	86		103
Unpaid principal balance	195		212
Related specific allowance	5		2
Average carrying value	105		108
Interest income recognized	0
Impaired financing receivable with specific allowance	16		13
Impaired financing receivable without specific allowance	$ 70		$ 90

LOANS - Corporate Troubled Debt

LOANS - Corporate Troubled Debt Restructurings (Details) - Corporate - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing receivable impaired
Carrying Value	$ 3	$ 71
Period within which default occurred post-modification	1 year
Number of days past due, default status	60 days
Carrying Value	$ 686	675
TDR in payment default	59	12
Commercial and industrial
Financing receivable impaired
Carrying Value	2	55
Carrying Value	507	390
TDR in payment default	59	9
Financial institutions
Financing receivable impaired
Carrying Value		15
Carrying Value	40	24
TDR in payment default	0	3
Mortgage and real estate
Financing receivable impaired
Carrying Value	1	1
Carrying Value	98	84
TDR in payment default	0	0
Other
Financing receivable impaired
Carrying Value	41	177
TDR in payment default	$ 0	0
Commercial banking loans
Financing receivable impaired
Number of days past due, default status	90 days
TDRs involving changes in the amount and/or timing of principal payments
Financing receivable impaired
Carrying Value	$ 0	0
TDRs involving changes in the amount and/or timing of principal payments | Commercial and industrial
Financing receivable impaired
Carrying Value	0	0
TDRs involving changes in the amount and/or timing of principal payments | Financial institutions
Financing receivable impaired
Carrying Value		0
TDRs involving changes in the amount and/or timing of principal payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	0	0
TDRs involving changes in the amount and/or timing of interest payments
Financing receivable impaired
Carrying Value	0	0
TDRs involving changes in the amount and/or timing of interest payments | Commercial and industrial
Financing receivable impaired
Carrying Value	0	0
TDRs involving changes in the amount and/or timing of interest payments | Financial institutions
Financing receivable impaired
Carrying Value		0
TDRs involving changes in the amount and/or timing of interest payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	0	0
TDRs involving changes in the amount and/or timing of both principal and interest payments
Financing receivable impaired
Carrying Value	3	71
TDRs involving changes in the amount and/or timing of both principal and interest payments | Commercial and industrial
Financing receivable impaired
Carrying Value	2	55
TDRs involving changes in the amount and/or timing of both principal and interest payments | Financial institutions
Financing receivable impaired
Carrying Value		15
TDRs involving changes in the amount and/or timing of both principal and interest payments | Mortgage and real estate
Financing receivable impaired
Carrying Value	$ 1	$ 1

ALLOWANCE FOR CREDIT LOSSES - A

ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,355	$ 12,060
Gross credit losses	(2,296)	(2,144)
Gross recoveries	429	435
Net credit losses (NCLs)	(1,867)	(1,709)
Net credit losses (NCLs)	1,867	1,709
Net reserve builds (releases)	102	(20)
Net specific reserve releases	(166)	(14)
Total provision for loan losses	1,803	1,675
Other, net	63	4
Allowance for loan losses at end of period	12,354	12,030
Allowance for credit losses on unfunded lending commitments
Allowance for credit losses on unfunded lending commitments at beginning of period	1,258	1,418
Provision (release) for unfunded lending commitments	28	(43)
Other, net	4	2
Allowance for credit losses on unfunded lending commitments at end of period	1,290	1,377
Total allowance for loans, leases and unfunded lending commitments	13,644	13,407
Sales or transfers of various consumer loan portfolios to HFS
Other, net	63	4
Consumer
Allowance for credit losses
Allowance for loan losses at beginning of period	9,869	9,358
Gross credit losses	(2,157)	(2,041)
Gross recoveries	386	369
Net credit losses (NCLs)	(1,771)	(1,672)
Net credit losses (NCLs)	1,771	1,672
Net reserve builds (releases)	121	146
Net specific reserve releases	(11)	(2)
Other, net	60	(7)
Allowance for loan losses at end of period	10,039	9,495
Sales or transfers of various consumer loan portfolios to HFS
Transfer of real estate loan portfolios	(53)	(37)
Transfer of other loan portfolios	(2)	(124)
Sales or transfers of various consumer loan portfolios to HFS	(55)	(161)
FX translation, consumer	118	164
Other, net	60	(7)
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,486	2,702
Gross credit losses	(139)	(103)
Gross recoveries	43	66
Net credit losses (NCLs)	(96)	(37)
Net credit losses (NCLs)	96	37
Net reserve builds (releases)	(19)	(166)
Net specific reserve releases	(155)	(12)
Other, net	3	11
Allowance for loan losses at end of period	2,315	2,535
Sales or transfers of various consumer loan portfolios to HFS
Other	0	1
Other, net	$ 3	$ 11

ALLOWANCE FOR CREDIT LOSSES -95

ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,355	$ 12,060
Charge-offs	(2,296)	(2,144)
Recoveries	429	435
Replenishment of net charge-offs	1,867	1,709
Net reserve builds (releases)	102	(20)
Net specific reserve builds (releases)	(166)	(14)
Other	63	4
Allowance for loan losses at end of period	12,354	12,030
Allowance for loan losses
Collectively evaluated in accordance with ASC 450			$ 10,785	$ 10,591
Individually evaluated in accordance with ASC 310-10-35			1,565	1,760
Purchased credit-impaired in accordance with ASC 310-30			4	4
Total allowance for loan losses	12,355	12,060	12,354	12,355
Loans, net of unearned income
Collectively evaluated in accordance with ASC 450			660,342	654,026
Individually evaluated in accordance with ASC 310-10-35			7,934	8,467
Held at fair value			4,536	4,374
Loans, net of unearned income			672,938	667,034
Receivables Acquired with Deteriorated Credit Quality
Loans, net of unearned income
Purchased credit-impaired in accordance with ASC 310-30			126	167
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,486	2,702
Charge-offs	(139)	(103)
Recoveries	43	66
Replenishment of net charge-offs	96	37
Net reserve builds (releases)	(19)	(166)
Net specific reserve builds (releases)	(155)	(12)
Other	3	11
Allowance for loan losses at end of period	2,315	2,535
Allowance for loan losses
Collectively evaluated in accordance with ASC 450			2,045	2,060
Individually evaluated in accordance with ASC 310-10-35			270	426
Purchased credit-impaired in accordance with ASC 310-30			0	0
Total allowance for loan losses	2,486	2,702	2,315	2,486
Loans, net of unearned income
Collectively evaluated in accordance with ASC 450			341,676	327,142
Individually evaluated in accordance with ASC 310-10-35			1,665	1,887
Held at fair value			4,513	4,349
Loans, net of unearned income			347,854	333,378
Corporate | Receivables Acquired with Deteriorated Credit Quality
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	9,869	9,358
Charge-offs	(2,157)	(2,041)
Recoveries	386	369
Replenishment of net charge-offs	1,771	1,672
Net reserve builds (releases)	121	146
Net specific reserve builds (releases)	(11)	(2)
Other	60	(7)
Allowance for loan losses at end of period	10,039	9,495
Allowance for loan losses
Collectively evaluated in accordance with ASC 450			8,740	8,531
Individually evaluated in accordance with ASC 310-10-35			1,295	1,334
Purchased credit-impaired in accordance with ASC 310-30			4	4
Total allowance for loan losses	$ 9,869	$ 9,358	10,039	9,869
Loans, net of unearned income
Collectively evaluated in accordance with ASC 450			318,666	326,884
Individually evaluated in accordance with ASC 310-10-35			6,269	6,580
Held at fair value			23	25
Loans, net of unearned income			325,084	333,656
Consumer | Receivables Acquired with Deteriorated Credit Quality
Loans, net of unearned income
Purchased credit-impaired in accordance with ASC 310-30			$ 126	$ 167

GOODWILL AND INTANGIBLE ASSET96

GOODWILL AND INTANGIBLE ASSETS - Changes in Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill
Balance of goodwill at beginning of period	$ 22,256
Foreign exchange translation and other	419
Divestiture	(16)
Balance of goodwill at end of period	22,659
Global Consumer Banking
Goodwill
Balance of goodwill at beginning of period	12,784
Foreign exchange translation and other	184
Divestiture	0
Balance of goodwill at end of period	12,968
Institutional Clients Group
Goodwill
Balance of goodwill at beginning of period	9,456
Foreign exchange translation and other	235
Divestiture	0
Balance of goodwill at end of period	9,691
Corporate/Other
Goodwill
Balance of goodwill at beginning of period	16
Foreign exchange translation and other	0
Divestiture	(16)
Balance of goodwill at end of period	$ 0

GOODWILL AND INTANGIBLE ASSET97

GOODWILL AND INTANGIBLE ASSETS - Components of Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	$ 11,653	$ 11,894
Accumulated amortization of Intangible assets (excluding MSRs)	7,203	7,306
Net carrying amount of Intangible assets (excluding MSRs)	4,450	4,588
Gross carrying amount, Mortgage servicing rights (MSRs)	587	558
Mortgage servicing rights (MSRs)	587	558
Gross carrying amount of Intangible assets	12,240	12,452
Accumulated amortization of Intangible assets	7,203	7,306
Total intangible assets	5,037	5,146
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	231	244
Accumulated amortization of Intangible assets (excluding MSRs)	0	0
Net carrying amount of Intangible assets (excluding MSRs)	231	244
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	5,308	5,375
Accumulated amortization of Intangible assets (excluding MSRs)	3,805	3,836
Net carrying amount of Intangible assets (excluding MSRs)	1,503	1,539
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	5,044	5,045
Accumulated amortization of Intangible assets (excluding MSRs)	2,542	2,456
Net carrying amount of Intangible assets (excluding MSRs)	2,502	2,589
Core deposit intangibles
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	449	639
Accumulated amortization of Intangible assets (excluding MSRs)	439	628
Net carrying amount of Intangible assets (excluding MSRs)	10	11
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	486	459
Accumulated amortization of Intangible assets (excluding MSRs)	294	272
Net carrying amount of Intangible assets (excluding MSRs)	192	187
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Gross carrying amount of Intangible assets (excluding MSRs)	35	32
Accumulated amortization of Intangible assets (excluding MSRs)	31	28
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	100
Accumulated amortization of Intangible assets (excluding MSRs)	92	86
Net carrying amount of Intangible assets (excluding MSRs)	$ 8	$ 14

GOODWILL AND INTANGIBLE ASSET98

GOODWILL AND INTANGIBLE ASSETS - Changes in Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	$ 4,588
Acquisitions/ divestitures	0
Amortization	(135)
FX translation and other	(3)
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	4,450	$ 4,588
Mortgage servicing rights (MSRs)	587	558
Total intangible assets	5,037	5,146
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	244
Acquisitions/ divestitures	0
Amortization	0
FX translation and other	(13)
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	231	244
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	1,539
Acquisitions/ divestitures	0
Amortization	(35)
FX translation and other	(1)
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	1,503	1,539
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	2,589
Acquisitions/ divestitures	0
Amortization	(86)
FX translation and other	(1)
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	2,502	2,589
Core deposit intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	11
Acquisitions/ divestitures	0
Amortization	(2)
FX translation and other	1
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	10	11
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	187
Acquisitions/ divestitures	0
Amortization	(6)
FX translation and other	11
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	192	187
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	4
Acquisitions/ divestitures	0
Amortization	0
FX translation and other	0
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	4	4
Other
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2017, Intangible assets (excluding MSRs)	14
Acquisitions/ divestitures	0
Amortization	(6)
FX translation and other	0
Net carrying amount at March 31, 2018, Intangible assets (excluding MSRs)	$ 8	$ 14
American Airlines, Sears, The Home Depot, Costco and AT&T | Customer Concentration Risk | Intangible Assets, Excluding Mortgage Servicing Rights | Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Concentration risk, percentage	97.00%	97.00%

DEBT - Short-Term Borrowings (D

DEBT - Short-Term Borrowings (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Commercial paper	$ 10,022	$ 9,940
Other borrowings	26,072	34,512
Total short-term borrowings	36,094	44,452
Collateralized short-term advances from Federal Home Loan Bank	$ 15,300	$ 23,800

DEBT - Long-Term Debt (Details)

DEBT - Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument
Long-term debt, at fair value	$ 237,938	$ 236,709
Citigroup Inc.
Debt Instrument
Long-term debt, at fair value	153,074	152,163
Bank
Debt Instrument
Long-term debt, at fair value	64,757	65,856
Bank | Senior notes
Debt Instrument
Collateralized long-term advances from Federal Home Loan Bank	15,700	19,300
Broker-dealer
Debt Instrument
Long-term debt, at fair value	$ 20,107	$ 18,690

DEBT - Trust Preferred Securiti

DEBT - Trust Preferred Securities (Details) $ in Millions	Mar. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)
Trust Preferred Securities
Trust preferred securities	$ 1,700	$ 1,700
Liquidation value	2,580
Junior subordinated debentures owned by the Trust, amount	$ 2,586
Citigroup Capital III
Trust Preferred Securities
Securities issued (in shares) | shares	194,053
Liquidation value	$ 194
Coupon rate	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 XVIII
Trust Preferred Securities
Securities issued (in shares) | shares	99,901
Liquidation value	$ 140
Common shares issued to parent (in shares) | shares	50
Junior subordinated debentures owned by the Trust, amount	$ 140
LIBOR | Citigroup Capital XIII
Trust Preferred Securities
Coupon rate - basis spread on variable rate	0.0637
LIBOR | Citigroup Capital XVIII
Trust Preferred Securities
Coupon rate - basis spread on variable rate	0.008875

CHANGES IN ACCUMULATED OTHER102

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Change in Each Component of AOCI (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		$ 201,672
Balance, end of period		202,866	$ 228,997
Net unrealized gains (losses) on investment securities
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(1,158)	(799)
Adjustment to opening balance, net of taxes				$ (3)	$ 504
Adjusted balance, beginning of period				(1,161)	(295)
Other comprehensive income before reclassifications		(949)	334
Increase (decrease) due to amounts reclassified from AOCI		(109)	(114)
Total other comprehensive income		(1,058)	220
Balance, end of period		(2,219)	(75)
Debt valuation adjustment (DVA)
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(921)	(352)
Adjustment to opening balance, net of taxes				0	0
Adjusted balance, beginning of period				(921)	(352)
Other comprehensive income before reclassifications		101	(55)
Increase (decrease) due to amounts reclassified from AOCI		27	(5)
Total other comprehensive income		128	(60)
Balance, end of period		(793)	(412)
Cash flow hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(698)	(560)
Adjustment to opening balance, net of taxes				0	0
Adjusted balance, beginning of period				(698)	(560)
Other comprehensive income before reclassifications		(243)	24
Increase (decrease) due to amounts reclassified from AOCI		21	(26)
Total other comprehensive income		(222)	(2)
Balance, end of period		(920)	(562)
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(6,183)	(5,164)
Adjustment to opening balance, net of taxes				0	0
Adjusted balance, beginning of period				(6,183)	(5,164)
Other comprehensive income before reclassifications		41	(49)
Increase (decrease) due to amounts reclassified from AOCI		47	37
Total other comprehensive income		88	(12)
Balance, end of period		(6,095)	(5,176)
Foreign currency translation adjustment (CTA), net of hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(25,708)	(25,506)
Adjustment to opening balance, net of taxes				0	0
Adjusted balance, beginning of period				(25,708)	(25,506)
Other comprehensive income before reclassifications		1,120	1,465
Increase (decrease) due to amounts reclassified from AOCI		0	(147)
Total other comprehensive income		1,120	1,318
Balance, end of period		(24,588)	(24,188)
Excluded component of fair value hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		0	0
Adjustment to opening balance, net of taxes				0	0
Adjusted balance, beginning of period				0	0
Other comprehensive income before reclassifications		(4)	0
Increase (decrease) due to amounts reclassified from AOCI		0	0
Total other comprehensive income		(4)	0
Balance, end of period		(4)	0
Accumulated other comprehensive income (loss)
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(34,668)	(32,381)
Adjustment to opening balance, net of taxes	[1]			(3)	504
Adjusted balance, beginning of period				$ (34,671)	$ (31,877)
Other comprehensive income before reclassifications		70	1,719
Increase (decrease) due to amounts reclassified from AOCI		(14)	(255)
Total other comprehensive income		52	1,464
Balance, end of period		$ (34,619)	$ (30,413)
[1]	See Note 1 to the Consolidated Financial Statements for additional details.

CHANGES IN ACCUMULATED OTHER103

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Schedule of Pre-Tax and After-Tax (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		$ 201,672
Balance, end of period		202,866	$ 228,997
Net unrealized gains (losses) on investment securities
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		(1,380)	346
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		322	(126)
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		(1,158)	(799)
Adjustment to opening balance				$ (3)	$ 504
Adjusted balance, beginning of period				(1,161)	(295)
Total other comprehensive income		(1,058)	220
Balance, end of period		(2,219)	(75)
Debt valuation adjustment (DVA)
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		167	(95)
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		(39)	35
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		(921)	(352)
Adjustment to opening balance				0	0
Adjusted balance, beginning of period				(921)	(352)
Total other comprehensive income		128	(60)
Balance, end of period		(793)	(412)
Cash flow hedges
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		(290)	1
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		68	(3)
Change in accumulated other comprehensive income (loss), after-tax
Total other comprehensive income		(222)	(2)
Benefit plans
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		91	(2)
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		(3)	(10)
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		(6,183)	(5,164)
Adjustment to opening balance				0	0
Adjusted balance, beginning of period				(6,183)	(5,164)
Total other comprehensive income		88	(12)
Balance, end of period		(6,095)	(5,176)
Foreign currency translation adjustment
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		1,130	1,468
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		(10)	(150)
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		(25,708)	(25,506)
Adjustment to opening balance				0	0
Adjusted balance, beginning of period				(25,708)	(25,506)
Total other comprehensive income		1,120	1,318
Balance, end of period		(24,588)	(24,188)
Excluded component of fair value hedges
Change in accumulated other comprehensive income (loss), pretax
Other comprehensive income (loss), pretax		(5)	0
Change in accumulated other comprehensive income (loss), tax effect
Other comprehensive income (loss), tax effect		1	0
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		0	0
Adjustment to opening balance				0	0
Adjusted balance, beginning of period				0	0
Total other comprehensive income		(4)	0
Balance, end of period		(4)	0
Citigroup's accumulated other comprehensive income (loss)
Change in accumulated other comprehensive income (loss), pretax
Balance, beginning of period, pretax		(41,228)	(42,035)
Adjustment to opening balance, pretax				(4)	803
Adjusted balance, beginning of period, pretax				(41,232)	(41,232)
Other comprehensive income (loss), pretax		(287)	1,718
Balance, end of period, pretax		(41,519)	(39,514)
Change in accumulated other comprehensive income (loss), tax effect
Balance, beginning of period, tax effect		6,560	9,654
Adjustment to opening balance, tax effect				1	(299)
Adjusted balance, beginning of period, tax effect				6,561	9,355
Other comprehensive income (loss), tax effect		339	(254)
Balance, end of period, tax effect		6,900	9,101
Change in accumulated other comprehensive income (loss), after-tax
Balance, beginning of period		(34,668)	(32,381)
Adjustment to opening balance	[1]			(3)	504
Adjusted balance, beginning of period				$ (34,671)	$ (31,877)
Total other comprehensive income		52	1,464
Balance, end of period		$ (34,619)	$ (30,413)
[1]	See Note 1 to the Consolidated Financial Statements for additional details.

CHANGES IN ACCUMULATED OTHER104

CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Reclassification out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments	$ (170)	$ (192)
Income from continuing operations before income taxes	(6,090)	(5,981)
Provision (benefits) for income taxes	1,441	1,863
Income (loss) from continuing operations	(4,649)	(4,118)
Realized gains (losses) on investment securities
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, after-tax	(109)	(114)
Realized gains (losses) on investment securities | (Gain) loss reclassified from AOCI
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments	(170)	(192)
Gross impairment losses	27	12
Income from continuing operations before income taxes	(143)	(180)
Provision (benefits) for income taxes	34	66
Income (loss) from continuing operations	(109)	(114)
Debt valuation adjustment (DVA)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, after-tax	27	(5)
Debt valuation adjustment (DVA) | (Gain) loss reclassified from AOCI
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Realized (gains) losses on sales of investments	35	(8)
Income from continuing operations before income taxes	35	(8)
Provision (benefits) for income taxes	(8)	3
Income (loss) from continuing operations	27	(5)
Cash flow hedges | (Gain) loss reclassified from AOCI
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes	29	(41)
Provision (benefits) for income taxes	(8)	15
Income (loss) from continuing operations	21	(26)
Cash flow hedges | (Gain) loss reclassified from AOCI | Interest rate contracts
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes	31	(44)
Cash flow hedges | (Gain) loss reclassified from AOCI | Foreign exchange contracts
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes	(2)	3
Pension liability adjustments
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, pretax	62	57
Total tax effect	(15)	(20)
Total amounts reclassified out of AOCI, after-tax	47	37
Prior service cost (benefit)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, pretax	(11)	(10)
Net actuarial loss
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, pretax	69	67
Curtailment/settlement impact
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, pretax	4	0
Foreign currency translation adjustment
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, after-tax	0	(147)
Foreign currency translation adjustment | (Gain) loss reclassified from AOCI
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Income from continuing operations before income taxes	0	(232)
Provision (benefits) for income taxes	0	85
Income (loss) from continuing operations	0	(147)
Citigroup's accumulated other comprehensive income (loss)
Pretax and after-tax amounts reclassified out of accumulated other comprehensive income (loss)
Total amounts reclassified out of AOCI, pretax	(17)	(404)
Total tax effect	3	149
Total amounts reclassified out of AOCI, after-tax	$ (14)	$ (255)

SECURITIZATIONS AND VARIABLE105

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Schedule of Variable Interest Entities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity
Total involvement with SPE assets	$ 308,003	$ 319,569
Consolidated VIE/SPE assets	72,116	76,394
Significant unconsolidated VIE assets	235,887	243,175
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	30,439	31,331
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	4,218	4,239
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	12,423	11,304
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	153	140
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	47,233	47,014
Credit card securitizations
Variable Interest Entity
Total involvement with SPE assets	46,540	50,795
Consolidated VIE/SPE assets	46,540	50,795
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-backed securities - U.S. agency-sponsored
Variable Interest Entity
Total involvement with SPE assets	111,980	116,610
Consolidated VIE/SPE assets	0	0
Significant unconsolidated VIE assets	111,980	116,610
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	2,690	2,647
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	87	74
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	2,777	2,721
Mortgage securitizations - Non-agency-sponsored
Variable Interest Entity
Total involvement with SPE assets	20,660	22,251
Consolidated VIE/SPE assets	1,891	2,035
Significant unconsolidated VIE assets	18,769	20,216
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	335	330
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	1	1
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	336	331
Citi-administered asset-backed commercial paper conduits (ABCP)
Variable Interest Entity
Total involvement with SPE assets	18,962	19,282
Consolidated VIE/SPE assets	18,962	19,282
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	16,491	20,588
Consolidated VIE/SPE assets	0	0
Significant unconsolidated VIE assets	16,491	20,588
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	5,362	5,956
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	9
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	5,371	5,965
Asset-based financing
Variable Interest Entity
Total involvement with SPE assets	63,019	60,472
Consolidated VIE/SPE assets	637	633
Significant unconsolidated VIE assets	62,382	59,839
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	19,190	19,478
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	571	583
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	6,904	5,878
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	26,665	25,939
Municipal securities tender option bond trusts (TOBs)
Variable Interest Entity
Total involvement with SPE assets	7,105	6,925
Consolidated VIE/SPE assets	2,165	2,166
Significant unconsolidated VIE assets	4,940	4,759
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	18	138
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	0	0
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	3,344	3,035
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	3,362	3,173
Municipal investments
Variable Interest Entity
Total involvement with SPE assets	19,265	19,119
Consolidated VIE/SPE assets	5	7
Significant unconsolidated VIE assets	19,260	19,112
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	2,769	2,709
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	3,632	3,640
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	2,129	2,344
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	8,530	8,693
Client intermediation
Variable Interest Entity
Total involvement with SPE assets	1,414	958
Consolidated VIE/SPE assets	1,279	824
Significant unconsolidated VIE assets	135	134
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	37	32
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	7	9
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	44	41
Investment funds
Variable Interest Entity
Total involvement with SPE assets	1,874	1,892
Consolidated VIE/SPE assets	603	616
Significant unconsolidated VIE assets	1,271	1,276
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	10	14
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	7	7
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	13	13
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	30	34
Other
Variable Interest Entity
Total involvement with SPE assets	693	677
Consolidated VIE/SPE assets	34	36
Significant unconsolidated VIE assets	659	641
Funded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, debt investments	28	27
Maximum exposure to loss in significant unconsolidated VIEs, equity investments	8	9
Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs, funding commitments	33	34
Maximum exposure to loss in significant unconsolidated VIEs, guarantees and derivatives	49	47
Funded and Unfunded Exposure
Maximum exposure to loss in significant unconsolidated VIEs	118	117
Mortgage-backed securities
Funded and Unfunded Exposure
Outstanding balance of mortgage loans securitized	$ 8,000	$ 9,000

SECURITIZATIONS AND VARIABLE106

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding Commitments (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 12,423	$ 11,304
Liquidity facilities
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,344	3,035
Liquidity facilities | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,344	3,035
Liquidity facilities | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	9,079	8,269
Loan / equity commitments | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	6,904	5,878
Loan / equity commitments | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	2,129	2,344
Loan / equity commitments | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	13	13
Loan / equity commitments | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 33	$ 34

SECURITIZATIONS AND VARIABLE107

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Carrying Amounts and Classifications of Consolidated Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Variable Interest Entity
Cash	$ 21,850	$ 23,775	$ 22,272
Trading account assets	268,808	252,790
Investments	351,971	352,290
Total loans, net of allowance	660,584	654,679
Other	105,882	103,926
Total assets	1,922,104	1,842,465
Significant unconsolidated VIE assets
Variable Interest Entity
Cash	0	0
Trading account assets	7,700	8,500
Investments	4,400	4,400
Total loans, net of allowance	21,900	22,200
Other	500	500
Total assets	$ 34,500	$ 35,600

SECURITIZATIONS AND VARIABLE108

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Credit Card Securitizations (Details) $ in Billions	3 Months Ended
	Mar. 31, 2018USD ($)trust	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
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	$ 28.8		$ 28.8
Retained by Citigroup as trust-issued securities	7.7		7.6
Retained by Citigroup via non-certificated interests	10.1		14.4
Total ownership interests in principal amount of trust credit card receivables	46.6		$ 50.8
Credit card securitizations
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	2.8	$ 2.5
Pay down of maturing notes	$ (2.8)	$ (2)

SECURITIZATIONS AND VARIABLE109

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding, Liquidity Facilities and Subordinated Interests (Details) - USD ($) $ in Billions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Citibank Credit Card Master Trust (Master Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	2 years 8 months 30 days	2 years 6 months 25 days
Term notes issued to third parties	$ 27.8	$ 27.8
Term notes retained by Citigroup affiliates	5.8	5.7
Total Master Trust liabilities	$ 33.6	$ 33.5
Citibank OMNI Master Trust (Omni Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	1 year 7 months	1 year 11 months
Term notes issued to third parties	$ 1	$ 1
Term notes retained by Citigroup affiliates	1.9	1.9
Total Master Trust liabilities	$ 2.9	$ 2.9

SECURITIZATIONS AND VARIABLE110

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Mortgage Securitizations (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Mortgage securitizations - U.S. agency sponsored
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	$ 8,000	$ 7,200
Contractual servicing fees received	0	$ 100
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	1,767		$ 1,634
Carrying value of retained interests, impact of 10% adverse change in discount rate	(47)		(44)
Carrying value of retained interests, impact of 20% adverse change in discount rate	(91)		(85)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	(37)		(41)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	$ (75)		$ (84)
Mortgage securitizations - U.S. agency sponsored | 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 (as a percent)	3.00%	2.40%
Constant prepayment rate (as a percent)	4.20%	3.80%
Weighted average life (in years)	7 years 8 months 12 days	6 years 6 months
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	0.80%		1.80%
Constant prepayment rate (as a percent)	4.30%		6.90%
Weighted average life (in years)	1 month 6 days		1 month 6 days
Mortgage securitizations - U.S. agency sponsored | 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 (as a percent)	11.40%	19.90%
Constant prepayment rate (as a percent)	16.00%	10.50%
Weighted average life (in years)	18 years	12 years 2 months 12 days
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	41.30%		84.20%
Constant prepayment rate (as a percent)	18.40%		27.80%
Weighted average life (in years)	27 years 6 months		27 years 9 months 18 days
Mortgage securitizations - U.S. agency sponsored | Weighted Average
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate (as a percent)	6.40%	13.00%
Constant prepayment rate (as a percent)	8.50%	6.20%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	6.20%		7.10%
Constant prepayment rate (as a percent)	10.30%		11.60%
Mortgage securitizations - Non-agency-sponsored
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations	$ 3,400	$ 1,400
Contractual servicing fees received	$ 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 (as a percent)	0.00%	0.00%
Constant prepayment rate (as a percent)	0.00%	0.00%
Anticipated net credit losses (as a percent)		0.00%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	6.50%
Constant prepayment rate (as a percent)	8.90%
Anticipated net credit losses (as a percent)	46.90%
Weighted average life (in years)	5 years 4 months 24 days
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	$ 245		$ 214
Carrying value of retained interests, impact of 10% adverse change in discount rate	0		(2)
Carrying value of retained interests, impact of 20% adverse change in discount rate	0		(4)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	0		(1)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	0		(1)
Carrying value of retained interests, impact of 10% adverse change in anticipated net credit losses	0		(3)
Carrying value of retained interests, impact of 20% adverse change in anticipated net credit losses	$ 0		$ (7)
Senior interests | Low end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)			5.80%
Constant prepayment rate (as a percent)			8.90%
Anticipated net credit losses (as a percent)			0.40%
Weighted average life (in years)			4 years 9 months 18 days
Senior interests | High end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)			100.00%
Constant prepayment rate (as a percent)			15.50%
Anticipated net credit losses (as a percent)			46.90%
Weighted average life (in years)			5 years 3 months 18 days
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 (as a percent)	0.00%	0.00%
Constant prepayment rate (as a percent)	0.00%	0.00%
Anticipated net credit losses (as a percent)	0.00%	0.00%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	6.50%		5.80%
Constant prepayment rate (as a percent)	8.90%		8.90%
Anticipated net credit losses (as a percent)	46.90%		46.90%
Subordinated interests
Key assumptions used in measuring fair value of retained interests at date of sale or securitization of mortgage receivables
Discount rate (as a percent)	0.00%	0.00%
Constant prepayment rate (as a percent)	0.00%	0.00%
Anticipated net credit losses (as a percent)	0.00%	0.00%
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests	$ 138		$ 139
Carrying value of retained interests, impact of 10% adverse change in discount rate	(2)		(3)
Carrying value of retained interests, impact of 20% adverse change in discount rate	(4)		(5)
Carrying value of retained interests, impact of 10% adverse change in constant prepayment rate	(1)		(1)
Carrying value of retained interests, impact of 20% adverse change in constant prepayment rate	(2)		(2)
Carrying value of retained interests, impact of 10% adverse change in anticipated net credit losses	0		0
Carrying value of retained interests, impact of 20% adverse change in anticipated net credit losses	$ (1)		$ 0
Subordinated interests | Low end of range
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	4.00%		2.80%
Constant prepayment rate (as a percent)	9.10%		8.60%
Anticipated net credit losses (as a percent)	35.10%		35.10%
Weighted average life (in years)	2 years 1 month 6 days		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 (as a percent)	11.20%		35.10%
Constant prepayment rate (as a percent)	13.10%		13.10%
Anticipated net credit losses (as a percent)	52.10%		52.10%
Weighted average life (in years)	18 years 3 months 18 days		18 years 7 months 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 (as a percent)	0.00%	0.00%
Constant prepayment rate (as a percent)	0.00%	0.00%
Anticipated net credit losses (as a percent)	0.00%	0.00%
Key assumptions used in measuring fair value related to transferor's continuing involvement
Discount rate (as a percent)	7.30%		9.00%
Constant prepayment rate (as a percent)	10.70%		10.60%
Anticipated net credit losses (as a percent)	44.50%		44.90%
Citicorp | Mortgage securitizations - U.S. agency sponsored
Cash Flows Between Transferor and Transferee
Gains recognized on the securitization	$ 5	$ 29
Citicorp | Mortgage securitizations - Non-agency-sponsored
Cash Flows Between Transferor and Transferee
Gains recognized on the securitization	$ 18	$ 20

SECURITIZATIONS AND VARIABLE111

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Capitalized MSRs
Balance, at beginning of period	$ 558
Balance, as of March 31	587
Mortgage servicing rights
Classification of Securitizations
Fair value of capitalized mortgage servicing rights	587	$ 567
Principal amount of loans and other financial instruments	64,000	71,000
Capitalized MSRs
Balance, at beginning of period	558	1,564
Originations	17	35
Changes in fair value of MSRs due to changes in inputs and assumptions	46	67
Other changes	(17)	(53)
Sale of MSRs	(17)	(1,046)
Balance, as of March 31	587	567
MSR fees
Servicing fees	46	106
Late fees	1	3
Ancillary fees	3	4
Total MSR fees	50	113
Mortgage securitizations - Non-agency-sponsored
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	74		$ 79
Original par value of re-securitizations deals in which the entity holds a retained interest	668		887
U.S. government-sponsored agency guaranteed
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	2,100		2,100
Securities transferred to re-securitization entities	7,000	$ 4,500
Market value of retained interest related to re-securitization transaction	744		854
Original fair value of re-securitizations deals in which the entity holds a retained interest	$ 65,200		$ 68,300

SECURITIZATIONS AND VARIABLE112

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset-Backed Commercial Paper Conduits (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Classification of Other Securitization Details
Commercial paper	$ 10,022,000,000	$ 9,940,000,000
Citi-administered asset-backed commercial paper conduits (ABCP)
Classification of Other Securitization Details
Purchased assets outstanding under conduits	19,000,000,000	19,300,000,000
Incremental funding commitments with clients	$ 15,200,000,000	$ 14,500,000,000
Weighted average life of commercial paper issued by conduits	43 days	51 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	$ 1,700,000,000
Commercial paper	$ 9,000,000,000	$ 9,300,000,000

SECURITIZATIONS AND VARIABLE113

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Collateralized Debt and Loan Obligations (Details) - Collateralized loan obligations (CLOs) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Variable Interest Entity
Proceeds from new securitizations	$ 1,400	$ 300
Carrying value of retained interests	3,713		$ 3,607
Carrying value of retained interests, impact of 10% adverse change in discount rate	(25)		(24)
Carrying value of retained interests, impact of 20% adverse change in discount rate	$ (49)		$ (47)
Minimum
Variable Interest Entity
Discount rate (as a percent)	1.10%		1.10%
Maximum
Variable Interest Entity
Discount rate (as a percent)	1.60%		1.60%

SECURITIZATIONS AND VARIABLE114

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset Based Financing (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity
Total unconsolidated VIE assets	$ 235,887	$ 243,175
Maximum exposure to unconsolidated VIEs	47,233	47,014
Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	62,382	59,839
Maximum exposure to unconsolidated VIEs	26,665	25,939
Commercial and other real estate | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	15,152	15,370
Maximum exposure to unconsolidated VIEs	4,815	5,445
Corporate loans | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	6,862	4,725
Maximum exposure to unconsolidated VIEs	5,731	3,587
Hedge funds and equities | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	449	542
Maximum exposure to unconsolidated VIEs	58	58
Airplanes, ships and other assets | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	39,919	39,202
Maximum exposure to unconsolidated VIEs	$ 16,061	$ 16,849

SECURITIZATIONS AND VARIABLE115

SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Municipal Securities Tender Option Bond Trusts (Details) - USD ($) $ in Billions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Client intermediation
Variable Interest Entity
Proceeds from new securitizations	$ 0.2	$ 0.5
Municipal securities tender option bond trusts (TOBs)
Variable Interest Entity
Liquidity agreements, customer TOB trust	3.4		$ 3.2
Notional amount of offsetting reimbursement agreements	2		2
Liquidity agreements, other trusts	$ 6.2		$ 6.1
Municipal securities tender option bond trusts (TOBs) | Maximum
Variable Interest Entity
The threshold ownership percentage on Residual value of customers TOBs for which the reimbursement agreement applied	25.00%

DERIVATIVES ACTIVITIES - Deriva

DERIVATIVES ACTIVITIES - Derivative Notionals (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Net Investment Hedging
Derivatives
Derivative notionals	$ 2	$ 63
Hedging instruments under ASC 815
Derivatives
Derivative notionals	279,640	270,445
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	197,828	189,779
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	197,328	189,779
Hedging instruments under ASC 815 | Interest rate futures and forwards
Derivatives
Derivative notionals	500	0
Hedging instruments under ASC 815 | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	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	81,721	80,643
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	40,063	37,162
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	39,102	33,103
Hedging instruments under ASC 815 | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	1,151	3,951
Hedging instruments under ASC 815 | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,405	6,427
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	91	23
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	91	23
Hedging instruments under ASC 815 | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts | 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	55,216,776	45,792,663
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	37,856,351	31,964,914
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	21,321,930	18,754,219
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	8,245,034	6,460,539
Other derivative instruments, Trading derivatives | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	4,578,837	3,516,131
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,710,550	3,234,025
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	14,317,143	10,950,471
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	6,940,579	5,576,357
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	4,465,416	3,097,700
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	1,460,614	1,127,728
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,450,534	1,148,686
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,105,494	1,006,565
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	243,567	215,834
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	67,910	72,616
Other derivative instruments, Trading derivatives | Equity contract options | Written or Sold
Derivatives
Derivative notionals	427,798	389,961
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	366,219	328,154
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	405,954	357,858
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	92,552	82,039
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	176,174	153,248
Other derivative instruments, Trading derivatives | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	71,136	62,045
Other derivative instruments, Trading derivatives | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	66,092	60,526
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,531,834	1,512,855
Other derivative instruments, Trading derivatives | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	741,700	735,142
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 790,134	$ 777,713

DERIVATIVES ACTIVITIES - Der117

DERIVATIVES ACTIVITIES - Derivative Mark-to-Market (MTM) Receivables/Payables Narrative (Details) - Rule Changes Adopted by Clearing Organizations - USD ($) $ in Billions	Mar. 31, 2018	Dec. 31, 2017
Derivatives
Reduction of derivative assets	$ 110	$ 100
Reduction of derivative liabilities	$ 100	$ 100

DERIVATIVES ACTIVITIES - Der118

DERIVATIVES ACTIVITIES - Derivative Mark-to-Market (MTM) Receivables/Payables (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting of cash collateral received	$ (40,951)	$ (38,532)
Less: Netting of cash collateral paid	(33,800)	(35,666)
Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	390,339	388,561
Cash collateral paid, net of amount used to offset derivative liabilities	8,676	7,541
Less: Netting agreements to assets	(303,169)	(306,401)
Less: Netting of cash collateral received	(40,951)	(38,532)
Total trading account derivatives, assets	54,895	51,169
Less: Cash collateral received	(924)	(872)
Less: Non-cash collateral received	(13,525)	(12,739)
Total Net receivables	40,446	37,558
Cash collateral paid, gross	42,476	43,207
Does not meet applicable offsetting guidance, assets	5,000	6,000
Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(163,000)	(283,000)
Less: Netting agreements to liabilities		(283,000)
Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(129,000)	(14,000)
Less: Netting agreements to liabilities		(14,000)
Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(11,000)	(9,000)
Less: Netting agreements to liabilities		(9,000)
Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	371,715	375,344
Cash collateral received, net of amount used to offset derivative assets	14,971	14,308
Less: Netting agreements to liabilities	(303,169)	(306,401)
Less: Netting of cash collateral paid	(33,800)	(35,666)
Total derivative liabilities	49,717	47,585
Less: Cash collateral paid	(113)	(121)
Less: Non-cash collateral paid	(20,260)	(6,929)
Total Net payables	29,344	40,535
Cash collateral received, gross	55,922	52,840
Does not meet applicable offsetting guidance, liabilities	7,000	8,000
Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(163,000)
Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(129,000)
Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(11,000)
Derivative instruments designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	2,969	3,222
Derivative instruments designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,416	1,376
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,958	2,079
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,896	1,969
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	62	110
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	217	226
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	92	134
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	125	92
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,011	1,143
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,011	1,143
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,199	1,150
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,199	1,150
Derivatives instruments not designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	387,370	385,339
Derivatives instruments not designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	370,299	373,968
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	193,871	202,908
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	184,682	195,677
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	8,972	7,129
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	217	102
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	175,369	184,413
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	163,259	173,937
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	11,926	10,381
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	184	95
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	129,206	120,816
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	125,761	119,092
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	3,426	1,690
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	19	34
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	122,355	119,622
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	119,004	117,473
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	3,343	2,028
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	8	121
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	29,435	26,978
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	18,737	17,221
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	12	21
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	10,686	9,736
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	34,115	31,373
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	23,424	21,201
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	17	25
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	10,674	10,147
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	15,831	14,103
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	15,189	13,499
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	642	604
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	18,851	17,027
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	18,134	16,362
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	717	665
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	19,027	20,534
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	12,059	12,972
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	6,968	7,562
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	19,609	21,533
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	11,633	12,958
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	$ 7,976	$ 8,575

DERIVATIVES ACTIVITIES - Gains

DERIVATIVES ACTIVITIES - Gains (Losses) Included in Other Revenue (Details) - Other revenue - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative gain (losses)
Gains (losses) recognized in Other revenue related to derivatives not designated in a qualifying hedging relationship	$ 453	$ (107)
Interest rate contracts
Derivative gain (losses)
Gains (losses) recognized in Other revenue related to derivatives not designated in a qualifying hedging relationship	(28)	(53)
Foreign exchange contracts
Derivative gain (losses)
Gains (losses) recognized in Other revenue related to derivatives not designated in a qualifying hedging relationship	527	225
Credit derivatives
Derivative gain (losses)
Gains (losses) recognized in Other revenue related to derivatives not designated in a qualifying hedging relationship	$ (46)	$ (279)

DERIVATIVES ACTIVITIES - Fair V

DERIVATIVES ACTIVITIES - Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Gain (loss) on fair value hedges
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges		$ 52
Other revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	$ 177	(385)
Gain (loss) on the hedged item in designated and qualifying fair value hedges	(248)	491
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	24	54
Net interest revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	878
Gain (loss) on the hedged item in designated and qualifying fair value hedges	(866)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	0
Interest rate contracts
Gain (loss) on fair value hedges
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges		(10)
Interest rate contracts | Other revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	0	(305)
Gain (loss) on the hedged item in designated and qualifying fair value hedges	0	296
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	0	1
Interest rate contracts | Net interest revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	878
Gain (loss) on the hedged item in designated and qualifying fair value hedges	(866)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	0
Foreign exchange contracts
Gain (loss) on fair value hedges
Amount of cross currency basis included in AOCI	5
Hedge ineffectiveness recognized in earnings on designated and qualifying fair value hedges		62
Foreign exchange contracts | Other revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	179	(82)
Gain (loss) on the hedged item in designated and qualifying fair value hedges	(249)	196
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	23	52
Foreign exchange contracts | Net interest revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	0
Gain (loss) on the hedged item in designated and qualifying fair value hedges	0
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	0
Commodity and other contracts | Other revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	(2)	2
Gain (loss) on the hedged item in designated and qualifying fair value hedges	1	(1)
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	1	$ 1
Commodity and other contracts | Net interest revenue
Gain (loss) on fair value hedges
Gain (loss) on the derivatives in designated and qualifying fair value hedges	0
Gain (loss) on the hedged item in designated and qualifying fair value hedges	0
Net gain (loss) excluded from assessment of the effectiveness of fair value hedges	$ 0

DERIVATIVES ACTIVITIES - Cumula

DERIVATIVES ACTIVITIES - Cumulative Basis Adjustment (Details) $ in Millions	Mar. 31, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Long-term debt, carrying amount of hedged asset (liability)	$ 139,786
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, active	(24)
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, de-designated	1,921
Investments available for sale, carrying amount of hedged asset (liability)	73,717
Investments available for sale, cumulative fair value hedging adjustment included in the carrying amount, active	259
Investments available for sale, cumulative fair value hedging adjustment included in the carrying amount, de-designated	$ 69

DERIVATIVES ACTIVITIES - Cash F

DERIVATIVES ACTIVITIES - Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pretax change in accumulated other comprehensive income (loss)
Total gain (loss) recognized in AOCI	$ (316)	$ 41
Other revenue	334	248
Net interest revenue	11,172	10,955
Revenue	18,872	18,366
Cash flow hedge gain expected to be reclassified from AOCI within 12 months	$ 142
Maximum length of time hedged in cash flow hedge	10 years
Interest rate contracts
Pretax change in accumulated other comprehensive income (loss)
Total gain (loss) recognized in AOCI	$ (322)	41
Foreign exchange contracts
Pretax change in accumulated other comprehensive income (loss)
Total gain (loss) recognized in AOCI	6	0
Cash flow hedges | (Gain) loss reclassified from AOCI
Pretax change in accumulated other comprehensive income (loss)
Other revenue	2
Net interest revenue	(31)
Revenue		41
Cash flow hedges | (Gain) loss reclassified from AOCI | Interest rate contracts
Pretax change in accumulated other comprehensive income (loss)
Other revenue	0
Net interest revenue	(31)
Revenue		44
Cash flow hedges | (Gain) loss reclassified from AOCI | Foreign exchange contracts
Pretax change in accumulated other comprehensive income (loss)
Other revenue	2
Net interest revenue	$ 0
Revenue		$ (3)

DERIVATIVES ACTIVITIES - Net In

DERIVATIVES ACTIVITIES - Net Investment Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Investment Hedging
Derivative gain (losses)
Gain (loss) recognized in OCI, effective portion, net	$ (491)	$ (1,716)

DERIVATIVES ACTIVITIES - Credit

DERIVATIVES ACTIVITIES - Credit Derivatives (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)agency	Dec. 31, 2017USD ($)
Credit Risk Derivatives
Fair values, Receivable	$ 19,027	$ 20,534
Fair values, Payable	19,609	21,533
Notionals, Protection purchased	790,134	777,713
Notionals, Protection sold	741,700	735,142
Fair value of derivative in liability position	29,000	29,000
Fair value of collateral already posted	$ 26,000	28,000
Number of rating agencies | agency	3
Additional collateral to be posted	$ 700
Collateral to be segregated	200
Aggregate cash obligations and collateral requirements	900
Purchased
Credit Risk Derivatives
Fair values, Receivable	3,016	3,195
Fair values, Payable	16,793	3,147
Sold
Credit Risk Derivatives
Fair values, Receivable	16,011	17,339
Fair values, Payable	2,816	18,386
Within 1 year
Credit Risk Derivatives
Fair values, Receivable	2,337	2,477
Fair values, Payable	2,517	2,914
Notionals, Protection purchased	228,396	231,878
Notionals, Protection sold	212,661	218,097
From 1 to 5 years
Credit Risk Derivatives
Fair values, Receivable	14,152	16,098
Fair values, Payable	14,223	16,435
Notionals, Protection purchased	477,627	498,606
Notionals, Protection sold	454,001	476,345
After 5 years
Credit Risk Derivatives
Fair values, Receivable	2,538	1,959
Fair values, Payable	2,869	2,184
Notionals, Protection purchased	84,111	47,229
Notionals, Protection sold	75,038	40,700
Investment grade
Credit Risk Derivatives
Fair values, Receivable	9,496	10,473
Fair values, Payable	9,594	10,616
Notionals, Protection purchased	597,093	588,324
Notionals, Protection sold	559,526	557,987
Non-investment grade
Credit Risk Derivatives
Fair values, Receivable	9,531	10,061
Fair values, Payable	10,015	10,917
Notionals, Protection purchased	193,041	189,389
Notionals, Protection sold	182,174	177,155
Credit default swaps and options
Credit Risk Derivatives
Fair values, Receivable	18,591	20,251
Fair values, Payable	18,787	20,554
Notionals, Protection purchased	766,018	754,114
Notionals, Protection sold	729,303	724,228
Total return swaps and other
Credit Risk Derivatives
Fair values, Receivable	436	283
Fair values, Payable	822	979
Notionals, Protection purchased	24,116	23,599
Notionals, Protection sold	12,397	10,914
Banks
Credit Risk Derivatives
Fair values, Receivable	6,782	7,471
Fair values, Payable	6,120	6,669
Notionals, Protection purchased	263,672	264,414
Notionals, Protection sold	272,815	273,711
Broker-dealers
Credit Risk Derivatives
Fair values, Receivable	2,155	2,325
Fair values, Payable	2,060	2,285
Notionals, Protection purchased	72,862	73,273
Notionals, Protection sold	83,585	83,229
Non-financial
Credit Risk Derivatives
Fair values, Receivable	75	70
Fair values, Payable	75	91
Notionals, Protection purchased	1,240	1,288
Notionals, Protection sold	2,313	1,140
Insurance and other financial institutions
Credit Risk Derivatives
Fair values, Receivable	10,015	10,668
Fair values, Payable	11,354	12,488
Notionals, Protection purchased	452,360	438,738
Notionals, Protection sold	382,987	377,062
Interest rate swaps
Credit Risk Derivatives
Cash proceeds received for assets derecognized	3,400	3,000
Fair value of derecognized assets	3,400	3,100
Fair value gross derivative assets	79	89
Trading derivatives, liability	$ 52	$ 15

FAIR VALUE MEASUREMENT - Market

FAIR VALUE MEASUREMENT - Market Valuation Adjustments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Credit and funding valuation adjustments contra-liability (contra-asset)
Counterparty CVA	$ (841)		$ (970)
Asset FVA	(438)		(447)
Citigroup (own-credit) CVA	364		287
Liability FVA	40		47
Total CVA—derivative instruments	(875)		$ (1,083)
Credit, Funding and Debt Valuation Adjustments Gain (Loss) [Abstract]
Counterparty CVA	23	$ 90
Asset FVA	9	92
Own-credit CVA	75	(72)
Liability FVA	(7)	(10)
Total CVA—derivative instruments	100	100
DVA related to own FVO liabilities	167	(95)
Total CVA and DVA	$ 267	$ 5

FAIR VALUE MEASUREMENT - Items

FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell, Netting	$ (86,543)	$ (73,476)
Trading account assets	268,808	252,790
Netting of cash collateral received	(40,951)	(38,532)
Investments	351,971	352,290
Loans	4,536	4,374
Mortgage servicing rights	587	558
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned or sold under agreements to repurchase, Netting	(86,543)	(73,476)
Netting of cash collateral paid	(33,800)	(35,666)
Assets transferred from Level 1 to Level 2	700	4,800
Assets transferred from Level 2 to Level 1	4,000	4,000
Liabilities transferred from Level 1 to Level 2		400
Liabilities transferred from Level 2 to Level 1	200	300
Investments measured at net asset value excluded from Level 3	433	404
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	222,952	188,587
Federal funds sold and securities borrowed or purchased under agreements to resell, Netting	(61,415)	(55,638)
Federal funds sold and securities borrowed or purchased under agreements to resell	161,537	132,949
Investments	292,659	291,716
Loans	4,536	4,374
Mortgage servicing rights	587	558
Assets before netting	1,154,105	1,101,517
Netting, Assets, total of netting agreements and cash collateral received	(405,535)	(400,571)
Total assets	748,570	700,946
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,686	1,465
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	107,255	96,276
Federal funds purchased and securities loaned or sold under agreements to repurchase, Netting	(61,415)	(55,638)
Federal funds purchased and securities loaned or sold under agreements to repurchase	45,840	40,638
Securities sold, not yet purchased	91,954	76,171
Trading liabilities	94,244	77,585
Short-term borrowings	4,467	4,627
Long-term debt	33,571	31,392
Total liabilities, Gross	643,461	614,958
Total liabilities, Netting	(398,384)	(397,705)
Total liabilities	245,077	217,253
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	371,715	375,344
Cash collateral received	14,971	14,308
Total trading derivatives and cash collateral, liability	386,686	389,652
Netting agreements	(303,169)	(306,401)
Netting of cash collateral paid	(33,800)	(35,666)
Netting, Liabilities, total of netting agreements and cash collateral received	(336,969)	(342,067)
Total derivative liabilities	49,717	47,585
Cash collateral received, gross	55,922	52,840
Recurring | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	175,586	184,639
Recurring | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	123,554	120,772
Recurring | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	34,115	31,373
Recurring | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	18,851	17,027
Recurring | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	19,609	21,533
Recurring | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Netting of cash collateral paid	(17)	0
Netting, Liabilities, total of netting agreements and cash collateral received	0
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	15,552	13,961
Total other assets and cash collateral, gross	15,552	13,961
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	2,290	1,414
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,523	22,964
Investments	41,288	41,741
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,227	813
Investments	2,759	2,884
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,475	1,366
Investments	308	332
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,225	25,143
Investments	44,355	44,957
Recurring | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	24,710	21,137
Investments	117,314	118,146
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,882	4,700
Investments	9,837	8,765
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	71,556	60,206
Investments	103,775	100,533
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	19,352	15,705
Investments	12,996	14,109
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	54,287	60,219
Investments	277	189
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,183	2,788
Investments	3,081	3,918
Recurring | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	11,718	11,723
Investments	165	297
Recurring | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	859	802
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	213,913	201,621
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	390,339	388,561
Cash collateral paid	8,676	7,541
Trading derivative, asset, gross net cash collateral paid	399,015	396,102
Netting agreements	(303,169)	(306,401)
Netting of cash collateral received	(40,951)	(38,532)
Total trading derivatives, netting	(344,120)	(344,933)
Trading derivatives	54,895	51,169
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral paid, gross	42,476	43,207
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	195,829	204,987
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	130,217	121,959
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	29,435	26,978
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	15,831	14,103
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	19,027	20,534
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Total trading derivatives, netting	0	0
Total other assets and cash collateral, gross	20,443	18,559
Other assets	20,443	18,559
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0
Investments	171,540	165,507
Loans	0	0
Mortgage servicing rights	0	0
Assets before netting	$ 305,253	$ 292,700
Total as a percentage of gross assets	26.60%	26.80%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 0	$ 0
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	0	0
Securities sold, not yet purchased	80,995	65,843
Trading liabilities	80,995	65,843
Short-term borrowings	0	0
Long-term debt	0	0
Total liabilities, Gross	$ 99,032	$ 82,437
Total as a percentage of gross liabilities	15.80%	13.70%
Recurring | Level 1 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 2,488	$ 2,691
Recurring | Level 1 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	218	137
Recurring | Level 1 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	4	9
Recurring | Level 1 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,126	2,430
Recurring | Level 1 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	138	115
Recurring | Level 1 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2	0
Recurring | Level 1 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	15,549	13,903
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	20,812	17,524
Investments	106,239	106,964
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	46,617	39,347
Investments	61,312	56,456
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	274	301
Investments	3,756	1,911
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	47,797	53,305
Investments	233	176
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	2	3
Investments	0	0
Recurring | Level 1 | Non-marketable equity investments measured using the measurement alternative
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	115,502	110,480
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,662	2,810
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	276	145
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	5	19
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,212	2,364
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	169	282
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	15,549	13,903
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	222,936	188,571
Investments	119,031	123,772
Loans	3,982	3,824
Mortgage servicing rights	0	0
Assets before netting	$ 828,750	$ 790,217
Total as a percentage of gross assets	72.40%	72.20%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 1,394	$ 1,179
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	106,398	95,550
Securities sold, not yet purchased	10,911	10,306
Trading liabilities	13,201	11,715
Short-term borrowings	4,386	4,609
Long-term debt	20,087	18,310
Total liabilities, Gross	$ 505,516	$ 494,879
Total as a percentage of gross liabilities	80.40%	82.40%
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 360,050	$ 363,466
Recurring | Level 2 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	173,128	182,372
Recurring | Level 2 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	123,117	120,316
Recurring | Level 2 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	29,689	26,472
Recurring | Level 2 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	16,242	14,482
Recurring | Level 2 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	17,874	19,824
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	0	50
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	2,290	1,409
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,317	22,801
Investments	41,265	41,717
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,084	649
Investments	2,759	2,884
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,440	1,309
Investments	303	329
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	24,841	24,759
Investments	44,327	44,930
Recurring | Level 2 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,898	3,613
Investments	11,075	11,182
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,671	4,426
Investments	9,155	8,028
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	24,918	20,843
Investments	42,393	43,985
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	18,826	15,129
Investments	9,164	12,127
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	6,253	6,794
Investments	43	11
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,586	1,198
Investments	2,584	3,091
Recurring | Level 2 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	11,000	11,105
Investments	165	297
Recurring | Level 2 | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	125	121
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	94,993	87,867
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	382,927	381,543
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	193,319	203,134
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	129,691	121,363
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	26,664	24,170
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	15,100	13,252
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	18,153	19,624
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	4,881	4,640
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	16	16
Investments	2,088	2,437
Loans	554	550
Mortgage servicing rights	587	558
Assets before netting	$ 11,426	$ 11,059
Total as a percentage of gross assets	1.00%	1.00%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 292	$ 286
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	857	726
Securities sold, not yet purchased	48	22
Trading liabilities	48	27
Short-term borrowings	81	18
Long-term debt	13,484	13,082
Total liabilities, Gross	$ 23,942	$ 23,334
Total as a percentage of gross liabilities	3.80%	3.90%
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 9,177	$ 9,187
Recurring | Level 3 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,240	2,130
Recurring | Level 3 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	433	447
Recurring | Level 3 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,300	2,471
Recurring | Level 3 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,471	2,430
Recurring | Level 3 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1,733	1,709
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	3	8
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	5
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	206	163
Investments	23	24
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	143	164
Investments	0	0
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	35	57
Investments	5	3
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	384	384
Investments	28	27
Recurring | Level 3 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	211	274
Investments	682	737
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	21	16
Investments	70	92
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	252	275
Investments	76	71
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	237	120
Investments	1	2
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,597	1,590
Investments	497	827
Recurring | Level 3 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	716	615
Investments	0	0
Recurring | Level 3 | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	734	681
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,418	3,274
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	4,750	4,208
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,234	1,708
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	521	577
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	559	444
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	562	569
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	874	910
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	$ 13	$ 16

FAIR VALUE MEASUREMENT - Level

FAIR VALUE MEASUREMENT - Level 3 Fair Value Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
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	$ (4,979)	$ (4,753)
Net realized/unrealized gains (losses) included in principal transactions	88	(696)
Transfers into Level 3	(99)	39
Transfers out of Level 3	523	(27)
Purchases	43	125
Issuances	0	0
Sales	(22)	(169)
Settlements	19	35
Balance at end of period, asset (liability), net	(4,427)	(5,446)
Unrealized gains (losses) still held	(338)	(440)
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	(422)	(663)
Net realized/unrealized gains (losses) included in principal transactions	381	(37)
Transfers into Level 3	5	(38)
Transfers out of Level 3	37	19
Purchases	7	6
Issuances	0	0
Sales	(16)	(113)
Settlements	2	53
Balance at end of period, asset (liability), net	(6)	(773)
Unrealized gains (losses) still held	(94)	(23)
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	130	413
Net realized/unrealized gains (losses) included in principal transactions	(62)	(390)
Transfers into Level 3	(1)	55
Transfers out of Level 3	8	(20)
Purchases	1	34
Issuances	0	0
Sales	0	(32)
Settlements	12	(12)
Balance at end of period, asset (liability), net	88	48
Unrealized gains (losses) still held	(155)	(341)
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	(2,027)	(1,557)
Net realized/unrealized gains (losses) included in principal transactions	(136)	(2)
Transfers into Level 3	(57)	0
Transfers out of Level 3	472	(16)
Purchases	13	85
Issuances	0	0
Sales	(7)	(24)
Settlements	1	(10)
Balance at end of period, asset (liability), net	(1,741)	(1,524)
Unrealized gains (losses) still held	156	202
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	(1,861)	(1,945)
Net realized/unrealized gains (losses) included in principal transactions	(33)	(175)
Transfers into Level 3	(47)	46
Transfers out of Level 3	8	(2)
Purchases	20	0
Issuances	0	0
Sales	0	0
Settlements	4	2
Balance at end of period, asset (liability), net	(1,909)	(2,074)
Unrealized gains (losses) still held	(42)	(170)
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	(799)	(1,001)
Net realized/unrealized gains (losses) included in principal transactions	(62)	(92)
Transfers into Level 3	1	(24)
Transfers out of Level 3	(2)	(8)
Purchases	2	0
Issuances	0	0
Sales	1	0
Settlements	0	2
Balance at end of period, asset (liability), net	(859)	(1,123)
Unrealized gains (losses) still held	(203)	(108)
Interest-bearing deposits
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	286	293
Net realized/unrealized gains (losses) included in principal transactions, liabilities	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	26	11
Transfers into Level 3, liabilities	12	20
Transfers out of Level 3, liabilities	0	0
Purchases, liability	0	0
Issuance, liability	20	0
Sales, liability	0	0
Settlements, liability	0	0
Balance at end of period, liability	292	302
Unrealized gains (losses) still held, liabilities	29	25
Federal funds purchased and securities loaned or sold under agreement to repurchase
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	726	849
Net realized/unrealized gains (losses) included in principal transactions, liabilities	14	6
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0
Transfers into Level 3, liabilities	0	0
Transfers out of Level 3, liabilities	0	0
Purchases, liability	0	0
Issuance, liability	147	0
Sales, liability	0	0
Settlements, liability	(2)	(34)
Balance at end of period, liability	857	809
Unrealized gains (losses) still held, liabilities	14	6
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, liability	22	1,177
Net realized/unrealized gains (losses) included in principal transactions, liabilities	(105)	54
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0
Transfers into Level 3, liabilities	3	11
Transfers out of Level 3, liabilities	(19)	(14)
Purchases, liability	0	0
Issuance, liability	0	0
Sales, liability	3	101
Settlements, liability	(66)	(70)
Balance at end of period, liability	48	1,151
Unrealized gains (losses) still held, liabilities	(7)	2
Trading account liabilities | Other trading liabilities
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	5	1
Net realized/unrealized gains (losses) included in principal transactions, liabilities	5	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0
Transfers into Level 3, liabilities	0	0
Transfers out of Level 3, liabilities	0	0
Purchases, liability	0	0
Issuance, liability	0	0
Sales, liability	0	0
Settlements, liability	0	(1)
Balance at end of period, liability	0	0
Unrealized gains (losses) still held, liabilities	(5)	0
Short-term borrowings
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	18	42
Net realized/unrealized gains (losses) included in principal transactions, liabilities	7	(9)
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0
Transfers into Level 3, liabilities	45	0
Transfers out of Level 3, liabilities	0	0
Purchases, liability	0	0
Issuance, liability	25	11
Sales, liability	0	0
Settlements, liability	0	(2)
Balance at end of period, liability	81	60
Unrealized gains (losses) still held, liabilities	(2)	22
Long-term debt
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	13,082	9,744
Net realized/unrealized gains (losses) included in principal transactions, liabilities	(236)	17
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0
Transfers into Level 3, liabilities	940	200
Transfers out of Level 3, liabilities	(764)	(409)
Purchases, liability	36	0
Issuance, liability	3	929
Sales, liability	(44)	0
Settlements, liability	(5)	(271)
Balance at end of period, liability	13,484	10,176
Unrealized gains (losses) still held, liabilities	254	116
Other financial liabilities
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	8	8
Net realized/unrealized gains (losses) included in principal transactions, liabilities	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	(2)
Transfers into Level 3, liabilities	0	0
Transfers out of Level 3, liabilities	(5)	0
Purchases, liability	0	(1)
Issuance, liability	2	1
Sales, liability	0	0
Settlements, liability	(2)	(6)
Balance at end of period, liability	3	4
Unrealized gains (losses) still held, liabilities	(1)	(2)
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, asset	16	1,496
Net realized/unrealized gains (losses) included in principal transactions	18	(56)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	(252)
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	0	0
Settlements, assets	(18)	(1)
Balance at end of period, asset	16	1,187
Unrealized gains (losses) still held, assets	3	4
Trading non-derivative assets
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	3,274	6,251
Net realized/unrealized gains (losses) included in principal transactions	341	277
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	253	423
Transfers out of Level 3, assets	(317)	(730)
Purchases, assets	821	1,329
Issuance, assets	5	1
Sales, assets	(954)	(1,988)
Settlements, assets	(5)	(26)
Balance at end of period, asset	3,418	5,537
Unrealized gains (losses) still held, assets	165	54
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, asset	163	176
Net realized/unrealized gains (losses) included in principal transactions	1	5
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	86	50
Transfers out of Level 3, assets	(49)	(17)
Purchases, assets	116	161
Issuance, assets	0	0
Sales, assets	(111)	(104)
Settlements, assets	0	0
Balance at end of period, asset	206	271
Unrealized gains (losses) still held, assets	0	0
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, asset	164	399
Net realized/unrealized gains (losses) included in principal transactions	22	15
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	35	17
Transfers out of Level 3, assets	(77)	(29)
Purchases, assets	46	50
Issuance, assets	0	0
Sales, assets	(47)	(84)
Settlements, assets	0	0
Balance at end of period, asset	143	368
Unrealized gains (losses) still held, assets	3	10
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, asset	57	206
Net realized/unrealized gains (losses) included in principal transactions	1	(8)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	4	17
Transfers out of Level 3, assets	(35)	(13)
Purchases, assets	15	190
Issuance, assets	0	0
Sales, assets	(7)	(126)
Settlements, assets	0	0
Balance at end of period, asset	35	266
Unrealized gains (losses) still held, assets	3	(4)
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, asset	384	781
Net realized/unrealized gains (losses) included in principal transactions	24	12
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	125	84
Transfers out of Level 3, assets	(161)	(59)
Purchases, assets	177	401
Issuance, assets	0	0
Sales, assets	(165)	(314)
Settlements, assets	0	0
Balance at end of period, asset	384	905
Unrealized gains (losses) still held, assets	6	6
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, asset	0	1
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	0	0
Settlements, assets	0	0
Balance at end of period, asset	0	1
Unrealized gains (losses) still held, assets	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, asset	274	296
Net realized/unrealized gains (losses) included in principal transactions	6	2
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	2
Transfers out of Level 3, assets	(44)	(47)
Purchases, assets	0	81
Issuance, assets	0	0
Sales, assets	(25)	(64)
Settlements, assets	0	0
Balance at end of period, asset	211	270
Unrealized gains (losses) still held, assets	(1)	2
Trading non-derivative assets | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	16	40
Net realized/unrealized gains (losses) included in principal transactions	0	4
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	2	78
Transfers out of Level 3, assets	0	(13)
Purchases, assets	14	44
Issuance, assets	0	0
Sales, assets	(11)	(27)
Settlements, assets	0	0
Balance at end of period, asset	21	126
Unrealized gains (losses) still held, assets	0	6
Trading non-derivative assets | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	275	324
Net realized/unrealized gains (losses) included in principal transactions	43	91
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	49	27
Transfers out of Level 3, assets	(72)	(52)
Purchases, assets	34	118
Issuance, assets	0	0
Sales, assets	(77)	(197)
Settlements, assets	0	(15)
Balance at end of period, asset	252	296
Unrealized gains (losses) still held, assets	84	12
Trading non-derivative assets | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	120	127
Net realized/unrealized gains (losses) included in principal transactions	75	15
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	1	2
Transfers out of Level 3, assets	(15)	(12)
Purchases, assets	168	7
Issuance, assets	0	0
Sales, assets	(112)	(29)
Settlements, assets	0	0
Balance at end of period, asset	237	110
Unrealized gains (losses) still held, assets	(3)	2
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, asset	1,590	1,868
Net realized/unrealized gains (losses) included in principal transactions	58	160
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	18	20
Transfers out of Level 3, assets	(15)	(16)
Purchases, assets	316	391
Issuance, assets	0	0
Sales, assets	(370)	(482)
Settlements, assets	0	0
Balance at end of period, asset	1,597	1,941
Unrealized gains (losses) still held, assets	73	81
Trading non-derivative assets | Other
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	615	2,814
Net realized/unrealized gains (losses) included in principal transactions	135	(7)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	58	210
Transfers out of Level 3, assets	(10)	(531)
Purchases, assets	112	287
Issuance, assets	5	1
Sales, assets	(194)	(875)
Settlements, assets	(5)	(11)
Balance at end of period, asset	716	1,888
Unrealized gains (losses) still held, assets	6	(55)
Investments
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	2,437	3,861
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	17	(66)
Transfers into Level 3	35	116
Transfers out of Level 3, assets	(353)	(148)
Purchases, assets	104	340
Issuance, assets	0	0
Sales, assets	(136)	(347)
Settlements, assets	(16)	(90)
Balance at end of period, asset	2,088	3,666
Unrealized gains (losses) still held, assets	(2)	12
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, asset	24	101
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(1)	2
Transfers into Level 3	0	1
Transfers out of Level 3, assets	0	(49)
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	0	0
Settlements, assets	0	0
Balance at end of period, asset	23	55
Unrealized gains (losses) still held, assets	2	2
Investments | Mortgage-backed securities - Residential
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	0	50
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	2
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	(47)
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	0	(5)
Settlements, assets	0	0
Balance at end of period, asset	0	0
Unrealized gains (losses) still held, assets	0	0
Investments | Mortgage-backed securities - Commercial
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	3	0
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	2	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	8
Issuance, assets	0	0
Sales, assets	0	(8)
Settlements, assets	0	0
Balance at end of period, asset	5	0
Unrealized gains (losses) still held, assets	0	0
Investments | Mortgage-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	27	151
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	1	4
Transfers into Level 3	0	1
Transfers out of Level 3, assets	0	(96)
Purchases, assets	0	8
Issuance, assets	0	0
Sales, assets	0	(13)
Settlements, assets	0	0
Balance at end of period, asset	28	55
Unrealized gains (losses) still held, assets	2	2
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, asset	0	2
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	0	(1)
Settlements, assets	0	0
Balance at end of period, asset	0	1
Unrealized gains (losses) still held, assets	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, asset	737	1,211
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(16)	12
Transfers into Level 3	0	37
Transfers out of Level 3, assets	(9)	(30)
Purchases, assets	29	54
Issuance, assets	0	0
Sales, assets	(59)	(51)
Settlements, assets	0	0
Balance at end of period, asset	682	1,233
Unrealized gains (losses) still held, assets	(33)	6
Investments | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	92	186
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(1)	1
Transfers into Level 3	0	2
Transfers out of Level 3, assets	(2)	(18)
Purchases, assets	57	142
Issuance, assets	0	0
Sales, assets	(76)	(78)
Settlements, assets	0	0
Balance at end of period, asset	70	235
Unrealized gains (losses) still held, assets	0	1
Investments | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	71	311
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(1)	2
Transfers into Level 3	3	59
Transfers out of Level 3, assets	0	(4)
Purchases, assets	3	91
Issuance, assets	0	0
Sales, assets	0	(120)
Settlements, assets	0	0
Balance at end of period, asset	76	339
Unrealized gains (losses) still held, assets	0	2
Investments | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	2	9
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	0
Issuance, assets	0	0
Sales, assets	(1)	0
Settlements, assets	0	0
Balance at end of period, asset	1	9
Unrealized gains (losses) still held, assets	0	0
Investments | Asset-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	827	660
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	10	9
Transfers into Level 3	2	17
Transfers out of Level 3, assets	(342)	0
Purchases, assets	0	26
Issuance, assets	0	0
Sales, assets	0	0
Settlements, assets	0	0
Balance at end of period, asset	497	712
Unrealized gains (losses) still held, assets	7	3
Investments | Other
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	0	0
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	11
Issuance, assets	0	0
Sales, assets	0	(11)
Settlements, assets	0	0
Balance at end of period, asset	0	0
Unrealized gains (losses) still held, assets	0	0
Investments | Non-marketable equity investments measured using the measurement alternative
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	681	1,331
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	24	(94)
Transfers into Level 3	30	0
Transfers out of Level 3, assets	0	0
Purchases, assets	15	8
Issuance, assets	0	0
Sales, assets	0	(73)
Settlements, assets	(16)	(90)
Balance at end of period, asset	734	1,082
Unrealized gains (losses) still held, assets	22	(2)
Loans
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	550	568
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	19	(4)
Transfers into Level 3	0	65
Transfers out of Level 3, assets	(1)	(16)
Purchases, assets	4	12
Issuance, assets	0	0
Sales, assets	(16)	(43)
Settlements, assets	(2)	(2)
Balance at end of period, asset	554	580
Unrealized gains (losses) still held, assets	26	74
Mortgage servicing rights
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	558	1,564
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	46	67
Transfers into Level 3	0	0
Transfers out of Level 3, assets	0	0
Purchases, assets	0	0
Issuance, assets	17	35
Sales, assets	(17)	(1,046)
Settlements, assets	(17)	(53)
Balance at end of period, asset	587	567
Unrealized gains (losses) still held, assets	46	83
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, asset	16	34
Net realized/unrealized gains (losses) included in principal transactions	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	8	(189)
Transfers into Level 3	0	3
Transfers out of Level 3, assets	0	(1)
Purchases, assets	4	0
Issuance, assets	12	29
Sales, assets	0	204
Settlements, assets	(27)	(53)
Balance at end of period, asset	13	27
Unrealized gains (losses) still held, assets	$ 18	$ (191)

FAIR VALUE MEASUREMENT - Lev128

FAIR VALUE MEASUREMENT - Level 3 Fair Value Rollforward Narrative (Details) - Long-term debt - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair value, assets and liabilities measured on recurring basis, level 3 fair-value category disclosures
Transfers into Level 3, liabilities	$ 940	$ 200
Transfers out of Level 3, liabilities	$ 764	$ 409

FAIR VALUE MEASUREMENT - Valuat

FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Fair Value Measurements (Details) - Level 3 - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Interest-bearing deposits | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total Liabilities	$ 292,000,000	$ 286,000,000
Interest-bearing deposits | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	0.00%	1.00%
Forward price (as a percent)		99.56%
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%
Interest-bearing deposits | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	7.85%	10.50%
Forward price (as a percent)		99.72%
Federal funds purchased and securities loaned or sold under agreement to repurchase | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total Liabilities	$ 857,000,000	$ 726,000,000
Federal funds purchased and securities loaned or sold under agreement to repurchase | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	1.74%	1.43%
Federal funds purchased and securities loaned or sold under agreement to repurchase | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.41%	2.16%
Federal funds purchased and securities loaned or sold under agreement to repurchase | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.40%	2.09%
Short-term borrowings and long-term debt | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total Liabilities	$ 13,559,000,000	$ 13,100,000,000
Short-term borrowings and long-term debt | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	3.00%
Forward price (as a percent)	63.73%	69.74%
Short-term borrowings and long-term debt | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	70.22%
Forward price (as a percent)	167.94%	161.11%
Short-term borrowings and long-term debt | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	18.48%
Forward price (as a percent)	103.12%	100.70%
Trading account assets and liabilities | Interest rate contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 4,440,000,000	$ 3,818,000,000
Trading account assets and liabilities | Interest rate contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	1.00%	1.00%
Inflation volatility	0.25%
IR normal volatility (as a percent)	0.12%	9.40%
Trading account assets and liabilities | Interest rate contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	20.00%	20.00%
Inflation volatility	2.70%
IR normal volatility (as a percent)	78.91%	77.40%
Trading account assets and liabilities | Interest rate contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Mean reversion (as a percent)	10.50%	10.50%
Inflation volatility	0.82%
IR normal volatility (as a percent)	50.71%	58.86%
Trading account assets and liabilities | Foreign exchange contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 877,000,000	$ 940,000,000
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)	0.23%	0.11%
FX Volatility (as a percent)	6.41%	4.58%
IR Basis (as a percent)	(0.74%)
IR-IR correlation (as a percent)	40.00%	(51.00%)
IR-FX Correlation (as a percent)	40.00%	(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)	78.23%	7.17%
FX Volatility (as a percent)	20.25%	15.02%
IR Basis (as a percent)	2.01%
IR-IR correlation (as a percent)	40.00%	40.00%
IR-FX Correlation (as a percent)	60.00%	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)	1.66%	1.73%
FX Volatility (as a percent)	12.75%	8.16%
IR Basis (as a percent)	(0.01%)
IR-IR correlation (as a percent)	40.00%	36.56%
IR-FX Correlation (as a percent)	50.00%	49.04%
Trading account assets and liabilities | Equity contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 2,835,000,000	$ 2,897,000,000
Trading account assets and liabilities | Equity contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	1.16%	3.00%
Forward price (as a percent)	63.73%	69.74%
Trading account assets and liabilities | Equity contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	70.22%	68.93%
Forward price (as a percent)	153.71%	154.19%
Trading account assets and liabilities | Equity contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	25.72%	24.66%
Forward price (as a percent)	101.21%	92.80%
Trading account assets and liabilities | Commodity contracts | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 2,940,000,000	$ 2,937,000,000
Trading account assets and liabilities | Commodity contracts | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	35.75%	3.66%
Commodity volatility (as a percent)	9.14%	8.60%
Commodity correlation (as a percent)	(51.36%)	(37.64%)
Trading account assets and liabilities | Commodity contracts | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	478.26%	290.59%
Commodity volatility (as a percent)	41.03%	66.73%
Commodity correlation (as a percent)	91.85%	91.71%
Trading account assets and liabilities | Commodity contracts | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	114.73%	114.16%
Commodity volatility (as a percent)	22.87%	25.04%
Commodity correlation (as a percent)	19.83%	15.21%
Trading account assets and liabilities | Credit derivatives | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 1,833,000,000	$ 1,797,000,000
Trading account assets and liabilities | Credit derivatives | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	25.00%	25.00%
Trading account assets and liabilities | Credit derivatives | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	85.00%	90.00%
Trading account assets and liabilities | Credit derivatives | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Credit correlation (as a percent)	43.30%	44.64%
Trading account assets and liabilities | Credit derivatives | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 774,000,000	$ 823,000,000
Trading account assets and liabilities | Credit derivatives | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	$ 7.54
Credit spread (as a percent)	0.06%	0.03%
Upfront points (as a percent)	3.84%	6.03%
Price		$ 1
Trading account assets and liabilities | Credit derivatives | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	$ 100
Credit spread (as a percent)	12.00%	16.36%
Upfront points (as a percent)	97.33%	97.26%
Price		$ 100.24
Trading account assets and liabilities | Credit derivatives | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	$ 64.58
Credit spread (as a percent)	1.15%	1.73%
Upfront points (as a percent)	59.81%	62.88%
Price		$ 57.63
Nontrading derivatives and other financial assets and liabilities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Derivatives (gross)	$ 19,000,000	$ 24,000,000
Nontrading derivatives and other financial assets and liabilities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.21%	0.38%
Upfront points (as a percent)	54.00%	61.00%
Recovery rate (as a percent)	25.00%	25.00%
Redemption rate	5.14%	10.72%
Nontrading derivatives and other financial assets and liabilities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	1.29%	2.75%
Upfront points (as a percent)	54.00%	61.00%
Recovery rate (as a percent)	46.00%	40.00%
Redemption rate	99.50%	99.50%
Nontrading derivatives and other financial assets and liabilities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.77%	1.27%
Upfront points (as a percent)	54.00%	61.00%
Recovery rate (as a percent)	38.21%	31.56%
Redemption rate	72.69%	74.24%
Securities sold, not yet purchased | Trading account liabilities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total Liabilities	$ 31,000,000
Securities sold, not yet purchased | Trading account liabilities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	3.00%
Securities sold, not yet purchased | Trading account liabilities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	70.22%
Securities sold, not yet purchased | Trading account liabilities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Equity volatility (as a percent)	31.84%
Securities sold, not yet purchased | Trading account liabilities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total Liabilities	$ 18,000,000	$ 21,000,000
Securities sold, not yet purchased | Trading account liabilities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	63.73%
Equity-equity correlation	(99.00%)
Equity-FX correlation	(80.37%)
Price, liability	$ 0	1
Securities sold, not yet purchased | Trading account liabilities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	153.71%
Equity-equity correlation	100.00%
Equity-FX correlation	56.00%
Price, liability	$ 100	287.64
Securities sold, not yet purchased | Trading account liabilities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Forward price (as a percent)	100.14%
Equity-equity correlation	59.65%
Equity-FX correlation	(29.86%)
Price, liability	$ 24.84	88.19
Mortgage-backed securities | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 220,000,000	$ 184,000,000
Mortgage-backed securities | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	2.18%	2.52%
Mortgage-backed securities | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	8.14%	14.06%
Mortgage-backed securities | Yield analysis | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	3.89%	5.97%
Mortgage-backed securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 147,000,000	$ 214,000,000
Mortgage-backed securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	6	2.96
Mortgage-backed securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	102.26	101
Mortgage-backed securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	74.57	56.52
Debt securities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	943,000,000	949,000,000
Debt securities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	3.47	0
Debt securities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	110.39	184.04
Debt securities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	88.85	91.74
Debt securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets		$ 914,000,000
Debt securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		2.36%
Credit spread (as a percent)		0.35%
Debt securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		14.25%
Credit spread (as a percent)		5.00%
Debt securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		6.03%
Credit spread (as a percent)		2.49%
Non-mortgage debt securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 883,000,000
Non-mortgage debt securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	2.00%
Credit spread (as a percent)	0.35%
Non-mortgage debt securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	14.88%
Credit spread (as a percent)	5.00%
Non-mortgage debt securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	6.54%
Credit spread (as a percent)	2.52%
Equity securities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 30,000,000	$ 55,000,000
Equity securities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)		2 years 6 months
Equity securities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)		2 years 6 months
Equity securities | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)		2 years 6 months
Equity securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	206,000,000	$ 65,000,000
Equity securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	0.01	0
Equity securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	18,320.07	25,450
Equity securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	654.81	2,526.62
Asset-backed securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	1,983,000,000	2,287,000,000
Asset-backed securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	2.33	4.25
Asset-backed securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	100.76	100.60
Asset-backed securities | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Price, asset	69.28	74.57
Non-marketable equity investments measured using the measurement alternative | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 265,000,000	$ 223,000,000
Non-marketable equity investments measured using the measurement alternative | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price	0.00%	0.00%
Price-to-book ratio	5	0.05
Non-marketable equity investments measured using the measurement alternative | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price	100.00%	100.00%
Price-to-book ratio	100	1
Non-marketable equity investments measured using the measurement alternative | Price-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Discount to price	13.24%	11.83%
Price-to-book ratio	68.86	0.32
Non-marketable equity investments measured using the measurement alternative | Comparable analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 431,000,000	$ 423,000,000
Non-marketable equity investments measured using the measurement alternative | Comparable analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
EBITDA multiples	7	6.90
Non-marketable equity investments measured using the measurement alternative | Comparable analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
EBITDA multiples	10.9	12.80
Non-marketable equity investments measured using the measurement alternative | Comparable analysis | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
EBITDA multiples	8.56	8.66
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	$ 16,000,000
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)	1.74%	1.43%
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)	2.41%	2.16%
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)	2.40%	2.09%
Loans and leases | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 520,000,000
Loans and leases | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	2.70%
Credit spread (as a percent)	0.17%
Loans and leases | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	4.06%
Credit spread (as a percent)	5.00%
Loans and leases | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	3.71%
Credit spread (as a percent)	0.92%
Mortgage servicing rights | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 87,000,000	$ 87,000,000
Mortgage servicing rights | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	4 years 29 days	3 years 9 months 29 days
Mortgage servicing rights | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	7 years 7 months 17 days	6 years 10 months 21 days
Mortgage servicing rights | Model-based | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
WAL (in years)	6 years 6 months 11 days	5 years 11 months 5 days
Mortgage servicing rights | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets	$ 500,000,000	$ 471,000,000
Mortgage servicing rights | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	4.26%	8.00%
Mortgage servicing rights | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	12.60%	16.38%
Mortgage servicing rights | Cash flow | Weighted Average
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	8.36%	11.47%
Loans | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Total assets		$ 391,000,000
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		$ 148,000,000
Loans | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)		3.09%
Credit spread (as a percent)		1.34%
Loans | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
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
Yield (as a percent)		3.13%
Credit spread (as a percent)		1.73%

FAIR VALUE MEASUREMENT - Ite130

FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Items Measured at Fair Value on a Nonrecurring Basis
Non-marketable equity investments measured using the measurement alternative		$ 8,245
Nonrecurring | Level 2
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	$ 1,430	2,066
Other real estate owned	41	10
Loans	179	216
Non-marketable equity investments measured using the measurement alternative	133
Total assets	1,783	2,292
Nonrecurring | Level 3
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	2,051	3,609
Other real estate owned	29	44
Loans	366	414
Non-marketable equity investments measured using the measurement alternative	55
Total assets	2,501	4,067
Fair value | Nonrecurring
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	3,481	5,675
Other real estate owned	70	54
Loans	545	630
Non-marketable equity investments measured using the measurement alternative	188
Total assets	$ 4,284	$ 6,359

FAIR VALUE MEASUREMENT - Val131

FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Nonrecurring Fair Value Measurements (Details) - Nonrecurring - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	$ 50,000,000	$ (52,000,000)
Loans held-for-sale
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(35,000,000)	(22,000,000)
Other real estate owned
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(3,000,000)	(2,000,000)
Loans
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(32,000,000)	$ (28,000,000)
Non-marketable equity investments measured using the measurement alternative
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	120,000,000
Level 3
Valuation techniques and inputs
Total assets	2,501,000,000		$ 4,067,000,000
Level 3 | Loans held-for-sale | Price-based
Valuation techniques and inputs
Total assets	2,015,000,000		3,186,000,000
Level 3 | Loans held-for-sale | Price-based | Minimum
Valuation techniques and inputs
Price	0.88		77.93
Level 3 | Loans held-for-sale | Price-based | Maximum
Valuation techniques and inputs
Price	100		100
Level 3 | Loans held-for-sale | Price-based | Weighted Average
Valuation techniques and inputs
Price	95.86		99.26
Level 3 | Other real estate owned | Price-based
Valuation techniques and inputs
Total assets	26,000,000		42,000,000
Level 3 | Other real estate owned | Price-based | Minimum
Valuation techniques and inputs
Price	0		30
Appraised value	20,290		$ 20,278
Discount to price			34.00%
Level 3 | Other real estate owned | Price-based | Maximum
Valuation techniques and inputs
Price	53.47		$ 50.36
Appraised value	8,423,945		$ 8,091,760
Discount to price			34.00%
Level 3 | Other real estate owned | Price-based | Weighted Average
Valuation techniques and inputs
Price	50.08		$ 49.09
Appraised value	4,273,507		$ 4,016,665
Discount to price			34.00%
Level 3 | Loans | Price-based
Valuation techniques and inputs
Total assets	102,000,000		$ 133,000,000
Level 3 | Loans | Price-based | Minimum
Valuation techniques and inputs
Price			2.80
Appraised value	35,490,000
Level 3 | Loans | Price-based | Maximum
Valuation techniques and inputs
Price			100
Appraised value	465,594,643
Level 3 | Loans | Price-based | Weighted Average
Valuation techniques and inputs
Price			62.46
Appraised value	74,229,249
Level 3 | Loans | Recovery analysis
Valuation techniques and inputs
Total assets	$ 125,000,000		127,000,000
Level 3 | Loans | Recovery analysis | Minimum
Valuation techniques and inputs
Appraised value			0
Recovery rate (as a percent)	9.00%
Level 3 | Loans | Recovery analysis | Maximum
Valuation techniques and inputs
Appraised value			45,500,000
Recovery rate (as a percent)	91.53%
Level 3 | Loans | Recovery analysis | Weighted Average
Valuation techniques and inputs
Appraised value			38,785,667
Recovery rate (as a percent)	31.51%
Level 3 | Loans | Cash flow
Valuation techniques and inputs
Total assets	$ 106,000,000		$ 129,000,000
Level 3 | Loans | Cash flow | Minimum
Valuation techniques and inputs
Price	2.80
Recovery rate (as a percent)			50.00%
Level 3 | Loans | Cash flow | Maximum
Valuation techniques and inputs
Price	100
Recovery rate (as a percent)			100.00%
Level 3 | Loans | Cash flow | Weighted Average
Valuation techniques and inputs
Price	81.82
Recovery rate (as a percent)			63.59%
Level 3 | Non-marketable equity investments measured using the measurement alternative | Price-based
Valuation techniques and inputs
Total assets	$ 55,000,000
Level 3 | Non-marketable equity investments measured using the measurement alternative | Price-based | Minimum
Valuation techniques and inputs
Discount to price	25.00%
Level 3 | Non-marketable equity investments measured using the measurement alternative | Price-based | Maximum
Valuation techniques and inputs
Discount to price	25.00%
Level 3 | Non-marketable equity investments measured using the measurement alternative | Price-based | Weighted Average
Valuation techniques and inputs
Discount to price	25.00%

FAIR VALUE MEASUREMENT - Estima

FAIR VALUE MEASUREMENT - Estimate Fair Value of Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets
Loans	$ 4,536	$ 4,374
Liabilities
Deposits	1,001,219	959,822
Allowance for loan losses	12,354	12,355	$ 12,030	$ 12,060
Lease finance receivables	1,700	1,700
Corporate
Assets
Loans	4,513	4,349
Liabilities
Allowance for loan losses	2,315	2,486	$ 2,535	$ 2,702
Carrying value
Assets
Investments	58,500	60,200
Federal funds sold and securities borrowed or purchased under agreements to resell	96,400	99,500
Loans	654,400	648,600
Other financial assets	274,200	242,600
Liabilities
Deposits	999,500	958,400
Federal funds purchased and securities loaned or sold under agreements to repurchase	125,900	115,600
Long-term debt	204,400	205,300
Other financial liabilities	116,500	115,900
Fair value
Assets
Investments	58,100	60,600
Federal funds sold and securities borrowed or purchased under agreements to resell	96,400	99,500
Loans	653,400	644,900
Other financial assets	274,600	243,000
Liabilities
Deposits	997,700	955,600
Federal funds purchased and securities loaned or sold under agreements to repurchase	125,900	115,600
Long-term debt	209,700	214,000
Other financial liabilities	116,500	115,900
Fair value | Level 1
Assets
Investments	1,100	500
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0
Loans	0	0
Other financial assets	188,300	166,400
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	54,800	57,500
Federal funds sold and securities borrowed or purchased under agreements to resell	91,400	94,400
Loans	4,300	6,000
Other financial assets	14,400	14,100
Liabilities
Deposits	850,200	816,100
Federal funds purchased and securities loaned or sold under agreements to repurchase	125,800	115,600
Long-term debt	189,500	187,200
Other financial liabilities	15,300	15,500
Fair value | Level 3
Assets
Investments	2,200	2,600
Federal funds sold and securities borrowed or purchased under agreements to resell	5,000	5,100
Loans	649,100	638,900
Other financial assets	71,900	62,500
Liabilities
Deposits	147,500	139,500
Federal funds purchased and securities loaned or sold under agreements to repurchase	100	0
Long-term debt	20,200	26,800
Other financial liabilities	101,200	100,400
Fair value | Level 3 | Corporate
Fair value measurements additional disclosures
Unfunded lending commitments	$ 4,300	$ 3,200

FAIR VALUE ELECTIONS - Changes

FAIR VALUE ELECTIONS - Changes in Fair Value Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Federal funds sold and securities borrowed or purchased under agreements to resell
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	$ (16)	$ (33)
Trading account assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(16)	430
Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	0	0
Corporate
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(123)	24
Consumer loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	0	0
Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(123)	24
MSRs
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	46	67
Certain mortgage loans held for sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	2	37
Total other assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	48	104
Total assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(107)	525
Interest-bearing deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	28	(14)
Federal funds purchased and securities loaned or sold under agreements to repurchase
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(111)	613
Trading account liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	(6)	26
Short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	177	19
Long-term debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	618	(332)
Total liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions.
Fair value elections, changes in fair value gains (losses)	$ 706	$ 312

FAIR VALUE ELECTIONS - Valuatio

FAIR VALUE ELECTIONS - Valuation Adjustments, Fair Value Option for Financial Assets and Financial Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value Option Quantitative Disclosures
Gain (loss) on change in estimated fair value of debt liabilities due to change in company's own credit risk	$ 167	$ (95)
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	19	$ 26
Certain loans and other credit product | Trading assets
Fair Value Option Quantitative Disclosures
Aggregate unpaid principal balance in excess of (less than) fair value	475		623
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 (less than) fair value	870		682
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	0		1
Certain debt host contracts across unallocated precious metals accounts
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	700		900
Certain Investments in Unallocated Precious Metals | Forward derivative contract | Purchased
Fair Value Option Quantitative Disclosures
Derivative notionals	12,000
Certain Investments in Unallocated Precious Metals | Forward derivative contract | Sold
Fair Value Option Quantitative Disclosures
Derivative notionals	10,100
Mortgage receivable
Fair Value Option Quantitative Disclosures
Aggregate unpaid principal balance in excess of (less than) fair value	7		14
Carrying amount | Certain loans and other credit product | Trading assets
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	9,194		8,851
Carrying amount | Certain loans and other credit product | Loans
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	4,536		4,374
Carrying amount | Loans held-for-sale
Fair Value Option Quantitative Disclosures
Carrying amount reported on the Consolidated Balance Sheet	333		426
Fair value | Certain loans and other credit product
Fair Value Option Quantitative Disclosures
Unfunded lending commitments	$ 408		$ 508

FAIR VALUE ELECTIONS - Certain

FAIR VALUE ELECTIONS - Certain Structured and Non-Structured Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	$ 31,300	$ 29,300
Long-term debt
Certain non-structured liabilities
Aggregate unpaid principal balance in excess of (less than) fair value, long-term	(93)	(579)
Long-term debt | Carrying amount
Certain non-structured liabilities
Carrying amount reported on the Consolidated Balance Sheet	33,571	31,392
Short-term borrowings
Certain non-structured liabilities
Aggregate unpaid principal balance in excess of (less than) fair value, short-term	463	74
Short-term borrowings | Carrying amount
Certain non-structured liabilities
Carrying amount reported on the Consolidated Balance Sheet	4,467	4,627
Interest rate linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	15,900	13,900
Foreign exchange linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	300	300
Equity linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	12,800	13,000
Commodity linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	400	200
Credit linked
Carrying value of structured notes, disaggregated by type of embedded derivative instrument
Carrying value of structured notes	$ 1,900	$ 1,900

GUARANTEES AND COMMITMENTS - Gu

GUARANTEES AND COMMITMENTS - Guarantees (Details)	Mar. 31, 2018USD ($)trust	Dec. 31, 2017USD ($)trust
Maximum potential amount of future payments
Expire within 1 year	$ 264,500,000,000	$ 235,600,000,000
Expire after 1 year	192,500,000,000	192,200,000,000
Total amount outstanding	457,000,000,000	427,800,000,000
Carrying value	$ 846,000,000	$ 809,000,000
Number of trusts funded by the reinsurer | trust	2	2
Fair value of securities in trusts funded by reinsurer relating to indemnification	$ 7,400,000,000	$ 7,500,000,000
Liability related to long-term care insurance indemnification	0	0
Cash collateral available to reimburse losses realized under guarantees and indemnifications	52,000,000,000	46,000,000,000
Securities and other marketable assets held as collateral	88,000,000,000	70,000,000,000
Letters of credit in favor of the Company held as collateral	3,900,000,000	3,700,000,000
Investment grade
Maximum potential amount of future payments
Total amount outstanding	102,100,000,000	99,700,000,000
Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	25,300,000,000	25,600,000,000
Not rated
Maximum potential amount of future payments
Total amount outstanding	329,600,000,000	302,500,000,000
Financial standby letters of credit
Maximum potential amount of future payments
Expire within 1 year	30,400,000,000	27,900,000,000
Expire after 1 year	63,000,000,000	65,900,000,000
Total amount outstanding	93,400,000,000	93,800,000,000
Carrying value	131,000,000	93,000,000
Financial standby letters of credit | Investment grade
Maximum potential amount of future payments
Total amount outstanding	68,100,000,000	68,100,000,000
Financial standby letters of credit | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	10,300,000,000	10,900,000,000
Financial standby letters of credit | Not rated
Maximum potential amount of future payments
Total amount outstanding	15,000,000,000	14,800,000,000
Performance guarantees
Maximum potential amount of future payments
Expire within 1 year	7,500,000,000	7,200,000,000
Expire after 1 year	4,100,000,000	4,100,000,000
Total amount outstanding	11,600,000,000	11,300,000,000
Carrying value	31,000,000	20,000,000
Performance guarantees | Investment grade
Maximum potential amount of future payments
Total amount outstanding	8,200,000,000	7,900,000,000
Performance guarantees | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	2,300,000,000	2,400,000,000
Performance guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	1,100,000,000	1,000,000,000
Derivative instruments deemed to be guarantees
Maximum potential amount of future payments
Expire within 1 year	17,000,000,000	11,000,000,000
Expire after 1 year	85,600,000,000	84,900,000,000
Total amount outstanding	102,600,000,000	95,900,000,000
Carrying value	432,000,000	423,000,000
Derivative instruments deemed to be guarantees | Investment grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Derivative instruments deemed to be guarantees | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	0	0
Derivative instruments deemed to be guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	102,600,000,000	95,900,000,000
Loans sold with recourse
Maximum potential amount of future payments
Expire within 1 year	0	0
Expire after 1 year	200,000,000	200,000,000
Total amount outstanding	200,000,000	200,000,000
Carrying value	8,000,000	9,000,000
Repurchase reserve for Consumer mortgages representations and warranties	66,000,000	66,000,000
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 1 year	126,900,000,000	103,700,000,000
Expire after 1 year	0	0
Total amount outstanding	126,900,000,000	103,700,000,000
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	126,900,000,000	103,700,000,000
Credit card merchant processing
Maximum potential amount of future payments
Expire within 1 year	82,500,000,000	85,500,000,000
Expire after 1 year	0	0
Total amount outstanding	82,500,000,000	85,500,000,000
Carrying value	0	0
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	82,500,000,000	85,500,000,000
Credit card arrangements with partners
Maximum potential amount of future payments
Expire within 1 year	200,000,000	300,000,000
Expire after 1 year	1,100,000,000	1,100,000,000
Total amount outstanding	1,300,000,000	1,400,000,000
Carrying value	162,000,000	205,000,000
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	1,300,000,000	1,400,000,000
Custody indemnifications and other
Maximum potential amount of future payments
Expire within 1 year	0	0
Expire after 1 year	38,500,000,000	36,000,000,000
Total amount outstanding	38,500,000,000	36,000,000,000
Carrying value	82,000,000	59,000,000
Custody indemnifications and other | Investment grade
Maximum potential amount of future payments
Total amount outstanding	25,800,000,000	23,700,000,000
Custody indemnifications and other | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	12,700,000,000	12,300,000,000
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
Amount of cash initial margin collected and remitted	$ 11,600,000,000	$ 10,700,000,000

GUARANTEES AND COMMITMENTS - Pe

GUARANTEES AND COMMITMENTS - Performance Risk (Details) - USD ($) $ in Billions	Mar. 31, 2018	Dec. 31, 2017
Guarantor Obligations
Maximum potential amount of future payments	$ 457	$ 427.8
Investment grade
Guarantor Obligations
Maximum potential amount of future payments	102.1	99.7
Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	25.3	25.6
Not rated
Guarantor Obligations
Maximum potential amount of future payments	329.6	302.5
Financial standby letters of credit
Guarantor Obligations
Maximum potential amount of future payments	93.4	93.8
Financial standby letters of credit | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	68.1	68.1
Financial standby letters of credit | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	10.3	10.9
Financial standby letters of credit | Not rated
Guarantor Obligations
Maximum potential amount of future payments	15	14.8
Performance guarantees
Guarantor Obligations
Maximum potential amount of future payments	11.6	11.3
Performance guarantees | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	8.2	7.9
Performance guarantees | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	2.3	2.4
Performance guarantees | Not rated
Guarantor Obligations
Maximum potential amount of future payments	1.1	1
Derivative instruments deemed to be guarantees
Guarantor Obligations
Maximum potential amount of future payments	102.6	95.9
Derivative instruments deemed to be guarantees | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Derivative instruments deemed to be guarantees | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Derivative instruments deemed to be guarantees | Not rated
Guarantor Obligations
Maximum potential amount of future payments	102.6	95.9
Loans sold with recourse
Guarantor Obligations
Maximum potential amount of future payments	0.2	0.2
Loans sold with recourse | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Loans sold with recourse | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Loans sold with recourse | Not rated
Guarantor Obligations
Maximum potential amount of future payments	0.2	0.2
Securities lending indemnifications
Guarantor Obligations
Maximum potential amount of future payments	126.9	103.7
Securities lending indemnifications | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Securities lending indemnifications | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Securities lending indemnifications | Not rated
Guarantor Obligations
Maximum potential amount of future payments	126.9	103.7
Credit card merchant processing
Guarantor Obligations
Maximum potential amount of future payments	82.5	85.5
Credit card merchant processing | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Credit card merchant processing | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Credit card merchant processing | Not rated
Guarantor Obligations
Maximum potential amount of future payments	82.5	85.5
Credit card arrangements with partners
Guarantor Obligations
Maximum potential amount of future payments	1.3	1.4
Credit card arrangements with partners | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Credit card arrangements with partners | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0	0
Credit card arrangements with partners | Not rated
Guarantor Obligations
Maximum potential amount of future payments	1.3	1.4
Custody indemnifications and other
Guarantor Obligations
Maximum potential amount of future payments	38.5	36
Custody indemnifications and other | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	25.8	23.7
Custody indemnifications and other | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	12.7	12.3
Custody indemnifications and other | Not rated
Guarantor Obligations
Maximum potential amount of future payments	$ 0	$ 0

GUARANTEES AND COMMITMENTS - Cr

GUARANTEES AND COMMITMENTS - Credit Commitments and Lines of Credit (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Guarantor Obligations
Credit commitments	$ 1,021,016	$ 985,174
Unsettled reverse repurchase and securities borrowing agreements	78,700	35,000
Unsettled repurchase and securities lending agreements	33,700	19,100
Commercial and similar letters of credit
Guarantor Obligations
Credit commitments	5,496	5,000
One- to four-family residential mortgages
Guarantor Obligations
Credit commitments	2,995	2,674
Revolving open-end loans secured by one- to four-family residential properties
Guarantor Obligations
Credit commitments	12,213	12,323
Commercial real estate, construction and land development
Guarantor Obligations
Credit commitments	11,101	11,151
Credit card lines
Guarantor Obligations
Credit commitments	685,635	678,300
Commercial and other consumer loan commitments
Guarantor Obligations
Credit commitments	300,715	272,655
Other commitments and contingencies
Guarantor Obligations
Credit commitments	2,861	$ 3,071
U.S.
Guarantor Obligations
Credit commitments	796,431
U.S. | Commercial and similar letters of credit
Guarantor Obligations
Credit commitments	821
U.S. | One- to four-family residential mortgages
Guarantor Obligations
Credit commitments	1,385
U.S. | Revolving open-end loans secured by one- to four-family residential properties
Guarantor Obligations
Credit commitments	10,703
U.S. | Commercial real estate, construction and land development
Guarantor Obligations
Credit commitments	8,955
U.S. | Credit card lines
Guarantor Obligations
Credit commitments	583,477
U.S. | Commercial and other consumer loan commitments
Guarantor Obligations
Credit commitments	188,945
U.S. | Other commitments and contingencies
Guarantor Obligations
Credit commitments	2,145
Outside of U.S.
Guarantor Obligations
Credit commitments	224,585
Outside of U.S. | Commercial and similar letters of credit
Guarantor Obligations
Credit commitments	4,675
Outside of U.S. | One- to four-family residential mortgages
Guarantor Obligations
Credit commitments	1,610
Outside of U.S. | Revolving open-end loans secured by one- to four-family residential properties
Guarantor Obligations
Credit commitments	1,510
Outside of U.S. | Commercial real estate, construction and land development
Guarantor Obligations
Credit commitments	2,146
Outside of U.S. | Credit card lines
Guarantor Obligations
Credit commitments	102,158
Outside of U.S. | Commercial and other consumer loan commitments
Guarantor Obligations
Credit commitments	111,770
Outside of U.S. | Other commitments and contingencies
Guarantor Obligations
Credit commitments	$ 716

CONTINGENCIES (Details)

CONTINGENCIES (Details) € in Billions, $ in Billions	Jan. 25, 2018EUR (€)	Mar. 31, 2018USD ($)
Loss Contingencies [Line Items]
Loss contingency, portion not accrued | $		$ 1
Citibank, N.A. | Milan Court of Appeal | Parmalat
Loss Contingencies [Line Items]
Loss contingency damages sought | €	€ 1.8

CONDENSED CONSOLIDATING FINA140

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statements of Income and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Dividends from subsidiaries	$ 0	$ 0
Interest revenue	16,332	14,521
Interest revenue—intercompany	0	0
Interest expense	5,160	3,566
Interest expense—intercompany	0	0
Net interest revenue	11,172	10,955
Commissions and fees	3,030	3,055
Commissions and fees—intercompany	0	0
Principal transactions	3,289	3,094
Principal transactions—intercompany	0	0
Other income	1,381	1,262
Other income—intercompany	0	0
Total non-interest revenues	7,700	7,411
Total revenues, net of interest expense	18,872	18,366
Provisions for credit losses and for benefits and claims	1,857	1,662
Operating expenses
Compensation and benefits	5,807	5,534
Compensation and benefits—intercompany	0	0
Other operating	5,118	5,189
Other operating—intercompany	0	0
Total operating expenses	10,925	10,723
Equity in undistributed income of subsidiaries	0	0
Income (loss) from continuing operations before income taxes	6,090	5,981
Provision for income taxes	1,441	1,863
Income from continuing operations	4,649	4,118
Income (loss) from discontinued operations, net of taxes	(7)	(18)
Net income before attribution of noncontrolling interests	4,642	4,100
Noncontrolling interests	22	10
Citigroup’s net income	4,620	4,090
Comprehensive income
Add: Other comprehensive income (loss)	52	1,464
Citigroup’s total comprehensive income	4,672	5,554
Add: Other comprehensive income attributable to noncontrolling interests	14	31
Add: Net income attributable to noncontrolling interests	22	10
Total comprehensive income (loss)	4,708	5,595
Reportable legal entities | Citigroup parent company
Revenues
Dividends from subsidiaries	5,585	3,750
Interest revenue	52	1
Interest revenue—intercompany	1,130	793
Interest expense	910	1,218
Interest expense—intercompany	587	90
Net interest revenue	(315)	(514)
Commissions and fees	0	0
Commissions and fees—intercompany	0	0
Principal transactions	1,031	(163)
Principal transactions—intercompany	(386)	204
Other income	(928)	(39)
Other income—intercompany	55	(123)
Total non-interest revenues	(228)	(121)
Total revenues, net of interest expense	5,042	3,115
Provisions for credit losses and for benefits and claims	0	0
Operating expenses
Compensation and benefits	134	(14)
Compensation and benefits—intercompany	34	31
Other operating	44	28
Other operating—intercompany	12	(59)
Total operating expenses	224	(14)
Equity in undistributed income of subsidiaries	(445)	587
Income (loss) from continuing operations before income taxes	4,373	3,716
Provision for income taxes	(247)	(374)
Income from continuing operations	4,620	4,090
Income (loss) from discontinued operations, net of taxes	0	0
Net income before attribution of noncontrolling interests	4,620	4,090
Noncontrolling interests	0	0
Citigroup’s net income	4,620	4,090
Comprehensive income
Add: Other comprehensive income (loss)	52	1,464
Citigroup’s total comprehensive income	4,672	5,554
Add: Other comprehensive income attributable to noncontrolling interests	0	0
Add: Net income attributable to noncontrolling interests	0	0
Total comprehensive income (loss)	4,672	5,554
Reportable legal entities | CGMHI
Revenues
Dividends from subsidiaries	0	0
Interest revenue	1,655	1,027
Interest revenue—intercompany	383	157
Interest expense	1,013	393
Interest expense—intercompany	772	428
Net interest revenue	253	363
Commissions and fees	1,252	1,323
Commissions and fees—intercompany	0	2
Principal transactions	921	1,658
Principal transactions—intercompany	192	(695)
Other income	153	65
Other income—intercompany	50	110
Total non-interest revenues	2,568	2,463
Total revenues, net of interest expense	2,821	2,826
Provisions for credit losses and for benefits and claims	0	0
Operating expenses
Compensation and benefits	1,265	1,262
Compensation and benefits—intercompany	0	0
Other operating	548	509
Other operating—intercompany	578	540
Total operating expenses	2,391	2,311
Equity in undistributed income of subsidiaries	0	0
Income (loss) from continuing operations before income taxes	430	515
Provision for income taxes	65	215
Income from continuing operations	365	300
Income (loss) from discontinued operations, net of taxes	0	0
Net income before attribution of noncontrolling interests	365	300
Noncontrolling interests	0	0
Citigroup’s net income	365	300
Comprehensive income
Add: Other comprehensive income (loss)	82	(20)
Citigroup’s total comprehensive income	447	280
Add: Other comprehensive income attributable to noncontrolling interests	0	0
Add: Net income attributable to noncontrolling interests	0	0
Total comprehensive income (loss)	447	280
Reportable legal entities | Other Citigroup subsidiaries and eliminations
Revenues
Dividends from subsidiaries	0	0
Interest revenue	14,625	13,493
Interest revenue—intercompany	(1,513)	(950)
Interest expense	3,237	1,955
Interest expense—intercompany	(1,359)	(518)
Net interest revenue	11,234	11,106
Commissions and fees	1,778	1,732
Commissions and fees—intercompany	0	(2)
Principal transactions	1,337	1,599
Principal transactions—intercompany	194	491
Other income	2,156	1,236
Other income—intercompany	(105)	13
Total non-interest revenues	5,360	5,069
Total revenues, net of interest expense	16,594	16,175
Provisions for credit losses and for benefits and claims	1,857	1,662
Operating expenses
Compensation and benefits	4,408	4,286
Compensation and benefits—intercompany	(34)	(31)
Other operating	4,526	4,652
Other operating—intercompany	(590)	(481)
Total operating expenses	8,310	8,426
Equity in undistributed income of subsidiaries	0	0
Income (loss) from continuing operations before income taxes	6,427	6,087
Provision for income taxes	1,623	2,022
Income from continuing operations	4,804	4,065
Income (loss) from discontinued operations, net of taxes	(7)	(18)
Net income before attribution of noncontrolling interests	4,797	4,047
Noncontrolling interests	22	10
Citigroup’s net income	4,775	4,037
Comprehensive income
Add: Other comprehensive income (loss)	(3,156)	(3,721)
Citigroup’s total comprehensive income	1,619	316
Add: Other comprehensive income attributable to noncontrolling interests	14	31
Add: Net income attributable to noncontrolling interests	22	10
Total comprehensive income (loss)	1,655	357
Consolidating adjustments
Revenues
Dividends from subsidiaries	(5,585)	(3,750)
Interest revenue	0	0
Interest revenue—intercompany	0	0
Interest expense	0	0
Interest expense—intercompany	0	0
Net interest revenue	0	0
Commissions and fees	0	0
Commissions and fees—intercompany	0	0
Principal transactions	0	0
Principal transactions—intercompany	0	0
Other income	0	0
Other income—intercompany	0	0
Total non-interest revenues	0	0
Total revenues, net of interest expense	(5,585)	(3,750)
Provisions for credit losses and for benefits and claims	0	0
Operating expenses
Compensation and benefits	0	0
Compensation and benefits—intercompany	0	0
Other operating	0	0
Other operating—intercompany	0	0
Total operating expenses	0	0
Equity in undistributed income of subsidiaries	445	(587)
Income (loss) from continuing operations before income taxes	(5,140)	(4,337)
Provision for income taxes	0	0
Income from continuing operations	(5,140)	(4,337)
Income (loss) from discontinued operations, net of taxes	0	0
Net income before attribution of noncontrolling interests	(5,140)	(4,337)
Noncontrolling interests	0	0
Citigroup’s net income	(5,140)	(4,337)
Comprehensive income
Add: Other comprehensive income (loss)	3,074	3,741
Citigroup’s total comprehensive income	(2,066)	(596)
Add: Other comprehensive income attributable to noncontrolling interests	0	0
Add: Net income attributable to noncontrolling interests	0	0
Total comprehensive income (loss)	$ (2,066)	$ (596)

CONDENSED CONSOLIDATING FINA141

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 21,850	$ 23,775
Cash and due from banks—intercompany	0	0
Deposits with banks	180,854	156,741
Deposits with banks - intercompany	0	0
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	257,887	232,478
Federal funds sold and resale agreements—intercompany	0	0
Trading account assets	268,808	252,790
Trading account assets—intercompany	0	0
Investments	351,971	352,290
Loans, net of unearned income	672,938	667,034
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	(12,354)	(12,355)	$ (12,030)	$ (12,060)
Total loans, net	660,584	654,679
Advances to subsidiaries	0	0
Investments in subsidiaries	0	0
Other assets	180,150	169,712
Other assets—intercompany	0	0
Total assets	1,922,104	1,842,465
Liabilities and equity
Deposits	1,001,219	959,822
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	171,759	156,277
Federal funds purchased and securities loaned or sold—intercompany	0	0
Trading account liabilities	143,961	125,170
Trading account liabilities—intercompany	0	0
Short-term borrowings	36,094	44,452
Short-term borrowings—intercompany	0	0
Long-term debt	237,938	236,709
Long-term debt—intercompany	0	0
Advances from subsidiaries	0	0
Other liabilities	128,267	118,363
Other liabilities—intercompany	0	0
Stockholders’ equity	202,866	201,672	$ 228,997
Total liabilities and equity	1,922,104	1,842,465
Other	105,882	103,926
Citigroup parent company
Liabilities and equity
Long-term debt	153,074	152,163
Citibank, N.A.
Liabilities and equity
Other	24,800	29,700
Reportable legal entities | Citigroup parent company
Assets
Cash and due from banks	2	0
Cash and due from banks—intercompany	14	13
Deposits with banks	0	0
Deposits with banks - intercompany	3,000	11,000
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	0	0
Federal funds sold and resale agreements—intercompany	0	0
Trading account assets	298	0
Trading account assets—intercompany	483	38
Investments	7,755	27
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	141,977	139,722
Investments in subsidiaries	209,808	210,537
Other assets	10,784	10,844
Other assets—intercompany	3,667	3,428
Total assets	377,788	375,609
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	0	0
Federal funds purchased and securities loaned or sold—intercompany	0	0
Trading account liabilities	2	0
Trading account liabilities—intercompany	241	15
Short-term borrowings	235	251
Short-term borrowings—intercompany	0	0
Long-term debt	153,074	152,163
Long-term debt—intercompany	0	0
Advances from subsidiaries	19,151	19,136
Other liabilities	2,832	2,673
Other liabilities—intercompany	338	631
Stockholders’ equity	201,915	200,740
Total liabilities and equity	377,788	375,609
Reportable legal entities | CGMHI
Assets
Cash and due from banks	423	378
Cash and due from banks—intercompany	5,225	3,750
Deposits with banks	3,005	3,348
Deposits with banks - intercompany	5,492	5,219
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	206,659	182,685
Federal funds sold and resale agreements—intercompany	14,284	16,091
Trading account assets	150,249	139,462
Trading account assets—intercompany	2,079	2,711
Investments	249	181
Loans, net of unearned income	875	900
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	0	0
Total loans, net	875	900
Advances to subsidiaries	0	0
Investments in subsidiaries	0	0
Other assets	66,723	58,299
Other assets—intercompany	47,051	43,613
Total assets	502,314	456,637
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	144,400	134,888
Federal funds purchased and securities loaned or sold—intercompany	20,444	18,597
Trading account liabilities	98,287	80,801
Trading account liabilities—intercompany	1,904	2,182
Short-term borrowings	3,159	3,568
Short-term borrowings—intercompany	41,097	32,871
Long-term debt	19,907	18,048
Long-term debt—intercompany	60,351	60,765
Advances from subsidiaries	0	0
Other liabilities	69,516	62,113
Other liabilities—intercompany	10,336	9,753
Stockholders’ equity	32,913	33,051
Total liabilities and equity	502,314	456,637
Reportable legal entities | Other Citigroup subsidiaries and eliminations
Assets
Cash and due from banks	21,425	23,397
Cash and due from banks—intercompany	(5,239)	(3,763)
Deposits with banks	177,849	153,393
Deposits with banks - intercompany	(8,492)	(16,219)
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	51,228	49,793
Federal funds sold and resale agreements—intercompany	(14,284)	(16,091)
Trading account assets	118,261	113,328
Trading account assets—intercompany	(2,562)	(2,749)
Investments	343,967	352,082
Loans, net of unearned income	672,063	666,134
Loans, net of unearned income—intercompany	0	0
Allowance for loan losses	(12,354)	(12,355)
Total loans, net	659,709	653,779
Advances to subsidiaries	(141,977)	(139,722)
Investments in subsidiaries	0	0
Other assets	102,643	100,569
Other assets—intercompany	(50,718)	(47,041)
Total assets	1,251,810	1,220,756
Liabilities and equity
Deposits	1,001,219	959,822
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	27,359	21,389
Federal funds purchased and securities loaned or sold—intercompany	(20,444)	(18,597)
Trading account liabilities	45,672	44,369
Trading account liabilities—intercompany	(2,145)	(2,197)
Short-term borrowings	32,700	40,633
Short-term borrowings—intercompany	(41,097)	(32,871)
Long-term debt	64,957	66,498
Long-term debt—intercompany	(60,351)	(60,765)
Advances from subsidiaries	(19,151)	(19,136)
Other liabilities	55,919	53,577
Other liabilities—intercompany	(10,674)	(10,384)
Stockholders’ equity	177,846	178,418
Total liabilities and equity	1,251,810	1,220,756
Consolidating adjustments
Assets
Cash and due from banks	0	0
Cash and due from banks—intercompany	0	0
Deposits with banks	0	0
Deposits with banks - intercompany	0	0
Federal funds sold and securities borrowed or purchased under agreements to resell (including $161,537 and $132,949 as of March 31, 2018 and December 31, 2017, respectively, at fair value)	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	(209,808)	(210,537)
Other assets	0	0
Other assets—intercompany	0	0
Total assets	(209,808)	(210,537)
Liabilities and equity
Deposits	0	0
Deposits—intercompany	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase (including $45,840 and $40,638 as of March 31, 2018 and December 31, 2017, respectively, 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	0	0
Short-term borrowings—intercompany	0	0
Long-term debt	0	0
Long-term debt—intercompany	0	0
Advances from subsidiaries	0	0
Other liabilities	0	0
Other liabilities—intercompany	0	0
Stockholders’ equity	(209,808)	(210,537)
Total liabilities and equity	(209,808)	(210,537)
Up to 30 days | Citibank, N.A.
Liabilities and equity
Placements with term of less than 30 days	$ 20,300	$ 18,900

CONDENSED CONSOLIDATING FINA142

CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities of continuing operations		$ 6,956	$ (3,052)
Cash flows from investing activities of continuing operations
Purchases of investments		(41,030)	(41,584)
Proceeds from sales of investments		20,688	29,456
Proceeds from maturities of investments		21,509	24,006
Change in loans		(8,717)	(7,953)
Proceeds from sales and securitizations of loans		1,654	3,191
Proceeds from significant disposals	[1]	0	2,732
Change in federal funds sold and resales		(25,409)	(6,116)
Changes in investments and advances—intercompany		0	0
Other investing activities		(819)	(607)
Net cash provided by (used in) investing activities of continuing operations		(32,124)	3,125
Cash flows from financing activities of continuing operations
Dividends paid		(1,095)	(744)
Redemption of preferred stock		(97)	0
Treasury stock acquired		(2,378)	(1,858)
Proceeds from issuance of long-term debt, net		2,887	(282)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0
Change in deposits		41,397	20,584
Change in federal funds purchased and repos		15,482	6,409
Change in short-term borrowings		(8,358)	(4,574)
Net change in short-term borrowings and other advances—intercompany		0	0
Capital contributions from (to) parent		0
Other financing activities		(475)	(397)
Net cash provided by financing activities of continuing operations		47,363	19,138
Effect of exchange rate changes on cash and due from banks		(7)	340
Change in cash and due from banks and deposits with banks	[2]	22,188	19,551
Cash, due from banks and deposits with banks at beginning of period	[2]	180,516	160,494
Cash, due from banks and deposits with banks at end of period	[2]	202,704	180,045
Cash and due from banks				$ 21,850	$ 23,775	$ 22,272
Deposits with banks				180,854	156,741	157,773
Cash, due from banks and deposits with banks at end of period	[2]	180,516	160,494	202,704	180,516	180,045
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		738	913
Cash paid during the period for interest		4,586	3,250
Non-cash investing activities
Transfers to loans HFS from loans		900	2,800
Transfers to OREO and other repossessed assets		26	30
Reportable legal entities | Citigroup parent company
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities of continuing operations		5,268	(652)
Cash flows from investing activities of continuing operations
Purchases of investments		(7,955)	0
Proceeds from sales of investments		0	116
Proceeds from maturities of investments		0	0
Change in loans		0	0
Proceeds from sales and securitizations of loans		0	0
Proceeds from significant disposals			0
Change in federal funds sold and resales		0	0
Changes in investments and advances—intercompany		(1,463)	(569)
Other investing activities		(729)	0
Net cash provided by (used in) investing activities of continuing operations		(10,147)	(453)
Cash flows from financing activities of continuing operations
Dividends paid		(1,095)	(744)
Redemption of preferred stock		(97)
Treasury stock acquired		(2,378)	(1,858)
Proceeds from issuance of long-term debt, net		699	(1,454)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0
Change in deposits		0	0
Change in federal funds purchased and repos		0	0
Change in short-term borrowings		0	0
Net change in short-term borrowings and other advances—intercompany		14	(14,901)
Capital contributions from (to) parent		0
Other financing activities		(261)	(397)
Net cash provided by financing activities of continuing operations		(3,118)	(19,354)
Effect of exchange rate changes on cash and due from banks		0	0
Change in cash and due from banks and deposits with banks		(7,997)	(20,459)
Cash, due from banks and deposits with banks at beginning of period		11,013	20,811
Cash, due from banks and deposits with banks at end of period		3,016	352
Cash and due from banks				16		352
Deposits with banks				3,000		0
Cash, due from banks and deposits with banks at end of period		11,013	20,811	3,016	11,013	352
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		(266)	(139)
Cash paid during the period for interest		883	1,153
Non-cash investing activities
Transfers to loans HFS from loans		0	0
Transfers to OREO and other repossessed assets		0	0
Reportable legal entities | CGMHI
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities of continuing operations		7,046	(3,404)
Cash flows from investing activities of continuing operations
Purchases of investments		0	0
Proceeds from sales of investments		0	0
Proceeds from maturities of investments		0	0
Change in loans		0	0
Proceeds from sales and securitizations of loans		0	0
Proceeds from significant disposals			0
Change in federal funds sold and resales		(22,167)	(2,623)
Changes in investments and advances—intercompany		(3,603)	(5,007)
Other investing activities		(9)	0
Net cash provided by (used in) investing activities of continuing operations		(25,779)	(7,630)
Cash flows from financing activities of continuing operations
Dividends paid		0	0
Redemption of preferred stock		0
Treasury stock acquired		0	0
Proceeds from issuance of long-term debt, net		2,004	5,175
Proceeds (repayments) from issuance of long-term debt—intercompany, net		(412)	(12,506)
Change in deposits		0	0
Change in federal funds purchased and repos		11,359	1,266
Change in short-term borrowings		(409)	605
Net change in short-term borrowings and other advances—intercompany		8,226	8,938
Capital contributions from (to) parent		(585)
Other financing activities		0	0
Net cash provided by financing activities of continuing operations		20,183	3,478
Effect of exchange rate changes on cash and due from banks		0	0
Change in cash and due from banks and deposits with banks		1,450	(7,556)
Cash, due from banks and deposits with banks at beginning of period		12,695	25,118
Cash, due from banks and deposits with banks at end of period		14,145	17,562
Cash and due from banks				5,648		3,647
Deposits with banks				8,497		13,915
Cash, due from banks and deposits with banks at end of period		12,695	25,118	14,145	12,695	17,562
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		29	64
Cash paid during the period for interest		1,627	822
Non-cash investing activities
Transfers to loans HFS from loans		0	0
Transfers to OREO and other repossessed assets		0	0
Reportable legal entities | Other Citigroup subsidiaries and eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities of continuing operations		(5,358)	1,004
Cash flows from investing activities of continuing operations
Purchases of investments		(33,075)	(41,584)
Proceeds from sales of investments		20,688	29,340
Proceeds from maturities of investments		21,509	24,006
Change in loans		(8,717)	(7,953)
Proceeds from sales and securitizations of loans		1,654	3,191
Proceeds from significant disposals			2,732
Change in federal funds sold and resales		(3,242)	(3,493)
Changes in investments and advances—intercompany		5,066	5,576
Other investing activities		(81)	(607)
Net cash provided by (used in) investing activities of continuing operations		3,802	11,208
Cash flows from financing activities of continuing operations
Dividends paid		0	0
Redemption of preferred stock		0
Treasury stock acquired		0	0
Proceeds from issuance of long-term debt, net		184	(4,003)
Proceeds (repayments) from issuance of long-term debt—intercompany, net		412	12,506
Change in deposits		41,397	20,584
Change in federal funds purchased and repos		4,123	5,143
Change in short-term borrowings		(7,949)	(5,179)
Net change in short-term borrowings and other advances—intercompany		(8,240)	5,963
Capital contributions from (to) parent		585
Other financing activities		(214)	0
Net cash provided by financing activities of continuing operations		30,298	35,014
Effect of exchange rate changes on cash and due from banks		(7)	340
Change in cash and due from banks and deposits with banks		28,735	47,566
Cash, due from banks and deposits with banks at beginning of period		156,808	114,565
Cash, due from banks and deposits with banks at end of period		185,543	162,131
Cash and due from banks				16,186		18,273
Deposits with banks				169,357		143,858
Cash, due from banks and deposits with banks at end of period		156,808	114,565	185,543	156,808	162,131
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		975	988
Cash paid during the period for interest		2,076	1,275
Non-cash investing activities
Transfers to loans HFS from loans		900	2,800
Transfers to OREO and other repossessed assets		26	30
Consolidating adjustments
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities of continuing operations		0	0
Cash flows from investing activities of continuing operations
Purchases of investments		0	0
Proceeds from sales of investments		0	0
Proceeds from maturities of investments		0	0
Change in loans		0	0
Proceeds from sales and securitizations of loans		0	0
Proceeds from significant disposals			0
Change in federal funds sold and resales		0	0
Changes in investments and advances—intercompany		0	0
Other investing activities		0	0
Net cash provided by (used in) investing activities of continuing operations		0	0
Cash flows from financing activities of continuing operations
Dividends paid		0	0
Redemption of preferred stock		0
Treasury stock acquired		0	0
Proceeds from issuance of long-term debt, net		0	0
Proceeds (repayments) from issuance of long-term debt—intercompany, net		0	0
Change in deposits		0	0
Change in federal funds purchased and repos		0	0
Change in short-term borrowings		0	0
Net change in short-term borrowings and other advances—intercompany		0	0
Capital contributions from (to) parent		0
Other financing activities		0	0
Net cash provided by financing activities of continuing operations		0	0
Effect of exchange rate changes on cash and due from banks		0	0
Change in cash and due from banks and deposits with banks		0	0
Cash, due from banks and deposits with banks at beginning of period		0	0
Cash, due from banks and deposits with banks at end of period		0	0
Cash and due from banks				0		0
Deposits with banks				0		0
Cash, due from banks and deposits with banks at end of period		0	0	$ 0	$ 0	$ 0
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the period for income taxes		0	0
Cash paid during the period for interest		0	0
Non-cash investing activities
Transfers to loans HFS from loans		0	0
Transfers to OREO and other repossessed assets		$ 0	$ 0
[1]	See Note 2 to the Consolidated Financial Statements for further information on significant disposals.
[2]	Includes the impact of ASU 2016-18, Restricted Cash. See Note 1 to the Consolidated Financial Statements.