Citizens Financial (CFG) 10-K 22 Feb 18 2017 Q4 Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 01, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Document Type	10-K
Entity Central Index Key	759,944
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q4
Trading Symbol	CFG
Entity Registrant Name	CITIZENS FINANCIAL GROUP INC/RI
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		487,325,116
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 18,016,585,315

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
ASSETS:
Cash and due from banks		$ 987	$ 955
Interest-bearing cash and due from banks		2,045	2,749
Interest-bearing deposits in banks		192	439
Securities available for sale, at fair value (including $91 and $256 pledged to creditors, respectively)	[1]	20,157	19,501
Securities held to maturity (fair value of $4,668 and $5,058, respectively)		4,685	5,071
Other investment securities, at fair value		169	96
Other investment securities, at cost		722	942
Loans held for sale, at fair value		497	583
Other loans held for sale		221	42
Loans and leases	[2],[3]	110,617	107,669
Less: Allowance for loan and lease losses		(1,236)	(1,236)
Net loans and leases		109,381	106,433
Derivative assets		617	627
Premises and equipment, net		685	601
Bank-owned life insurance		1,656	1,612
Goodwill		6,887	6,876
Due from broker		6	0
Other assets		3,429	2,993
TOTAL ASSETS		152,336	149,520
Deposits:
Noninterest-bearing		29,279	28,472
Interest-bearing		85,810	81,332
Total deposits		115,089	109,804
Federal funds purchased and securities sold under agreements to repurchase		815	1,148
Other short-term borrowed funds		1,856	3,211
Derivative liabilities		310	659
Deferred taxes, net		571	714
Long-term borrowed funds		11,765	12,790
Other liabilities		1,660	1,447
TOTAL LIABILITIES		132,066	129,773
Contingencies (refer to Note 18)
Preferred stock, $25.00 par value, authorized 100,000,000 shares:
Series A, non-cumulative perpetual, $25 par value,(liquidation preference $1,000), 250,000 shares authorized and issued net of issuance costs and related premium at December 31, 2017 and December 31, 2016		247	247
Common stock:
$0.01 par value, 1,000,000,000 shares authorized, 565,850,984 shares issued and 490,812,912 shares outstanding at December 31, 2017 and 1,000,000,000 shares authorized, 564,630,542 shares issued and 511,954,871 shares outstanding at December 31, 2016		6	6
Additional paid-in capital		18,781	18,722
Retained earnings		4,164	2,703
Treasury stock, at cost, 75,038,072 and 52,675,671 shares at December 31, 2017 and December 31, 2016, respectively		(2,108)	(1,263)
Accumulated other comprehensive loss		(820)	(668)
TOTAL STOCKHOLDERS’ EQUITY		20,270	19,747
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY		$ 152,336	$ 149,520
[1]	Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.
[2]	Excluded from the table above are loans held for sale totaling $718 million and $625 million as of December 31, 2017 and 2016, respectively.
[3]	Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $20.3 billion and $17.3 billion at December 31, 2017 and 2016, respectively.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
ASSETS:
Securities held-to-maturity, fair value	$ 4,668	$ 5,058
STOCKHOLDERS’ EQUITY:
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, issued (in shares)	565,850,984	564,630,542
Common stock, outstanding (in shares)	490,812,912	511,954,871
Treasury stock (in shares)	75,038,072	52,675,671
Series A Preferred Stock
STOCKHOLDERS’ EQUITY:
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, authorized (in shares)	250,000	250,000
Preferred stock, issued (in shares)	250,000	250,000
Preferred stock, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Available-for-sale Securities
ASSETS:
Securities, pledged to creditors	$ 91	$ 256
Held-to-maturity Securities
ASSETS:
Securities held-to-maturity, fair value	$ 4,668	$ 5,058

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST INCOME:
Interest and fees on loans and leases	$ 4,249	$ 3,653	$ 3,211
Interest and fees on loans held for sale, at fair value	18	15	10
Interest and fees on other loans held for sale	10	6	7
Investment securities	625	584	621
Interest-bearing deposits in banks	18	8	5
Total interest income	4,920	4,266	3,854
INTEREST EXPENSE:
Deposits	441	270	237
Federal funds purchased and securities sold under agreements to repurchase	3	2	16
Other short-term borrowed funds	31	40	67
Long-term borrowed funds	272	196	132
Total interest expense	747	508	452
Net interest income	4,173	3,758	3,402
Provision for credit losses	321	369	302
Net interest income after provision for credit losses	3,852	3,389	3,100
NONINTEREST INCOME:
Service charges and fees	516	522	500
Card fees	233	203	232
Capital markets fees	194	136	104
Trust and investment services fees	158	146	157
Letter of credit and loan fees	121	112	110
Foreign exchange and interest rate products	109	103	90
Mortgage banking fees	108	112	101
Securities gains, net	11	16	29
Net securities impairment losses recognized in earnings	(7)	(12)	(7)
Other income	91	159	106
Total noninterest income	1,534	1,497	1,422
NONINTEREST EXPENSE:
Salaries and employee benefits	1,761	1,709	1,636
Outside services	404	377	371
Occupancy	319	307	319
Equipment expense	263	263	257
Amortization of software	180	170	146
Other operating expense	547	526	530
Total noninterest expense	3,474	3,352	3,259
Income before income tax expense	1,912	1,534	1,263
Income tax expense	260	489	423
NET INCOME	1,652	1,045	840
Net income available to common stockholders	$ 1,638	$ 1,031	$ 833
Weighted-average common shares outstanding:
Basic (in shares)	502,157,440	522,093,545	535,599,731
Diluted (in shares)	503,685,091	523,930,718	538,220,898
Per common share information:
Basic earnings (in dollars per share)	$ 3.26	$ 1.97	$ 1.55
Diluted earnings (in dollars per share)	3.25	1.97	1.55
Dividends declared and paid (in dollars per share)	$ 0.64	$ 0.46	$ 0.4

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 1,652	$ 1,045	$ 840
Other comprehensive loss:
Net unrealized derivative instrument (losses) gains arising during the periods, net of income taxes of ($9), ($38) and $57, respectively	(14)	(62)	93
Reclassification adjustment for net derivative gains included in net income, net of income taxes of ($9), ($22), and ($9), respectively	(16)	(36)	(14)
Net unrealized securities losses arising during the periods, net of income taxes of ($4), ($82), and ($38), respectively	(6)	(139)	(66)
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes of $0, ($10), and ($14), respectively	0	(17)	(22)
Reclassification of net securities gains to net income, net of income taxes of ($2), ($2) and ($8), respectively	(2)	(2)	(14)
Employee benefit plans:
Actuarial gain (loss), net of income taxes of $12, ($20) and ($3), respectively	19	(34)	(3)
Amortization of actuarial loss, net of income taxes of $5, $6 and $3, respectively	13	10	12
Amortization of prior service cost, net of income taxes of $0, $0 and $0, respectively	(1)	(1)	(1)
Total other comprehensive loss, net of income taxes	(7)	(281)	(15)
Total comprehensive income	$ 1,645	$ 764	$ 825

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net unrealized derivative instrument (losses) gains arising during the periods, tax	$ (9)	$ (38)	$ 57
Reclassification adjustment for net derivative gains included in net income, tax	(9)	(22)	(9)
Net unrealized securities losses arising during the periods, tax	(4)	(82)	(38)
Other-than-temporary impairment not recognized in earnings on securities, tax	0	(10)	(14)
Reclassification of net securities gains to net income, tax	(2)	(2)	(8)
Actuarial loss, tax	12	(20)	(3)
Amortization of actuarial loss, tax	5	6	3
Amortization of net prior service credit, tax	$ 0	$ 0	$ 0

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock, at Cost	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2014		0	546,000,000
Beginning balance at Dec. 31, 2014	$ 19,268	$ 0	$ 6	$ 18,676	$ 1,294	$ (336)	$ (372)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends to common stockholders	(214)				(214)
Dividends to preferred stockholders	(7)				(7)
Issuance of preferred stock (in shares)		0
Issuance of preferred stock	247	$ 247
Treasury stock purchased (in shares)			(20,000,000)
Treasury stock purchased	(500)					(500)
Share-based compensation plans (in shares)			2,000,000
Share-based compensation plans	18			40		(22)
Employee stock purchase plan shares purchased	9			9
Net income	840				840
Total comprehensive income:
Other comprehensive loss	(15)						(15)
Total comprehensive income	825				840		(15)
Ending balance (in shares) at Dec. 31, 2015		0	528,000,000
Ending balance at Dec. 31, 2015	19,646	$ 247	$ 6	18,725	1,913	(858)	(387)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends to common stockholders	(241)				(241)
Dividends to preferred stockholders	$ (14)				(14)
Treasury stock purchased (in shares)	(17,332,684)		(17,000,000)
Treasury stock purchased	$ (430)			(25)		(405)
Share-based compensation plans (in shares)			1,000,000
Share-based compensation plans	12			12		0
Employee stock purchase plan shares purchased	10			10
Net income	1,045				1,045
Total comprehensive income:
Other comprehensive loss	(281)						(281)
Total comprehensive income	764				1,045		(281)
Ending balance (in shares) at Dec. 31, 2016		0	512,000,000
Ending balance at Dec. 31, 2016	19,747	$ 247	$ 6	18,722	2,703	(1,263)	(668)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends to common stockholders	(322)				(322)
Dividends to preferred stockholders	$ (14)				(14)
Treasury stock purchased (in shares)	(22,362,401)		(22,000,000)
Treasury stock purchased	$ (820)			25		(845)
Share-based compensation plans (in shares)			1,000,000
Share-based compensation plans	22			22		0
Employee stock purchase plan shares purchased	12			12
Net income	1,652				1,652
Total comprehensive income:
Other comprehensive loss	(7)						(7)
Total comprehensive income	1,645				1,652		(7)
Ending balance (in shares) at Dec. 31, 2017		0	491,000,000
Total comprehensive income:
Reclassification of tax effects resulting from the 2017 Tax Legislation	145				145		(145)	[1]
Ending balance at Dec. 31, 2017	$ 20,270	$ 247	$ 6	$ 18,781	$ 4,164	$ (2,108)	$ (820)
[1]	As of December 31, 2017, the balance of AOCI reflects the retrospective adoption of FASB ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. For further discussion, see Note 22 “Income Taxes.”

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income		$ 1,652	$ 1,045	$ 840
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses		321	369	302
Originations of mortgage loans held for sale		(2,911)	(2,829)	(2,363)
Proceeds from sales of mortgage loans held for sale		3,161	2,652	2,381
Purchases of commercial loans held for sale		(2,057)	(1,355)	(1,176)
Proceeds from sales of commercial loans held for sale		1,963	1,335	1,158
Amortization of terminated cash flow hedges, net		(15)	(8)	17
Depreciation, amortization and accretion		502	523	471
Mortgage servicing rights valuation recovery		(2)	(4)	(9)
Securities impairment		7	12	7
Deferred income taxes		(136)	153	249
Share-based compensation		48	23	24
Net gain on sales of:
Debt securities		(11)	(16)	(29)
Marketable equity securities available for sale		(1)	(3)	(3)
Premises and equipment		0	(2)	(9)
Extinguishment of debt		0	0	(3)
Other loans held for sale		(17)	(72)	0
Increase in other assets		(502)	(274)	(467)
Decrease in other liabilities		(119)	(59)	(161)
Net cash provided by operating activities		1,883	1,490	1,229
INVESTING ACTIVITIES
Purchases of securities available for sale		(5,394)	(7,664)	(6,783)
Proceeds from maturities and paydowns of securities available for sale		3,470	3,785	3,420
Proceeds from sales of securities available for sale		1,257	1,966	3,916
Purchases of securities held to maturity		(171)	(523)	(932)
Proceeds from maturities and paydowns of securities held to maturity		561	720	761
Proceeds from sales of securities held to maturity		0	0	72
Purchases of other investment securities, at fair value		(326)	(246)	(157)
Proceeds from sales of other investment securities, at fair value		253	220	120
Purchases of other investment securities, at cost		(400)	(166)	(91)
Proceeds from sales of other investment securities, at cost		637	87	95
Net decrease (increase) in interest-bearing deposits in banks		247	(83)	14
Purchases of mortgage servicing rights		(28)	0	0
Net increase in loans and leases		(3,634)	(9,074)	(6,019)
Net increase in bank-owned life insurance		(44)	(48)	(37)
Premises and equipment:
Purchases		(253)	(138)	(121)
Proceeds from sales		0	3	15
Capitalization of software		(159)	(165)	(178)
Net cash used in investing activities		(3,984)	(11,326)	(5,905)
FINANCING ACTIVITIES
Net increase in deposits		5,285	7,265	6,832
Net (decrease) increase in federal funds purchased and securities sold under agreements to repurchase		(333)	346	(3,474)
Net decrease in other short-term borrowed funds		(4,959)	(3,186)	(4,383)
Proceeds from issuance of long-term borrowed funds		15,363	15,144	6,750
Repayments of long-term borrowed funds		(12,751)	(8,429)	(766)
Treasury stock purchased		(820)	(430)	(500)
Net proceeds from issuance of preferred stock		0	0	247
Dividends declared and paid to common stockholders		(322)	(241)	(214)
Dividends declared and paid to preferred stockholders		(14)	(14)	(7)
Payments Related to Tax Withholding for Share-based Compensation		(20)	0	0
Net cash provided by financing activities		1,429	10,455	4,485
(Decrease) increase in cash and cash equivalents	[1]	(672)	619	(191)
Cash and cash equivalents at beginning of period	[1]	3,704	3,085	3,276
Cash and cash equivalents at end of period	[1]	3,032	3,704	3,085
Supplemental disclosures:
Interest paid		716	505	454
Income taxes paid		371	94	157
Non-cash items:
Loans securitized and transferred to securities available for sale		134	68	3
Stock purchased for share-based compensation plans		22	12	40
Stock purchased for Employee Stock Purchase Plan		12	10	9
Due from broker for securities sold but not settled		6	0	0
Income tax withholding on stock purchased for share based compensation		$ 0	$ 0	$ 22
[1]	Cash and cash equivalents includes cash and due from banks and interest-bearing cash and due from banks as reflected on the Consolidated Balance Sheets.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The accounting and reporting policies of Citizens Financial Group, Inc. conform to GAAP. The Company’s principal business activity is banking, conducted through its subsidiaries Citizens Bank, National Association and Citizens Bank of Pennsylvania. Basis of Presentation The Consolidated Financial Statements include the accounts of the Company and subsidiaries in which the Company has a controlling financial interest. All intercompany transactions and balances have been eliminated. The Company has evaluated its unconsolidated entities and does not believe that any entity in which it has an interest, but does not currently consolidate, meets the requirements to be consolidated as a variable interest entity. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near-term relate to the determination of the allowance for credit losses, evaluation of unrealized losses on securities for other-than-temporary impairment, accounting for income taxes, the valuation of AFS and HTM securities, and derivatives. Certain prior period noninterest income amounts reported in the Consolidated Statement of Operations have been reclassified to conform to the current period presentation and student loans were renamed “education” loans to more closely align with the full range of services offered to borrowers, from loan origination to refinancing. These changes had no effect on net income, to tal comprehensive income, total assets or total stockholders’ equity as previously reported. Additionally, certain prior period balances in the table of deferred tax assets and liabilities in Note 22 — “Income Taxes” have been reclassified to reflect current year presentation. These changes had no effect on net income, total comprehensive income, total assets or total stockholders’ equity as previously reported. Significant Accounting Policies Revenue Recognition Revenue is recognized to the extent that it is probable that the economic benefits will flow to the Company and the revenue can be reliably measured. Interest income on loans and securities classified as AFS or HTM is determined using the effective interest method. This method calculates periodic interest income at a constant effective yield on the net investment in the loan or security, to provide a constant rate of return over the terms of the financial assets. Financial assets accounted for using the fair value option are measured at fair value with corresponding changes recognized in noninterest income. Other types of noninterest revenues, such as service charges on deposits, interchange income on credit cards and trust revenues, are accrued and recognized into income as services are provided and the amount of fees earned are reasonably determinable. Transfer of Financial Assets A transfer of financial assets is accounted for as a sale when control over the assets transferred is surrendered. Assets transferred that satisfy the conditions of a sale are derecognized, and all assets obtained and liabilities incurred in a purchase are recognized and measured at fair value. Servicing rights retained in the transfer of financial assets are initially recognized at fair value. Subsequent to the initial recognition date, servicing rights are accounted for at the lower of cost or market. The Company recognizes periodic amortization expense of servicing rights and assesses servicing rights for impairment. The following table identifies the Company’s significant accounting policies and the Note and Page where a detailed description of each policy can be found. Policy Note Page Cash and Due From Banks Note 2 130 Securities Note 3 130 Loans and Leases Note 4 135 Allowance for Credit Losses Note 5 138 Premises, Equipment and Software Note 6 152 Operating Lease Assets Note 6 152 Mortgage Servicing Rights Note 8 153 Goodwill Note 9 155 Variable Interest Entities Note 10 157 Derivative Instruments Note 13 161 Employee Benefits Note 14 164 Treasury Stock Note 16 171 Employee Share-Based Compensation Note 17 172 Fair Value Measurement Note 19 176 Other Income Note 20 183 Income Taxes Note 22 183 Earnings Per Share Note 23 186 Accounting and Reporting Developments Accounting Pronouncements Adopted in 2017 Pronouncement Summary of Guidance Effects on Financial Statements Reporting Comprehensive Income Issued February 2018 • If elected, requires a reclassification between AOCI and retained earnings for the effect of remeasuring deferred tax assets and liabilities to the newly enacted tax rate of 21% under the 2017 Tax Legislation. • The amount of the reclassification is the difference between the amount initially charged or credited directly to other comprehensive income at the previously enacted U.S. federal corporate income tax rate that remained in AOCI and the amount that would have been charged or credited directly to other comprehensive income using the newly enacted 21% U.S. federal corporate income tax rate, excluding the effect of any valuation allowance previously charged to income from continuing operations. • The Company adopted retrospectively to December 31, 2017, ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, elected to reclassify $145 million between AOCI and retained earnings, including indirect impacts from the decreased federal tax effect on future state tax benefits, and reflected this reclassification in the Company’s 2017 Consolidated Financial Statements, included in this report. Stock Compensation Issued March 2016 • Requires that all excess tax benefits and excess tax deductions that pertain to employee stock-based incentive payments are recognized within income tax expense in the Consolidated Statement of Operations, rather than within additional paid in capital. • This standard also allows entities to make a one-time policy election to account for forfeitures when they occur, which the Company elected to do. • Adopted January 1, 2017. • Adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. Accounting Pronouncements Pending Adoption Pronouncement Summary of Guidance Effects on Financial Statements Stock Compensation Issued May 2017 • Requires modification accounting unless the fair value, vesting conditions, and classification of the modified award are the same as the original award immediately before the modification. • Applied prospectively to all modifications of share-based awards after the adoption date. • Required effective date: January 1, 2018. Early adoption is permitted. The Company will adopt the new standard in the first quarter of 2018. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost Issued March 2017 • Requires the service cost component of net periodic pension and postretirement benefit cost to be reported separately in the Consolidated Statements of Operations from the other components (e.g., expected return on assets, interest costs, amortization of gains/losses and prior service costs). • Requires presentation in the Consolidated Statements of Operations of the service cost component in the same line item as other employee compensation costs and presentation of the other components in a different line item from the service cost component. • Retrospective application is required for all periods presented. • Required effective date: January 1, 2018. Early adoption is permitted. The Company will adopt the new standard in the first quarter of 2018. • Adoption will have no impact on the Company’s net income, but based on recent experience that the expected return on assets exceeds the sum of the other components, the Company expects that the guidance will result in an increase in salaries and employee benefits expense and a reduction in other operating expense. Revenue Recognition: Revenue from Contracts with Customers Issued May 2014 • Requires that revenue from contracts with customers be recognized upon transfer of control of a good or service in the amount of consideration expected to be received. • Changes the accounting for certain contract costs including whether they may be offset against revenues in the Consolidated Statements of Operations. • Requires new qualitative and quantitative disclosures, including information about disaggregation of revenue and performance obligations. • May be adopted using a full retrospective basis or a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2018. Early adoption is permitted. • The Company will adopt the revenue guidance in the first quarter of 2018 using the modified retrospective method. Net interest income on financial assets and liabilities is explicitly excluded from the scope of the pronouncement. • The Company’s implementation efforts included the identification of revenue within the scope of the guidance, as well as the evaluation of revenue contracts and related accounting policies. Based on these efforts, the adoption will not result in a material change in the timing or amount of revenue recognized from contracts with customers. • Upon adoption, underwriting costs will be presented on a gross basis as expense. Currently such costs are presented net of the related underwriting fees. • The Company has completed its evaluation of the expanded disclosure requirements and the most significant item will be the disaggregation of revenue. Recognition and Measurement of Financial Assets and Financial Liabilities Issued January 2016 • Requires equity securities with readily determinable fair values to be measured at fair value on the balance sheet, with changes in the fair value recognized through earnings. • Requires separate presentation of financial assets and financial liabilities by measurement category and form of financial assets on the balance sheet or the notes to the financial statements. • Makes several other targeted amendments to the existing accounting and disclosure requirements for financial instruments, including revised guidance related to valuation allowance assessments when recognizing deferred tax assets on unrealized losses on debt securities available for sale. • Required effective date: January 1, 2018. Early adoption is permitted. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Pronouncement Summary of Guidance Effects on Financial Statements Classification of Certain Cash Receipts and Cash Payments Issued August 2016 • Amends current guidance on specific cashflows to determine the appropriate classification as operating, investing or financing activities which has required significant judgment. • The application of judgment has resulted in diversity in how certain cash receipts and cash payments are classified. • Required effective date: January 1, 2018. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Derivatives and Hedging Issued August 2017 • Reduces the complexity and operational burdens of the current hedge accounting model and portrays more clearly the effects of hedge accounting in the financial statements. • Modifies current requirements to facilitate the application of hedge accounting to partial-term hedges, hedges of prepayable financial instruments, and other strategies. Adoption of these optional changes would occur on a prospective basis. • Requires the effects of fair value hedges to be classified in the same income statement line as the earnings effect of the hedged item. Adoption of this change will occur on a prospective basis. • Requires all effects of cash flow hedges to be deferred in other comprehensive income until the hedged cash flows affect earnings. Periodic hedge ineffectiveness will no longer be recognized in earnings. Adoption of this change will occur on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2019. Early adoption is permitted. The Company is still evaluating whether or not it will adopt this guidance prior to the required effective date. • The transition entries required upon adoption are not expected to have a material impact on the Company’s Consolidated Financial Statements. Premium Amortization on Purchased Callable Debt Securities Issued March 2017 • Requires amortization of premiums to the earliest call date on debt securities with call features that are explicit, noncontingent and callable at fixed prices and on preset dates. • Requires adoption on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2019. • Adoption is not expected to have a material impact on the Company’s Consolidated Financial Statements. The Company does not currently hold callable debt securities. Pronouncement Summary of Guidance Effects on Financial Statements Leases Issued February 2016 • Requires lessees to recognize a right-of-use asset and corresponding lease liability for all leases with a lease term of greater than one year. • Requires lessees and lessors to classify most leases using principles similar to existing lease accounting, but eliminates the “bright line” classification tests. • Requires that for finance leases, a lessee recognize interest expense on the lease liability separately from the amortization of the right-of-use asset in the Consolidated Statements of Operations, while for operating leases, such amounts should be recognized as a combined expense. • Requires expanded disclosures about the nature and terms of lease agreements. • Requires adoption using a modified cumulative effect approach wherein the guidance is applied to all periods presented. • Required effective date: January 1, 2019. Early adoption is permitted. The Company does not intend to adopt the guidance prior to the effective date. • The Company occupies certain banking offices and equipment under non-cancelable operating lease agreements, which currently are not reflected on its Consolidated Balance Sheets. • The Company expects to report increased assets and liabilities as a result of recognizing right-of-use assets and lease liabilities in its Consolidated Balance Sheets. As of December 31, 2017, the Company was committed to $842 million of minimum lease payments under non-cancelable operating lease agreements. • The evaluation of the impact of the leasing pronouncement will be adjusted based on execution of new leases, termination of existing leases prior to the effective date, and any changes to key lease assumptions such as renewals, extensions and discount rates. • The Company does not expect a material change to the timing of expense recognition on the Consolidated Statements of Operations. Goodwill Issued January 2017 • Requires an impairment loss to be recognized when the estimated fair value of a reporting unit falls below its carrying value. • Eliminates the second condition in the current guidance that requires an impairment loss to be recognized only if the estimated implied fair value of the goodwill is below its carrying value. • Applied prospectively to all goodwill impairment tests performed after the adoption date. • Required effective date: January 1, 2020. Early adoption is permitted. The Company does not currently intend to early adopt the new standard. • Adoption is not expected to have a material impact on the Company’s Consolidated Financial Statements. Financial Instruments - Credit Losses Issued June 2016 • Replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost (including securities HTM), which will reflect management’s estimate of credit losses over the full remaining expected life of the financial assets. • Amends existing impairment guidance for securities AFS to incorporate an allowance, which will allow for reversals of impairment losses in the event that the credit of an issuer improves. • Requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. • Required effective date: January 1, 2020. Early adoption permitted on January 1, 2019. The Company does not intend to adopt the guidance prior to the effective date. • The Company established a company-wide, cross-discipline governance structure to implement the new standard. The Company is currently identifying key interpretive issues and is comparing existing credit loss forecasting models and processes with the new guidance to determine what modifications may be required. • While the Company is currently evaluating the impact the standard will have on its Consolidated Financial Statements, the Company expects the standard will result in an earlier recognition of credit losses and an increase in the allowance for credit losses. The magnitude of the increase in the Company’s allowance for loan losses at the adoption date will be dependent upon the nature of the characteristics of the portfolio at the adoption date, as well as macroeconomic conditions and forecasts at that date.

CASH AND DUE FROM BANKS

CASH AND DUE FROM BANKS	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
CASH AND DUE FROM BANKS	CASH AND DUE FROM BANKS For the purposes of reporting cash flows, cash and cash equivalents have original maturities of three months or less and include cash and due from banks and interest-bearing cash and due from banks, primarily at the FRB. The Company’s subsidiary banks maintain certain average reserve balances and compensating balances for check clearing and other services with the FRB. At December 31, 2017 and 2016 , the balance of deposits at the FRB amounted to $2.0 billion and $2.7 billion , respectively. Average balances maintained with the FRB during the years ended December 31, 2017 , 2016 , and 2015 exceeded amounts required by law for the FRB’s requirements. All amounts, both required and excess reserves, held at the FRB currently earn interest at a fixed rate of 150 basis points . The Company recorded interest income on FRB deposits of $16 million , $7 million , and $4 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively, in interest-bearing deposits in banks in the Consolidated Statement of Operations.

SECURITIES

SECURITIES	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
SECURITIES	SECURITIES Investments include debt and marketable equity securities and other investment securities. The Company classifies debt securities as AFS, HTM, or trading based on management’s intent to hold to maturity at the time of purchase, and marketable equity securities as AFS or trading. Securities that will be held for indefinite periods of time and may be sold in response to changes in interest rates, changes in prepayment risk, or other factors considered in managing the Company’s asset/liability strategy are classified as AFS and reported at fair value, with unrealized gains and losses reported in OCI as a separate component of stockholders’ equity, net of taxes. Gains and losses on the sales of securities are recognized in noninterest income and are computed using the specific identification method. Debt securities for which the Company has the ability and intent to hold to maturity are classified as HTM. The securities are reported at amortized cost. Transfers of debt securities to the HTM classification are recognized at fair value at the date of transfer. For debt securities classified as AFS or HTM, interest income is recorded on the accrual basis and is adjusted for the amortization of premiums and the accretion of discounts. Premiums and discounts on debt securities are amortized or accreted using the effective interest method over the estimated lives of the individual securities. The Company uses actual prepayment experience and estimates of future prepayments to determine the constant effective yield necessary to apply the effective interest method of income recognition. Estimates of future prepayments are based on the underlying collateral characteristics of each security and are derived from market sources. Judgment is involved in making determinations about prepayment expectations and in changing those expectations in response to changes in interest rates and macroeconomic conditions. The amortization of premiums and discounts associated with mortgage-backed securities may be significantly impacted by changes in prepayment assumptions. Securities that are classified as trading are bought and held principally for the purpose of selling them in the near term and are carried at fair value, with changes in fair value recognized in earnings. When applicable, realized and unrealized gains and losses on such assets are reported in noninterest income in the Consolidated Statements of Operations. Other investment securities are primarily composed of FHLB stock and FRB stock (which are carried at cost) and money market mutual fund investments held by the Company’s broker-dealers (which are carried at fair value, with changes in fair value recognized in noninterest income). Other investment securities that are carried at cost are reviewed at least annually for impairment, with valuation adjustments recognized in noninterest income. The following table presents the major components of securities at amortized cost and fair value: December 31, 2017 December 31, 2016 (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities Available for Sale U.S. Treasury and other $12 $— $— $12 $30 $— $— $30 State and political subdivisions 6 — — 6 8 — — 8 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 20,065 40 (277 ) 19,828 19,231 78 (264 ) 19,045 Other/non-agency 311 7 (7 ) 311 427 2 (28 ) 401 Total mortgage-backed securities 20,376 47 (284 ) 20,139 19,658 80 (292 ) 19,446 Total debt securities available for sale 20,394 47 (284 ) 20,157 19,696 80 (292 ) 19,484 Marketable equity securities — — — — 5 — — 5 Other equity securities — — — — 12 — — 12 Total equity securities available for sale — — — — 17 — — 17 Total securities available for sale $20,394 $47 ($284 ) $20,157 $19,713 $80 ($292 ) $19,501 Securities Held to Maturity Mortgage-backed securities: Federal agencies and U.S. government sponsored entities $3,853 $7 ($46 ) $3,814 $4,126 $12 ($44 ) $4,094 Other/non-agency 832 22 — 854 945 19 — 964 Total securities held to maturity $4,685 $29 ($46 ) $4,668 $5,071 $31 ($44 ) $5,058 Other Investment Securities, at Fair Value Money market mutual fund $165 $— $— $165 $91 $— $— $91 Other investments 4 — — 4 5 — — 5 Total other investment securities, at fair value $169 $— $— $169 $96 $— $— $96 Other Investment Securities, at Cost Federal Reserve Bank stock $463 $— $— $463 $463 $— $— $463 Federal Home Loan Bank stock 252 — — 252 479 — — 479 Other equity securities 7 — — 7 — — — — Total other investment securities, at cost $722 $— $— $722 $942 $— $— $942 The amortized cost and fair value of debt securities by contractual maturity are presented below. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without incurring penalties. Distribution of Maturities (in millions) 1 Year or Less 1-5 Years 5-10 Years After 10 Years Total Amortized Cost: Debt securities available for sale U.S. Treasury and other $12 $— $— $— $12 State and political subdivisions — — — 6 6 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — 261 1,067 18,737 20,065 Other/non-agency 1 21 — 289 311 Total debt securities available for sale 13 282 1,067 19,032 20,394 Debt securities held to maturity: Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — — — 3,853 3,853 Other/non-agency — — — 832 832 Total debt securities held to maturity — — — 4,685 4,685 Total amortized cost of debt securities $13 $282 $1,067 $23,717 $25,079 Fair Value: Debt securities available for sale U.S. Treasury and other $12 $— $— $— $12 State and political subdivisions — — — 6 6 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — 261 1,071 18,496 19,828 Other/non-agency 1 21 — 289 311 Total debt securities available for sale 13 282 1,071 18,791 20,157 Debt securities held to maturity Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — — — 3,814 3,814 Other/non-agency — — — 854 854 Total debt securities held to maturity — — — 4,668 4,668 Total fair value of debt securities $13 $282 $1,071 $23,459 $24,825 Taxable interest income from investment securities as presented on the Consolidated Statements of Operations was $625 million , $584 million and $621 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Realized gains and losses on securities are presented below: Year Ended December 31, (in millions) 2017 2016 2015 Gains on sale of debt securities $11 $18 $41 Losses on sale of debt securities — (2 ) (12 ) Debt securities gains, net $11 $16 $29 Equity securities gains $1 $3 $3 In advance of the July 2017 Volcker Rule’s effective date, during the year ended December 31, 2015, the Company sold a $73 million mortgage-backed security that was classified as HTM, which would have been prohibited under the Volcker Rule, and recognized a $2 million gain. The amortized cost and fair value of securities pledged are presented below: December 31, 2017 December 31, 2016 (in millions) Amortized Cost Fair Value Amortized Cost Fair Value Pledged against repurchase agreements $358 $357 $631 $620 Pledged against FHLB borrowed funds 839 861 953 972 Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law 3,113 3,082 3,575 3,563 The Company regularly enters into security repurchase agreements with unrelated counterparties. Repurchase agreements are financial transactions that involve the transfer of a security from one party to another and a subsequent transfer of substantially the same security back to the original party. The Company’s repurchase agreements are typically short-term transactions, but they may be extended to longer terms to maturity. Such transactions are accounted for as secured borrowed funds on the Company’s Consolidated Balance Sheets. When permitted by GAAP, the Company offsets short-term receivables associated with its reverse repurchase agreements against short-term payables associated with its repurchase agreements. The Company recognized no offsetting of short-term receivables or payables as of December 31, 2017 or 2016 . The Company offsets certain derivative assets and derivative liabilities on the Consolidated Balance Sheets. For further information see Note 13 “Derivatives.” Securitizations of mortgage loans retained in the investment portfolio for the years ended December 31, 2017 , 2016 and 2015 , were $134 million , $68 million and $3 million , respectively. These securitizations included a substantive guarantee by third parties. In 2017, the guarantors were Fannie Mae, Freddie Mac, and Ginnie Mae. In 2016, the guarantors were Fannie Mae and Ginnie Mae. In 2015, the guarantor was Freddie Mac. These securitizations were accounted for as a sale of the transferred loans and as a purchase of securities. The securities received from the guarantors are classified as AFS. Impairment The Company reviews its securities for other-than-temporary impairment on a quarterly basis or more frequently if a potential loss triggering event occurs. The initial indicator of other-than-temporary impairment for both debt and equity securities is a decline in fair value below its recorded investment amount, as well as the severity and duration of the decline. For a security of which there has been a decline in fair value below the cost basis, the Company recognizes other-than-temporary impairment if (i) management has the intent to sell the security, (ii) it is more likely than not it will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire cost basis of the security. Estimating the recovery of the amortized cost basis of a debt security is based upon an assessment of the cash flows expected to be collected. If the present value of cash flows expected to be collected, discounted at the security’s original effective yield, is less than amortized cost, other-than-temporary impairment is considered to have occurred. In addition to these cash flow projections, several other characteristics of each debt security are reviewed when determining whether a credit loss exists and the period over which the debt security is expected to recover. These characteristics include: (i) the type of investment, (ii) various market factors affecting the fair value of the security (e.g., interest rates, spread levels, liquidity in the sector, etc.), (iii) the length and severity of impairment, and (iv) the public credit rating of the instrument. The Company estimates the portion of loss attributable to credit using a collateral loss model and integrated cash flow engine. The model calculates prepayment, default and loss severity assumptions using collateral performance data. These assumptions are used to produce cash flows that generate loss projections. These loss projections are reviewed on a quarterly basis by a cross-functional governance committee to determine whether security impairments are other-than-temporary. If the Company intends to sell an impaired security, or if it is more likely than not it will be required to sell the security before recovery, the impairment loss recognized in current period earnings equals the difference between the amortized cost basis and the fair value of the security. If the Company does not intend to sell the impaired security, and it is not likely that the Company will be required to sell the impaired security, the other-than-temporary impairment write-down is separated into an amount representing the credit loss, which is recognized in current period earnings and the amount related to all other factors, is recognized in OCI. The following table presents the net securities impairment losses recognized in earnings: Year Ended December 31, (in millions) 2017 2016 2015 Other-than-temporary impairment: Total other-than-temporary impairment losses ($7 ) ($39 ) ($43 ) Portions of loss recognized in other comprehensive income (before taxes) — 27 36 Net securities impairment losses recognized in earnings ($7 ) ($12 ) ($7 ) The following tables present securities whose fair values are below carrying values, segregated by those that have been in a continuous unrealized loss position for less than twelve months and those that have been in a continuous unrealized loss position for twelve months or longer: December 31, 2017 Less than 12 Months 12 Months or Longer Total (dollars in millions) Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 294 $10,163 ($97 ) 152 $8,061 ($226 ) 446 $18,224 ($323 ) Other/non-agency 6 55 (1 ) 10 84 (6 ) 16 139 (7 ) Total mortgage-backed securities 300 10,218 (98 ) 162 8,145 (232 ) 462 18,363 (330 ) Total 300 $10,218 ($98 ) 162 $8,145 ($232 ) 462 $18,363 ($330 ) December 31, 2016 Less than 12 Months 12 Months or Longer Total (dollars in millions) Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses State and political subdivisions 1 $8 $— — $— $— 1 $8 $— Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 323 15,387 (292 ) 25 461 (16 ) 348 15,848 (308 ) Other/non-agency 4 8 — 20 302 (28 ) 24 310 (28 ) Total mortgage-backed securities 327 15,395 (292 ) 45 763 (44 ) 372 16,158 (336 ) Total 328 $15,403 ($292 ) 45 $763 ($44 ) 373 $16,166 ($336 ) The following table presents the cumulative credit related losses recognized in earnings on debt securities held by the Company: Year Ended December 31, (in millions) 2017 2016 2015 Cumulative balance at beginning of period $75 $66 $62 Credit impairments recognized in earnings on securities that have been previously impaired 7 12 7 Reductions due to increases in cash flow expectations on impaired securities (1) (2 ) (3 ) (3 ) Cumulative balance at end of period $80 $75 $66 (1) Reported in interest income from investment securities on the Consolidated Statements of Operations. Cumulative credit losses recognized in earnings for impaired AFS debt securities held as of December 31, 2017 , 2016 and 2015 were $80 million , $75 million and $66 million , respectively. There were no credit losses recognized in earnings for the Company’s HTM portfolio as of December 31, 2017 , 2016 and 2015 . For the years ended December 31, 2017 , 2016 and 2015 , the Company incurred non-agency MBS credit related other-than-temporary impairment losses in earnings of $7 million , $12 million and $7 million , respectively. Other-than-temporary impairment losses for the year ended December 31, 2016 included the $5 million impact of a one-time adjustment from a new model implementation. This adjustment was the result of the Company migrating in June 2016 from a proprietary internal process to a vendor-based model to estimate other-than-temporary impairment. There were no credit impaired debt securities sold during the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company does not currently have the intent to sell these debt securities, and it is not more likely than not that the Company will be required to sell these debt securities prior to the recovery of their amortized cost bases. The Company has determined that credit losses are not expected to be incurred on the remaining agency and non-agency MBS identified with unrealized losses as of December 31, 2017 . The unrealized losses on these debt securities reflect non- credit-related factors such as changing interest rates and market liquidity. Therefore, the Company has determined that these debt securities are not other-than-temporarily impaired because the Company does not currently have the intent to sell these debt securities, and it is not more likely than not that the Company will be required to sell these debt securities prior to the recovery of their amortized cost bases. Any subsequent increases in the valuation of impaired debt securities do not impact their recorded cost bases. Additionally, as of December 31, 2017 , there were no pre-tax non-credit related losses deferred in AOCI and there were $27 million and $36 million for the years ended December 31, 2016 and 2015 , respectively.

LOANS AND LEASES

LOANS AND LEASES	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
LOANS AND LEASES	LOANS AND LEASES Loans held for investment are reported at the amount of their outstanding principal, net of charge-offs, unearned income, deferred loan origination fees and costs, and unamortized premiums or discounts on purchased loans. Deferred loan origination fees and costs and purchase premiums and discounts are amortized as an adjustment of yield over the life of the loan, using the effective interest method. Unamortized amounts remaining upon prepayment or sale are recorded as interest income or gain (loss) on sale, respectively. Credit card receivables include billed and uncollected interest and fees. Interest income on loans is determined using the effective interest method. This method calculates periodic interest income at a constant effective yield on the net investment in the loan, to provide a constant rate of return over the term. Loans accounted for using the fair value option, are measured at fair value with corresponding changes recognized in noninterest income. Loan commitment fees for loans that are likely to be drawn down, and other credit related fees, are deferred (together with any incremental costs) and recognized as an adjustment to the effective interest rate over the loan term. When it is unlikely that a loan will be drawn down, the loan commitment fees are recognized over the commitment period on a straight-line basis. Leases are classified at the inception of the lease. Direct financing lease receivables are reported at the aggregate of minimum lease payments receivable plus the estimated residual value of the leased property, less unearned and deferred income, including unamortized investment credits. Leveraged leases, which are a form of direct financing leases, are recorded net of related non-recourse debt. Lease residual values are reviewed at least annually for other-than-temporary impairment; with valuation adjustments recognized currently against other income for direct financing and leveraged leases. Unearned income is recognized as a constant percentage of outstanding lease financing balances over the lease term in interest income. Loans and leases are disclosed in portfolio segments and classes. The Company’s loan and lease portfolio segments are commercial and retail. The classes of loans and leases are: commercial, commercial real estate, leases, residential mortgages, home equity loans, home equity lines of credit, home equity loans serviced by others, home equity lines of credit serviced by others, automobile, education, credit cards and other retail. The Company’s SBO portfolio consists of purchased home equity loans and lines that were originally serviced by others, which the Company now services a portion of internally. A summary of the loans and leases portfolio is presented below: December 31, (in millions) 2017 2016 Commercial $37,562 $37,274 Commercial real estate 11,308 10,624 Leases 3,161 3,753 Total commercial loans and leases 52,031 51,651 Residential mortgages 17,045 15,115 Home equity loans 1,392 1,858 Home equity lines of credit 13,483 14,100 Home equity loans serviced by others 542 750 Home equity lines of credit serviced by others 149 219 Automobile 13,204 13,938 Education (1) 8,134 6,610 Credit cards 1,848 1,691 Other retail 2,789 1,737 Total retail loans 58,586 56,018 Total loans and leases (2)(3) $110,617 $107,669 (1) During first quarter 2017, student loans were renamed “education” loans. Refer to Note 1 “Significant Accountant Policies” for more information. (2) Excluded from the table above are loans held for sale totaling $718 million and $625 million as of December 31, 2017 and 2016 , respectively. (3) Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $20.3 billion and $17.3 billion at December 31, 2017 and 2016 , respectively. Loans are classified upon origination or acquisition as either held-for-investment or held-for-sale. This classification is based on management’s initial intent and ability to hold the loans for the foreseeable future. Loans held for sale are carried at the lower of cost or fair value, with any write-downs or subsequent recoveries charged to other income. The Company accounts for certain loans held for sale, including those loans associated with its mortgage banking business and secondary loan trading desk, under the fair value option at fair value. Refer to Note 19, “Fair Value Measurements” for additional discussion. The following tables present balances of loan purchases and sales: Year Ended December 31, 2017 (in millions) Education Automobile Residential mortgages Home equity loans Commercial Total Purchases $862 $153 $— $— $— $1,015 Sales — — 254 29 603 886 Year Ended December 31, 2016 (in millions) Education Automobile Residential mortgages Home equity loans Commercial Total Purchases $1,224 $695 $539 $— $— $2,458 Sales — — 699 55 147 901 Reflected in the previous table are retail TDR sales during the year ended December 31, 2017 of $78 million , including $49 million of residential mortgages and $29 million of home equity loans, which resulted in a pre-tax gain of $17 million reported in other income on the Consolidated Statements of Operations. Also reflected in the previous table are $6 million of commercial TDR sales during the year ended December 31, 2017. During the year ended December 31, 2016 , the Company sold $310 million of TDRs, including $255 million of residential mortgages and $55 million of home equity loans, which resulted in a pre-tax gain of $72 million reported in other income on the Consolidated Statements of Operations. Loans held for sale at fair value totaled $497 million and $583 million at December 31, 2017 and 2016 , respectively, and consisted of residential mortgages originated for sale of $326 million and loans in the commercial trading portfolio of $171 million as of December 31, 2017 . As of December 31, 2016 , of the $583 million , residential mortgages originated for sale were $504 million and loans in the commercial trading portfolio totaled $79 million . Other loans held for sale totaled $221 million and $42 million as of December 31, 2017 and 2016 , respectively, and consisted of commercial loan syndications. Loans pledged as collateral for FHLB borrowed funds, primarily residential mortgages and home equity loans, totaled $24.9 billion and $24.0 billion at December 31, 2017 and 2016 , respectively. Loans pledged as collateral to support the contingent ability to borrow at the FRB discount window, if necessary, was primarily comprised of auto and commercial loans, and totaled $18.1 billion and $16.8 billion at December 31, 2017 and 2016 , respectively. The Company is engaged in the leasing of equipment for commercial use, with primary lease concentrations to Fortune 1000 companies for large capital equipment acquisitions. A lessee is evaluated from a credit perspective using the same underwriting standards and procedures as for a loan borrower. A lessee is expected to make rental payments based on its cash flows and the viability of its operations. Leases are usually not evaluated as collateral-based transactions, and therefore the lessee’s overall financial strength is the most important credit evaluation factor. A summary of the investment in leases, before the ALLL, is presented below: December 31, (in millions) 2017 2016 Direct financing leases $3,122 $3,670 Leveraged leases 39 83 Total leases $3,161 $3,753 The components of the investment in leases, before the ALLL, are presented below: December 31, (in millions) 2017 2016 Total future minimum lease rentals $2,347 $2,922 Estimated residual value of leased equipment (non-guaranteed) 1,072 1,166 Initial direct costs 15 20 Unearned income on minimum lease rentals and estimated residual value of leased equipment (273 ) (355 ) Total leases $3,161 $3,753 The future minimum lease rentals on direct financing and leveraged leases at December 31, 2017 are presented below: Year (in millions) 2018 $602 2019 553 2020 399 2021 300 2022 201 Thereafter 292 Total $2,347

ALLOWANCE FOR CREDIT LOSSES, NO

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK	ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK Allowance for Credit Losses Management’s estimate of probable losses in the Company’s loan and lease portfolios is recorded in the ALLL and the reserve for unfunded lending commitments. On a quarterly basis, the Company evaluates the adequacy of the ALLL by performing reviews of certain individual loans and leases, analyzing changes in the composition, size and delinquency of the portfolio, reviewing previous loss experience and considering current and anticipated economic factors. The ALLL is established in accordance with the Company’s credit reserve policies, as approved by the Audit Committee of the Board of Directors. The Chief Financial Officer and Chief Risk Officer review the adequacy of the ALLL each quarter, together with risk management. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for credit losses. The ALLL is maintained at a level that management considers reflective of probable losses, and is established through charges to earnings in the form of a provision for credit losses. The ALLL may be adjusted to reflect the Company’s current assessment of various qualitative risks, factors and events that may not be measured in the statistical analysis. Such factors include trends in economic conditions, loan growth, back testing results, credit underwriting policy exceptions, regulatory and audit findings, and peer comparisons. Amounts determined to be uncollectible are deducted from the ALLL and subsequent recoveries, if any, are added to the ALLL. While management uses available information to estimate loan and lease losses, future additions to the ALLL may be necessary based on changes in economic conditions. The evaluation of the adequacy of the commercial, commercial real estate, and lease ALLL and reserve for unfunded lending commitments is primarily based on risk rating models that assess probability of default, loss given default and exposure at default on an individual loan basis. The models are primarily driven by individual customer financial characteristics and are validated against historical experience. Additionally, qualitative factors may be included in the risk rating models. After the aggregation of individual borrower incurred loss, additional overlays can be made based on back-testing against historical losses. For non-impaired retail loans, the ALLL is based upon an incurred loss model utilizing the probability of default, loss given default and exposure at default on an individual loan basis. When developing these factors, the Company may consider the loan product and collateral type, delinquency status, LTV ratio, lien position, borrower’s credit, age of the loan, geographic location and incurred loss period. Certain retail portfolios, including SBO home equity loans and commercial credit card receivables utilize roll rate models to estimate the ALLL. For the portfolios measured using the incurred loss model, roll rate models are also run as challenger models and can be used to support management overlays if deemed necessary. For nonaccruing commercial and commercial real estate loans with an outstanding balance of $3 million or greater and for all commercial and commercial real estate TDRs (regardless of size), the Company conducts further analysis to determine the probable amount of loss and establishes a specific allowance for the loan, if appropriate. The Company estimates the impairment amount by comparing the loan’s carrying amount to the estimated present value of its future cash flows, the fair value of its underlying collateral, or the loan’s observable market price. For collateral-dependent impaired commercial and commercial real estate loans, the excess of the Company’s recorded investment in the loan over the fair value of the collateral, less cost to sell, is charged off to the ALLL. For retail TDRs that are not collateral-dependent, allowances are developed using the present value of expected future cash flows compared to the recorded investment in the loans. Expected re-default factors are considered in this analysis. Retail TDRs that are deemed collateral-dependent are written down to fair market value less cost to sell. The fair value of collateral is periodically monitored subsequent to the modification. In addition to the ALLL, the Company also estimates probable credit losses associated with off balance sheet financial instruments such as standby letters of credit, financial guarantees and binding unfunded loan commitments. Off balance sheet financial instruments are subject to individual reviews and are analyzed and segregated by risk according to the Company’s internal risk rating scale. These risk classifications, in conjunction with historical loss experience, economic conditions and performance trends within specific portfolio segments, result in the estimate of the reserve for unfunded lending commitments. The ALLL and the reserve for unfunded lending commitments are reported on the Consolidated Balance Sheets in the allowance for loan and lease losses and in other liabilities, respectively. Provision for credit losses related to the loans and leases portfolio and the unfunded lending commitments are reported in the Consolidated Statements of Operations as provision for credit losses. As of December 31, 2017, the Company enhanced the method for assessing various qualitative risks, factors and events that may not be measured in the modeled results. The new methodology includes a statistical analysis of prior charge-off rates on a historical basis combined with a qualitative assessment based on quantitative measures affecting the determination of incurred losses in the loan and lease portfolio, and provides better alignment of the qualitative ALLL to the commercial and retail loan portfolios. The impact of the change is an increase of approximately $50 million to the commercial ALLL with a corresponding decrease to the retail ALLL; there was not a significant impact on the total qualitative ALLL as of December 31, 2017. There were no other material changes in assumptions or estimation techniques compared with prior years that impacted the determination of the current year’s ALLL and the reserve for unfunded lending commitments. Loan Charge-Offs Commercial loans are charged off when it is highly certain that a loss has been realized, including situations where a loan is determined to be both impaired and collateral-dependent. The determination of whether to recognize a charge-off involves many factors, including the prioritization of the Company’s claim in bankruptcy, expectations of the workout/restructuring of the loan and valuation of the borrower’s equity or the loan collateral. Retail loans are generally fully charged-off or written down to the net realizable value of the underlying collateral, with an offset to the ALLL, upon reaching specified stages of delinquency in accordance with standards established by the FFIEC. Residential real estate loans, credit card loans and unsecured open end loans are generally charged off in the month in which the account becomes 180 days past due. Auto loans, education loans and unsecured closed end loans are generally charged off in the month in which the account becomes 120 days past due. Certain retail loans will be charged off earlier than the FFIEC standards in the following circumstances: • A charge-off is recognized when a loan is modified in a TDR if the loan is determined to be collateral-dependent. A loan is considered to be collateral-dependent when repayment of the loan is expected to be provided solely by the underlying collateral, rather than by cash flows from the borrower’s operations, income or other resources. • Loans to borrowers who have experienced an event (e.g. bankruptcy) that suggests a loss is either known or highly certain are subject to accelerated charge-off standards. Residential real estate and auto loans are charged down to the net realizable value when the loan becomes 60 days past due, or sooner if the loan is determined to be collateral-dependent. Credit card loans are fully charged off within 60 days of receiving notification of the bankruptcy filing or other event. Education loans are generally charged off when the loan becomes 60 days past due after receiving notification of a bankruptcy. • Auto loans are written down to net realizable value upon repossession of the collateral. A summary of changes in the allowance for credit losses is presented below: Year Ended December 31, 2017 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $663 $573 $1,236 Charge-offs (75 ) (437 ) (512 ) Recoveries 40 167 207 Net charge-offs (35 ) (270 ) (305 ) Provision charged to income (1) 57 248 305 Allowance for loan and lease losses, end of period 685 551 1,236 Reserve for unfunded lending commitments, beginning of period 72 — 72 Provision for unfunded lending commitments 16 — 16 Reserve for unfunded lending commitments, end of period 88 — 88 Total allowance for credit losses, end of period $773 $551 $1,324 (1) Includes an increase of approximately $50 million to commercial and corresponding decrease to retail for the impact of the enhancement to the assessment of qualitative risks, factors and events that may not be measured in the modeled results. Year Ended December 31, 2016 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $596 $620 $1,216 Charge-offs (79 ) (457 ) (536 ) Recoveries 33 168 201 Net charge-offs (46 ) (289 ) (335 ) Provision charged to income 113 242 355 Allowance for loan and lease losses, end of period 663 573 1,236 Reserve for unfunded lending commitments, beginning of period 58 — 58 Provision for unfunded lending commitments 14 — 14 Reserve for unfunded lending commitments, end of period 72 — 72 Total allowance for credit losses, end of period $735 $573 $1,308 Year Ended December 31, 2015 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $544 $651 $1,195 Charge-offs (36 ) (444 ) (480 ) Recoveries 49 147 196 Net recoveries (charge-offs) 13 (297 ) (284 ) Provision charged to income 39 266 305 Allowance for loan and lease losses, end of period 596 620 1,216 Reserve for unfunded lending commitments, beginning of period 61 — 61 Provision (credit) for unfunded lending commitments (3 ) — (3 ) Reserve for unfunded lending commitments as of period end 58 — 58 Total allowance for credit losses as of period end $654 $620 $1,274 The recorded investment in loans and leases based on the Company’s evaluation methodology is presented below: December 31, 2017 December 31, 2016 (in millions) Commercial Retail Total Commercial Retail Total Individually evaluated $370 $761 $1,131 $424 $799 $1,223 Formula-based evaluation 51,661 57,825 109,486 51,227 55,219 106,446 Total $52,031 $58,586 $110,617 $51,651 $56,018 $107,669 A summary of the allowance for credit losses by evaluation method is presented below: December 31, 2017 December 31, 2016 (in millions) Commercial Retail Total Commercial Retail Total Individually evaluated $47 $34 $81 $63 $43 $106 Formula-based evaluation 726 517 1,243 672 530 1,202 Allowance for credit losses $773 $551 $1,324 $735 $573 $1,308 For commercial loans and leases, the Company utilizes regulatory classification ratings to monitor credit quality. Loans with a “pass” rating are those that the Company believes will be fully repaid in accordance with the contractual loan terms. Commercial loans and leases that are “criticized” are those that have some weakness or potential weakness that indicate an increased probability of future loss. “Criticized” loans are grouped into three categories, “special mention,” “substandard” and “doubtful.” Special mention loans have potential weaknesses that, if left uncorrected, may result in deterioration of the Company’s credit position at some future date. Substandard loans are inadequately protected loans; these loans have well-defined weaknesses that could hinder normal repayment or collection of the debt. Doubtful loans have the same weaknesses as substandard, with the added characteristics that the possibility of loss is high and collection of the full amount of the loan is improbable. For retail loans, the Company primarily uses the loan’s payment and delinquency status to monitor credit quality. The further a loan is past due, the greater the likelihood of future credit loss. These credit quality indicators for both commercial and retail loans are continually updated and monitored. The recorded investment in commercial loans and leases based on regulatory classification ratings is presented below: December 31, 2017 Criticized (in millions) Pass Special Mention Substandard Doubtful Total Commercial $35,430 $1,143 $785 $204 $37,562 Commercial real estate 10,706 500 74 28 11,308 Leases 3,069 73 19 — 3,161 Total commercial loans and leases $49,205 $1,716 $878 $232 $52,031 December 31, 2016 Criticized (in millions) Pass Special Mention Substandard Doubtful Total Commercial $35,010 $1,015 $1,027 $222 $37,274 Commercial real estate 10,146 370 58 50 10,624 Leases 3,583 52 103 15 3,753 Total commercial loans and leases $48,739 $1,437 $1,188 $287 $51,651 The recorded investment in classes of retail loans, categorized by delinquency status is presented below: December 31, 2017 Days Past Due (in millions) Current 1-29 30-59 60-89 90 or More Total Residential mortgages $16,714 $147 $46 $18 $120 $17,045 Home equity loans 1,212 102 20 4 54 1,392 Home equity lines of credit 12,756 438 78 23 188 13,483 Home equity loans serviced by others 477 29 10 4 22 542 Home equity lines of credit serviced by others 116 21 4 1 7 149 Automobile 11,596 1,273 220 55 60 13,204 Education 7,898 160 23 12 41 8,134 Credit cards 1,747 63 12 9 17 1,848 Other retail 2,679 68 20 12 10 2,789 Total retail loans $55,195 $2,301 $433 $138 $519 $58,586 December 31, 2016 Days Past Due (in millions) Current 1-29 30-59 60-89 90 or More Total Residential mortgages $14,807 $108 $53 $12 $135 $15,115 Home equity loans 1,628 127 23 7 73 1,858 Home equity lines of credit 13,432 396 57 20 195 14,100 Home equity loans serviced by others 673 41 14 5 17 750 Home equity lines of credit serviced by others 158 25 3 2 31 219 Automobile 12,509 1,177 172 38 42 13,938 Education 6,379 151 24 13 43 6,610 Credit cards 1,611 43 12 9 16 1,691 Other retail 1,676 45 8 4 4 1,737 Total retail loans $52,873 $2,113 $366 $110 $556 $56,018 Nonperforming Assets Nonperforming loans and leases are those on which accrual of interest has been suspended. Loans (other than certain retail loans insured by U.S. government agencies) are placed on nonaccrual status and considered nonperforming when full payment of principal and interest is in doubt, unless the loan is both well secured and in the process of collection. When the Company places a loan on nonaccrual status, the accrued unpaid interest receivable is reversed against interest income and amortization of any net deferred fees is suspended. Interest collections on nonaccruing loans and leases for which the ultimate collectability of principal is uncertain are generally applied to first reduce the carrying value of the loan. Otherwise, interest income may be recognized to the extent of the cash received. A loan may be returned to accrual status if (i) principal and interest payments have been brought current, and the Company expects repayment of the remaining contractual principal and interest, (ii) the loan or lease has otherwise become well-secured and in the process of collection, or (iii) the borrower has been making regularly scheduled payments in full for the prior six months and the Company is reasonably assured that the loan or lease will be brought fully current within a reasonable period. Commercial loans, commercial real estate loans, and leases are generally placed on nonaccrual status when contractually past due 90 days or more, or earlier if management believes that the probability of collection is insufficient to warrant further accrual. Some of these loans and leases may remain on accrual status when contractually past due 90 days or more if management considers the loan collectible. Residential mortgages are generally placed on nonaccrual status when past due 120 days, or sooner if determined to be collateral-dependent, unless repayment of the loan is insured by the Federal Housing Administration. Credit card balances are placed on nonaccrual status when past due 90 days or more and are restored to accruing status if they subsequently become less than 90 days past due. All other retail loans are generally placed on nonaccrual status when past due 90 days or more, or earlier if management believes that the probability of collection is insufficient to warrant further accrual. Loans less than 90 days past due may be placed on nonaccrual status upon the death of the borrower, fraud or bankruptcy. The following table presents nonperforming loans and leases and loans accruing and 90 days or more past due: Nonperforming (1) Accruing and 90 days or more past due (in millions) December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Commercial $238 $322 $5 $2 Commercial real estate 27 50 3 — Leases — 15 — — Total commercial loans and leases 265 387 8 2 Residential mortgages (1) 128 144 16 18 Home equity loans 72 98 — — Home equity lines of credit 233 243 — — Home equity loans serviced by others 25 32 — — Home equity lines of credit serviced by others 18 33 — — Automobile 70 50 — — Education 38 38 3 5 Credit card 17 16 — — Other retail 5 4 5 1 Total retail loans 606 658 24 24 Total $871 $1,045 $32 $26 (1) Nonperforming balances exclude first lien residential mortgage loans that are 100% guaranteed by the Federal Housing Administration. These loans, which are accruing and 90 days or more past due, totaled $15 million and $18 million as of December 31, 2017 and 2016, respectively. Nonperforming balances also exclude guaranteed residential mortgage loans sold to GNMA for which the Company has the right, but not the obligation, to repurchase. These loans totaled $30 million and $32 million as of December 31, 2017 and 2016, respectively. These loans are included in the Company’s Consolidated Balance Sheets. Other nonperforming assets consisted primarily of other real estate owned and was presented in other assets on the Consolidated Balance Sheets. Other real estate owned, net of valuation allowance, was $36 million and $49 million as of December 31, 2017 and 2016, respectively. A summary of key performance indicators is presented below: December 31, 2017 2016 Nonperforming commercial loans and leases as a percentage of total loans and leases 0.24 % 0.36 % Nonperforming retail loans as a percentage of total loans and leases 0.55 0.61 Total nonperforming loans and leases as a percentage of total loans and leases 0.79 % 0.97 % Nonperforming commercial assets as a percentage of total assets 0.17 % 0.26 % Nonperforming retail assets as a percentage of total assets 0.43 0.47 Total nonperforming assets as a percentage of total assets 0.60 % 0.73 % The recorded investment in mortgage loans collateralized by residential real estate property for which formal foreclosure proceedings are in-process was $181 million and $177 million as of December 31, 2017 and 2016 , respectively. An analysis of the age of both accruing and nonaccruing loan and lease past due amounts is presented below: December 31, 2017 December 31, 2016 Days Past Due Days Past Due (in millions) 30-59 60-89 90 or More Total 30-59 60-89 90 or More Total Commercial $26 $4 $243 $273 $36 $4 $324 $364 Commercial real estate 38 20 30 88 1 2 50 53 Leases 4 1 — 5 1 — 15 16 Total commercial loans and leases 68 25 273 366 38 6 389 433 Residential mortgages 46 18 120 184 53 12 135 200 Home equity loans 20 4 54 78 23 7 73 103 Home equity lines of credit 78 23 188 289 57 20 195 272 Home equity loans serviced by others 10 4 22 36 14 5 17 36 Home equity lines of credit serviced by others 4 1 7 12 3 2 31 36 Automobile 220 55 60 335 172 38 42 252 Education 23 12 41 76 24 13 43 80 Credit cards 12 9 17 38 12 9 16 37 Other retail 20 12 10 42 8 4 4 16 Total retail loans 433 138 519 1,090 366 110 556 1,032 Total $501 $163 $792 $1,456 $404 $116 $945 $1,465 Impaired Loans A loan is considered to be impaired when, based on current information and events, it is probable that the Company will be unable to collect all of the contractual interest and principal payments as scheduled in the loan agreement. This evaluation is generally based on delinquency information, an assessment of the borrower’s financial condition and the adequacy of collateral, if any. Impaired loans include nonaccruing larger balance (greater than $3 million carrying value), non-homogeneous commercial and commercial real estate loans, and restructured loans that are deemed TDRs. When a loan is identified as impaired, the impairment is measured on an individual loan level as the difference between the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount) and the present value of expected future cash flows, discounted at the loan’s effective interest rate. When collateral is the sole source of repayment for the impaired loan, rather than the borrower’s income or other sources of repayment, the Company charges down the loan to its net realizable value. A summary of impaired loans by class is presented below: December 31, 2017 (in millions) Impaired Loans With a Related Allowance Allowance on Impaired Loans Impaired Loans Without a Related Allowance Unpaid Contractual Balance Total Recorded Investment in Impaired Loans Commercial $183 $42 $159 $403 $342 Commercial real estate 25 5 3 40 28 Leases — — — — — Total commercial loans and leases 208 47 162 443 370 Residential mortgages 25 2 126 197 151 Home equity loans 41 4 80 162 121 Home equity lines of credit 16 1 181 241 197 Home equity loans serviced by others 29 2 22 67 51 Home equity lines of credit serviced by others 2 — 7 14 9 Automobile 2 — 21 30 23 Education 154 17 21 175 175 Credit cards 24 7 1 25 25 Other retail 5 1 4 10 9 Total retail loans 298 34 463 921 761 Total $506 $81 $625 $1,364 $1,131 December 31, 2016 (in millions) Impaired Loans With a Related Allowance Allowance on Impaired Loans Impaired Loans Without a Related Allowance Unpaid Contractual Balance Total Recorded Investment in Impaired Loans Commercial $247 $55 $134 $431 $381 Commercial real estate 39 8 4 44 43 Leases — — — — — Total commercial loans and leases 286 63 138 475 424 Residential mortgages 37 2 141 235 178 Home equity loans 51 3 94 191 145 Home equity lines of credit 23 1 173 240 196 Home equity loans serviced by others 41 4 19 70 60 Home equity lines of credit serviced by others 2 — 7 13 9 Automobile 4 — 15 25 19 Education 154 25 1 155 155 Credit cards 26 6 — 26 26 Other retail 10 2 1 13 11 Total retail loans 348 43 451 968 799 Total $634 $106 $589 $1,443 $1,223 Additional information on impaired loans is presented below: Year Ended December 31, 2017 2016 2015 (in millions) Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Commercial $4 $380 $5 $295 $4 $135 Commercial real estate — 37 — 53 1 44 Leases — — — 3 — — Total commercial loans and leases 4 417 5 351 5 179 Residential mortgages 4 136 4 161 15 415 Home equity loans 6 121 7 144 9 222 Home equity lines of credit 6 176 6 178 4 173 Home equity loans serviced by others 3 49 3 60 4 75 Home equity lines of credit serviced by others — 9 — 9 — 9 Automobile 1 18 — 14 — 11 Education 9 173 7 150 7 157 Credit cards 2 22 2 23 2 26 Other retail — 9 1 12 1 16 Total retail loans 31 713 30 751 42 1,104 Total $35 $1,130 $35 $1,102 $47 $1,283 Troubled Debt Restructurings In situations where, for economic or legal reasons related to the borrower’s financial difficulties, the Company grants a concession to the borrower that it would not otherwise consider, the related loan is classified as a TDR. TDRs typically result from the Company’s loss mitigation efforts and are undertaken in order to improve the likelihood of recovery and continuity of the relationship. The Company’s loan modifications are handled on a case-by-case basis and are negotiated to achieve mutually agreeable terms that maximize loan collectability and meet the borrower’s financial needs. Concessions granted in TDRs for all classes of loans may include lowering the interest rate, forgiving a portion of principal, extending the loan term, lowering scheduled payments for a specified period of time, waiving or delaying a scheduled payment of principal or interest for other than an insignificant time period, or capitalizing past due amounts. A rate increase can be a concession if the increased rate is lower than a market rate for debt with risk similar to that of the restructured loan. TDRs for commercial loans and leases may also involve creating a multiple note structure, accepting non-cash assets, accepting an equity interest, or receiving a performance-based fee. In some cases, a TDR may involve multiple concessions. The financial effects of TDRs for all loan classes may include lower income (either due to a lower interest rate or a delay in the timing of cash flows), larger loan loss provisions, and accelerated charge-offs if the modification renders the loan collateral-dependent. In some cases, interest income throughout the term of the loan may increase if, for example, the loan is extended or the interest rate is increased as a result of the restructuring. Retail and commercial loans whose contractual terms have been modified in a TDR and are current at the time of restructuring may remain on accrual status if there is demonstrated performance prior to the restructuring and payment in full under the restructured terms is expected. Retail loans that were discharged in bankruptcy and not reaffirmed by the borrower are deemed to be collateral-dependent TDRs and are generally charged off to the fair value of the collateral, less cost to sell, and less amounts recoverable under a government guarantee (if any). Cash receipts on nonaccruing impaired loans, including nonaccruing loans involved in TDRs, are generally applied to reduce the unpaid principal balance. Certain TDRs that are current in payment status are classified as nonaccrual in accordance with regulatory guidance. Income on these loans is generally recognized on a cash basis if management believes that the remaining book value of the loan is realizable. Nonaccruing TDRs that meet the guidelines above for accrual status can be returned to accruing if supported by a well-documented evaluation of the borrowers’ financial condition, and if they have been current for at least six months. Because TDRs are impaired loans, the Company measures impairment by comparing the present value of expected future cash flows, or when appropriate, the fair value of collateral less costs to sell, to the loan’s recorded investment. Any excess of recorded investment over the present value of expected future cash flows or collateral value is included in the ALLL. Any portion of the loan’s recorded investment the Company does not expect to collect as a result of the modification is charged off at the time of modification. For Retail TDR accounts where the expected value of cash flows is utilized, any recorded investment in excess of the present value of expected cash flows is recognized by creating or increasing the ALLL. For Retail TDR accounts assessed based on the fair value of collateral, any portion of the loan’s recorded investment in excess of the collateral value less costs to sell is charged off at the time of modification or at the time of subsequent and regularly recurring valuations. The table below summarizes TDRs by class and total unfunded commitments: December 31, (in millions) 2017 2016 Commercial $129 $120 Retail 761 799 Unfunded commitments tied to TDRs 39 42 The table below summarizes how loans were modified during the year ended December 31, 2017 , the charge-offs related to the modifications, and the impact on the ALLL. The reported balances can include loans that became TDRs during 2017 and were paid off in full, charged off, or sold prior to December 31, 2017 . Primary Modification Types Interest Rate Reduction (1) Maturity Extension (2) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial 7 $1 $1 45 $22 $22 Commercial real estate — — — 1 — — Leases — — — — — — Total commercial loans and leases 7 1 1 46 22 22 Residential mortgages 71 9 10 73 12 13 Home equity loans 82 5 6 1 — — Home equity lines of credit 50 3 3 235 30 30 Home equity loans serviced by others 15 1 1 — — — Home equity lines of credit serviced by others 5 — — 2 — — Automobile 130 2 2 29 1 1 Education — — — — — — Credit cards 2,363 13 13 — — — Other retail 1 — — — — — Total retail loans 2,717 33 35 340 43 44 Total 2,724 $34 $36 386 $65 $66 Primary Modification Types Other (3) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Net Change to ALLL Resulting from Modification Charge-offs Resulting from Modification Commercial 15 $70 $71 ($1 ) $— Commercial real estate 1 — — — — Leases — — — — — Total commercial loans and leases 16 70 71 (1 ) — Residential mortgages 171 19 19 (1 ) — Home equity loans 232 13 13 — — Home equity lines of credit 395 27 27 — 1 Home equity loans serviced by others 52 2 2 — — Home equity lines of credit serviced by others 26 2 2 — — Automobile 1,336 24 20 — 4 Education 329 7 7 2 — Credit cards — — — 3 — Other retail 5 — — (2 ) — Total retail loans 2,546 94 90 2 5 Total 2,562 $164 $161 $1 $5 (1) Includes modifications that consist of multiple concessions, one of which is an interest rate reduction. (2) Includes modifications that consist of multiple concessions, one of which is a maturity extension (unless one of the other concessions was an interest rate reduction). (3) Includes modifications other than interest rate reductions or maturity extensions, such as lowering scheduled payments for a specified period of time, principal forgiveness, and capitalizing arrearages. Also included are the following: deferrals, trial modifications, certain bankruptcies, loans in forbearance and prepayment plans. Modifications can include the deferral of accrued interest resulting in post modification balances being higher than pre-modification. The table below summarizes how loans were modified during the year ended December 31, 2016 , the charge-offs related to the modifications, and the impact on the ALLL. The reported balances can include loans that became TDRs during 2016 and were paid off in full, charged off, or sold prior to December 31, 2016 . Primary Modification Types Interest Rate Reduction (1) Maturity Extension (2) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial 12 $1 $1 81 $20 $21 Commercial real estate 1 — — 1 5 5 Leases — — — — — — Total commercial loans and leases 13 1 1 82 25 26 Residential mortgages 71 10 10 60 10 10 Home equity loans 97 6 6 39 4 5 Home equity lines of credit 49 4 4 121 13 12 Home equity loans serviced by others 18 1 1 — — — Home equity lines of credit serviced by others 8 — — 5 1 1 Automobile 138 3 3 41 1 1 Education — — — — — — Credit cards 2,187 12 12 — — — Other retail 4 — — — — — Total retail loans 2,572 36 36 266 29 29 Total 2,585 $37 $37 348 $54 $55 Primary Modification Types Other (3) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Net Change to ALLL Resulting from Modification Charge-offs Resulting from Modification Commercial 14 $48 $48 $3 $— Commercial real estate — — — — — Leases — — — — — Total commercial loans and leases 14 48 48 3 — Residential mortgages 247 26 26 (1 ) — Home equity loans 279 18 17 (1 ) — Home equity lines of credit 304 23 22 — 1 Home equity loans serviced by others 60 2 2 — — Home equity lines of credit serviced by others 24 1 1 — — Automobile 1,0

PREMISES, EQUIPMENT, AND SOFTWA

PREMISES, EQUIPMENT, AND SOFTWARE	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
PREMISES, EQUIPMENT, AND SOFTWARE	PREMISES, EQUIPMENT AND SOFTWARE Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization have been computed using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the life of the lease (including renewal options if exercise of those options is reasonably assured) or their estimated useful life, whichever is shorter. Additions to premises and equipment are recorded at cost. The cost of major additions, improvements and betterments is capitalized. Normal repairs and maintenance and other costs that do not improve the property, extend the useful life or otherwise do not meet capitalization criteria are charged to expense as incurred. The Company evaluates premises and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. A summary of the carrying value of premises and equipment is presented below: December 31, (dollars in millions) Useful Lives 2017 2016 Land and land improvements 10 years $47 $47 Buildings and leasehold improvements 5-40 years 719 684 Furniture, fixtures and equipment 5-15 years 1,824 1,714 Total premises and equipment, gross 2,590 2,445 Accumulated depreciation (1,905 ) (1,844 ) Total premises and equipment, net $685 $601 The previous table includes capital leases with book values of $30 million and $45 million and related accumulated depreciation of $20 million and $30 million as of December 31, 2017 and 2016 , respectively. Depreciation charged to noninterest expense totaled $124 million , $130 million , and $116 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively, and is presented in the Consolidated Statements of Operations in both occupancy and equipment expense. Software Costs related to computer software developed or obtained for internal use are capitalized if the projects improve functionality and provide long-term future operational benefits. Capitalized costs are amortized using the straight-line method over the asset’s expected useful life, based upon the basic pattern of consumption and economic benefits provided by the asset. The Company begins to amortize the software when the asset (or identifiable component of the asset) is substantially complete and ready for its intended use. All other costs incurred in connection with an internal-use software project are expensed as incurred. Capitalized software is included in other assets on the Consolidated Balance Sheets. The Company had capitalized software assets of $1.7 billion and $1.5 billion and related accumulated amortization of $869 million and $691 million as of December 31, 2017 and 2016 , respectively. Amortization expense was $180 million , $170 million , and $146 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The estimated future amortization expense for capitalized software assets is presented below: Year (in millions) 2018 $171 2019 141 2020 109 2021 71 2022 36 Thereafter 92 Total (1) $620 (1) Excluded from this balance is $178 million of in-process software at December 31, 2017 . Operating Lease Assets Other assets on the Consolidated Balance Sheets included assets subject to operating leases, where the Company was the lessor, of $112 million and $158 million as of December 31, 2017 and 2016, respectively. Operating lease rental income for leased assets is recognized in other income on a straight-line basis over the lease term. Related depreciation expense is recorded on a straight-line basis over the estimated useful life, considering the estimated residual value of the leased asset. On a periodic basis, leased assets are reviewed for impairment. Impairment loss is recognized in other noninterest expense if the carrying amount of the leased assets exceeds fair value and is not recoverable. The carrying amount of leased assets is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the lease payments and the estimated residual value upon the eventual disposition of the asset.

LEASE COMMITMENTS

LEASE COMMITMENTS	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
LEASE COMMITMENTS	LEASE COMMITMENTS The Company is committed under long-term leases for the rental of premises and equipment. These leases have varying renewal options and in certain instances, require the payment of insurance, real estate taxes and other operating expenses. At December 31, 2017 , the aggregate minimum rental commitments under these non-cancelable operating leases and capital leases, exclusive of renewals, are presented below for the years ended December 31: (in millions) Operating Leases Capital Leases 2018 $171 $3 2019 148 2 2020 130 2 2021 111 2 2022 81 1 Thereafter 201 8 Total minimum lease payments $842 $18 Amounts representing interest — (8 ) Present value of net minimum lease $842 $10 Occupancy and equipment expense including rental expense for non-cancelable operating leases and capital leases totaled $211 million , $208 million , and $205 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

MORTGAGE BANKING

MORTGAGE BANKING	12 Months Ended
	Dec. 31, 2017
Mortgage Banking [Abstract]
MORTGAGE BANKING	MORTGAGE BANKING In its mortgage banking business, the Company sells residential mortgages to government-sponsored entities and other parties, who may issue securities backed by pools of such loans. The Company retains no beneficial interests in these sales, but may retain the servicing rights for the loans sold. The Company is obligated to subsequently repurchase a loan if the purchaser discovers a standard representation or warranty violation such as noncompliance with eligibility requirements, customer fraud, or servicing violations. This primarily occurs during a loan file review. Mortgage loans held for sale are accounted for at fair value on an individual loan basis. Changes in the fair value, and realized gains and losses on the sales of mortgage loans, are reported in mortgage banking fees. Information related to residential mortgage loan sales and the Company's mortgage banking activity is presented below: Year Ended December 31, (in millions) 2017 2016 2015 Residential mortgage loan sale proceeds (1) $3,161 $2,652 $2,667 Gain on sales 35 69 51 Mortgage servicing fees 53 51 55 Repurchased residential mortgages 3 6 10 Valuation recoveries (2 ) (4 ) (9 ) (1) Represents the unpaid principal balance at the time of the sale. The Company recognizes the right to service mortgage loans for others, or MSRs, as assets whether the Company purchases the MSRs or the MSRs result from a sale. MSRs are initially recognized at fair value, and subsequently accounted for in the Consolidated Balance Sheets at the lower of cost or fair value, net of accumulated amortization, which is recorded in proportion to, and over the period of, net servicing income. The Company’s identification of MSRs in a single class is determined based on the availability of market inputs and the Company’s method of managing MSR risks. For the purpose of impairment evaluation and measurement, MSRs are stratified based on predominant risk characteristics (such as interest rate, loan size, origination date, term, or geographic location) of the underlying loans. An allowance is then established in the event the recorded value of an individual stratum exceeds fair value. MSRs are presented in other assets on the Consolidated Balance Sheets. Changes related to MSRs are presented below: As of and for the Year Ended December 31, (in millions) 2017 2016 MSRs: Balance as of beginning of period $167 $173 Amount capitalized 37 29 Purchases 28 — Amortization (31 ) (35 ) Carrying amount before valuation allowance 201 167 Valuation allowance for servicing assets: Balance as of beginning of period 5 9 Valuation recoveries (2 ) (4 ) Balance at end of period 3 5 Net carrying value of MSRs $198 $162 The fair value of MSRs is estimated using a valuation model that calculates the present value of estimated future net servicing cash flows, taking into consideration actual and expected mortgage loan prepayment rates, discount rates, contractual servicing fee income, servicing costs, default rates, ancillary income, and other economic factors, which are determined based on current market conditions. The valuation model uses a static discounted cash flow methodology incorporating current market interest rates. A static model does not attempt to forecast or predict the future direction of interest rates; rather it estimates the amount and timing of future servicing cash flows using current market interest rates. The current mortgage interest rate influences the expected prepayment rate and therefore, the length of the cash flows associated with the servicing asset, while the discount rate determines the present value of those cash flows. Expected mortgage loan prepayment assumptions are obtained using the QRM Multi Component prepayment model. The Company periodically obtains third-party valuations of its MSRs to assess the reasonableness of the fair value calculated by the valuation model. The key economic assumptions used to estimate the value of MSRs are presented in the following table: December 31, 2017 2016 (dollars in millions) Weighted-Average Range Weighted-Average Range Fair value $218 Min Max $182 Min Max Weighted-average life (in years) 5.9 2.3 8.4 5.7 2.6 7.3 Weighted-average constant prepayment rate 10.0% 6.6% 20.1% 10.8% 8.8% 22.3% Weighted-average discount rate 9.9% 9.1% 12.1% 9.7% 9.1% 12.1% The key economic assumptions used in estimating the fair value of MSRs capitalized during the period are presented below: Year Ended December 31, 2017 2016 2015 Weighted-average life (in years) 7.3 6.1 5.9 Weighted-average constant prepayment rate 8.7% 11.0% 10.7% Weighted-average discount rate 9.8% 9.7% 9.7% The sensitivity analysis below presents the impact to current fair value of an immediate 50 basis point and 100 basis point adverse change in the key economic assumptions and presents the decline in fair value that would occur if the adverse change were realized. These sensitivities are hypothetical, with the effect of a variation in a particular assumption on the fair value of the mortgage servicing rights calculated independently without changing any other assumption. In reality, changes in one factor may result in changes in another (e.g., changes in interest rates, which drive changes in prepayment rates, could result in changes in the discount rates), which may amplify or counteract the sensitivities. The primary risk inherent in the Company’s MSRs is an increase in prepayments of the underlying mortgage loans serviced, which is dependent upon market movements of interest rates. December 31, (in millions) 2017 2016 Prepayment rate: Decline in fair value from a 50 basis point decrease in interest rates $22 $9 Decline in fair value from a 100 basis point decrease in interest rates 46 25 Weighted-average discount rate: Decline in fair value from a 50 basis point increase in weighted-average discount rate 4 3 Decline in fair value from a 100 basis point increase in weighted-average discount rate 8 6 The Company accounts for derivatives in its mortgage banking operations at fair value on the balance sheet as derivative assets or derivative liabilities, depending on whether the derivative had a positive (asset) or negative (liability) fair value as of the balance sheet date. The Company’s mortgage banking derivatives include commitments to originate mortgages held for sale, certain loan sale agreements, and other financial instruments that meet the definition of a derivative.

GOODWILL

GOODWILL	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL Goodwill is the purchase premium associated with the acquisition of a business and is assigned to reporting units at the acquisition date. A reporting unit is a business operating segment or a component of a business operating segment. Once goodwill has been assigned to reporting units, it no longer retains its association with a particular acquisition, and all of the activities within a reporting unit, whether acquired or organically grown, are available to support the value of the goodwill. The Company has identified and allocated goodwill to two reporting units - Consumer Banking and Commercial Banking - based upon reviews of the structure of the Company’s executive team and supporting functions, resource allocations and financial reporting processes. Goodwill is not amortized, but is subject to annual impairment tests. The goodwill impairment analysis is a two-step test. The first step, used to identify potential impairment, involves comparing each reporting unit’s fair value to its carrying value, including goodwill. If the fair value of a reporting unit exceeds its carrying value, applicable goodwill is deemed to be not impaired. If the carrying value exceeds fair value, there is an indication of impairment and the second step is performed to measure the amount of impairment. The second step involves calculating an implied fair value of goodwill for each reporting unit for which the first step indicated impairment. The implied fair value of goodwill is determined in the same manner as the amount of goodwill recognized in a business combination, which is the excess of the fair value of the reporting unit, as determined in the first step, over the aggregate fair values of the individual assets, liabilities and identifiable intangible. If the implied fair value of goodwill exceeds the carrying value of goodwill assigned to the reporting unit, there is no impairment. If the carrying value of goodwill assigned to a reporting unit exceeds the implied fair value of the goodwill, an impairment charge is recorded for the excess. An impairment loss that is recognized cannot exceed the amount of goodwill assigned to a reporting unit, and the loss establishes a new basis in the goodwill. Subsequent reversal of goodwill impairment losses is not permitted. The Company reviews goodwill for impairment annually as of October 31 st or more often if events or circumstances indicate that it is more likely than not that the fair value of one or more reporting units is below its carrying value. The fair values of the Company’s reporting units are determined using a combination of income and market-based approaches. The Company relies on the income approach (discounted cash flow method) for determining fair value. Market and transaction approaches are used as benchmarks only to corroborate the value determined by the discounted cash flow method. The Company relies on several assumptions when estimating the fair value of its reporting units using the discounted cash flow method. These assumptions include the discount rate, as well as projected loan loss, income tax and capital retention rates. Discount rates are estimated based on the Capital Asset Pricing Model, which considers the risk-free interest rate, market risk premium, beta, and size premium adjustments specific to a particular reporting unit. The discount rates are also calibrated on the assessment of the risks related to the projected cash flows of each reporting unit. Cash flow projections include estimates for projected loan loss, income tax and capital retention rates. Multi-year financial forecasts are developed for each reporting unit by considering several key business drivers such as new business initiatives, customer retention standards, market share changes, anticipated loan and deposit growth, forward interest rates, historical performance, and industry and economic trends, among other considerations. The long-term growth rate used in determining the terminal value of each reporting unit is estimated based on management’s assessment of the minimum expected terminal growth rate of each reporting unit, as well as broader economic considerations such as GDP and inflation. The Company bases its fair value estimates on assumptions it believes to be representative of assumptions that a market participant would use in valuing the reporting unit but that are unpredictable and inherently uncertain, including estimates of future growth rates and operating margins and assumptions about the overall economic climate and the competitive environment for its reporting units. There can be no assurances that future estimates and assumptions made for purposes of goodwill testing will prove accurate predictions of the future. If the assumptions regarding business plans, competitive environments or anticipated growth rates are not achieved, the Company may be required to record goodwill impairment charges in future periods. Since 1988, the Company has completed more than 25 acquisitions of banks or assets of banks. In May 2017, Citizens Capital Markets, Inc., a wholly owned subsidiary of the Company, acquired the assets of Western Reserve Partners, LLC, a Cleveland-based merger and acquisition advisory firm. The acquisition resulted in an increase to goodwill of $11 million . Changes in the carrying value of goodwill for the years ended December 31, 2017 and 2016 are presented below: (in millions) Consumer Banking Commercial Banking Total Balance at December 31, 2015 $2,136 $4,740 $6,876 Adjustments — — — Balance at December 31, 2016 $2,136 $4,740 $6,876 Business acquisition — 11 11 Adjustments — — — Balance at December 31, 2017 $2,136 $4,751 $6,887 Accumulated impairment losses related to the Consumer Banking reporting unit totaled $5.9 billion at December 31, 2017 and 2016 . The accumulated impairment losses related to the Commercial Banking reporting unit totaled $50 million at December 31, 2017 and 2016 . No impairment was recorded for the years ended December 31, 2017 , 2016 and 2015 .

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES The Company makes equity investments in various entities that are considered VIEs, as defined by GAAP. A VIE typically does not have sufficient equity at risk to finance its activities without additional subordinated financial support from other parties. The Company’s variable interest arises from contractual, ownership or other monetary interests in the entity, which change with fluctuations in the fair value of the entity's net assets. The Company consolidates a VIE if it is the primary beneficiary of the entity. The Company is the primary beneficiary of a VIE if its variable interest provides it with the power to direct the activities that most significantly impact the VIE and the right to receive benefits (or the obligation to absorb losses) that could potentially be significant to the VIE. To determine whether or not a variable interest held could potentially be significant to the VIE, the Company considers both qualitative and quantitative factors regarding the nature, size and form of its involvement with the VIE. The Company assesses whether or not it is the primary beneficiary of a VIE on an ongoing basis. The Company’s equity investments primarily include ownership interests in limited partnerships that sponsor affordable housing projects and ownership interests in limited liability companies that sponsor renewable energy projects. The Company’s maximum exposure to loss as a result of its involvement with these entities is limited to the balance sheet carrying amounts of its equity investments. A summary of these investments is presented below: December 31, (in millions) 2017 2016 LIHTC investment included in other assets $951 $793 LIHTC unfunded commitments included in other liabilities 491 428 Renewable energy investments included in other assets 335 220 Low Income Housing Tax Credit Partnerships The purpose of the Company’s equity investments is to assist in achieving goals of the Community Reinvestment Act and to earn an adequate return of capital. LIHTC partnerships are managed by unrelated general partners that have the power to direct the activities which most significantly affect the performance of the partnerships. The Company is therefore not the primary beneficiary of any LIHTC partnerships. Accordingly, the Company does not consolidate these VIEs and accounts for these investments in other assets on the Consolidated Balance Sheets. The Company applies the proportional amortization method to account for its LIHTC investments. Under the proportional amortization method, the Company applies a practical expedient and amortizes the initial cost of the investment in proportion to the tax credits received in the current period as compared to the total tax credits expected to be received over the life of the investment. The amortization and tax benefits are included as a component of income tax expense. The tax credits received are reported as a reduction of income tax expense (or increase to income tax benefit) related to these transactions. The following table presents other information related to the Company’s affordable housing tax credit investments: Year Ended December 31, (in millions) 2017 2016 Tax credits included in income tax expense $83 $59 Amortization expense included in income tax expense 94 59 Other tax benefits included in income tax expense 31 21 No LIHTC investment impairment losses were recognized during the years ended December 31, 2017 and 2016 . Renewable Energy Entities The Company’s investments in renewable energy entities provide benefits from a return generated by government incentives plus other tax attributes that are associated with tax ownership (e.g., tax depreciation). As a tax equity investor, the Company does not have the power to direct the activities which most significantly affect the performance of these entities and therefore is not the primary beneficiary of any renewable energy entities. Accordingly, the Company does not consolidate these VIEs.

DEPOSITS

DEPOSITS	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
DEPOSITS	DEPOSITS Interest-bearing deposits in banks are carried at cost and include deposits that mature within one year. The major components of deposits are presented below: December 31, (in millions) 2017 2016 Demand $29,279 $28,472 Checking with interest 22,229 20,714 Regular savings 9,518 8,964 Money market accounts 37,454 38,176 Term deposits 16,609 13,478 Total deposits $115,089 $109,804 The maturity distribution of term deposits as of December 31, 2017 is presented below: Year (in millions) 2018 $13,754 2019 1,985 2020 351 2021 452 2022 62 2023 and thereafter 5 Total $16,609 Of these deposits, the amount of term deposits with a denomination of $100,000 or more was $11.4 billion at December 31, 2017 . The remaining maturities of these deposits are presented below: (in millions) Three months or less $4,948 After three months through six months 1,925 After six months through twelve months 3,040 After twelve months 1,453 Total term deposits $11,366

BORROWED FUNDS

BORROWED FUNDS	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
BORROWED FUNDS	BORROWED FUNDS A summary of the Company’s short-term borrowed funds is presented below: December 31, (in millions) 2017 2016 Federal funds purchased $460 $533 Securities sold under agreements to repurchase 355 615 Other short-term borrowed funds 1,856 3,211 Total short-term borrowed funds $2,671 $4,359 Key data related to short-term borrowed funds is presented in the following table: As of and for the Year Ended December 31, (in millions, except ratio data) 2017 2016 2015 Weighted-average interest rate at year-end: (1) Federal funds purchased and securities sold under agreements to repurchase 0.74 % 0.26 % 0.15 % Other short-term borrowed funds 1.72 0.94 0.44 Maximum amount outstanding at month-end during the year: Federal funds purchased and securities sold under agreements to repurchase (2) $1,174 $1,522 $5,375 Other short-term borrowed funds 3,508 5,461 7,004 Average amount outstanding during the year: Federal funds purchased and securities sold under agreements to repurchase (2) $776 $947 $3,364 Other short-term borrowed funds 2,321 3,207 5,865 Weighted-average interest rate during the year: (1) Federal funds purchased and securities sold under agreements to repurchase 0.36 % 0.09 % 0.22 % Other short-term borrowed funds 1.32 0.64 0.28 (1) Rates exclude certain hedging costs. (2) Balances are net of certain short-term receivables associated with reverse repurchase agreements, as applicable. A summary of the Company’s long-term borrowed funds is presented below: December 31, (in millions) 2017 2016 Parent Company: 2.375% fixed-rate senior unsecured debt, due 2021 $349 $348 4.150% fixed-rate subordinated debt, due 2022 348 347 5.158% fixed-to-floating rate subordinated debt, due 2023, converting to floating at 333 333 3.750% fixed-rate subordinated debt, due 2024 250 250 4.023% fixed-rate subordinated debt, due 2024 42 42 4.350% fixed-rate subordinated debt, due 2025 249 249 4.300% fixed-rate subordinated debt, due 2025 749 749 Banking Subsidiaries: 2.300% senior unsecured notes, due 2018 (1) (2) — 745 2.450% senior unsecured notes, due 2019 (1) 743 747 2.500% senior unsecured notes, due 2019 (1) 741 741 2.250% senior unsecured notes, due 2020 (1) 692 — Floating-rate senior unsecured notes, due 2020 (1) 299 — Floating-rate senior unsecured notes, due 2020 (1) 249 — 2.200% senior unsecured notes, due 2020 (1) 498 — 2.250% senior unsecured notes, due 2020 (1) 742 — 2.550% senior unsecured notes, due 2021 (1) 964 965 Floating-rate senior unsecured notes, due 2022 (1) 249 — 2.650% senior unsecured notes, due 2022 (1) 491 — Federal Home Loan advances due through 2033 3,761 7,264 Other 16 10 Total long-term borrowed funds $11,765 $12,790 (1) Issued under CBNA’s Global Bank Note Program. (2) Reclassified to short-term borrowed funds. The Parent Company’s long-term borrowed funds as of December 31, 2017 and 2016 included principal balances of $2.3 billion and unamortized deferred issuance costs and/or discounts of ($5) million and ($7) million , respectively. The banking subsidiaries’ long-term borrowed funds as of December 31, 2017 and 2016 include principal balances of $9.5 billion and $10.5 billion , respectively, with unamortized deferred issuance costs and/or discounts of ($19) million and ($12) million , respectively, and hedging basis adjustments of ($63) million and ($40) million , respectively. See Note 13 “Derivatives” for further information about the Company’s hedging of certain long-term borrowed funds. Advances, lines of credit, and letters of credit from the FHLB are collateralized by pledged mortgages and pledged securities at least sufficient to satisfy the collateral maintenance level established by the FHLB. The utilized borrowing capacity for FHLB advances and letters of credit was $9.4 billion and $13.4 billion at December 31, 2017 and 2016 , respectively. The Company’s available FHLB borrowing capacity was $8.0 billion and $2.8 billion at December 31, 2017 and 2016 , respectively. The Company can also borrow from the FRB discount window to meet short-term liquidity requirements. Collateral, such as investment securities and loans, is pledged to provide borrowing capacity at the FRB. At December 31, 2017 , the Company’s unused secured borrowing capacity was approximately $41.2 billion , which includes unencumbered securities, FHLB borrowing capacity, and FRB discount window capacity. A summary of maturities for the Company’s long-term borrowed funds at December 31, 2017 is presented below: (in millions) Parent Company Banking Subsidiaries Consolidated Year 2018 $— $— $— 2019 — 5,235 5,235 2020 — 2,492 2,492 2021 349 967 1,316 2022 348 744 1,092 2023 and thereafter 1,623 7 1,630 Total $2,320 $9,445 $11,765

DERIVATIVES

DERIVATIVES	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES	DERIVATIVES In the normal course of business, the Company enters into a variety of derivative transactions in order to meet the financing needs of its customers and to reduce its own exposure to fluctuations in interest rates and foreign currency exchange rates. These transactions include interest rate swap contracts, interest rate options, foreign exchange contracts, residential loan commitment rate locks, forward sale contracts and purchase options. The Company monitors the results of each transaction to ensure that management’s intent is satisfied. The Company does not use derivatives for speculative purposes. The Company’s derivative instruments are recognized on the Consolidated Balance Sheets at fair value. Information regarding the valuation methodology and inputs used to estimate the fair value of the Company’s derivative instruments is described in Note 19 “Fair Value Measurements.” Derivative assets and derivative liabilities are netted by counterparty on the balance sheet if a “right of setoff” has been established in a master netting agreement between the Company and the counterparty. This netted derivative asset or liability position is also netted against the fair value of any cash collateral that has been pledged or received in accordance with a Credit Support Annex. At December 31, 2017 , the total derivative net asset value decreased $10 million and the total net liability value decreased by $349 million from December 31, 2016 . These decreases were primarily due to a change in the presentation of variation margin payments in the Consolidated Balance Sheet in 2017. Effective January 3, 2017, variation margin payments made on certain centrally cleared derivative contracts were classified as settlement of those derivatives rather than the posting of collateral. As a result of this change, on a prospective basis the Company modified its balance sheet presentation of certain interest rate swaps in 2017, such that the fair value of the swaps and the associated variation margin balances are reported as a single unit of account in derivative assets and/or derivative liabilities. At December 31, 2016, these variation margin balances were characterized as collateral. Variation margin balances characterized as collateral are reported in interest-bearing cash and due from banks on the Consolidated Balance Sheets. The following table presents derivative instruments included on the Consolidated Balance Sheets in derivative assets and derivative liabilities: December 31, 2017 December 31, 2016 (in millions) Notional Amount (1) Derivative Assets (2) Derivative Liabilities (2) Notional Amount (1) Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate contracts $13,300 $— $— $13,350 $52 $193 Derivatives not designated as hedging instruments: Interest rate contracts 80,180 538 379 54,656 557 452 Foreign exchange contracts 9,882 148 149 8,039 134 126 Other contracts 1,039 7 5 1,498 16 7 Total derivatives not designated as hedging instruments 693 533 707 585 Gross derivative fair values 693 533 759 778 Less: Gross amounts offset in the Consolidated Balance Sheets (3) (72 ) (72 ) (106 ) (106 ) Less: Cash collateral applied (3) (4 ) (151 ) (26 ) (13 ) Total net derivative fair values presented in the Consolidated Balance Sheets $617 $310 $627 $659 (1) The notional or contractual amount of interest rate derivatives and foreign exchange contracts is the amount upon which interest and other payments under the contract are based. For interest rate contracts, the notional amount is typically not exchanged. Therefore, notional amounts should not be taken as the measure of credit or market risk, as they do not measure the true economic risk of these contracts. (2) Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives. (3) Amounts represent the impact of enforceable master netting agreements that allow the Company to net settle positive and negative positions. The Company’s derivative transactions are internally divided into three sub-groups: institutional, customer and residential loan. Institutional derivatives The institutional derivatives portfolio primarily consists of interest rate swap agreements that are used to hedge the interest rate risk associated with the Company’s loans and financing liabilities (i.e., borrowed funds, deposits, etc.). The Company enters into certain interest rate swap agreements to hedge the risk associated with floating rate loans. By entering into receive-fixed/pay-floating interest rate swaps, the Company is able to minimize the variability in the cash flows of these assets due to changes in interest rates. The Company also uses receive-fixed/pay-floating interest rate swaps to manage the interest rate exposure on its medium term borrowings by effectively converting a portion of the fixed rate debt to floating. The Company has outstanding interest rate swap agreements designed to hedge a portion of the Company’s borrowed funds and deposit liabilities. By entering into a pay-fixed/receive-floating interest rate swap, a portion of these liabilities has been effectively converted to a fixed rate liability for the term of the interest rate swap agreement. The goal of the Company’s interest rate hedging activity is to manage interest rate sensitivity so that movements in interest rates do not significantly adversely affect net interest income. For derivatives designated for hedging purposes, net interest accruals are treated as an adjustment of interest income or interest expense of the item being hedged. Customer derivatives The customer derivatives portfolio consists of interest rate swap agreements and option contracts that are transacted to meet the financing needs of the Company’s customers. Swap agreements and interest rate option agreements are transacted to effectively minimize the Company’s market risk associated with the customer derivative products. The customer derivatives portfolio also includes foreign exchange contracts that are entered into on behalf of customers for the purpose of hedging exposure related to cash orders and loans and deposits denominated in foreign currencies. The primary risks associated with these transactions arise from exposure to changes in foreign currency exchange rates and the ability of the counterparties to meet the terms of the contract. To manage this market risk, the Company enters into offsetting foreign exchange contracts. Residential loan derivatives The Company enters into residential loan commitments that allow residential mortgage customers to lock in the interest rate on a residential mortgage while the loan undergoes the underwriting process. The Company also uses forward sales contracts to protect the value of residential mortgage loans and loan commitments that are being underwritten for future sale to investors in the secondary market. The Company has certain derivative transactions which are designated as fair value or cash flow hedges, described as follows: Derivatives designated as hedging instruments The Company’s institutional derivatives portfolio qualifies for hedge accounting treatment. This includes interest rate swaps that are designated as highly effective fair value and cash flow hedging relationships. The Company formally documents at inception all hedging relationships, as well as risk management objectives and strategies for undertaking various accounting hedges. Additionally, the Company uses dollar offset or regression analysis at the hedge’s inception, and monthly thereafter, to assess whether the derivatives are expected to be, or have been, highly effective in offsetting changes in the hedged item’s expected cash flows. The Company discontinues hedge accounting treatment when it is determined that a derivative is not expected to be, or has ceased to be, effective as a hedge and then reflects changes in fair value in earnings after termination of the hedge relationship. Fair value hedges If a derivative is designated as a fair value hedge, gains or losses attributable to the change in fair value of the derivative instrument, as well as the gains and losses attributable to the change in fair value of the hedged item, are recognized in other income in the period in which the change in fair value occurs. Hedge ineffectiveness is recognized as other income to the extent the changes in fair value of the derivative do not offset the changes in fair value of the hedged item. Changes in the fair value of derivatives that do not qualify as hedges are recognized immediately in other income. The Company has entered into interest rate swap agreements to manage the interest rate exposure on its medium term borrowings. The change in value of fair value hedges, to the extent that the hedging relationship is effective, is recorded through other income and offset against the change in the fair value of the hedged item. The following table presents the effect on other income of fair value hedges described above, in millions: Amounts Recognized in Other Income for the Year Ended December 31, 2017 2016 2015 Derivative Hedged Item Hedge Ineffectiveness Derivative Hedged Item Hedge Ineffectiveness Derivative Hedged Item Hedge Ineffectiveness ($26 ) $27 $1 ($6 ) $5 ($1 ) ($2 ) $2 $— Cash flow hedges The Company has outstanding interest rate swap agreements designed to hedge a portion of the Company’s floating rate assets, and financing liabilities (including its borrowed funds). All of these swaps have been deemed as highly effective cash flow hedges. The effective portion of the hedging gains and losses associated with these hedges are recorded in OCI; the ineffective portion of the hedging gains and losses is recorded in earnings (other income). Hedging gains and losses on derivative contracts reclassified from OCI to current period earnings are included in the line item in the accompanying Consolidated Statements of Operations in which the hedged item is recorded and in the same period that the hedged item affects earnings. During the next 12 months, there are $1 million in pre-tax net losses on derivative instruments included in OCI expected to be reclassified to net interest income in the Consolidated Statements of Operations. Hedging gains and losses associated with the Company’s cash flow hedges are immediately reclassified from OCI to current period earnings (other income) if it becomes probable that the hedged forecasted transactions will not occur during the originally specified time period. The following table presents the effect of cash flow hedges on net income and stockholders’ equity: Amounts Recognized for the Year Ended December 31, (in millions) 2017 2016 2015 Effective portion of (loss) gain recognized in OCI (1) ($23 ) ($100 ) $150 Amounts reclassified from OCI to interest income (2) 25 90 82 Amounts reclassified from OCI to interest expense (2) — (27 ) (59 ) Amounts reclassified from OCI to other income (3) — (5 ) — (1) The cumulative effective gains and losses on the Company’s cash flow hedging activities are included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets. (2) This amount includes both (a) the amortization of effective gains and losses associated with the Company’s terminated cash flow hedges and (b) the current reporting period’s interest settlements realized on the Company’s active cash flow hedges. Both (a) and (b) were previously included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets and were subsequently recorded as adjustments to the interest income or expense of the underlying hedged item. (3) This includes gains and losses attributable to previously hedged cash flows where the likelihood occurrence of those cash flows is no longer probable. Derivatives not designated as hedging instruments Economic hedges The Company’s customer derivatives are recorded on the Consolidated Balance Sheets at fair value. These include interest rate and foreign exchange derivative contracts that are designed to meet the hedging and financing needs of the Company’s customers. Mark-to-market adjustments to the fair value of these contracts are included in foreign exchange and interest rate products on the Consolidated Statement of Operations. The mark-to-market gains and losses associated with the customer derivatives are mitigated by the mark-to-market gains and losses on the offsetting interest rate and foreign exchange derivative contracts transacted. The Company’s residential loan derivatives (including residential loan commitments and forward sales contracts) are recorded on the Consolidated Balance Sheets at fair value. Mark-to-market adjustments to the fair value of residential loan commitments and forward sale contracts are included in noninterest income under mortgage banking fees. The following table presents the effect of customer derivatives and economic hedges on noninterest income: Amounts Recognized in Noninterest Income for the Year Ended December 31, (in millions) 2017 2016 2015 Customer derivative contracts Customer interest rate contracts (1) $5 ($23 ) $140 Customer foreign exchange contracts (1) 172 (81 ) (18 ) Residential loan commitments (2) 2 (2 ) (4 ) Economic hedges Offsetting derivatives transactions to hedge interest rate risk on customer interest rate contracts (1) 46 70 (106 ) Offsetting derivatives transactions to hedge foreign exchange risk on customer foreign exchange contracts (1) (151 ) 95 19 Forward sale contracts (2) (8 ) 6 1 Total $66 $65 $32 (1) Reported in foreign exchange and interest rate products on the Consolidated Statements of Operations. (2) Reported in mortgage banking fees on the Consolidated Statements of Operations.

EMPLOYEE BENEFITS

EMPLOYEE BENEFITS	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
EMPLOYEE BENEFITS	EMPLOYEE BENEFITS Pension Plans The Company maintains a non-contributory pension plan (the “Plan” or “qualified plan”) that was closed to new hires and re-hires effective January 1, 2009, and frozen to all participants effective December 31, 2012. Benefits under the Plan are based on employees’ years of service and highest five -year average of eligible compensation. The Plan is funded on a current basis, in compliance with the requirements of ERISA. The Company also provides an unfunded, non-qualified supplemental retirement plan (the “non-qualified plan”), which was closed and frozen effective December 31, 2012. The qualified plan’s allocation by asset category is presented below: Target Asset Allocation Actual Asset Allocation Asset Category 2017 2017 2016 Equity securities 48-58% 54.0 % 49.6 % Debt securities 41-51% 45.0 % 45.2 % Other 1.0 % 5.2 % Total 100.0 % 100.0 % The written Pension Plan Investment Policy, set forth by the CFG Retirement Committee, formulates investment principles and guidelines that are appropriate for the needs and objectives of the Plan, and defines the management, structure, and monitoring procedures adopted for the ongoing operation of the aggregate funds of the Plan. Stated goals and objectives are: • Achieve a total return, consistent with prudent investment management, that together with any new contributions from the Employer, will be sufficient to meet the benefits which the Plan seeks to provide. • The nominal return target for the overall Plan is to meet or exceed the Plan’s Policy Index; • Total portfolio risk exposure should generally rank in the mid-range of comparable funds. Risk-adjusted returns are expected to consistently rank in the top-half of comparable funds; and • Investment managers shall meet or exceed the return of the designated benchmark index and rank in the top-half of the appropriate asset class and style universe. The CFG Retirement Committee reviews, at least annually, the assets and net cash flow of the Plan, discusses the current economic outlook and the Plan’s investment strategy with the investment managers, reviews the current asset mix and its compliance with the Policy, and receives and considers statistics on the investment performance of the Plan and its managers. The equity investment mandates follows a global equity approach. Investments are made in broadly diversified portfolios that contain investments in U.S. and non-U.S. developed and developing economies. The fixed income investment mandates are US investment grade mandates and follow a long duration investment approach. Investment in high-yield bonds are not allowed unless an investment grade bond is downgraded to a non-investment grade category. The assets of the qualified plan may be invested in any or all of the following asset categories: • Equity-oriented investments: ◦ domestic and foreign common and preferred stocks, and related rights, warrants, convertible debentures, and other common share equivalents • Fixed income-oriented investments: ◦ domestic and foreign bonds, debentures and notes ◦ mortgages ◦ mortgage-backed securities ◦ asset-backed securities ◦ money market securities or cash ◦ financial futures and options on financial futures ◦ forward contracts In addition, derivatives may be employed under the guidelines established for individual managers in order to manage risk exposures and/or to increase the efficiency of strategies. The extent to which derivatives are utilized will be specified in the investment guidelines for each manager. The Plan will not be exposed to losses through derivatives that exceed the capital invested. In selecting the expected long-term rate of return on assets, the Company considers the average rate of earnings expected on the funds invested or to be invested to provide for the benefits of this Plan. This includes considering the trust’s asset allocation and the expected returns likely to be earned over the life of the Plan. This basis is consistent with the prior year. Changes in the fair value of defined benefit pension plan assets, projected benefit obligation, funded status, and accumulated benefit obligation are presented below: Year Ended December 31, Qualified Plan Non-Qualified Plan (in millions) 2017 2016 2017 2016 Fair value of plan assets as of January 1 $1,015 $917 $— $— Actual return on plan assets 185 82 — — Employer contributions — 75 8 8 Benefits and administrative expenses paid (61 ) (59 ) (8 ) (8 ) Fair value of plan assets as of December 31 1,139 1,015 — — Projected benefit obligation 1,089 1,024 106 105 Pension asset (obligation) $50 ($9 ) ($106 ) ($105 ) Accumulated benefit obligation $1,089 $1,024 $106 $105 The Company recognized actuarial gains and losses (for the qualified and non-qualified plans) in AOCI resulting in an ending balance of $585 million and $634 million at December 31, 2017 and 2016 , respectively. Approximately $17 million of net actuarial loss recorded in AOCI as of December 31, 2017 is expected to be recognized as a component of net periodic benefit costs during 2018 . Other changes in plan assets and benefit obligations recognized in OCI (for the qualified, non-qualified and postretirement plans) are presented below: Year Ended December 31, (in millions) 2017 2016 2015 Net periodic pension income ($2 ) ($1 ) ($7 ) Net actuarial (gain) loss (31 ) 54 7 Amortization of prior service credit 1 1 — Amortization of net actuarial loss (18 ) (16 ) (15 ) Total recognized in other comprehensive income (loss) (48 ) 39 (8 ) Total recognized in net periodic pension cost and other comprehensive income (loss) ($50 ) $38 ($15 ) Pension costs under defined benefit plans are actuarially computed and include current service costs and amortization of prior service costs over the participants’ average future working lifetime. The actuarial cost method used in determining the net periodic pension cost is the projected unit method. The components of net periodic pension (income) cost for the Company's qualified and non-qualified plans are presented below: Year Ended December 31, Qualified Plan Non-Qualified Plan Total (in millions) 2017 2016 2015 2017 2016 2015 2017 2016 2015 Service cost $3 $3 $3 $— $— $— $3 $3 $3 Interest cost 42 44 44 4 4 4 46 48 48 Expected return on plan assets (69 ) (68 ) (74 ) — — — (69 ) (68 ) (74 ) Amortization of actuarial loss 16 14 13 2 2 2 18 16 15 Net periodic pension (income) cost ($8 ) ($7 ) ($14 ) $6 $6 $6 ($2 ) ($1 ) ($8 ) Net periodic pension (income) cost is presented in the accompanying consolidated statements of operations in salaries and employee benefits. Weighted-average rates assumed in determining the actuarial present value of benefit obligations and net periodic benefit cost are presented below: As of and for the Year Ended December 31, 2017 2016 2015 Assumptions for benefit obligations Discount rate-qualified plan 3.670 % 4.190 % 4.640 % Discount rate-non-qualified plan 3.530 % 4.050 % 4.540 % Expected long-term rate of return on plan assets 7.000 % 7.500 % 7.500 % Assumptions for net periodic pension cost Discount rate-qualified plan 4.190 % 4.640 % 4.125 % Discount rate-non-qualified plan 4.050 % 4.540 % 3.875 % Expected long-term rate of return on plan assets 7.000 % 7.500 % 7.500 % On September 7, 2016, the Company made a contribution of $75 million to the qualified plan. No contribution was made to the qualified plan in 2017. The Company expects to contribute approximately $8 million to the non-qualified plan in 2018. No contribution to the qualified plan is planned in 2018. Expected future benefit payments for the qualified and non-qualified plans are presented below: (in millions) Expected benefit payments by fiscal year ending December 31, 2018 $65 December 31, 2019 66 December 31, 2020 66 December 31, 2021 67 December 31, 2022 68 December 31, 2023 - 2027 346 Fair Value Measurements The following valuation techniques are used to measure the qualified pension plan assets at fair value: Cash and money market funds: Cash and money market funds represent instruments that generally mature in one year or less and are valued at cost, which approximates fair value. Cash and money market funds are classified as Level 2. U.S. government obligations, municipal obligations, corporate bonds, asset-backed securities and mortgage-backed securities-Managed portfolio: U.S. government obligations, municipal obligations, corporate bonds, asset-backed securities and mortgage-backed securities are valued at the quoted market prices determined in the active markets in which the securities are traded. If quoted market prices are not available, the fair value for the security is estimated by using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. These investments are classified as Level 2, because they currently trade in active markets for similar securities and the inputs to the valuations are observable. The following table presents qualified pension plan assets measured at fair value within the fair value hierarchy: Fair Value Measurements as of December 31, 2017 (in millions) Total Level 1 Level 2 Level 3 Assets: Managed portfolio assets: U.S. government obligations 8 — 8 — Non-U.S. government obligations 2 — 2 — Municipal obligations 1 — 1 — Corporate bonds 102 — 102 — Asset-backed securities 1 — 1 — Total assets in the fair value hierarchy 114 — 114 — Investments measured at net asset value (1) 1,024 Assets at fair value at measurement date of December 31, 2017 $1,138 $— $114 $— (1) Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table presents qualified pension plan assets measured at fair value within the fair value hierarchy: Fair Value Measurements as of December 31, 2016 (in millions) Total Level 1 Level 2 Level 3 Assets: Managed portfolio assets Cash and money market funds 2 — 2 — U.S. government obligations 10 — 10 — Municipal obligations 2 — 2 — Corporate bonds 89 — 89 — Asset-backed securities 1 — 1 — Total assets in the fair value hierarchy 104 — 104 — Investments measured at net asset value (1) 918 Assets at fair value at measurement date of December 31, 2016 $1,022 $— $104 $— (1) Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. There were no transfers among Levels 1, 2 or 3 during the years ended December 31, 2017 , and 2016 . The fair values of participation units held in the common and collective funds and limited partnerships are based on NAV. The following table presents the unfunded commitments, redemption frequency and redemption notice period for Plan investments that utilize net asset value to determine fair value: Fair Value Estimated Using Net Asset Value per Share December 31, Unfunded Redemption Redemption Redemption Investment (dollars in millions) 2017 2016 Commitment Frequency Restrictions Notice Period Liquid Cash Fund $11 $9 $— Daily None Same day before 5:30pm ET Equity Mutual Fund (1) — 40 — Daily None 7 days Common and Collective Funds: Global equities funds 472 386 — Daily None 3 days Balanced funds 214 193 — Daily None 2 days Fixed income fund 150 133 — Daily None 3 days Managed Portfolio - Fixed Income Mutual Fund (2) 35 30 — Daily None 1 days Limited Partnerships: International equity fund 142 117 — Monthly None 3 days Offshore feeder fund — 10 — Monthly None 14 days Total $1,024 $918 $— (1) The equity mutual fund seeks to offer participants capital appreciation by primarily investing in common stocks via investments in several underlying funds of the same fund family. The principal investment objective is to generate positive total return. (2) The managed portfolio fixed income mutual fund seeks to outperform the Barclay’s U.S. Long Credit Index or similar benchmark. Postretirement Benefits The Company provides health care insurance benefits to eligible retirees and their spouses through age 65, at which time Medicare becomes the primary coverage provider. Employees enrolled in medical coverage immediately prior to retirement and meeting eligibility requirements can elect retiree medical coverage. Coverage must be elected at the time of retirement and cannot be elected at a future date. Spouses may be covered only if the spouse is covered at the time of the employee’s retirement. The Company reviews coverage on an annual basis and reserves the right to modify or cancel coverage at any renewal date. Effective July 1, 2014, the Company utilizes a private health care exchange to provide medical and dental benefits to current and future Medicare-eligible plan participants. The Company provides a fixed subsidy to a small, closed group of retirees and spouses based on the subsidy levels prior to July 1, 2014; retirees and spouses pay the cost of benefits in excess of the fixed subsidy. The cost of postretirement benefits other than pensions is recognized on an accrual basis during the periods employees provide services to earn those benefits. Expected future benefit payments for the postretirement benefit plan are presented below: (in millions) Expected benefit payments by fiscal year ending December 31, 2018 $2 December 31, 2019 2 December 31, 2020 1 December 31, 2021 1 December 31, 2022 1 December 31, 2023 - 2027 5 The Company expects to contribute approximately $2 million to the plan during 2018 . The discount rate assumed in determining the actuarial present value of benefit obligations was 3.20% as of December 31, 2017 compared with 3.53% as of December 31, 2016 . For measurement purposes, the assumed annual rate of increase in the per capita cost of covered health care benefits was 7% in December 31, 2017 and in 2016 , and is expected to decrease gradually to 5.0% by 2022. Weighted-average rates assumed in determining the net periodic benefit cost of the postretirement benefits plan are as follows: For the Year Ended December 31, (dollars in millions) 2017 2016 Discount rate 3.530 % 3.930 % Rate of compensation increase N/A N/A Ultimate health care cost trend rate 5.000 % 5.000 % Effect on accumulated postretirement benefit obligation: One percent increase in assumed health care cost trend $— $— One percent decrease in assumed health care cost trend — — 401(k) Plan The Company sponsors a 401(k) plan under which employee tax-deferred/Roth after-tax contributions to the plan are matched by the Company after completion of one year of service. Effective January 1, 2013, contributions were matched at 100% up to an overall limitation of 5% on a pay period basis. Subsequently, effective January 1, 2015, 100% of matching contributions was reduced from 5% to 4% on a pay period basis. Substantially all employees will receive an additional 2% of earnings after completion of one year of service, subject to limits set by the Internal Revenue Service. Amounts contributed and expensed by the Company were $61 million in 2017 compared to $55 million in 2016 and $52 million in 2015 .

RECLASSIFICATIONS OUT OF ACCUMU

RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS	RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS The following table presents the changes in the balances, net of income taxes, of each component of AOCI: (in millions) Net Unrealized (Losses) Gains on Derivatives Net Unrealized (Losses) Gains on Securities Employee Benefit Plans Total AOCI Balance at January 1, 2015 ($69 ) $74 ($377 ) ($372 ) Other comprehensive income before reclassifications 93 (66 ) — 27 Other-than-temporary impairment not recognized in earnings on securities — (22 ) — (22 ) Amounts reclassified from other comprehensive income (14 ) (14 ) 8 (20 ) Net other comprehensive loss 79 (102 ) 8 (15 ) Balance at December 31, 2015 $10 ($28 ) ($369 ) ($387 ) Other comprehensive income before reclassifications (62 ) (139 ) — (201 ) Other-than-temporary impairment not recognized in earnings on securities — (17 ) — (17 ) Amounts reclassified from other comprehensive income (36 ) (2 ) (25 ) (63 ) Net other comprehensive loss (98 ) (158 ) (25 ) (281 ) Balance at December 31, 2016 ($88 ) ($186 ) ($394 ) ($668 ) Other comprehensive income before reclassifications (14 ) (6 ) — (20 ) Amounts reclassified from other comprehensive income (16 ) (2 ) 31 13 Net other comprehensive loss (30 ) (8 ) 31 (7 ) Reclassification of tax effects resulting from the 2017 Tax Legislation (1) (25 ) (42 ) (78 ) (145 ) Balance at December 31, 2017 ($143 ) ($236 ) ($441 ) ($820 ) (1) As of December 31, 2017, the balance of AOCI reflects the retrospective adoption of FASB ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . For further discussion, see Note 22 “Income Taxes.” The following table reports the amounts reclassified out of each component of AOCI and into the Consolidated Statements of Operations: Year Ended December 31, (in millions) 2017 2016 2015 Details about AOCI Components Affected Line Item in the Consolidated Statements of Operations Reclassification adjustment for net derivative gains (losses) included in net income: $25 $90 $82 Interest income — (27 ) (59 ) Interest expense — (5 ) — Other income 25 58 23 Income before income tax expense 9 22 9 Income tax expense $16 $36 $14 Net income Reclassification of net securities gains (losses) to net income: $11 $16 $29 Securities gains, net (7 ) (12 ) (7 ) Net securities impairment losses recognized in earnings 4 4 22 Income before income tax expense 2 2 8 Income tax expense $2 $2 $14 Net income Reclassification of changes related to the employee benefit plan: ($48 ) $39 ($8 ) Salaries and employee benefits (48 ) 39 (8 ) Income before income tax expense (17 ) 14 — Income tax expense ($31 ) $25 ($8 ) Net income Total reclassification (losses) gains ($13 ) $63 $20 Net income The following table presents the effects to net income of the amounts reclassified out of AOCI: Year Ended December 31, (in millions) 2017 2016 2015 Net interest income (includes $25, $63 and $23 of AOCI reclassifications, respectively) $4,173 $3,758 $3,402 Provision for credit losses 321 369 302 Noninterest income (includes $4, ($1) and $22 of AOCI reclassifications, respectively) 1,534 1,497 1,422 Noninterest expense (includes $48, ($39) and $8 of AOCI reclassifications, respectively) 3,474 3,352 3,259 Income before income tax expense 1,912 1,534 1,263 Income tax expense (includes ($6), $38 and $17 income tax net expense from reclassification items, respectively) 260 489 423 Net income $1,652 $1,045 $840

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Preferred Stock The Company had 100,000,000 shares authorized and 250,000 shares outstanding of $25.00 par value undesignated preferred stock as of December 31, 2017 and 2016 . The Board of Directors or any authorized committee thereof are authorized to provide for the issuance of these shares in one or more series, and by filing a certificate pursuant to applicable law of the State of Delaware, to establish or change from time to time the number of shares of each such series, and to fix the designations, powers, including voting powers, full or limited, or no voting powers, preferences and the relative, participating, optional or other special rights of the shares of each series and any qualifications, limitations and restrictions thereof. On April 6, 2015, the Company issued $250 million , or 250,000 shares, of 5.500% fixed-to-floating rate non-cumulative perpetual Series A Preferred Stock, par value of $25.00 per share with a liquidation preference $1,000 per share (the “Series A Preferred Stock”) to the initial purchasers in reliance on the exemption from registration provided by Section (4)(a)(2) of the Securities Act of 1933, as amended, for resale pursuant to Rule 144A and Regulation S under the Securities Act of 1933, as amended. As a result of this issuance, the Company received net proceeds of $247 million after underwriting discount. The Series A Preferred Stock has no stated maturity and is not subject to any sinking fund or other obligation of the Company. Holders of the Series A Preferred Stock will be entitled to receive dividend payments when, and if, declared by the Company’s Board of Directors or a duly authorized committee thereof. Any such dividends will be payable on a semi-annual basis at an annual rate equal to 5.500% . On April 6, 2020, the Series A Preferred Stock converts to a quarterly floating-rate basis equal to three-month U.S. dollar LIBOR on the related dividend determination date plus 3.960% . Citizens may redeem the Series A Preferred Stock, in whole or in part on any dividend payment date, on or after April 6, 2020 or, in whole but not in part, at any time within 90 days following a regulatory capital treatment event at a redemption price equal to $1,000 per share, plus any declared and unpaid dividends, without accumulation of any undeclared dividends. Citizens may not redeem shares of the Series A Preferred Stock without obtaining the prior approval of the FRB if then required under applicable capital guidelines. Shares of the Series A Preferred Stock have priority over the Company's common stock with regard to the payment of dividends and, as such, the Company may not pay dividends on or repurchase, redeem, or otherwise acquire for consideration shares of its common stock unless dividends for the latest completed dividend period for the Series A Preferred Stock have been declared and paid (or declared and sufficient funds have been set aside to make payment). Except in certain limited circumstances, the Series A Preferred Stock does not have any voting rights. Treasury Stock The purchase of the Company’s common stock is recorded at cost. At the date of retirement or subsequent reissuance, treasury stock is reduced by the cost of such stock on a first-in, first-out basis with differences recorded in additional paid-in capital or retained earnings, as applicable. During the year ended December 31, 2017 , the Company paid $820 million to repurchase 22,362,401 common shares at a weighted-average price of $36.67 ; $845 million was recorded in treasury stock and $25 million was recorded in additional paid in capital. The repurchased shares are held in treasury stock. During the year ended December 31, 2017, the Company recorded no shares of treasury stock associated with share-based compensation plan activity. During the year ended December 31, 2016 , the Company paid $430 million to repurchase 17,332,684 common shares at an average price of $24.81 ; $405 million was recorded in treasury stock and $25 million was recorded in additional paid in capital. The repurchased shares are held in treasury stock. During the year ended December 31, 2016, the Company recorded no shares of treasury stock associated with share-based compensation plan activity.

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION The Company has share-based employee compensation plans as outlined below, pursuant to which stock awards are granted to employees and non-employee directors. The Company measures compensation expense related to stock awards based upon the fair value of the awards on the grant date, adjusted for forfeitures as they occur. The related expense is charged to earnings on a straight-line basis over the requisite service period (e.g., vesting period) of the award. With respect to performance-based stock awards, compensation expense is adjusted upward or downward based upon the probability of achievement of performance. Awards that continue to vest after retirement are expensed over the shorter of the period of time from grant date to the final vesting date or from the grant date to the date when an employee is retirement eligible. Awards granted to employees who are retirement eligible at the grant date are generally expensed immediately upon grant. Employees of the Company hold time-based restricted stock units and performance-based restricted stock units. A restricted stock unit is the right to receive shares of stock on a future date, which may be subject to time-based vesting conditions and/or performance-based vesting conditions. If a dividend is paid on shares underlying the awards prior to the date such shares are distributed, those dividends will be distributed following vesting in the same form as the dividend that has been paid to common stockholders generally. Citizens Financial Group, Inc. Converted Equity 2010 Long Term Incentive Plan. In March 2014, The Royal Bank of Scotland Group plc granted special IPO awards to certain Citizens employees pursuant to this plan. These awards were granted half in the form of restricted stock units in respect of The Royal Bank of Scotland Group plc shares and half as a fixed convertible bond. Pursuant to their terms, upon the closing of the Company’s IPO, these awards were converted into Company restricted stock units and the performance condition was met. These awards remained subject to the original vesting schedule and terms following the IPO, with half becoming vested in March 2016 and the remaining portion becoming vested in March 2017. No additional awards have been granted under this plan. Citizens Financial Group, Inc. Converted Equity 2010 Deferral Plan. Prior to the Company’s IPO, The Royal Bank of Scotland Group plc granted time-based restricted stock units to certain Citizens employees pursuant to this plan. Pursuant to their terms, upon the closing of the Company’s IPO these awards were converted into Company restricted stock units and remained subject to the original vesting schedules and terms. No additional awards have been granted under this plan. Citizens Financial Group, Inc. 2014 Omnibus Incentive Plan. Certain employees of the Company hold time-based restricted stock units and performance-based restricted stock units granted under this plan. Time-based restricted stock units granted generally become vested ratably over a three -year period and performance-based restricted stock units granted generally become vested at the end of a three -year performance period, depending on the level of performance achieved during such period. Citizens Financial Group, Inc. 2014 Non-Employee Directors Compensation Plan. Non-employee directors receive grants of time-based restricted stock units under this plan as compensation for their services pursuant to the Citizens Financial Group, Inc. Directors Compensation Policy. Starting with grants made in August 2017, restricted stock units granted to directors are fully vested on the grant date, with settlement of the awards deferred until a director’s cessation of service. Citizens Financial Group, Inc. 2014 Employee Stock Purchase Plan. The Company also maintains the Citizens Financial Group, Inc. Employee Stock Purchase Plan (the “ESPP”), which provides eligible employees an opportunity to purchase its common stock at a 10% discount, through accumulated payroll deductions. Eligible employees may contribute up to 10% of eligible compensation to the ESPP, up to a maximum purchase of $25,000 worth of stock in any calendar year. Offering periods under the ESPP are quarterly. Shares of CFG common stock are purchased for a participant on the last day of each quarter at a 10% discount from the fair market value (fair market value under the plan is defined as the closing price on the day of purchase). Prior to the date the shares are purchased, participants do not have any rights or privileges as a stockholder with respect to shares to be purchased at the end of the offering period. Summary of Share-Based Plans Activity The following table presents the activity related to the Company’s share-based plans (excluding the ESPP) for the year ended December 31, 2017 : CFG Share Awards Shares Weighted-Average Grant Price Outstanding, January 1 2,909,029 $23.92 Granted 1,256,816 39.09 Vested & Distributed (1,426,850 ) 21.91 Forfeited (117,481 ) 32.12 Outstanding, December 31 2,621,514 $33.30 During the years ended December 31, 2017, 2016 and 2015, the following number of CFG share awards were granted: 2017: ( 1,256,816 granted with a weighted-average grant price of $39.09 ); 2016 ( 1,552,416 granted with weighted-average grant price of $24.53 ); and 2015 ( 1,315,572 granted with weighted-average grant price of $25.18 ). In addition, the following number of CFG share awards became vested and distributed: 2017 ( 1,426,850 vested and distributed with a weighted-average grant price of $21.91 ); 2016 ( 1,762,655 vested with weighted-average grant price of $22.14 ); and 2015 ( 2,496,092 vested with weighted-average grant price of $22.15 ). There are 57,543,638 shares of Company common stock available for awards to be granted under its employee share plans ( including the “ESPP”). Upon settlement of share-based awards, the Company generally issues new shares, but may also issue shares from treasury stock. Compensation Expense The Company measures compensation expense related to stock awards based upon the fair value of the awards on the grant date. Compensation expense is adjusted for forfeitures as they occur. The related expense is charged to earnings on a straight-line basis over the requisite service period (e.g., vesting period) of the award. With respect to performance-based stock awards, compensation expense is adjusted upward or downward based upon the probability of achievement of performance. Awards that continue to vest after retirement are expensed over the shorter of the period of time from grant date to the final vesting date or from the grant date to the date when an employee is retirement eligible. Awards granted to employees who are retirement eligible at the grant date are generally expensed immediately upon grant. Compensation expense related to the above share plans (including the ESPP) was $39 million , $23 million , and $24 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. At December 31, 2017 , the total unrecognized compensation expense for nonvested equity awards granted was $47 million . This expense is expected to be recognized over a weighted-average period of two years . No share-based compensation costs were capitalized during the years ended December 31, 2017 , 2016 , and 2015 . The income tax benefit recognized in earnings based on the compensation expense recognized for all share-based compensation arrangements amounted to $9 million , $8 million and $5 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES A summary of outstanding off-balance sheet arrangements is presented below: December 31, (in millions) 2017 2016 Undrawn commitments to extend credit $62,959 $60,872 Financial standby letters of credit 2,036 1,892 Performance letters of credit 47 40 Commercial letters of credit 53 43 Marketing rights 41 44 Risk participation agreements 16 19 Residential mortgage loans sold with recourse 7 8 Total $65,159 $62,918 Commitments to Extend Credit Commitments to extend credit are agreements to lend to customers in accordance with conditions contractually agreed upon in advance. Generally, the commitments have fixed expiration dates or termination clauses and may require payment of a fee. Since many of these commitments are expected to expire without being drawn upon, the contract amounts are not necessarily indicative of future cash requirements. Letters of Credit Standby letters of credit, both financial and performance, are issued by the Company for its customers. They are used as conditional guarantees of payment to a third party in the event the customer either fails to make specific payments (financial) or fails to complete a specific project (performance). Commercial letters of credit are used to facilitate the import of goods. The commercial letter of credit is used as the method of payment to the Company’s customers’ suppliers. The Company’s exposure to credit loss in the event of counterparty nonperformance in connection with the above instruments is represented by the contractual amount of those instruments, net of the value of collateral held. Standby letters of credit and commercial letters of credit are issued for terms of up to ten years and one year , respectively. Generally, letters of credit are collateralized by cash, accounts receivable, inventory or investment securities. Credit risk associated with letters of credit is considered in determining the appropriate amounts of reserves for unfunded commitments. The Company recognizes a liability on the Consolidated Balance Sheets representing its obligation to stand ready to perform over the term of the standby letters of credit in the event that the specified triggering events occur. The liability for these guarantees was $3 million at December 31, 2017 and 2016 . Marketing Rights During 2003, the Company entered into a 25 -year agreement to acquire the naming and marketing rights of a baseball stadium in Pennsylvania. The Company paid $3 million for the years ended December 31, 2017 and 2016 , and is obligated to pay $41 million over the remainder of the contract. Risk Participation Agreements RPAs are guarantees issued by the Company to other parties for a fee, whereby the Company agrees to participate in the credit risk of a derivative customer of the other party. Under the terms of these agreements, the “participating bank” receives a fee from the “lead bank” in exchange for the guarantee of reimbursement if the customer defaults on an interest rate swap. The interest rate swap is transacted such that any and all exchanges of interest payments (favorable and unfavorable) are made between the lead bank and the customer. In the event that an early termination of the swap occurs and the customer is unable to make a required close out payment, the participating bank assumes that obligation and is required to make this payment. RPAs where the Company acts as the lead bank are referred to as “participations-out,” in reference to the credit risk associated with the customer derivatives being transferred out of the Company. Participations-out generally occur concurrently with the sale of new customer derivatives. RPAs where the Company acts as the participating bank are referred to as “participations-in,” in reference to the credit risk associated with the counterparty’s derivatives being assumed by the Company. The Company’s maximum credit exposure is based on its proportionate share of the settlement amount of the referenced interest rate swap. Settlement amounts are generally calculated based on the fair value of the swap plus outstanding accrued interest receivable from the customer. The Company’s estimate of the credit exposure associated with its risk participations-in as of December 31, 2017 and 2016 is $16 million and $19 million , respectively. The current amount of credit exposure is spread out over 88 counterparties. RPAs generally have terms ranging from one to five years; however, certain outstanding agreements have terms as long as nine years . Residential Loans Sold with Recourse The Company is an originator and servicer of residential mortgages and routinely sells such mortgage loans in the secondary market and to government-sponsored entities. In the context of such sales, the Company makes certain representations and warranties regarding the characteristics of the underlying loans and, as a result, may be contractually required to repurchase such loans or indemnify certain parties against losses for certain breaches of those representations and warranties. Other Commitments During 2017, the Company entered into an agreement to purchase education loans on a quarterly basis. As of December 31, 2017, the Company completed all purchases under this arrangement. The Company’s commercial loan trading desk provides ongoing secondary market support and liquidity to its clients. Unsettled loan trades (i.e., loan purchase contracts) represent firm commitments to purchase loans from a third party at an agreed-upon price. Principal amounts associated with unsettled commercial loan trades are off-balance sheet commitments until delivery of the loans has taken place. Fair value adjustments associated with each unsettled loan trade are recognized on the Consolidated Balance Sheets and classified within other assets or other liabilities, depending on whether the fair value of the unsettled trade represents an unrealized gain or unrealized loss. The principal balances of unsettled commercial loan trade purchases and sales were $65 million and $132 million , respectively, at December 31, 2017 and $127 million and $177 million , respectively, at December 31, 2016. Settled loans purchased by the trading desk are classified as loans held for sale, at fair value on the Consolidated Balance Sheets. Refer to Note 19 “Fair Value Measurements” for further information. Contingencies The Company operates in a legal and regulatory environment that exposes it to potentially significant risks. A certain amount of litigation ordinarily results from the nature of the Company’s banking and other businesses. The Company is a party to legal proceedings, including class actions. The Company is also the subject of investigations, reviews, subpoenas, and regulatory matters arising out of its normal business operations, which, in some instances, relate to concerns about fair lending, unfair and/or deceptive practices, mortgage-related issues, and mis-selling of certain products. In addition, the Company engages in discussions with relevant governmental and regulatory authorities on a regular and ongoing basis regarding various issues, and any issues discussed or identified may result in investigatory or other action being taken. Litigation and regulatory matters may result in settlements, damages, fines, penalties, public or private censure, increased costs, required remediation, restrictions on business activities, or other impacts on the Company. In these disputes and proceedings, the Company contests liability and the amount of damages as appropriate. Given their complex nature, and based on the Company's experience, it may be years before some of these matters are finally resolved. Moreover, before liability can be reasonably estimated for a claim, numerous legal and factual issues may need to be examined, including through potentially lengthy discovery and determination of important factual matters, and by addressing novel or unsettled legal issues relevant to the proceedings in question. The Company cannot predict with certainty if, how, or when such claims will be resolved or what the eventual settlement, fine, penalty or other relief, if any, may be, particularly for claims that are at an early stage in their development or where claimants seek substantial or indeterminate damages. The Company recognizes a provision for a claim when, in the opinion of management after seeking legal advice, it is probable that a liability exists and the amount of loss can be reasonably estimated. In many proceedings, however, it is not possible to determine whether any loss is probable or to estimate the amount of any loss. Based on information currently available, the advice of legal counsel and other advisers, and established reserves, management believes that the aggregate liabilities, if any, potentially arising from these proceedings will not have a materially adverse effect on the Company’s Consolidated Financial Statements. As previously reported, CBNA entered into a consent order with the OCC in November 2015 in connection with past billing practices. All financial penalties and remediation associated with this legacy matter have been paid and completed.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The Company measures or monitors many of its assets and liabilities on a fair value basis. Fair value is used on a recurring basis for assets and liabilities for which fair value is the required or elected measurement basis of accounting. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or for disclosure purposes. Nonrecurring fair value adjustments typically involve the application of lower of cost or market accounting or write-downs of individual assets. The Company also applies the fair value measurement guidance to determine amounts reported for certain disclosures in this Note for assets and liabilities not required to be reported at fair value in the financial statements. Recurring Fair Value Measurements The Company measures fair value using the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is based upon quoted market prices in an active market, where available. If quoted prices are not available, observable market-based inputs or independently sourced parameters are used to develop fair value, whenever possible. Such inputs may include prices of similar assets or liabilities, yield curves, interest rates, prepayment speeds, and foreign exchange rates. A portion of the Company’s assets and liabilities is carried at fair value, including securities available for sale, derivative instruments and other investment securities. In addition, the Company elects to account for its loans associated with its mortgage banking business and secondary loan trading desk at fair value. The Company classifies its assets and liabilities that are carried at fair value in accordance with the three-level valuation hierarchy: • Level 1. Quoted prices (unadjusted) in active markets for identical assets or liabilities. • Level 2. Observable inputs other than Level 1 prices, such as quoted prices for similar instruments, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by market data for substantially the full term of the asset or liability. • Level 3. Unobservable inputs that are supported by little or no market information and that are significant to the fair value measurement. Classification in the hierarchy is based upon the lowest level input that is significant to the fair value measurement of the asset or liability. For instruments classified in Levels 1 and 2 where inputs are primarily based upon observable market data, there is less judgment applied in arriving at the fair value. For instruments classified in Level 3, management judgment is more significant due to the lack of observable market data. The Company reviews and updates the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in fair value measurements may result in a reclassification between the fair value hierarchy levels and are recognized based on period-end balances. The Company utilizes a variety of valuation techniques to measure its assets and liabilities at fair value. The valuation methodologies used for significant assets and liabilities carried on the balance sheet at fair value on a recurring basis are presented below: Securities available for sale The fair value of securities classified as AFS is based upon quoted prices, if available. Where observable quoted prices are available in an active market, securities are classified as Level 1 in the fair value hierarchy. Classes of instruments that are valued using this market approach include debt securities issued by the U.S. Treasury. If quoted market prices are not available, the fair value for the security is estimated under the market or income approach using pricing models. These instruments are classified as Level 2 because they currently trade in active markets and the inputs to the valuations are observable. The pricing models used to value securities generally begin with market prices (or rates) for similar instruments and make adjustments based on the characteristics of the instrument being valued. These adjustments reflect assumptions made regarding the sensitivity of each security’s value to changes in interest rates and prepayment speeds. Classes of instruments that are valued using this market approach include specified pool mortgage “pass-through” securities and other debt securities issued by U.S. government-sponsored entities and state and political subdivisions. The pricing models used to value securities under the income approach generally begin with the contractual cash flows of each security and make adjustments based on forecasted prepayment speeds, default rates, and other market-observable information. The adjusted cash flows are then discounted at a rate derived from observed rates of return for comparable assets or liabilities that are traded in the market. Classes of instruments that are valued using this market approach include residential and commercial CMOs. A significant majority of the Company’s Level 1 and 2 securities are priced using an external pricing service. The Company verifies the accuracy of the pricing provided by its primary outside pricing service on a quarterly basis. This process involves using a secondary external vendor to provide valuations for the Company’s securities portfolio for comparison purposes. Any securities with discrepancies beyond a certain threshold are researched and, if necessary, valued by an independent outside broker. In certain cases where there is limited activity or less transparency around inputs to the valuation model, securities are classified as Level 3. Residential loans held for sale See the “ Fair Value Option, Residential Mortgage Loans Held for Sale” discussion below. Commercial loans held for sale See the “ Fair Value Option, Commercial and Commercial Real Estate Loans Held for Sale” discussion below. Derivatives The vast majority of the Company’s derivatives portfolio is composed of “plain vanilla” interest rate swaps, which are traded in over-the-counter markets where quoted market prices are not readily available. For these interest rate derivatives, fair value is determined utilizing models that primarily use market observable inputs, such as swap rates and yield curves. The pricing models used to value interest rate swaps calculate the sum of each instrument’s fixed and variable cash flows, which are then discounted using an appropriate yield curve (i.e., LIBOR or Overnight Index Swap curve) to arrive at the fair value of each swap. The pricing models do not contain a high level of subjectivity as the methodologies used do not require significant judgment. The Company also considers certain adjustments to the modeled price that market participants would make when pricing each instrument, including a credit valuation adjustment that reflects the credit quality of the swap counterparty. The Company incorporates the effect of exposure to a particular counterparty’s credit by netting its derivative contracts with the collateral available and calculating a credit valuation adjustment on the basis of the net position with the counterparty where permitted. The determination of this adjustment requires judgment on behalf of Company management; however, the total amount of this portfolio-level adjustment is not material to the total fair value of the interest rate swaps in their entirety . Therefore, interest rate swaps are classified as Level 2 in the valuation hierarchy. The Company’s other derivatives include foreign exchange contracts. The fair value of foreign exchange derivatives uses the mid-point of daily quoted currency spot prices. A valuation model estimates fair value based on the quoted spot rates together with interest rate yield curves and forward currency rates. Since all of these inputs are observable in the market, foreign exchange derivatives are classified as Level 2 in the fair value hierarchy. Money Market Mutual Fund Fair value is determined based upon unadjusted quoted market prices and is considered a Level 1 fair value measurement. Other investments The fair values of the Company’s other investments are based on security prices in markets that are not active; therefore, these investments are classified as Level 2 in the fair value hierarchy. The following table presents assets and liabilities measured at fair value, including gross derivative assets and liabilities on a recurring basis at December 31, 2017 : (in millions) Total Level 1 Level 2 Level 3 Securities available for sale: Mortgage-backed securities $20,139 $— $20,139 $— State and political subdivisions 6 — 6 — U.S. Treasury and other 12 12 — — Total securities available for sale 20,157 12 20,145 — Loans held for sale, at fair value: Residential loans held for sale 326 — 326 — Commercial loans held for sale 171 — 171 — Total loans held for sale, at fair value 497 — 497 — Derivative assets (1) Interest rate swaps 538 — 538 — Foreign exchange contracts 148 — 148 — Other contracts 7 — 7 — Total derivative assets 693 — 693 — Other investment securities, at fair value: Money market mutual fund 165 165 — — Other investments 4 — 4 — Total other investment securities, at fair value 169 165 4 — Total assets $21,516 $177 $21,339 $— Derivative liabilities (1) Interest rate swaps $379 $— $379 $— Foreign exchange contracts 149 — 149 — Other contracts 5 — 5 — Total derivative liabilities 533 — 533 — Total liabilities $533 $— $533 $— (1) Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives. The following table presents assets and liabilities measured at fair value including gross derivative assets and liabilities on a recurring basis at December 31, 2016 : (in millions) Total Level 1 Level 2 Level 3 Securities available for sale: Mortgage-backed securities $19,446 $— $19,446 $— State and political subdivisions 8 — 8 — Equity securities 17 — 17 — U.S. Treasury 30 30 — — Total securities available for sale 19,501 30 19,471 — Loans held for sale, at fair value: Residential loans held for sale 504 — 504 — Commercial loans held for sale 79 — 79 — Total loans held for sale, at fair value 583 — 583 — Derivative assets: Interest rate swaps 609 — 609 — Foreign exchange contracts 134 — 134 — Other contracts 16 — 16 — Total derivative assets 759 — 759 — Other investment securities, at fair value: Money market mutual fund 91 91 — — Other investments 5 — 5 — Total other investment securities, at fair value 96 91 5 — Total assets $20,939 $121 $20,818 $— Derivative liabilities: Interest rate swaps $645 $— $645 $— Foreign exchange contracts 126 — 126 — Other contracts 7 — 7 — Total derivative liabilities 778 — 778 — Total liabilities $778 $— $778 $— There were no Level 3 assets measured at fair value on a recurring basis. Fair Value Option The Company elected to account for residential mortgage loans held for sale and certain commercial and commercial real estate loans held for sale at fair value. Applying fair value accounting to the residential mortgage loans held for sale better aligns the reported results of the economic changes in the value of these loans and their related hedge instruments. Certain commercial and commercial real estate held for sale loans are managed by a commercial secondary loan desk that provides liquidity to banks, finance companies and institutional investors. Applying fair value accounting to this portfolio is appropriate because the Company holds these loans with the intent to sell within short-term periods. Residential Mortgage Loans Held for Sale The fair value of residential mortgage loans held for sale is derived from observable mortgage security prices and includes adjustments for loan servicing value, agency guarantee fees, and other loan level attributes which are mostly observable in the marketplace. Credit risk does not significantly impact the valuation since these loans are sold shortly after origination. Therefore, the Company classifies the residential mortgage loans held for sale in Level 2 of the fair value hierarchy. The election of the fair value option for financial assets and financial liabilities is optional and irrevocable. The loans accounted for under the fair value option are initially measured at fair value (i.e., acquisition cost) when the financial asset is acquired. Subsequent changes in fair value are recognized in mortgage banking fees on the Consolidated Statements of Operations. The Company recognized changes in fair value in mortgage banking fees of $6 million , ($5) million , and ($2) million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Interest income on residential mortgage loans held for sale is calculated based on the contractual interest rate of the loan and is recorded in interest income. Commercial and Commercial Real Estate Loans Held for Sale The fair value of commercial and commercial real estate loans held for sale is estimated using observable prices of identical or similar loans that transact in the marketplace. In addition, the Company uses external pricing services that provide estimates of fair values based on quotes from various dealers transacting in the market, sector curves or benchmarking techniques. Therefore, the Company classifies the commercial and commercial real estate loans managed by the commercial secondary loan desk in Level 2 of the fair value hierarchy given the observable market inputs. There were no loans in this portfolio that were 90 days or more past due or nonaccruing as of December 31, 2017 . The loans accounted for under the fair value option are initially measured at fair value when the financial asset is recognized. Subsequent changes in fair value are recognized in current earnings. Since all loans in the Company’s commercial trading portfolio consist of floating rate obligations, all changes in fair value are due to changes in credit risk. Such credit-related fair value changes may include observed changes in overall credit spreads and/or changes to the creditworthiness of an individual borrower. Unsettled trades within the commercial trading portfolio are not recognized on the Consolidated Balance Sheets and represent off-balance sheet commitments. Refer to Note 18 “Commitments and Contingencies” for further information. The following table presents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans held for sale measured at fair value: December 31, 2017 December 31, 2016 (in millions) Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Aggregate Unpaid Principal Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Aggregate Unpaid Principal Residential mortgage loans held for sale, at fair value $326 $326 $— $504 $505 ($1 ) Commercial and commercial real estate loans held for sale, at fair value 171 171 — 79 79 — Interest income on commercial and commercial real estate loans held for sale is calculated based on the contractual interest rate of the loan and is recorded in interest income. The Company recognized $4 million , $4 million and $3 million for the years ended December 31, 2017 , 2016 and 2015 , respectively, in other noninterest income related to its commercial trading portfolio. Nonrecurring Fair Value Measurements Fair value is also used on a nonrecurring basis to evaluate certain assets for impairment or for disclosure purposes. Examples of nonrecurring uses of fair value include MSRs accounted for by the amortization method, loan impairments for certain loans and leases, and goodwill. The following valuation techniques are utilized to measure significant assets for which the Company utilizes fair value on a nonrecurring basis: Impaired Loans The carrying amount of collateral-dependent impaired loans is compared to the appraised value of the collateral less costs to dispose and is classified as Level 2. Any excess of carrying amount over the appraised value is charged to the ALLL. Mortgage Servicing Rights MSRs do not trade in an active market with readily observable prices. MSRs are classified as Level 3 since the valuation methodology utilizes significant unobservable inputs. The fair value was calculated using a discounted cash flow model, which used assumptions, including weighted-average life, weighted-average constant prepayment rate and weighted-average discount rate. Refer to Note 8 “Mortgage Banking” for more information. Foreclosed assets Foreclosed assets consist primarily of residential properties. Foreclosed assets are carried at the lower of cost or fair value less costs to sell. Fair value is based upon independent market prices or appraised values of the collateral and is classified as Level 2. Leased assets The fair value of assets under operating leases is determined using collateral specific pricing digests, external appraisals, broker opinions, recent sales data from industry equipment dealers, and discounted cash flows derived from the underlying lease agreement. As market data for similar assets and lease agreements is available and used in the valuation, these assets are classified as Level 2 fair value measurement. The following table presents gains (losses) on assets and liabilities measured at fair value on a nonrecurring basis and recorded in earnings: Year Ended December 31, (in millions) 2017 2016 2015 Impaired collateral-dependent loans ($35 ) ($33 ) ($32 ) MSRs 2 4 9 Foreclosed assets (3 ) (3 ) (3 ) Leased assets (15 ) 11 — The following table presents assets and liabilities measured at fair value on a nonrecurring basis: December 31, 2017 December 31, 2016 (in millions) Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Impaired collateral-dependent loans $393 $— $393 $— $355 $— $355 $— MSRs 218 — — 218 182 — — 182 Foreclosed assets 31 — 31 — 44 — 44 — Leased assets 112 — 112 — 158 — 158 — Disclosures about Fair Value of Financial Instruments Following is a description of valuation methodologies used to estimate the fair value of financial instruments for disclosure purposes (these instruments are not recorded in the financial statements at fair value): Securities held to maturity The fair values of securities classified as HTM are estimated under the market or income approach using the same pricing models as those used to measure the fair value of the Company’s securities available for sale. For more information, see “Recurring Fair Value Measurements — Securities Available for Sale,” within this Note. Other investment securities, at cost The cost basis of other investment securities, at cost, such as FHLB stock and FRB stock, is assumed to approximate the fair value of these securities. As a member of the FHLB and FRB, the Company is required to hold FHLB and FRB stock. The stock can be sold only to the FHLB and FRB upon termination of membership, or redeemed at the FHLB’s or FRB’s sole discretion. The stock may only be sold or redeemed at par, and therefore the cost basis represents the best estimate of fair value. Loans and leases For loans and leases not recorded at fair value on a recurring basis that are not accounted for as collateral-dependent impaired loans, fair value is estimated by using one of two methods: a discounted cash flow method or a securitization method. The discounted cash flow method involves discounting the expected future cash flows using current rates which a market participant would likely use to value similar pools of loans. Inputs used in this method include observable information such as contractual cash flows (net of servicing cost) and unobservable information such as estimated prepayment speeds, credit loss exposures, and discount rates. The securitization method involves utilizing market securitization data to value the assets as if a securitization transaction had been executed. Inputs used include observable market-based MBS data and pricing adjustments based on unobservable data reflecting the liquidity risk, credit loss exposure and other characteristics of the underlying loans. The internal risk-weighted balances of loans are grouped by product type for purposes of these estimated valuations. For nonaccruing loans, fair value is estimated by discounting management’s estimate of future cash flows with a discount rate commensurate with the risk associated with such assets. Fair value of collateral-dependent loans is primarily based on the appraised value of the collateral. Other loans held for sale Balances represent loans that were transferred to other loans held for sale and are reported at the lower of cost or fair value. When applicable, the fair value of other loans held for sale is estimated using one of two methods: a discounted cash flow method or a securitization method (as described above). Deposits The fair value of demand deposits, checking with interest accounts, regular savings, money market accounts, and other deposits is the amount payable on demand at the balance sheet date. The fair value of term deposits is estimated by discounting the expected future cash flows using rates currently offered for deposits of similar remaining maturities. Federal funds purchased and securities sold under agreements to repurchase, other short-term borrowed funds, and long-term borrowed funds Rates currently available to the Company for debt of similar terms and remaining maturities are used to discount the expected cash flows of existing debt. The following table presents the estimated fair value for financial instruments not recorded at fair value in the Consolidated Financial Statements. The carrying amounts are recorded in the Consolidated Balance Sheets under the indicated captions: December 31, 2017 Total Level 1 Level 2 Level 3 (in millions) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Securities held to maturity $4,685 $4,668 $— $— $4,685 $4,668 $— $— Other investment securities, at cost 722 722 — — 722 722 — — Other loans held for sale 221 221 — — — — 221 221 Loans and leases 110,617 111,168 — — 393 393 110,224 110,775 Financial Liabilities: Deposits 115,089 115,039 — — 115,089 115,039 — — Federal funds purchased and securities sold under agreements to repurchase 815 815 — — 815 815 — — Other short-term borrowed funds 1,856 1,856 — — 1,856 1,856 — — Long-term borrowed funds 11,765 11,891 — — 11,765 11,891 — — December 31, 2016 Total Level 1 Level 2 Level 3 (in millions) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Securities held to maturity $5,071 $5,058 $— $— $5,071 $5,058 $— $— Other investment securities, at cost 942 942 — — 942 942 — — Other loans held for sale 42 42 — — — — 42 42 Loans and leases 107,669 107,537 — — 355 355 107,314 107,182 Financial Liabilities: Deposits 109,804 109,796 — — 109,804 109,796 — — Federal funds purchased and securities sold under agreements to repurchase 1,148 1,148 — — 1,148 1,148 — — Other short-term borrowed funds 3,211 3,211 — — 3,211 3,211 — — Long-term borrowed funds 12,790 12,849 — — 12,790 12,849 — —

OTHER INCOME

OTHER INCOME	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
OTHER INCOME	OTHER INCOME The following table presents the details of other income: Year Ended December 31, (in millions) 2017 2016 2015 Bank-owned life insurance income $54 $54 $56 Other 37 105 50 Other income $91 $159 $106 Bank-Owned Life Insurance Bank-owned life insurance is stated at its cash surrender value. The Company is the beneficiary of life insurance policies on current and former officers and selected employees of the Company.

OTHER OPERATING EXPENSE

OTHER OPERATING EXPENSE	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
OTHER OPERATING EXPENSE	OTHER OPERATING EXPENSE The following table presents the details of other operating expense: Year Ended December 31, (in millions) 2017 2016 2015 Deposit insurance $137 $120 $115 Promotional expense 105 98 101 Settlements and operating losses 54 62 43 Other 251 246 271 Other operating expense $547 $526 $530

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company uses an asset and liability (balance sheet) approach for financial accounting and reporting of income taxes. This results in two components of income tax expense: current and deferred. Current income tax expense approximates taxes to be paid or refunded for the current period. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. These gross deferred tax assets and liabilities represent decreases or increases in taxes expected to be paid in the future because of future reversals of temporary differences in the bases of assets and liabilities, as measured by tax laws, and their bases, as reported in the Consolidated Financial Statements. The Company also assesses the probability that the positions taken, or expected to be taken, in its income tax returns will be sustained by taxing authorities. A “more likely than not” (more than 50 percent) recognition threshold must be met before a tax benefit can be recognized. Tax positions that are more likely than not to be sustained are reflected in the Company’s Consolidated Financial Statements. Total income tax expense is presented below: Year Ended December 31, (in millions) 2017 2016 2015 Income tax expense $260 $489 $423 Tax effect of changes in OCI (7 ) (168 ) (12 ) Total comprehensive income tax expense $253 $321 $411 Components of income tax expense are presented below: (in millions) Current Deferred Total Year Ended December 31, 2017 U.S. federal $376 ($142 ) $234 State and local 20 6 26 Total $396 ($136 ) $260 Year Ended December 31, 2016 U.S. federal $292 $159 $451 State and local 44 (6 ) 38 Total $336 $153 $489 Year Ended December 31, 2015 U.S. federal $162 $225 $387 State and local 12 24 36 Total $174 $249 $423 The effective income tax rate differed from the U.S. federal income tax rate of 35% in 2017 , 2016 and 2015 as presented below: Year Ended December 31, 2017 2016 2015 (in millions, except ratio data) Amount Rate Amount Rate Amount Rate U.S. Federal income tax expense and tax rate $669 35.0 % $537 35.0 % $442 35.0 % Increase (decrease) resulting from: 2017 Tax Legislation (331 ) (17.3 %) — — — — State and local income taxes (net of federal benefit) 46 2.4 38 2.5 27 2.1 Bank-owned life insurance (19 ) (1.0 ) (19 ) (1.2 ) (20 ) (1.6 ) Tax-exempt interest (21 ) (1.1 ) (19 ) (1.3 ) (17 ) (1.3 ) Tax advantaged investments (including related credits) (51 ) (2.7 ) (31 ) (2.0 ) (16 ) (1.2 ) Other tax credits (3 ) (0.1 ) (14 ) (0.9 ) — — Adjustments for uncertain tax positions (23 ) (1.2 ) — — — — Non-deductible expenses — — — — 8 0.6 Other (7 ) (0.4 ) (3 ) (0.2 ) (1 ) (0.1 ) Total income tax expense and tax rate $260 13.6 % $489 31.9 % $423 33.5 % On December 22, 2017, President Trump signed the 2017 Tax Legislation which included a reduction in the corporate tax rate from 35% to 21%. For Citizens, this required a revaluation of the Company’s net deferred tax liability with a corresponding adjustment to current tax expense, and resulted in a $331 million net tax benefit. Included in this net tax benefit was $145 million of expense related to the revaluation of the Company’s deferred tax assets associated with unrealized losses in AOCI. FASB standards in-place at December 31, 2017 required the Company to revalue all deferred taxes, including those related to balances in AOCI, through current tax expense. As a result, the Company’s unrealized loss balance in AOCI was not revalued to reflect the new corporate tax rate. This impact, commonly referred to as the “stranded tax effect”, was taken under consideration by FASB in January 2018 to address concerns primarily raised by banking institutions, including distortion of net income and regulatory capital. In February 2018, to address the “stranded tax effect”, FASB issued ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which provides entities the election to reclassify the difference between the new and old corporate tax rates resulting from the 2017 Tax Legislation between retained earnings and AOCI for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company has retrospectively adopted ASU 2018-02, elected to reclassify $145 million between AOCI and retained earnings, including indirect impacts from the decreased federal tax effect on future state tax benefits, and reflected this reclassification in the Company’s 2017 Consolidated Financial Statements, included in this report. The decrease in the effective tax rate from 2015 to 2016 is primarily attributable to the benefits of federal and state tax credits. The effective income tax rate for the year ended December 31, 2015 reflected the adoption of ASU No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects . The application of this guidance, which began on January 1, 2015, resulted in the reclassification of the amortization of these investments to income tax expense from noninterest income. Additionally, the 2015 effective tax rate was affected by the impact of non-deductible permanent expense items incurred by the Company in 2015. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities are presented below: December 31, (in millions) 2017 2016 Deferred tax assets: Other comprehensive income $271 $409 Allowance for credit losses 310 471 State net operating loss carryforwards 88 75 Accrued expenses not currently deductible 40 129 Investment and other tax credit carryforwards 65 52 Deferred income — 22 Fair value adjustments 27 40 Other — 6 Total deferred tax assets 801 1,204 Valuation allowance (105 ) (107 ) Deferred tax assets, net of valuation allowance 696 1,097 Deferred tax liabilities: Leasing transactions 525 881 Amortization of intangibles 352 522 Depreciation 182 234 Pension and other employee compensation plans 110 103 Partnerships 37 22 Deferred Income 27 — MSRs 34 49 Total deferred tax liabilities 1,267 1,811 Net deferred tax liability $571 $714 Certain 2016 balances in the table above were reclassified to better conform to the current year presentation. These adjustments included presenting the deferred tax liability attributable to partnerships separately which in 2016 was presented in the other deferred tax liability category offset by certain deferred tax assets. Deferred tax assets are recognized for net operating loss carryforwards and tax credit carryforwards. Valuation allowances are recorded as necessary to reduce deferred tax assets to the amounts that management concludes are more likely than not to be realized. At December 31, 2017 , the Company had state tax net operating loss carryforwards of $1.4 billion . Limitations on the ability to realize these carryforwards are reflected in the associated valuation allowance. At December 31, 2017 , the Company had a valuation allowance of $105 million against various deferred tax assets related to state net operating losses and state tax credits, as it is management’s current assessment that it is more likely than not that the Company will not recognize a portion of the deferred tax asset related to these items. The valuation allowance decreased $2 million during the year ended December 31, 2017 . Effective with the fiscal year ended September 30, 1997, the reserve method for bad debts was no longer permitted for tax purposes. The repeal of the reserve method required the recapture of the reserve balance in excess of certain base year reserve amounts attributable to years ended prior to 1988. At December 31, 2017 , the Company’s base year loan loss reserves attributable to years ended prior to 1988, for which no deferred income taxes have been provided, was $557 million . This base year reserve may become taxable if certain distributions are made with respect to the stock of the Company or if the Company ceases to qualify as a bank for tax purposes. No actions are planned that would cause this reserve to become wholly or partially taxable. The Company files income tax returns in the U.S. federal jurisdiction and various state and local jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal or state and local income tax examinations by major tax authorities for years before 2014. A reconciliation of the beginning and ending amount of unrecognized tax benefits is presented below: December 31, (in millions) 2017 2016 2015 Balance at the beginning of the year $42 $62 $72 Gross decrease for tax positions related to prior years (27 ) (19 ) (6 ) Gross increase for tax positions related to prior years — 1 — Decreases for tax positions as a result of the lapse of the statutes of limitations (1 ) (2 ) (3 ) Decreases for tax positions related to settlements with taxing authorities (9 ) — (1 ) Balance at end of year $5 $42 $62 Tax positions are measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The difference between the benefit recognized for a position and the tax benefit claimed on a tax return is referred to as an unrecognized tax benefit. Included in the total amount of unrecognized tax benefits at December 31, 2017 , are potential benefits of $5 million that, if recognized, would impact the effective tax rate. The Company classifies interest and penalties related to unrecognized tax benefits as a component of income taxes. The Company released $8 million , accrued $8 million , and accrued less than $1 million of interest expense through December 31, 2017 , 2016 , and 2015 , respectively. The Company had approximately $1 million , $22 million , and $14 million accrued for the payment of interest at December 31, 2017 , 2016 , and 2015 , respectively. There were no amounts accrued for penalties as of December 31, 2017 , 2016 , and 2015 , and there were no penalties recognized during 2017 , 2016 , and 2015 .

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during each period. Net income available to common stockholders represents net income after preferred stock dividends, accretion of the discount on preferred stock issuances, and gains or losses from any repurchases of preferred stock. Diluted EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during each period, plus potential dilutive shares such as share-based payment awards and warrants using the treasury stock method. Year Ended December 31, (in millions, except share and per-share data) 2017 2016 2015 Numerator (basic and diluted): Net income $1,652 $1,045 $840 Less: Preferred stock dividends 14 14 7 Net income available to common stockholders $1,638 $1,031 $833 Denominator: Weighted-average common shares outstanding - basic 502,157,440 522,093,545 535,599,731 Dilutive common shares: share-based awards 1,527,651 1,837,173 2,621,167 Weighted-average common shares outstanding - diluted 503,685,091 523,930,718 538,220,898 Earnings per common share: Basic $3.26 $1.97 $1.55 Diluted 3.25 1.97 1.55 Potential dilutive common shares are excluded from the computation of diluted EPS in the periods where the effect would be antidilutive. The diluted EPS computation for the year ended December 31, 2017 excluded 533 average share-based awards because their inclusion would have been antidilutive. The Company did not have any antidilutive shares for the years ended December 31, 2016 and 2015 .

REGULATORY MATTERS

REGULATORY MATTERS	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
REGULATORY MATTERS	REGULATORY MATTERS As a bank holding company, the Company is subject to regulation and supervision by the FRB. The primary subsidiaries of the Company are its two insured depository institutions CBNA, a national banking association whose primary federal regulator is the OCC, and CBPA, a Pennsylvania-chartered savings bank regulated by the Department of Banking of the Commonwealth of Pennsylvania and supervised by the FDIC, its primary federal regulator. Under the U.S. Basel III capital framework, the Company and its banking subsidiaries must meet specific minimum requirements for the following ratios: common equity tier 1 capital, tier 1 capital, total capital, and tier 1 leverage. In addition, the Company must not be subject to a written agreement, order or capital directive with any of its regulators. Failure to meet minimum capital requirements can result in the initiation of certain actions that, if undertaken, could have a material effect on the Company’s Consolidated Financial Statements. On December 22, 2017, President Trump signed the 2017 Tax Legislation which included a reduction in the corporate tax rate from 35% to 21% For Citizens, this required a revaluation of the Company’s net deferred tax liability with a corresponding adjustment to current tax expense, and resulted in a $331 million net tax benefit. Included in this net tax benefit was $145 million of expense related to the revaluation of the Company’s deferred tax assets associated with unrealized losses in AOCI. FASB standards in-place at December 31, 2017 required the Company to revalue all deferred taxes, including those related to balances in AOCI, through current tax expense. As a result, the Company’s unrealized loss balance in AOCI was not revalued to reflect the new corporate tax rate. This impact, commonly referred to as the “stranded tax effect”, was taken under consideration by FASB in January 2018 to address concerns primarily raised by banking institutions, including distortion of net income and regulatory capital. In February 2018, to address the “stranded tax effect”, FASB issued ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which provides entities the election to reclassify the difference between the new and old corporate tax rates resulting from the 2017 Tax Legislation between retained earnings and AOCI for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company has retrospectively adopted ASU 2018-02, elected to reclassify $145 million between AOCI and retained earnings, including indirect impacts from the decreased federal tax effect on future state tax benefits, and reflected this reclassification in the Company’s 2017 Consolidated Financial Statements, included in this report. The following table presents the Company’s capital and capital ratios under U.S. Basel III Standardized Transitional rules. The Company has declared itself as an “AOCI opt-out” institution, which means the Company is not required to recognize in regulatory capital the impacts of net unrealized gains and losses included within AOCI for securities that are available for sale or held to maturity, accumulated net gains and losses on cash-flow hedges and certain defined benefit pension plan assets. Transitional Basel III FDIA Requirements Actual Minimum Capital Adequacy Classification as Well-capitalized (6) (in millions, except ratio data) Amount Ratio Amount Ratio (5) Amount Ratio As of December 31, 2017 Common equity tier 1 capital (1) $14,309 11.2 % $7,342 5.750 % $8,300 6.5 % Tier 1 capital (2) 14,556 11.4 9,258 7.250 10,215 8.0 Total capital (3) 17,781 13.9 11,812 9.250 12,769 10.0 Tier 1 leverage (4) 14,556 10.0 5,824 4.000 7,280 5.0 As of December 31, 2016 Common equity tier 1 capital (1) $13,822 11.2 % $6,348 5.125 % $8,051 6.5 % Tier 1 capital (2) 14,069 11.4 8,206 6.625 9,909 8.0 Total capital (3) 17,347 14.0 10,683 8.625 12,386 10.0 Tier 1 leverage (4) 14,069 9.9 5,667 4.000 7,084 5.0 (1) “Common equity tier 1 capital ratio” represents CET1 capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (2) “Tier 1 capital ratio” is tier 1 capital, which includes CET1 capital plus non-cumulative perpetual preferred equity that qualifies as additional tier 1 capital, divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (3) “Total capital ratio” is total capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (4) “Tier 1 leverage ratio” is tier 1 capital divided by quarterly average total assets as defined under U.S. Basel III Standardized approach. (5) “Minimum Capital ratio” includes capital conservation buffer of 1.250% for 2017 and 0.625% for 2016; N/A to Tier 1 leverage. (6) Presented for informational purposes. Prompt corrective action provisions apply only to the Company’s insured depository institutions - CBNA and CBPA. Under the FRB’s Capital Plan Rule, the Company may only make capital distributions, including payment of dividends, in accordance with a capital plan that has been reviewed by the FRB with no objection. On April 5, 2017, the Company submitted its 2017 Capital Plan to the Federal Reserve under the annual CCAR process. On June 28, 2017, the FRB informed the Company that it did not object to the Company’s 2017 Capital Plan or to its proposed capital actions for the period beginning July 1, 2017 and ending June 30, 2018. The Company’s 2017 Capital Plan includes quarterly common dividends of $0.18 per share through the end of 2017, increasing the quarterly common dividend to $0.22 per share in 2018, and a share repurchase plan through the second quarter of 2018. The timing and exact amount of future dividends and share repurchases will depend on various factors, including capital position, financial performance and market conditions. For the year ended December 31, 2017 , the Company paid total common dividends of $322 million and repurchased outstanding common shares for $820 million , compared to $241 million in common dividends paid, $430 million in outstanding common shares repurchased and $625 million of qualified subordinated notes repurchased for the year ended December 31, 2016 . Additionally, the Company paid total preferred dividends of $14 million for both periods. In accordance with federal and state banking regulations, dividends paid by the Company’s banking subsidiaries to the Parent Company are generally limited to the retained earnings of the respective banking subsidiaries unless specifically approved by the appropriate bank regulator.

BUSINESS OPERATING SEGMENTS

BUSINESS OPERATING SEGMENTS	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
BUSINESS OPERATING SEGMENTS	BUSINESS OPERATING SEGMENTS The Company is managed by its Chief Executive Officer on a segment basis. The Company’s two business operating segments are Consumer Banking and Commercial Banking. The business segments are determined based on the products and services provided, or the type of customer served. Each segment has one or more segment heads who report directly to the Chief Executive Officer. The Chief Executive Officer has final authority over resource allocation decisions and performance assessment. The business segments reflect this management structure and the manner in which financial information is currently evaluated by the Chief Executive Officer. Reportable Segments Segment results are determined based upon the Company’s management reporting system, which assigns balance sheet and statement of operations items to each of the business segments. The process is designed around the Company’s organizational and management structure and accordingly, the results derived are not necessarily comparable with similar information published by other financial institutions. A description of each reportable segment and table of financial results is presented below: Consumer Banking The Consumer Banking segment focuses on retail customers and small businesses with annual revenues of up to $ 25 million . It offers traditional banking products and services, including checking, savings, home loans, education loans, credit cards, business loans, and unsecured product finance and personal loans in addition to financial management services. It also operates an indirect auto financing business, providing financing for both new and used vehicles through auto dealerships. The segment’s distribution channels include a branch network, ATMs and a work force of experienced specialists ranging from financial consultants, mortgage loan officers and business banking officers to private bankers. The Company’s Consumer Banking value proposition is based on providing simple, easy to understand product offerings and a convenient banking experience with a more personalized approach. Commercial Banking The Commercial Banking segment primarily targets companies with annual revenues from $25 million to $2.5 billion and provides a full complement of financial products and solutions, including loans, leases, trade financing, deposits, cash management, commercial cards, foreign exchange, interest rate risk management, corporate finance and capital markets advisory capabilities. It focuses on middle-market companies, large corporations and institutions and has dedicated teams with industry expertise in government banking, not-for-profit, healthcare, technology, professionals, oil and gas, asset finance, franchise finance, asset-based lending, commercial real estate, private equity and sponsor finance. While the segment’s business development efforts are predominantly focused in the Company’s footprint, some of its specialized industry businesses also operate selectively on a national basis (such as healthcare, asset finance and franchise finance). A key component of Commercial Banking’s growth strategy is to bring ideas to clients that help their businesses thrive, and in doing so, expand the loan portfolio and ancillary product sales. Non-segment Operations Other Non-segment operations are classified as Other, which includes corporate functions, the Treasury function, the securities portfolio, wholesale funding activities, intangible assets, community development, non-core assets (including legacy Royal Bank of Scotland Group plc aircraft loans and leases placed in runoff in the third quarter of 2016), and other unallocated assets, liabilities, capital, revenues, provision for credit losses and expenses, including income tax expense. In addition to non-segment operations, Other includes goodwill and any associated goodwill impairment charges. For impairment testing purposes, the Company allocates goodwill to its Consumer Banking and Commercial Banking reporting units. For management reporting purposes, the Company presents the goodwill balance (and any related impairment charges) in Other. As of and for the Year Ended December 31, 2017 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,651 $1,411 $111 $4,173 Noninterest income 905 538 91 1,534 Total revenue 3,556 1,949 202 5,707 Noninterest expense 2,593 772 109 3,474 Profit before provision for credit losses 963 1,177 93 2,233 Provision for credit losses 265 19 37 321 Income before income tax expense (benefit) 698 1,158 56 1,912 Income tax expense (benefit) 246 384 (370 ) 260 Net income $452 $774 $426 $1,652 Total average assets $59,714 $49,747 $40,492 $149,953 As of and for the Year Ended December 31, 2016 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,443 $1,288 $27 $3,758 Noninterest income 883 466 148 1,497 Total revenue 3,326 1,754 175 5,255 Noninterest expense 2,547 741 64 3,352 Profit before provision for credit losses 779 1,013 111 1,903 Provision for credit losses 243 47 79 369 Income before income tax expense (benefit) 536 966 32 1,534 Income tax expense (benefit) 191 335 (37 ) 489 Net income $345 $631 $69 $1,045 Total average assets $56,388 $47,159 $39,636 $143,183 As of and for the Year Ended December 31, 2015 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,198 $1,162 $42 $3,402 Noninterest income 910 415 97 1,422 Total revenue 3,108 1,577 139 4,824 Noninterest expense 2,456 709 94 3,259 Profit before provision for credit losses 652 868 45 1,565 Provision for credit losses 252 (13 ) 63 302 Income (loss) before income tax expense (benefit) 400 881 (18 ) 1,263 Income tax expense (benefit) 138 302 (17 ) 423 Net income (loss) $262 $579 ($1 ) $840 Total average assets $52,848 $42,800 $39,422 $135,070 Management accounting practices utilized by the Company as the basis of presentation for segment results include the following: FTP adjustments The Company utilizes an FTP system to eliminate the effect of interest rate risk from the segments’ net interest income because such risk is centrally managed within the Treasury function. The FTP system credits (or charges) the segments with the economic value of the funds created (or used) by the segments. The FTP system provides a funds credit for sources of funds and a funds charge for the use of funds by each segment. The sum of the interest income/expense and FTP charges/credits for each segment is its designated net interest income. The variance between the Company’s cumulative FTP charges and cumulative FTP credits is offset in Other. Provision for credit losses allocations Provision for credit losses is allocated to each business segment based on actual net charge-offs recognized by the business segment. The difference between the consolidated provision for credit losses and the business segments’ net charge-offs is reflected in Other. Income tax allocations Income taxes are assessed to each line of business at a standard tax rate with the residual tax expense or benefit to arrive at the consolidated effective tax rate included in Other. Expense allocations Noninterest expenses incurred by centrally managed operations or business lines that directly support another business line’s operations are charged to the applicable business line based on its utilization of those services. Goodwill For impairment testing purposes, the Company allocates goodwill to its Consumer Banking and Commercial Banking reporting units. For management reporting purposes, the Company presents the goodwill balance (and any related impairment charges) in Other. Substantially all revenues generated and long-lived assets held by the Company’s business segments are derived from clients that reside in the United States. Neither business segment earns revenue from a single external customer that represents ten percent or more of the Company’s total revenues.

PARENT COMPANY FINANCIALS

PARENT COMPANY FINANCIALS	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
PARENT COMPANY FINANCIALS	PARENT COMPANY FINANCIALS Condensed Statements of Operations Year Ended December 31, (in millions) 2017 2016 2015 OPERATING INCOME: Income from consolidated subsidiaries and excluding equity in undistributed earnings: Dividends from banking subsidiaries $1,055 $555 $345 Interest 43 53 54 Management and service fees 31 26 20 Income from nonbank subsidiaries and excluding equity in undistributed earnings: Dividends from nonbank subsidiaries 4 — — Interest 1 — — Equity securities gains 1 3 3 All other operating income 1 7 4 Total operating income 1,136 644 426 OPERATING EXPENSE: Salaries and employee benefits 40 37 15 Interest expense 97 99 108 All other expenses 22 15 38 Total operating expense 159 151 161 Income before taxes and undistributed income 977 493 265 Income taxes (10 ) (26 ) (29 ) Income before undistributed earnings of subsidiaries 987 519 294 Equity in undistributed earnings of subsidiaries: Bank 655 522 543 Nonbank 10 4 3 Net income $1,652 $1,045 $840 Other comprehensive (loss) income, net of income taxes: Net pension plan activity arising during the period ($1 ) ($2 ) $1 Net unrealized derivative instrument gains (losses) arising during the period 1 (8 ) 2 Net unrealized securities losses arising during the period — — (2 ) Other comprehensive (loss) income activity of the Parent Company, net of income taxes — (10 ) 1 Other comprehensive loss activity of Bank subsidiaries, net of income taxes (7 ) (271 ) (16 ) Total other comprehensive loss, net of income taxes (7 ) (281 ) (15 ) Total comprehensive income $1,645 $764 $825 In accordance with federal and state banking regulations, dividends paid by the Company’s banking subsidiaries to the Company are generally limited to the retained earnings of the respective banking subsidiaries unless specifically approved by the appropriate bank regulator. The Company declared and paid total common stock dividends of $322 million in 2017 , $241 million in 2016 , and $214 million in 2015 . The Company also declared and paid preferred stock dividends of $14 million in 2017 , $14 million in 2016 and $7 million in 2015. Condensed Balance Sheets (in millions) December 31, 2017 December 31, 2016 ASSETS: Cash and due from banks $563 $671 Loans and advances to: Bank subsidiaries 1,160 1,156 Nonbank subsidiaries 70 20 Investments in subsidiaries: Bank subsidiaries 20,765 20,116 Nonbank subsidiaries 73 50 Other assets 125 128 TOTAL ASSETS $22,756 $22,141 LIABILITIES: Long-term borrowed funds due to: Unaffiliated companies $2,320 $2,318 Other liabilities 166 76 TOTAL LIABILITIES 2,486 2,394 TOTAL STOCKHOLDERS’ EQUITY 20,270 19,747 TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY $22,756 $22,141 Condensed Cash Flow Statements Year Ended December 31, (in millions) 2017 2016 2015 OPERATING ACTIVITIES Net income $1,652 $1,045 $840 Adjustments to reconcile net income to net cash provided by operating activities: Deferred income taxes (11 ) 5 49 Gain on sales of assets (1 ) (3 ) (3 ) Equity in undistributed earnings of subsidiaries (665 ) (526 ) (546 ) Increase (decrease) in other liabilities 99 (19 ) (48 ) Decrease (increase) in other assets 5 35 (16 ) Other operating, net (1 ) (4 ) 3 Total adjustments (574 ) (512 ) (561 ) Net cash provided by operating activities 1,078 533 279 INVESTING ACTIVITIES Proceeds from sales of securities available for sale — — 8 Investments in and advances to subsidiaries (230 ) (40 ) (215 ) Repayment of investments in and advances to subsidiaries 167 588 376 Other investing, net (1 ) (2 ) — Net cash (used) provided by investing activities (64 ) 546 169 FINANCING ACTIVITIES Proceeds from issuance of long-term borrowed funds — 349 1,000 Repayments of long-term borrowed funds — (625 ) (750 ) Proceeds from issuance of common stock 34 22 27 Treasury stock purchased (820 ) (430 ) (500 ) Net proceeds from issuance of preferred stock — — 247 Dividends declared and paid to common stockholders (322 ) (241 ) (214 ) Dividends declared and paid to preferred stockholders (14 ) (14 ) (7 ) Net cash used by financing activities (1,122 ) (939 ) (197 ) (Decrease) increase in cash and due from banks (108 ) 140 251 Cash and due from banks at beginning of year 671 531 280 Cash and due from banks at end of year $563 $671 $531

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS The Company has evaluated the impacts of events that have occurred subsequent to December 31, 2017 through the filing date of the Consolidated Financial Statements with the SEC. Based on this evaluation, the Company has determined none of these events were required to be recognized or disclosed in the Consolidated Financial Statements and related Notes.

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The Consolidated Financial Statements include the accounts of the Company and subsidiaries in which the Company has a controlling financial interest. All intercompany transactions and balances have been eliminated. The Company has evaluated its unconsolidated entities and does not believe that any entity in which it has an interest, but does not currently consolidate, meets the requirements to be consolidated as a variable interest entity. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near-term relate to the determination of the allowance for credit losses, evaluation of unrealized losses on securities for other-than-temporary impairment, accounting for income taxes, the valuation of AFS and HTM securities, and derivatives.
Reclassifications	Certain prior period noninterest income amounts reported in the Consolidated Statement of Operations have been reclassified to conform to the current period presentation and student loans were renamed “education” loans to more closely align with the full range of services offered to borrowers, from loan origination to refinancing. These changes had no effect on net income, to tal comprehensive income, total assets or total stockholders’ equity as previously reported. Additionally, certain prior period balances in the table of deferred tax assets and liabilities in Note 22 — “Income Taxes” have been reclassified to reflect current year presentation. These changes had no effect on net income, total comprehensive income, total assets or total stockholders’ equity as previously reported.
Revenue Recognition	Revenue Recognition Revenue is recognized to the extent that it is probable that the economic benefits will flow to the Company and the revenue can be reliably measured. Interest income on loans and securities classified as AFS or HTM is determined using the effective interest method. This method calculates periodic interest income at a constant effective yield on the net investment in the loan or security, to provide a constant rate of return over the terms of the financial assets. Financial assets accounted for using the fair value option are measured at fair value with corresponding changes recognized in noninterest income. Other types of noninterest revenues, such as service charges on deposits, interchange income on credit cards and trust revenues, are accrued and recognized into income as services are provided and the amount of fees earned are reasonably determinable.
Transfer of Financial Assets	Transfer of Financial Assets A transfer of financial assets is accounted for as a sale when control over the assets transferred is surrendered. Assets transferred that satisfy the conditions of a sale are derecognized, and all assets obtained and liabilities incurred in a purchase are recognized and measured at fair value. Servicing rights retained in the transfer of financial assets are initially recognized at fair value. Subsequent to the initial recognition date, servicing rights are accounted for at the lower of cost or market. The Company recognizes periodic amortization expense of servicing rights and assesses servicing rights for impairment.
Accounting and Reporting Developments	Accounting and Reporting Developments Accounting Pronouncements Adopted in 2017 Pronouncement Summary of Guidance Effects on Financial Statements Reporting Comprehensive Income Issued February 2018 • If elected, requires a reclassification between AOCI and retained earnings for the effect of remeasuring deferred tax assets and liabilities to the newly enacted tax rate of 21% under the 2017 Tax Legislation. • The amount of the reclassification is the difference between the amount initially charged or credited directly to other comprehensive income at the previously enacted U.S. federal corporate income tax rate that remained in AOCI and the amount that would have been charged or credited directly to other comprehensive income using the newly enacted 21% U.S. federal corporate income tax rate, excluding the effect of any valuation allowance previously charged to income from continuing operations. • The Company adopted retrospectively to December 31, 2017, ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, elected to reclassify $145 million between AOCI and retained earnings, including indirect impacts from the decreased federal tax effect on future state tax benefits, and reflected this reclassification in the Company’s 2017 Consolidated Financial Statements, included in this report. Stock Compensation Issued March 2016 • Requires that all excess tax benefits and excess tax deductions that pertain to employee stock-based incentive payments are recognized within income tax expense in the Consolidated Statement of Operations, rather than within additional paid in capital. • This standard also allows entities to make a one-time policy election to account for forfeitures when they occur, which the Company elected to do. • Adopted January 1, 2017. • Adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. Accounting Pronouncements Pending Adoption Pronouncement Summary of Guidance Effects on Financial Statements Stock Compensation Issued May 2017 • Requires modification accounting unless the fair value, vesting conditions, and classification of the modified award are the same as the original award immediately before the modification. • Applied prospectively to all modifications of share-based awards after the adoption date. • Required effective date: January 1, 2018. Early adoption is permitted. The Company will adopt the new standard in the first quarter of 2018. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost Issued March 2017 • Requires the service cost component of net periodic pension and postretirement benefit cost to be reported separately in the Consolidated Statements of Operations from the other components (e.g., expected return on assets, interest costs, amortization of gains/losses and prior service costs). • Requires presentation in the Consolidated Statements of Operations of the service cost component in the same line item as other employee compensation costs and presentation of the other components in a different line item from the service cost component. • Retrospective application is required for all periods presented. • Required effective date: January 1, 2018. Early adoption is permitted. The Company will adopt the new standard in the first quarter of 2018. • Adoption will have no impact on the Company’s net income, but based on recent experience that the expected return on assets exceeds the sum of the other components, the Company expects that the guidance will result in an increase in salaries and employee benefits expense and a reduction in other operating expense. Revenue Recognition: Revenue from Contracts with Customers Issued May 2014 • Requires that revenue from contracts with customers be recognized upon transfer of control of a good or service in the amount of consideration expected to be received. • Changes the accounting for certain contract costs including whether they may be offset against revenues in the Consolidated Statements of Operations. • Requires new qualitative and quantitative disclosures, including information about disaggregation of revenue and performance obligations. • May be adopted using a full retrospective basis or a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2018. Early adoption is permitted. • The Company will adopt the revenue guidance in the first quarter of 2018 using the modified retrospective method. Net interest income on financial assets and liabilities is explicitly excluded from the scope of the pronouncement. • The Company’s implementation efforts included the identification of revenue within the scope of the guidance, as well as the evaluation of revenue contracts and related accounting policies. Based on these efforts, the adoption will not result in a material change in the timing or amount of revenue recognized from contracts with customers. • Upon adoption, underwriting costs will be presented on a gross basis as expense. Currently such costs are presented net of the related underwriting fees. • The Company has completed its evaluation of the expanded disclosure requirements and the most significant item will be the disaggregation of revenue. Recognition and Measurement of Financial Assets and Financial Liabilities Issued January 2016 • Requires equity securities with readily determinable fair values to be measured at fair value on the balance sheet, with changes in the fair value recognized through earnings. • Requires separate presentation of financial assets and financial liabilities by measurement category and form of financial assets on the balance sheet or the notes to the financial statements. • Makes several other targeted amendments to the existing accounting and disclosure requirements for financial instruments, including revised guidance related to valuation allowance assessments when recognizing deferred tax assets on unrealized losses on debt securities available for sale. • Required effective date: January 1, 2018. Early adoption is permitted. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Pronouncement Summary of Guidance Effects on Financial Statements Classification of Certain Cash Receipts and Cash Payments Issued August 2016 • Amends current guidance on specific cashflows to determine the appropriate classification as operating, investing or financing activities which has required significant judgment. • The application of judgment has resulted in diversity in how certain cash receipts and cash payments are classified. • Required effective date: January 1, 2018. • Adoption will not have a material impact on the Company’s Consolidated Financial Statements. Derivatives and Hedging Issued August 2017 • Reduces the complexity and operational burdens of the current hedge accounting model and portrays more clearly the effects of hedge accounting in the financial statements. • Modifies current requirements to facilitate the application of hedge accounting to partial-term hedges, hedges of prepayable financial instruments, and other strategies. Adoption of these optional changes would occur on a prospective basis. • Requires the effects of fair value hedges to be classified in the same income statement line as the earnings effect of the hedged item. Adoption of this change will occur on a prospective basis. • Requires all effects of cash flow hedges to be deferred in other comprehensive income until the hedged cash flows affect earnings. Periodic hedge ineffectiveness will no longer be recognized in earnings. Adoption of this change will occur on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2019. Early adoption is permitted. The Company is still evaluating whether or not it will adopt this guidance prior to the required effective date. • The transition entries required upon adoption are not expected to have a material impact on the Company’s Consolidated Financial Statements. Premium Amortization on Purchased Callable Debt Securities Issued March 2017 • Requires amortization of premiums to the earliest call date on debt securities with call features that are explicit, noncontingent and callable at fixed prices and on preset dates. • Requires adoption on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. • Required effective date: January 1, 2019. • Adoption is not expected to have a material impact on the Company’s Consolidated Financial Statements. The Company does not currently hold callable debt securities. Pronouncement Summary of Guidance Effects on Financial Statements Leases Issued February 2016 • Requires lessees to recognize a right-of-use asset and corresponding lease liability for all leases with a lease term of greater than one year. • Requires lessees and lessors to classify most leases using principles similar to existing lease accounting, but eliminates the “bright line” classification tests. • Requires that for finance leases, a lessee recognize interest expense on the lease liability separately from the amortization of the right-of-use asset in the Consolidated Statements of Operations, while for operating leases, such amounts should be recognized as a combined expense. • Requires expanded disclosures about the nature and terms of lease agreements. • Requires adoption using a modified cumulative effect approach wherein the guidance is applied to all periods presented. • Required effective date: January 1, 2019. Early adoption is permitted. The Company does not intend to adopt the guidance prior to the effective date. • The Company occupies certain banking offices and equipment under non-cancelable operating lease agreements, which currently are not reflected on its Consolidated Balance Sheets. • The Company expects to report increased assets and liabilities as a result of recognizing right-of-use assets and lease liabilities in its Consolidated Balance Sheets. As of December 31, 2017, the Company was committed to $842 million of minimum lease payments under non-cancelable operating lease agreements. • The evaluation of the impact of the leasing pronouncement will be adjusted based on execution of new leases, termination of existing leases prior to the effective date, and any changes to key lease assumptions such as renewals, extensions and discount rates. • The Company does not expect a material change to the timing of expense recognition on the Consolidated Statements of Operations. Goodwill Issued January 2017 • Requires an impairment loss to be recognized when the estimated fair value of a reporting unit falls below its carrying value. • Eliminates the second condition in the current guidance that requires an impairment loss to be recognized only if the estimated implied fair value of the goodwill is below its carrying value. • Applied prospectively to all goodwill impairment tests performed after the adoption date. • Required effective date: January 1, 2020. Early adoption is permitted. The Company does not currently intend to early adopt the new standard. • Adoption is not expected to have a material impact on the Company’s Consolidated Financial Statements. Financial Instruments - Credit Losses Issued June 2016 • Replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost (including securities HTM), which will reflect management’s estimate of credit losses over the full remaining expected life of the financial assets. • Amends existing impairment guidance for securities AFS to incorporate an allowance, which will allow for reversals of impairment losses in the event that the credit of an issuer improves. • Requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. • Required effective date: January 1, 2020. Early adoption permitted on January 1, 2019. The Company does not intend to adopt the guidance prior to the effective date. • The Company established a company-wide, cross-discipline governance structure to implement the new standard. The Company is currently identifying key interpretive issues and is comparing existing credit loss forecasting models and processes with the new guidance to determine what modifications may be required. • While the Company is currently evaluating the impact the standard will have on its Consolidated Financial Statements, the Company expects the standard will result in an earlier recognition of credit losses and an increase in the allowance for credit losses. The magnitude of the increase in the Company’s allowance for loan losses at the adoption date will be dependent upon the nature of the characteristics of the portfolio at the adoption date, as well as macroeconomic conditions and forecasts at that date.
Cash and Cash Equivalents	For the purposes of reporting cash flows, cash and cash equivalents have original maturities of three months or less and include cash and due from banks and interest-bearing cash and due from banks, primarily at the FRB.
Securities	Investments include debt and marketable equity securities and other investment securities. The Company classifies debt securities as AFS, HTM, or trading based on management’s intent to hold to maturity at the time of purchase, and marketable equity securities as AFS or trading. Securities that will be held for indefinite periods of time and may be sold in response to changes in interest rates, changes in prepayment risk, or other factors considered in managing the Company’s asset/liability strategy are classified as AFS and reported at fair value, with unrealized gains and losses reported in OCI as a separate component of stockholders’ equity, net of taxes. Gains and losses on the sales of securities are recognized in noninterest income and are computed using the specific identification method. Debt securities for which the Company has the ability and intent to hold to maturity are classified as HTM. The securities are reported at amortized cost. Transfers of debt securities to the HTM classification are recognized at fair value at the date of transfer. For debt securities classified as AFS or HTM, interest income is recorded on the accrual basis and is adjusted for the amortization of premiums and the accretion of discounts. Premiums and discounts on debt securities are amortized or accreted using the effective interest method over the estimated lives of the individual securities. The Company uses actual prepayment experience and estimates of future prepayments to determine the constant effective yield necessary to apply the effective interest method of income recognition. Estimates of future prepayments are based on the underlying collateral characteristics of each security and are derived from market sources. Judgment is involved in making determinations about prepayment expectations and in changing those expectations in response to changes in interest rates and macroeconomic conditions. The amortization of premiums and discounts associated with mortgage-backed securities may be significantly impacted by changes in prepayment assumptions. Securities that are classified as trading are bought and held principally for the purpose of selling them in the near term and are carried at fair value, with changes in fair value recognized in earnings. When applicable, realized and unrealized gains and losses on such assets are reported in noninterest income in the Consolidated Statements of Operations. Other investment securities are primarily composed of FHLB stock and FRB stock (which are carried at cost) and money market mutual fund investments held by the Company’s broker-dealers (which are carried at fair value, with changes in fair value recognized in noninterest income). Other investment securities that are carried at cost are reviewed at least annually for impairment, with valuation adjustments recognized in noninterest income. The Company reviews its securities for other-than-temporary impairment on a quarterly basis or more frequently if a potential loss triggering event occurs. The initial indicator of other-than-temporary impairment for both debt and equity securities is a decline in fair value below its recorded investment amount, as well as the severity and duration of the decline. For a security of which there has been a decline in fair value below the cost basis, the Company recognizes other-than-temporary impairment if (i) management has the intent to sell the security, (ii) it is more likely than not it will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire cost basis of the security. Estimating the recovery of the amortized cost basis of a debt security is based upon an assessment of the cash flows expected to be collected. If the present value of cash flows expected to be collected, discounted at the security’s original effective yield, is less than amortized cost, other-than-temporary impairment is considered to have occurred. If the Company intends to sell an impaired security, or if it is more likely than not it will be required to sell the security before recovery, the impairment loss recognized in current period earnings equals the difference between the amortized cost basis and the fair value of the security. If the Company does not intend to sell the impaired security, and it is not likely that the Company will be required to sell the impaired security, the other-than-temporary impairment write-down is separated into an amount representing the credit loss, which is recognized in current period earnings and the amount related to all other factors, is recognized in OCI.
Loans and Leases	Loans are classified upon origination or acquisition as either held-for-investment or held-for-sale. This classification is based on management’s initial intent and ability to hold the loans for the foreseeable future. Loans held for sale are carried at the lower of cost or fair value, with any write-downs or subsequent recoveries charged to other income. The Company accounts for certain loans held for sale, including those loans associated with its mortgage banking business and secondary loan trading desk, under the fair value option at fair value. Loans held for investment are reported at the amount of their outstanding principal, net of charge-offs, unearned income, deferred loan origination fees and costs, and unamortized premiums or discounts on purchased loans. Deferred loan origination fees and costs and purchase premiums and discounts are amortized as an adjustment of yield over the life of the loan, using the effective interest method. Unamortized amounts remaining upon prepayment or sale are recorded as interest income or gain (loss) on sale, respectively. Credit card receivables include billed and uncollected interest and fees. Interest income on loans is determined using the effective interest method. This method calculates periodic interest income at a constant effective yield on the net investment in the loan, to provide a constant rate of return over the term. Loans accounted for using the fair value option, are measured at fair value with corresponding changes recognized in noninterest income. Loan commitment fees for loans that are likely to be drawn down, and other credit related fees, are deferred (together with any incremental costs) and recognized as an adjustment to the effective interest rate over the loan term. When it is unlikely that a loan will be drawn down, the loan commitment fees are recognized over the commitment period on a straight-line basis. Leases are classified at the inception of the lease. Direct financing lease receivables are reported at the aggregate of minimum lease payments receivable plus the estimated residual value of the leased property, less unearned and deferred income, including unamortized investment credits. Leveraged leases, which are a form of direct financing leases, are recorded net of related non-recourse debt. Lease residual values are reviewed at least annually for other-than-temporary impairment; with valuation adjustments recognized currently against other income for direct financing and leveraged leases. Unearned income is recognized as a constant percentage of outstanding lease financing balances over the lease term in interest income. Loans and leases are disclosed in portfolio segments and classes. The Company’s loan and lease portfolio segments are commercial and retail. The classes of loans and leases are: commercial, commercial real estate, leases, residential mortgages, home equity loans, home equity lines of credit, home equity loans serviced by others, home equity lines of credit serviced by others, automobile, education, credit cards and other retail. The Company’s SBO portfolio consists of purchased home equity loans and lines that were originally serviced by others, which the Company now services a portion of internally.
Allowance for Credit Losses	Management’s estimate of probable losses in the Company’s loan and lease portfolios is recorded in the ALLL and the reserve for unfunded lending commitments. On a quarterly basis, the Company evaluates the adequacy of the ALLL by performing reviews of certain individual loans and leases, analyzing changes in the composition, size and delinquency of the portfolio, reviewing previous loss experience and considering current and anticipated economic factors. The ALLL is established in accordance with the Company’s credit reserve policies, as approved by the Audit Committee of the Board of Directors. The Chief Financial Officer and Chief Risk Officer review the adequacy of the ALLL each quarter, together with risk management. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for credit losses. The ALLL is maintained at a level that management considers reflective of probable losses, and is established through charges to earnings in the form of a provision for credit losses. The ALLL may be adjusted to reflect the Company’s current assessment of various qualitative risks, factors and events that may not be measured in the statistical analysis. Such factors include trends in economic conditions, loan growth, back testing results, credit underwriting policy exceptions, regulatory and audit findings, and peer comparisons. Amounts determined to be uncollectible are deducted from the ALLL and subsequent recoveries, if any, are added to the ALLL. While management uses available information to estimate loan and lease losses, future additions to the ALLL may be necessary based on changes in economic conditions. The evaluation of the adequacy of the commercial, commercial real estate, and lease ALLL and reserve for unfunded lending commitments is primarily based on risk rating models that assess probability of default, loss given default and exposure at default on an individual loan basis. The models are primarily driven by individual customer financial characteristics and are validated against historical experience. Additionally, qualitative factors may be included in the risk rating models. After the aggregation of individual borrower incurred loss, additional overlays can be made based on back-testing against historical losses. For non-impaired retail loans, the ALLL is based upon an incurred loss model utilizing the probability of default, loss given default and exposure at default on an individual loan basis. When developing these factors, the Company may consider the loan product and collateral type, delinquency status, LTV ratio, lien position, borrower’s credit, age of the loan, geographic location and incurred loss period. Certain retail portfolios, including SBO home equity loans and commercial credit card receivables utilize roll rate models to estimate the ALLL. For the portfolios measured using the incurred loss model, roll rate models are also run as challenger models and can be used to support management overlays if deemed necessary. For nonaccruing commercial and commercial real estate loans with an outstanding balance of $3 million or greater and for all commercial and commercial real estate TDRs (regardless of size), the Company conducts further analysis to determine the probable amount of loss and establishes a specific allowance for the loan, if appropriate. The Company estimates the impairment amount by comparing the loan’s carrying amount to the estimated present value of its future cash flows, the fair value of its underlying collateral, or the loan’s observable market price. For collateral-dependent impaired commercial and commercial real estate loans, the excess of the Company’s recorded investment in the loan over the fair value of the collateral, less cost to sell, is charged off to the ALLL. For retail TDRs that are not collateral-dependent, allowances are developed using the present value of expected future cash flows compared to the recorded investment in the loans. Expected re-default factors are considered in this analysis. Retail TDRs that are deemed collateral-dependent are written down to fair market value less cost to sell. The fair value of collateral is periodically monitored subsequent to the modification. In addition to the ALLL, the Company also estimates probable credit losses associated with off balance sheet financial instruments such as standby letters of credit, financial guarantees and binding unfunded loan commitments. Off balance sheet financial instruments are subject to individual reviews and are analyzed and segregated by risk according to the Company’s internal risk rating scale. These risk classifications, in conjunction with historical loss experience, economic conditions and performance trends within specific portfolio segments, result in the estimate of the reserve for unfunded lending commitments. The ALLL and the reserve for unfunded lending commitments are reported on the Consolidated Balance Sheets in the allowance for loan and lease losses and in other liabilities, respectively. Provision for credit losses related to the loans and leases portfolio and the unfunded lending commitments are reported in the Consolidated Statements of Operations as provision for credit losses. As of December 31, 2017, the Company enhanced the method for assessing various qualitative risks, factors and events that may not be measured in the modeled results. The new methodology includes a statistical analysis of prior charge-off rates on a historical basis combined with a qualitative assessment based on quantitative measures affecting the determination of incurred losses in the loan and lease portfolio, and provides better alignment of the qualitative ALLL to the commercial and retail loan portfolios. The impact of the change is an increase of approximately $50 million to the commercial ALLL with a corresponding decrease to the retail ALLL; there was not a significant impact on the total qualitative ALLL as of December 31, 2017. There were no other material changes in assumptions or estimation techniques compared with prior years that impacted the determination of the current year’s ALLL and the reserve for unfunded lending commitments.
Loan Charge-Offs	Commercial loans are charged off when it is highly certain that a loss has been realized, including situations where a loan is determined to be both impaired and collateral-dependent. The determination of whether to recognize a charge-off involves many factors, including the prioritization of the Company’s claim in bankruptcy, expectations of the workout/restructuring of the loan and valuation of the borrower’s equity or the loan collateral. Retail loans are generally fully charged-off or written down to the net realizable value of the underlying collateral, with an offset to the ALLL, upon reaching specified stages of delinquency in accordance with standards established by the FFIEC. Residential real estate loans, credit card loans and unsecured open end loans are generally charged off in the month in which the account becomes 180 days past due. Auto loans, education loans and unsecured closed end loans are generally charged off in the month in which the account becomes 120 days past due. Certain retail loans will be charged off earlier than the FFIEC standards in the following circumstances: • A charge-off is recognized when a loan is modified in a TDR if the loan is determined to be collateral-dependent. A loan is considered to be collateral-dependent when repayment of the loan is expected to be provided solely by the underlying collateral, rather than by cash flows from the borrower’s operations, income or other resources. • Loans to borrowers who have experienced an event (e.g. bankruptcy) that suggests a loss is either known or highly certain are subject to accelerated charge-off standards. Residential real estate and auto loans are charged down to the net realizable value when the loan becomes 60 days past due, or sooner if the loan is determined to be collateral-dependent. Credit card loans are fully charged off within 60 days of receiving notification of the bankruptcy filing or other event. Education loans are generally charged off when the loan becomes 60 days past due after receiving notification of a bankruptcy. • Auto loans are written down to net realizable value upon repossession of the collateral.
Nonperforming Loans and Leases	Nonperforming loans and leases are those on which accrual of interest has been suspended. Loans (other than certain retail loans insured by U.S. government agencies) are placed on nonaccrual status and considered nonperforming when full payment of principal and interest is in doubt, unless the loan is both well secured and in the process of collection. When the Company places a loan on nonaccrual status, the accrued unpaid interest receivable is reversed against interest income and amortization of any net deferred fees is suspended. Interest collections on nonaccruing loans and leases for which the ultimate collectability of principal is uncertain are generally applied to first reduce the carrying value of the loan. Otherwise, interest income may be recognized to the extent of the cash received. A loan may be returned to accrual status if (i) principal and interest payments have been brought current, and the Company expects repayment of the remaining contractual principal and interest, (ii) the loan or lease has otherwise become well-secured and in the process of collection, or (iii) the borrower has been making regularly scheduled payments in full for the prior six months and the Company is reasonably assured that the loan or lease will be brought fully current within a reasonable period. Commercial loans, commercial real estate loans, and leases are generally placed on nonaccrual status when contractually past due 90 days or more, or earlier if management believes that the probability of collection is insufficient to warrant further accrual. Some of these loans and leases may remain on accrual status when contractually past due 90 days or more if management considers the loan collectible. Residential mortgages are generally placed on nonaccrual status when past due 120 days, or sooner if determined to be collateral-dependent, unless repayment of the loan is insured by the Federal Housing Administration. Credit card balances are placed on nonaccrual status when past due 90 days or more and are restored to accruing status if they subsequently become less than 90 days past due. All other retail loans are generally placed on nonaccrual status when past due 90 days or more, or earlier if management believes that the probability of collection is insufficient to warrant further accrual. Loans less than 90 days past due may be placed on nonaccrual status upon the death of the borrower, fraud or bankruptcy.
Impaired Loans	A loan is considered to be impaired when, based on current information and events, it is probable that the Company will be unable to collect all of the contractual interest and principal payments as scheduled in the loan agreement. This evaluation is generally based on delinquency information, an assessment of the borrower’s financial condition and the adequacy of collateral, if any. Impaired loans include nonaccruing larger balance (greater than $3 million carrying value), non-homogeneous commercial and commercial real estate loans, and restructured loans that are deemed TDRs. When a loan is identified as impaired, the impairment is measured on an individual loan level as the difference between the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount) and the present value of expected future cash flows, discounted at the loan’s effective interest rate. When collateral is the sole source of repayment for the impaired loan, rather than the borrower’s income or other sources of repayment, the Company charges down the loan to its net realizable value.
Troubled Debt Restructuring	In situations where, for economic or legal reasons related to the borrower’s financial difficulties, the Company grants a concession to the borrower that it would not otherwise consider, the related loan is classified as a TDR. TDRs typically result from the Company’s loss mitigation efforts and are undertaken in order to improve the likelihood of recovery and continuity of the relationship. The Company’s loan modifications are handled on a case-by-case basis and are negotiated to achieve mutually agreeable terms that maximize loan collectability and meet the borrower’s financial needs. Concessions granted in TDRs for all classes of loans may include lowering the interest rate, forgiving a portion of principal, extending the loan term, lowering scheduled payments for a specified period of time, waiving or delaying a scheduled payment of principal or interest for other than an insignificant time period, or capitalizing past due amounts. A rate increase can be a concession if the increased rate is lower than a market rate for debt with risk similar to that of the restructured loan. TDRs for commercial loans and leases may also involve creating a multiple note structure, accepting non-cash assets, accepting an equity interest, or receiving a performance-based fee. In some cases, a TDR may involve multiple concessions. The financial effects of TDRs for all loan classes may include lower income (either due to a lower interest rate or a delay in the timing of cash flows), larger loan loss provisions, and accelerated charge-offs if the modification renders the loan collateral-dependent. In some cases, interest income throughout the term of the loan may increase if, for example, the loan is extended or the interest rate is increased as a result of the restructuring. Retail and commercial loans whose contractual terms have been modified in a TDR and are current at the time of restructuring may remain on accrual status if there is demonstrated performance prior to the restructuring and payment in full under the restructured terms is expected. Retail loans that were discharged in bankruptcy and not reaffirmed by the borrower are deemed to be collateral-dependent TDRs and are generally charged off to the fair value of the collateral, less cost to sell, and less amounts recoverable under a government guarantee (if any). Cash receipts on nonaccruing impaired loans, including nonaccruing loans involved in TDRs, are generally applied to reduce the unpaid principal balance. Certain TDRs that are current in payment status are classified as nonaccrual in accordance with regulatory guidance. Income on these loans is generally recognized on a cash basis if management believes that the remaining book value of the loan is realizable. Nonaccruing TDRs that meet the guidelines above for accrual status can be returned to accruing if supported by a well-documented evaluation of the borrowers’ financial condition, and if they have been current for at least six months. Because TDRs are impaired loans, the Company measures impairment by comparing the present value of expected future cash flows, or when appropriate, the fair value of collateral less costs to sell, to the loan’s recorded investment. Any excess of recorded investment over the present value of expected future cash flows or collateral value is included in the ALLL. Any portion of the loan’s recorded investment the Company does not expect to collect as a result of the modification is charged off at the time of modification. For Retail TDR accounts where the expected value of cash flows is utilized, any recorded investment in excess of the present value of expected cash flows is recognized by creating or increasing the ALLL. For Retail TDR accounts assessed based on the fair value of collateral, any portion of the loan’s recorded investment in excess of the collateral value less costs to sell is charged off at the time of modification or at the time of subsequent and regularly recurring valuations.
Premises and Equipment	Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization have been computed using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the life of the lease (including renewal options if exercise of those options is reasonably assured) or their estimated useful life, whichever is shorter. Additions to premises and equipment are recorded at cost. The cost of major additions, improvements and betterments is capitalized. Normal repairs and maintenance and other costs that do not improve the property, extend the useful life or otherwise do not meet capitalization criteria are charged to expense as incurred. The Company evaluates premises and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable.
Software	Costs related to computer software developed or obtained for internal use are capitalized if the projects improve functionality and provide long-term future operational benefits. Capitalized costs are amortized using the straight-line method over the asset’s expected useful life, based upon the basic pattern of consumption and economic benefits provided by the asset. The Company begins to amortize the software when the asset (or identifiable component of the asset) is substantially complete and ready for its intended use. All other costs incurred in connection with an internal-use software project are expensed as incurred. Capitalized software is included in other assets on the Consolidated Balance Sheets.
Operating Lease Assets	Operating lease rental income for leased assets is recognized in other income on a straight-line basis over the lease term. Related depreciation expense is recorded on a straight-line basis over the estimated useful life, considering the estimated residual value of the leased asset. On a periodic basis, leased assets are reviewed for impairment. Impairment loss is recognized in other noninterest expense if the carrying amount of the leased assets exceeds fair value and is not recoverable. The carrying amount of leased assets is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the lease payments and the estimated residual value upon the eventual disposition of the asset.
Mortgage Banking	The Company accounts for derivatives in its mortgage banking operations at fair value on the balance sheet as derivative assets or derivative liabilities, depending on whether the derivative had a positive (asset) or negative (liability) fair value as of the balance sheet date. The Company’s mortgage banking derivatives include commitments to originate mortgages held for sale, certain loan sale agreements, and other financial instruments that meet the definition of a derivative. The Company recognizes the right to service mortgage loans for others, or MSRs, as assets whether the Company purchases the MSRs or the MSRs result from a sale. MSRs are initially recognized at fair value, and subsequently accounted for in the Consolidated Balance Sheets at the lower of cost or fair value, net of accumulated amortization, which is recorded in proportion to, and over the period of, net servicing income. The Company’s identification of MSRs in a single class is determined based on the availability of market inputs and the Company’s method of managing MSR risks. For the purpose of impairment evaluation and measurement, MSRs are stratified based on predominant risk characteristics (such as interest rate, loan size, origination date, term, or geographic location) of the underlying loans. An allowance is then established in the event the recorded value of an individual stratum exceeds fair value. Mortgage loans held for sale are accounted for at fair value on an individual loan basis. Changes in the fair value, and realized gains and losses on the sales of mortgage loans, are reported in mortgage banking fees.
Goodwill	Goodwill is the purchase premium associated with the acquisition of a business and is assigned to reporting units at the acquisition date. A reporting unit is a business operating segment or a component of a business operating segment. Once goodwill has been assigned to reporting units, it no longer retains its association with a particular acquisition, and all of the activities within a reporting unit, whether acquired or organically grown, are available to support the value of the goodwill. The Company has identified and allocated goodwill to two reporting units - Consumer Banking and Commercial Banking - based upon reviews of the structure of the Company’s executive team and supporting functions, resource allocations and financial reporting processes. Goodwill is not amortized, but is subject to annual impairment tests. The goodwill impairment analysis is a two-step test. The first step, used to identify potential impairment, involves comparing each reporting unit’s fair value to its carrying value, including goodwill. If the fair value of a reporting unit exceeds its carrying value, applicable goodwill is deemed to be not impaired. If the carrying value exceeds fair value, there is an indication of impairment and the second step is performed to measure the amount of impairment. The second step involves calculating an implied fair value of goodwill for each reporting unit for which the first step indicated impairment. The implied fair value of goodwill is determined in the same manner as the amount of goodwill recognized in a business combination, which is the excess of the fair value of the reporting unit, as determined in the first step, over the aggregate fair values of the individual assets, liabilities and identifiable intangible. If the implied fair value of goodwill exceeds the carrying value of goodwill assigned to the reporting unit, there is no impairment. If the carrying value of goodwill assigned to a reporting unit exceeds the implied fair value of the goodwill, an impairment charge is recorded for the excess. An impairment loss that is recognized cannot exceed the amount of goodwill assigned to a reporting unit, and the loss establishes a new basis in the goodwill. Subsequent reversal of goodwill impairment losses is not permitted. The Company reviews goodwill for impairment annually as of October 31 st or more often if events or circumstances indicate that it is more likely than not that the fair value of one or more reporting units is below its carrying value. The fair values of the Company’s reporting units are determined using a combination of income and market-based approaches. The Company relies on the income approach (discounted cash flow method) for determining fair value. Market and transaction approaches are used as benchmarks only to corroborate the value determined by the discounted cash flow method. The Company relies on several assumptions when estimating the fair value of its reporting units using the discounted cash flow method. These assumptions include the discount rate, as well as projected loan loss, income tax and capital retention rates. Discount rates are estimated based on the Capital Asset Pricing Model, which considers the risk-free interest rate, market risk premium, beta, and size premium adjustments specific to a particular reporting unit. The discount rates are also calibrated on the assessment of the risks related to the projected cash flows of each reporting unit. Cash flow projections include estimates for projected loan loss, income tax and capital retention rates. Multi-year financial forecasts are developed for each reporting unit by considering several key business drivers such as new business initiatives, customer retention standards, market share changes, anticipated loan and deposit growth, forward interest rates, historical performance, and industry and economic trends, among other considerations. The long-term growth rate used in determining the terminal value of each reporting unit is estimated based on management’s assessment of the minimum expected terminal growth rate of each reporting unit, as well as broader economic considerations such as GDP and inflation. The Company bases its fair value estimates on assumptions it believes to be representative of assumptions that a market participant would use in valuing the reporting unit but that are unpredictable and inherently uncertain, including estimates of future growth rates and operating margins and assumptions about the overall economic climate and the competitive environment for its reporting units. There can be no assurances that future estimates and assumptions made for purposes of goodwill testing will prove accurate predictions of the future. If the assumptions regarding business plans, competitive environments or anticipated growth rates are not achieved, the Company may be required to record goodwill impairment charges in future periods.
Variable Interest Entities	The Company makes equity investments in various entities that are considered VIEs, as defined by GAAP. A VIE typically does not have sufficient equity at risk to finance its activities without additional subordinated financial support from other parties. The Company’s variable interest arises from contractual, ownership or other monetary interests in the entity, which change with fluctuations in the fair value of the entity's net assets. The Company consolidates a VIE if it is the primary beneficiary of the entity. The Company is the primary beneficiary of a VIE if its variable interest provides it with the power to direct the activities that most significantly impact the VIE and the right to receive benefits (or the obligation to absorb losses) that could potentially be significant to the VIE. To determine whether or not a variable interest held could potentially be significant to the VIE, the Company considers both qualitative and quantitative factors regarding the nature, size and form of its involvement with the VIE. The Company assesses whether or not it is the primary beneficiary of a VIE on an ongoing basis.
Interest-Bearing Deposits in Banks	Interest-bearing deposits in banks are carried at cost and include deposits that mature within one year.
Derivatives	For derivatives designated for hedging purposes, net interest accruals are treated as an adjustment of interest income or interest expense of the item being hedged. In the normal course of business, the Company enters into a variety of derivative transactions in order to meet the financing needs of its customers and to reduce its own exposure to fluctuations in interest rates and foreign currency exchange rates. These transactions include interest rate swap contracts, interest rate options, foreign exchange contracts, residential loan commitment rate locks, forward sale contracts and purchase options. The Company monitors the results of each transaction to ensure that management’s intent is satisfied. The Company does not use derivatives for speculative purposes. The Company’s derivative instruments are recognized on the Consolidated Balance Sheets at fair value. Information regarding the valuation methodology and inputs used to estimate the fair value of the Company’s derivative instruments is described in Note 19 “Fair Value Measurements.” Derivative assets and derivative liabilities are netted by counterparty on the balance sheet if a “right of setoff” has been established in a master netting agreement between the Company and the counterparty. This netted derivative asset or liability position is also netted against the fair value of any cash collateral that has been pledged or received in accordance with a Credit Support Annex. If a derivative is designated as a fair value hedge, gains or losses attributable to the change in fair value of the derivative instrument, as well as the gains and losses attributable to the change in fair value of the hedged item, are recognized in other income in the period in which the change in fair value occurs. Hedge ineffectiveness is recognized as other income to the extent the changes in fair value of the derivative do not offset the changes in fair value of the hedged item. Changes in the fair value of derivatives that do not qualify as hedges are recognized immediately in other income.
Employee Benefits	Pension costs under defined benefit plans are actuarially computed and include current service costs and amortization of prior service costs over the participants’ average future working lifetime. The actuarial cost method used in determining the net periodic pension cost is the projected unit method. The cost of postretirement benefits other than pensions is recognized on an accrual basis during the periods employees provide services to earn those benefits.
Treasury Stock	The purchase of the Company’s common stock is recorded at cost. At the date of retirement or subsequent reissuance, treasury stock is reduced by the cost of such stock on a first-in, first-out basis with differences recorded in additional paid-in capital or retained earnings, as applicable.
Share-Based Compensation	The Company measures compensation expense related to stock awards based upon the fair value of the awards on the grant date. Compensation expense is adjusted for forfeitures as they occur. The related expense is charged to earnings on a straight-line basis over the requisite service period (e.g., vesting period) of the award. With respect to performance-based stock awards, compensation expense is adjusted upward or downward based upon the probability of achievement of performance. Awards that continue to vest after retirement are expensed over the shorter of the period of time from grant date to the final vesting date or from the grant date to the date when an employee is retirement eligible. Awards granted to employees who are retirement eligible at the grant date are generally expensed immediately upon grant.
Fair Value	Fair value is also used on a nonrecurring basis to evaluate certain assets for impairment or for disclosure purposes. Examples of nonrecurring uses of fair value include MSRs accounted for by the amortization method, loan impairments for certain loans and leases, and goodwill. The Company measures fair value using the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is based upon quoted market prices in an active market, where available. If quoted prices are not available, observable market-based inputs or independently sourced parameters are used to develop fair value, whenever possible. Such inputs may include prices of similar assets or liabilities, yield curves, interest rates, prepayment speeds, and foreign exchange rates. A portion of the Company’s assets and liabilities is carried at fair value, including securities available for sale, derivative instruments and other investment securities. In addition, the Company elects to account for its loans associated with its mortgage banking business and secondary loan trading desk at fair value. The Company classifies its assets and liabilities that are carried at fair value in accordance with the three-level valuation hierarchy: • Level 1. Quoted prices (unadjusted) in active markets for identical assets or liabilities. • Level 2. Observable inputs other than Level 1 prices, such as quoted prices for similar instruments, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by market data for substantially the full term of the asset or liability. • Level 3. Unobservable inputs that are supported by little or no market information and that are significant to the fair value measurement. Classification in the hierarchy is based upon the lowest level input that is significant to the fair value measurement of the asset or liability. For instruments classified in Levels 1 and 2 where inputs are primarily based upon observable market data, there is less judgment applied in arriving at the fair value. For instruments classified in Level 3, management judgment is more significant due to the lack of observable market data. The Company reviews and updates the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in fair value measurements may result in a reclassification between the fair value hierarchy levels and are recognized based on period-end balances.
Bank-Owned Life Insurance	Bank-owned life insurance is stated at its cash surrender value. The Company is the beneficiary of life insurance policies on current and former officers and selected employees of the Company.
Income Taxes	Deferred tax assets are recognized for net operating loss carryforwards and tax credit carryforwards. Valuation allowances are recorded as necessary to reduce deferred tax assets to the amounts that management concludes are more likely than not to be realized. The Company uses an asset and liability (balance sheet) approach for financial accounting and reporting of income taxes. This results in two components of income tax expense: current and deferred. Current income tax expense approximates taxes to be paid or refunded for the current period. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. These gross deferred tax assets and liabilities represent decreases or increases in taxes expected to be paid in the future because of future reversals of temporary differences in the bases of assets and liabilities, as measured by tax laws, and their bases, as reported in the Consolidated Financial Statements. The Company also assesses the probability that the positions taken, or expected to be taken, in its income tax returns will be sustained by taxing authorities. A “more likely than not” (more than 50 percent) recognition threshold must be met before a tax benefit can be recognized. Tax positions that are more likely than not to be sustained are reflected in the Company’s Consolidated Financial Statements. Tax positions are measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The difference between the benefit recognized for a position and the tax benefit claimed on a tax return is referred to as an unrecognized tax benefit.
Earnings Per Share	Basic EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during each period. Net income available to common stockholders represents net income after preferred stock dividends, accretion of the discount on preferred stock issuances, and gains or losses from any repurchases of preferred stock. Diluted EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during each period, plus potential dilutive shares such as share-based payment awards and warrants using the treasury stock method.

SECURITIES (Tables)

SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of securities held	The following table presents the major components of securities at amortized cost and fair value: December 31, 2017 December 31, 2016 (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities Available for Sale U.S. Treasury and other $12 $— $— $12 $30 $— $— $30 State and political subdivisions 6 — — 6 8 — — 8 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 20,065 40 (277 ) 19,828 19,231 78 (264 ) 19,045 Other/non-agency 311 7 (7 ) 311 427 2 (28 ) 401 Total mortgage-backed securities 20,376 47 (284 ) 20,139 19,658 80 (292 ) 19,446 Total debt securities available for sale 20,394 47 (284 ) 20,157 19,696 80 (292 ) 19,484 Marketable equity securities — — — — 5 — — 5 Other equity securities — — — — 12 — — 12 Total equity securities available for sale — — — — 17 — — 17 Total securities available for sale $20,394 $47 ($284 ) $20,157 $19,713 $80 ($292 ) $19,501 Securities Held to Maturity Mortgage-backed securities: Federal agencies and U.S. government sponsored entities $3,853 $7 ($46 ) $3,814 $4,126 $12 ($44 ) $4,094 Other/non-agency 832 22 — 854 945 19 — 964 Total securities held to maturity $4,685 $29 ($46 ) $4,668 $5,071 $31 ($44 ) $5,058 Other Investment Securities, at Fair Value Money market mutual fund $165 $— $— $165 $91 $— $— $91 Other investments 4 — — 4 5 — — 5 Total other investment securities, at fair value $169 $— $— $169 $96 $— $— $96 Other Investment Securities, at Cost Federal Reserve Bank stock $463 $— $— $463 $463 $— $— $463 Federal Home Loan Bank stock 252 — — 252 479 — — 479 Other equity securities 7 — — 7 — — — — Total other investment securities, at cost $722 $— $— $722 $942 $— $— $942
Schedule of investments classified by maturity date	The amortized cost and fair value of debt securities by contractual maturity are presented below. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without incurring penalties. Distribution of Maturities (in millions) 1 Year or Less 1-5 Years 5-10 Years After 10 Years Total Amortized Cost: Debt securities available for sale U.S. Treasury and other $12 $— $— $— $12 State and political subdivisions — — — 6 6 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — 261 1,067 18,737 20,065 Other/non-agency 1 21 — 289 311 Total debt securities available for sale 13 282 1,067 19,032 20,394 Debt securities held to maturity: Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — — — 3,853 3,853 Other/non-agency — — — 832 832 Total debt securities held to maturity — — — 4,685 4,685 Total amortized cost of debt securities $13 $282 $1,067 $23,717 $25,079 Fair Value: Debt securities available for sale U.S. Treasury and other $12 $— $— $— $12 State and political subdivisions — — — 6 6 Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — 261 1,071 18,496 19,828 Other/non-agency 1 21 — 289 311 Total debt securities available for sale 13 282 1,071 18,791 20,157 Debt securities held to maturity Mortgage-backed securities: Federal agencies and U.S. government sponsored entities — — — 3,814 3,814 Other/non-agency — — — 854 854 Total debt securities held to maturity — — — 4,668 4,668 Total fair value of debt securities $13 $282 $1,071 $23,459 $24,825
Schedule of income recognized on investment securities	Realized gains and losses on securities are presented below: Year Ended December 31, (in millions) 2017 2016 2015 Gains on sale of debt securities $11 $18 $41 Losses on sale of debt securities — (2 ) (12 ) Debt securities gains, net $11 $16 $29 Equity securities gains $1 $3 $3
Schedule of financial instruments owned and pledged as collateral	The amortized cost and fair value of securities pledged are presented below: December 31, 2017 December 31, 2016 (in millions) Amortized Cost Fair Value Amortized Cost Fair Value Pledged against repurchase agreements $358 $357 $631 $620 Pledged against FHLB borrowed funds 839 861 953 972 Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law 3,113 3,082 3,575 3,563
Other than temporary impairment recognized in earnings	The following table presents the net securities impairment losses recognized in earnings: Year Ended December 31, (in millions) 2017 2016 2015 Other-than-temporary impairment: Total other-than-temporary impairment losses ($7 ) ($39 ) ($43 ) Portions of loss recognized in other comprehensive income (before taxes) — 27 36 Net securities impairment losses recognized in earnings ($7 ) ($12 ) ($7 )
Schedule of unrealized loss on investments	The following tables present securities whose fair values are below carrying values, segregated by those that have been in a continuous unrealized loss position for less than twelve months and those that have been in a continuous unrealized loss position for twelve months or longer: December 31, 2017 Less than 12 Months 12 Months or Longer Total (dollars in millions) Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 294 $10,163 ($97 ) 152 $8,061 ($226 ) 446 $18,224 ($323 ) Other/non-agency 6 55 (1 ) 10 84 (6 ) 16 139 (7 ) Total mortgage-backed securities 300 10,218 (98 ) 162 8,145 (232 ) 462 18,363 (330 ) Total 300 $10,218 ($98 ) 162 $8,145 ($232 ) 462 $18,363 ($330 ) December 31, 2016 Less than 12 Months 12 Months or Longer Total (dollars in millions) Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses Number of Issues Fair Value Gross Unrealized Losses State and political subdivisions 1 $8 $— — $— $— 1 $8 $— Mortgage-backed securities: Federal agencies and U.S. government sponsored entities 323 15,387 (292 ) 25 461 (16 ) 348 15,848 (308 ) Other/non-agency 4 8 — 20 302 (28 ) 24 310 (28 ) Total mortgage-backed securities 327 15,395 (292 ) 45 763 (44 ) 372 16,158 (336 ) Total 328 $15,403 ($292 ) 45 $763 ($44 ) 373 $16,166 ($336 )
Schedule of credit losses recognized in earnings	The following table presents the cumulative credit related losses recognized in earnings on debt securities held by the Company: Year Ended December 31, (in millions) 2017 2016 2015 Cumulative balance at beginning of period $75 $66 $62 Credit impairments recognized in earnings on securities that have been previously impaired 7 12 7 Reductions due to increases in cash flow expectations on impaired securities (1) (2 ) (3 ) (3 ) Cumulative balance at end of period $80 $75 $66 (1) Reported in interest income from investment securities on the Consolidated Statements of Operations.

LOANS AND LEASES (Tables)

LOANS AND LEASES (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of loans and leases	A summary of the loans and leases portfolio is presented below: December 31, (in millions) 2017 2016 Commercial $37,562 $37,274 Commercial real estate 11,308 10,624 Leases 3,161 3,753 Total commercial loans and leases 52,031 51,651 Residential mortgages 17,045 15,115 Home equity loans 1,392 1,858 Home equity lines of credit 13,483 14,100 Home equity loans serviced by others 542 750 Home equity lines of credit serviced by others 149 219 Automobile 13,204 13,938 Education (1) 8,134 6,610 Credit cards 1,848 1,691 Other retail 2,789 1,737 Total retail loans 58,586 56,018 Total loans and leases (2)(3) $110,617 $107,669 (1) During first quarter 2017, student loans were renamed “education” loans. Refer to Note 1 “Significant Accountant Policies” for more information. (2) Excluded from the table above are loans held for sale totaling $718 million and $625 million as of December 31, 2017 and 2016 , respectively. (3) Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $20.3 billion and $17.3 billion at December 31, 2017 and 2016 , respectively.
Schedule of loan purchases and sales	The following tables present balances of loan purchases and sales: Year Ended December 31, 2017 (in millions) Education Automobile Residential mortgages Home equity loans Commercial Total Purchases $862 $153 $— $— $— $1,015 Sales — — 254 29 603 886 Year Ended December 31, 2016 (in millions) Education Automobile Residential mortgages Home equity loans Commercial Total Purchases $1,224 $695 $539 $— $— $2,458 Sales — — 699 55 147 901
Schedule of investment in leases, before the ALLL	A summary of the investment in leases, before the ALLL, is presented below: December 31, (in millions) 2017 2016 Direct financing leases $3,122 $3,670 Leveraged leases 39 83 Total leases $3,161 $3,753 The components of the investment in leases, before the ALLL, are presented below: December 31, (in millions) 2017 2016 Total future minimum lease rentals $2,347 $2,922 Estimated residual value of leased equipment (non-guaranteed) 1,072 1,166 Initial direct costs 15 20 Unearned income on minimum lease rentals and estimated residual value of leased equipment (273 ) (355 ) Total leases $3,161 $3,753
Schedule of future minimum lease rentals on direct financing and leveraged leases	The future minimum lease rentals on direct financing and leveraged leases at December 31, 2017 are presented below: Year (in millions) 2018 $602 2019 553 2020 399 2021 300 2022 201 Thereafter 292 Total $2,347

ALLOWANCE FOR CREDIT LOSSES, 39

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of changes in the allowance for credit losses	A summary of changes in the allowance for credit losses is presented below: Year Ended December 31, 2017 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $663 $573 $1,236 Charge-offs (75 ) (437 ) (512 ) Recoveries 40 167 207 Net charge-offs (35 ) (270 ) (305 ) Provision charged to income (1) 57 248 305 Allowance for loan and lease losses, end of period 685 551 1,236 Reserve for unfunded lending commitments, beginning of period 72 — 72 Provision for unfunded lending commitments 16 — 16 Reserve for unfunded lending commitments, end of period 88 — 88 Total allowance for credit losses, end of period $773 $551 $1,324 (1) Includes an increase of approximately $50 million to commercial and corresponding decrease to retail for the impact of the enhancement to the assessment of qualitative risks, factors and events that may not be measured in the modeled results. Year Ended December 31, 2016 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $596 $620 $1,216 Charge-offs (79 ) (457 ) (536 ) Recoveries 33 168 201 Net charge-offs (46 ) (289 ) (335 ) Provision charged to income 113 242 355 Allowance for loan and lease losses, end of period 663 573 1,236 Reserve for unfunded lending commitments, beginning of period 58 — 58 Provision for unfunded lending commitments 14 — 14 Reserve for unfunded lending commitments, end of period 72 — 72 Total allowance for credit losses, end of period $735 $573 $1,308 Year Ended December 31, 2015 (in millions) Commercial Retail Total Allowance for loan and lease losses, beginning of period $544 $651 $1,195 Charge-offs (36 ) (444 ) (480 ) Recoveries 49 147 196 Net recoveries (charge-offs) 13 (297 ) (284 ) Provision charged to income 39 266 305 Allowance for loan and lease losses, end of period 596 620 1,216 Reserve for unfunded lending commitments, beginning of period 61 — 61 Provision (credit) for unfunded lending commitments (3 ) — (3 ) Reserve for unfunded lending commitments as of period end 58 — 58 Total allowance for credit losses as of period end $654 $620 $1,274
Schedule of loans and leases based on evaluation method	The recorded investment in loans and leases based on the Company’s evaluation methodology is presented below: December 31, 2017 December 31, 2016 (in millions) Commercial Retail Total Commercial Retail Total Individually evaluated $370 $761 $1,131 $424 $799 $1,223 Formula-based evaluation 51,661 57,825 109,486 51,227 55,219 106,446 Total $52,031 $58,586 $110,617 $51,651 $56,018 $107,669
Schedule of allowance for credit losses by evaluation method	A summary of the allowance for credit losses by evaluation method is presented below: December 31, 2017 December 31, 2016 (in millions) Commercial Retail Total Commercial Retail Total Individually evaluated $47 $34 $81 $63 $43 $106 Formula-based evaluation 726 517 1,243 672 530 1,202 Allowance for credit losses $773 $551 $1,324 $735 $573 $1,308
Schedule of classes of commercial loans and leases based on regulatory classifications	The recorded investment in commercial loans and leases based on regulatory classification ratings is presented below: December 31, 2017 Criticized (in millions) Pass Special Mention Substandard Doubtful Total Commercial $35,430 $1,143 $785 $204 $37,562 Commercial real estate 10,706 500 74 28 11,308 Leases 3,069 73 19 — 3,161 Total commercial loans and leases $49,205 $1,716 $878 $232 $52,031 December 31, 2016 Criticized (in millions) Pass Special Mention Substandard Doubtful Total Commercial $35,010 $1,015 $1,027 $222 $37,274 Commercial real estate 10,146 370 58 50 10,624 Leases 3,583 52 103 15 3,753 Total commercial loans and leases $48,739 $1,437 $1,188 $287 $51,651
Schedule of retail loan investments categorized by delinquency status	The recorded investment in classes of retail loans, categorized by delinquency status is presented below: December 31, 2017 Days Past Due (in millions) Current 1-29 30-59 60-89 90 or More Total Residential mortgages $16,714 $147 $46 $18 $120 $17,045 Home equity loans 1,212 102 20 4 54 1,392 Home equity lines of credit 12,756 438 78 23 188 13,483 Home equity loans serviced by others 477 29 10 4 22 542 Home equity lines of credit serviced by others 116 21 4 1 7 149 Automobile 11,596 1,273 220 55 60 13,204 Education 7,898 160 23 12 41 8,134 Credit cards 1,747 63 12 9 17 1,848 Other retail 2,679 68 20 12 10 2,789 Total retail loans $55,195 $2,301 $433 $138 $519 $58,586 December 31, 2016 Days Past Due (in millions) Current 1-29 30-59 60-89 90 or More Total Residential mortgages $14,807 $108 $53 $12 $135 $15,115 Home equity loans 1,628 127 23 7 73 1,858 Home equity lines of credit 13,432 396 57 20 195 14,100 Home equity loans serviced by others 673 41 14 5 17 750 Home equity lines of credit serviced by others 158 25 3 2 31 219 Automobile 12,509 1,177 172 38 42 13,938 Education 6,379 151 24 13 43 6,610 Credit cards 1,611 43 12 9 16 1,691 Other retail 1,676 45 8 4 4 1,737 Total retail loans $52,873 $2,113 $366 $110 $556 $56,018
Schedule of nonperforming loans and leases by class	The following table presents nonperforming loans and leases and loans accruing and 90 days or more past due: Nonperforming (1) Accruing and 90 days or more past due (in millions) December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Commercial $238 $322 $5 $2 Commercial real estate 27 50 3 — Leases — 15 — — Total commercial loans and leases 265 387 8 2 Residential mortgages (1) 128 144 16 18 Home equity loans 72 98 — — Home equity lines of credit 233 243 — — Home equity loans serviced by others 25 32 — — Home equity lines of credit serviced by others 18 33 — — Automobile 70 50 — — Education 38 38 3 5 Credit card 17 16 — — Other retail 5 4 5 1 Total retail loans 606 658 24 24 Total $871 $1,045 $32 $26 (1) Nonperforming balances exclude first lien residential mortgage loans that are 100% guaranteed by the Federal Housing Administration. These loans, which are accruing and 90 days or more past due, totaled $15 million and $18 million as of December 31, 2017 and 2016, respectively. Nonperforming balances also exclude guaranteed residential mortgage loans sold to GNMA for which the Company has the right, but not the obligation, to repurchase. These loans totaled $30 million and $32 million as of December 31, 2017 and 2016, respectively. These loans are included in the Company’s Consolidated Balance Sheets.
Summary of key performance indicators	A summary of key performance indicators is presented below: December 31, 2017 2016 Nonperforming commercial loans and leases as a percentage of total loans and leases 0.24 % 0.36 % Nonperforming retail loans as a percentage of total loans and leases 0.55 0.61 Total nonperforming loans and leases as a percentage of total loans and leases 0.79 % 0.97 % Nonperforming commercial assets as a percentage of total assets 0.17 % 0.26 % Nonperforming retail assets as a percentage of total assets 0.43 0.47 Total nonperforming assets as a percentage of total assets 0.60 % 0.73 %
Analysis of age of past due amounts	An analysis of the age of both accruing and nonaccruing loan and lease past due amounts is presented below: December 31, 2017 December 31, 2016 Days Past Due Days Past Due (in millions) 30-59 60-89 90 or More Total 30-59 60-89 90 or More Total Commercial $26 $4 $243 $273 $36 $4 $324 $364 Commercial real estate 38 20 30 88 1 2 50 53 Leases 4 1 — 5 1 — 15 16 Total commercial loans and leases 68 25 273 366 38 6 389 433 Residential mortgages 46 18 120 184 53 12 135 200 Home equity loans 20 4 54 78 23 7 73 103 Home equity lines of credit 78 23 188 289 57 20 195 272 Home equity loans serviced by others 10 4 22 36 14 5 17 36 Home equity lines of credit serviced by others 4 1 7 12 3 2 31 36 Automobile 220 55 60 335 172 38 42 252 Education 23 12 41 76 24 13 43 80 Credit cards 12 9 17 38 12 9 16 37 Other retail 20 12 10 42 8 4 4 16 Total retail loans 433 138 519 1,090 366 110 556 1,032 Total $501 $163 $792 $1,456 $404 $116 $945 $1,465
Schedule of impaired loans by class	A summary of impaired loans by class is presented below: December 31, 2017 (in millions) Impaired Loans With a Related Allowance Allowance on Impaired Loans Impaired Loans Without a Related Allowance Unpaid Contractual Balance Total Recorded Investment in Impaired Loans Commercial $183 $42 $159 $403 $342 Commercial real estate 25 5 3 40 28 Leases — — — — — Total commercial loans and leases 208 47 162 443 370 Residential mortgages 25 2 126 197 151 Home equity loans 41 4 80 162 121 Home equity lines of credit 16 1 181 241 197 Home equity loans serviced by others 29 2 22 67 51 Home equity lines of credit serviced by others 2 — 7 14 9 Automobile 2 — 21 30 23 Education 154 17 21 175 175 Credit cards 24 7 1 25 25 Other retail 5 1 4 10 9 Total retail loans 298 34 463 921 761 Total $506 $81 $625 $1,364 $1,131 December 31, 2016 (in millions) Impaired Loans With a Related Allowance Allowance on Impaired Loans Impaired Loans Without a Related Allowance Unpaid Contractual Balance Total Recorded Investment in Impaired Loans Commercial $247 $55 $134 $431 $381 Commercial real estate 39 8 4 44 43 Leases — — — — — Total commercial loans and leases 286 63 138 475 424 Residential mortgages 37 2 141 235 178 Home equity loans 51 3 94 191 145 Home equity lines of credit 23 1 173 240 196 Home equity loans serviced by others 41 4 19 70 60 Home equity lines of credit serviced by others 2 — 7 13 9 Automobile 4 — 15 25 19 Education 154 25 1 155 155 Credit cards 26 6 — 26 26 Other retail 10 2 1 13 11 Total retail loans 348 43 451 968 799 Total $634 $106 $589 $1,443 $1,223
Schedule of additional information on impaired loans	Additional information on impaired loans is presented below: Year Ended December 31, 2017 2016 2015 (in millions) Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Commercial $4 $380 $5 $295 $4 $135 Commercial real estate — 37 — 53 1 44 Leases — — — 3 — — Total commercial loans and leases 4 417 5 351 5 179 Residential mortgages 4 136 4 161 15 415 Home equity loans 6 121 7 144 9 222 Home equity lines of credit 6 176 6 178 4 173 Home equity loans serviced by others 3 49 3 60 4 75 Home equity lines of credit serviced by others — 9 — 9 — 9 Automobile 1 18 — 14 — 11 Education 9 173 7 150 7 157 Credit cards 2 22 2 23 2 26 Other retail — 9 1 12 1 16 Total retail loans 31 713 30 751 42 1,104 Total $35 $1,130 $35 $1,102 $47 $1,283
Troubled debt restructurings on financing receivables	The table below summarizes TDRs by class and total unfunded commitments: December 31, (in millions) 2017 2016 Commercial $129 $120 Retail 761 799 Unfunded commitments tied to TDRs 39 42 The table below summarizes how loans were modified during the year ended December 31, 2017 , the charge-offs related to the modifications, and the impact on the ALLL. The reported balances can include loans that became TDRs during 2017 and were paid off in full, charged off, or sold prior to December 31, 2017 . Primary Modification Types Interest Rate Reduction (1) Maturity Extension (2) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial 7 $1 $1 45 $22 $22 Commercial real estate — — — 1 — — Leases — — — — — — Total commercial loans and leases 7 1 1 46 22 22 Residential mortgages 71 9 10 73 12 13 Home equity loans 82 5 6 1 — — Home equity lines of credit 50 3 3 235 30 30 Home equity loans serviced by others 15 1 1 — — — Home equity lines of credit serviced by others 5 — — 2 — — Automobile 130 2 2 29 1 1 Education — — — — — — Credit cards 2,363 13 13 — — — Other retail 1 — — — — — Total retail loans 2,717 33 35 340 43 44 Total 2,724 $34 $36 386 $65 $66 Primary Modification Types Other (3) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Net Change to ALLL Resulting from Modification Charge-offs Resulting from Modification Commercial 15 $70 $71 ($1 ) $— Commercial real estate 1 — — — — Leases — — — — — Total commercial loans and leases 16 70 71 (1 ) — Residential mortgages 171 19 19 (1 ) — Home equity loans 232 13 13 — — Home equity lines of credit 395 27 27 — 1 Home equity loans serviced by others 52 2 2 — — Home equity lines of credit serviced by others 26 2 2 — — Automobile 1,336 24 20 — 4 Education 329 7 7 2 — Credit cards — — — 3 — Other retail 5 — — (2 ) — Total retail loans 2,546 94 90 2 5 Total 2,562 $164 $161 $1 $5 (1) Includes modifications that consist of multiple concessions, one of which is an interest rate reduction. (2) Includes modifications that consist of multiple concessions, one of which is a maturity extension (unless one of the other concessions was an interest rate reduction). (3) Includes modifications other than interest rate reductions or maturity extensions, such as lowering scheduled payments for a specified period of time, principal forgiveness, and capitalizing arrearages. Also included are the following: deferrals, trial modifications, certain bankruptcies, loans in forbearance and prepayment plans. Modifications can include the deferral of accrued interest resulting in post modification balances being higher than pre-modification. The table below summarizes how loans were modified during the year ended December 31, 2016 , the charge-offs related to the modifications, and the impact on the ALLL. The reported balances can include loans that became TDRs during 2016 and were paid off in full, charged off, or sold prior to December 31, 2016 . Primary Modification Types Interest Rate Reduction (1) Maturity Extension (2) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial 12 $1 $1 81 $20 $21 Commercial real estate 1 — — 1 5 5 Leases — — — — — — Total commercial loans and leases 13 1 1 82 25 26 Residential mortgages 71 10 10 60 10 10 Home equity loans 97 6 6 39 4 5 Home equity lines of credit 49 4 4 121 13 12 Home equity loans serviced by others 18 1 1 — — — Home equity lines of credit serviced by others 8 — — 5 1 1 Automobile 138 3 3 41 1 1 Education — — — — — — Credit cards 2,187 12 12 — — — Other retail 4 — — — — — Total retail loans 2,572 36 36 266 29 29 Total 2,585 $37 $37 348 $54 $55 Primary Modification Types Other (3) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Net Change to ALLL Resulting from Modification Charge-offs Resulting from Modification Commercial 14 $48 $48 $3 $— Commercial real estate — — — — — Leases — — — — — Total commercial loans and leases 14 48 48 3 — Residential mortgages 247 26 26 (1 ) — Home equity loans 279 18 17 (1 ) — Home equity lines of credit 304 23 22 — 1 Home equity loans serviced by others 60 2 2 — — Home equity lines of credit serviced by others 24 1 1 — — Automobile 1,081 20 18 — 3 Education 479 12 12 4 — Credit cards — — — 3 — Other retail 13 — — — — Total retail loans 2,487 102 98 5 4 Total 2,501 $150 $146 $8 $4 (1) Includes modifications that consist of multiple concessions, one of which is an interest rate reduction. (2) Includes modifications that consist of multiple concessions, one of which is a maturity extension (unless one of the other concessions was an interest rate reduction). (3) Includes modifications other than interest rate reductions or maturity extensions, such as lowering scheduled payments for a specified period of time, principal forgiveness, and capitalizing arrearages. Also included are the following: deferrals, trial modifications, certain bankruptcies, loans in forbearance and prepayment plans. Modifications can include the deferral of accrued interest resulting in post modification balances being higher than pre-modification. The table below summarizes how loans were modified during the year ended December 31, 2015 , the charge-offs related to the modifications, and the impact on the ALLL. The reported balances can include loans that became TDRs during 2015 and were paid off in full, charged off, or sold prior to December 31, 2015 . Primary Modification Types Interest Rate Reduction (1) Maturity Extension (2) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Commercial 25 $19 $19 160 $22 $22 Commercial real estate 1 — — 1 — — Leases — — — — — — Total commercial loans and leases 26 19 19 161 22 22 Residential mortgages 153 31 31 40 7 6 Home equity loans 96 5 5 191 35 35 Home equity lines of credit 4 1 1 23 2 2 Home equity loans serviced by others 29 2 2 — — — Home equity lines of credit serviced by others 2 — — 1 — — Automobile 108 2 2 5 — — Education — — — — — — Credit cards 2,413 13 13 — — — Other retail 3 — — — — — Total retail loans 2,808 54 54 260 44 43 Total 2,834 $73 $73 421 $66 $65 Primary Modification Types Other (3) (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Net Change to ALLL Resulting from Modification Charge-offs Resulting from Modification Commercial 16 $34 $34 ($1 ) $1 Commercial real estate 1 4 4 — — Leases — — — — — Total commercial loans and leases 17 38 38 (1 ) 1 Residential mortgages 275 33 33 (1 ) — Home equity loans 448 28 28 — 1 Home equity lines of credit 320 21 19 — 2 Home equity loans serviced by others 124 6 5 — 1 Home equity lines of credit serviced by others 41 3 2 — — Automobile 812 14 12 — 2 Education 1,204 22 22 4 — Credit cards — — — 2 — Other retail 20 — — — — Total retail loans 3,244 127 121 5 6 Total 3,261 $165 $159 $4 $7 (1) Includes modifications that consist of multiple concessions, one of which is an interest rate reduction. (2) Includes modifications that consist of multiple concessions, one of which is a maturity extension (unless one of the other concessions was an interest rate reduction). (3) Includes modifications other than interest rate reductions or maturity extensions, such as lowering scheduled payments for a specified period of time, principal forgiveness, and capitalizing arrearages. Also included are the following: deferrals, trial modifications, certain bankruptcies, loans in forbearance and prepayment plans. Modifications can include the deferral of accrued interest resulting in post-modification balances being higher than pre-modification.
Schedule of defaults	The table below summarizes TDRs that defaulted within 12 months of their modification date during 2017 , 2016 and 2015 . For purposes of this table, a payment default refers to a loan that becomes 90 days or more past due under the modified terms. Amounts represent the loan’s recorded investment at the time of payment default. Loan data includes loans meeting the criteria that were paid off in full, charged off, or sold prior to December 31, 2017 and 2016 . If a TDR of any loan type becomes 90 days past due after being modified, the loan is written down to the fair value of collateral less cost to sell. The amount written off is charged to the ALLL. Year Ended December 31, 2017 2016 2015 (dollars in millions) Number of Contracts Balance Defaulted Number of Contracts Balance Defaulted Number of Contracts Balance Defaulted Commercial 8 $5 22 $13 23 $2 Commercial real estate 1 4 1 — — — Leases — — — — — — Total commercial loans and leases 9 9 23 13 23 2 Residential mortgages 152 19 187 24 168 21 Home equity loans 43 2 50 3 184 13 Home equity lines of credit 200 14 155 13 131 7 Home equity loans serviced by others 23 — 37 1 43 1 Home equity lines of credit serviced by others 10 1 17 — 22 1 Automobile 140 1 110 2 87 1 Education 44 1 59 1 171 3 Credit cards 491 3 433 3 455 3 Other retail 4 — 3 — 4 — Total retail loans 1,107 41 1,051 47 1,265 50 Total 1,116 $50 1,074 $60 1,288 $52
Schedule of loans that may increase credit exposure	The following tables present balances of loans with these characteristics: December 31, 2017 (in millions) Residential Mortgages Home Equity Loans and Lines of Credit Home Equity Products Serviced by Others Credit Cards Education Total High loan-to-value $366 $166 $264 $— $— $796 Interest only/negative amortization 1,763 — — — 1 1,764 Low introductory rate — — — 197 — 197 Multiple characteristics and other 1 — — — — 1 Total $2,130 $166 $264 $197 $1 $2,758 December 31, 2016 (in millions) Residential Mortgages Home Equity Loans and Lines of Credit Home Equity Products Serviced by Others Credit Cards Education Total High loan-to-value $566 $550 $476 $— $— $1,592 Interest only/negative amortization 1,582 — — — 1 1,583 Low introductory rate — — — 112 — 112 Multiple characteristics and other 3 — — — — 3 Total $2,151 $550 $476 $112 $1 $3,290

PREMISES, EQUIPMENT, AND SOFT40

PREMISES, EQUIPMENT, AND SOFTWARE (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of the carrying value of premises and equipment	A summary of the carrying value of premises and equipment is presented below: December 31, (dollars in millions) Useful Lives 2017 2016 Land and land improvements 10 years $47 $47 Buildings and leasehold improvements 5-40 years 719 684 Furniture, fixtures and equipment 5-15 years 1,824 1,714 Total premises and equipment, gross 2,590 2,445 Accumulated depreciation (1,905 ) (1,844 ) Total premises and equipment, net $685 $601
Schedule of estimated future amortization expense for capitalized software assets	The estimated future amortization expense for capitalized software assets is presented below: Year (in millions) 2018 $171 2019 141 2020 109 2021 71 2022 36 Thereafter 92 Total (1) $620 (1) Excluded from this balance is $178 million of in-process software at December 31, 2017 .

LEASE COMMITMENTS (Tables)

LEASE COMMITMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of aggregate minimum rental commitments	At December 31, 2017 , the aggregate minimum rental commitments under these non-cancelable operating leases and capital leases, exclusive of renewals, are presented below for the years ended December 31: (in millions) Operating Leases Capital Leases 2018 $171 $3 2019 148 2 2020 130 2 2021 111 2 2022 81 1 Thereafter 201 8 Total minimum lease payments $842 $18 Amounts representing interest — (8 ) Present value of net minimum lease $842 $10

MORTGAGE BANKING (Tables)

MORTGAGE BANKING (Tables)	12 Months Ended
	Dec. 31, 2017
Mortgage Banking [Abstract]
Schedule of mortgage banking activities	Information related to residential mortgage loan sales and the Company's mortgage banking activity is presented below: Year Ended December 31, (in millions) 2017 2016 2015 Residential mortgage loan sale proceeds (1) $3,161 $2,652 $2,667 Gain on sales 35 69 51 Mortgage servicing fees 53 51 55 Repurchased residential mortgages 3 6 10 Valuation recoveries (2 ) (4 ) (9 ) (1) Represents the unpaid principal balance at the time of the sale.
Schedule of valuation allowance for impairment of recognized servicing assets	Changes related to MSRs are presented below: As of and for the Year Ended December 31, (in millions) 2017 2016 MSRs: Balance as of beginning of period $167 $173 Amount capitalized 37 29 Purchases 28 — Amortization (31 ) (35 ) Carrying amount before valuation allowance 201 167 Valuation allowance for servicing assets: Balance as of beginning of period 5 9 Valuation recoveries (2 ) (4 ) Balance at end of period 3 5 Net carrying value of MSRs $198 $162
Servicing asset at amortized cost	Changes related to MSRs are presented below: As of and for the Year Ended December 31, (in millions) 2017 2016 MSRs: Balance as of beginning of period $167 $173 Amount capitalized 37 29 Purchases 28 — Amortization (31 ) (35 ) Carrying amount before valuation allowance 201 167 Valuation allowance for servicing assets: Balance as of beginning of period 5 9 Valuation recoveries (2 ) (4 ) Balance at end of period 3 5 Net carrying value of MSRs $198 $162
Schedule of fair value assumptions used to estimate the value of Mortgage Servicing Rights	The key economic assumptions used to estimate the value of MSRs are presented in the following table: December 31, 2017 2016 (dollars in millions) Weighted-Average Range Weighted-Average Range Fair value $218 Min Max $182 Min Max Weighted-average life (in years) 5.9 2.3 8.4 5.7 2.6 7.3 Weighted-average constant prepayment rate 10.0% 6.6% 20.1% 10.8% 8.8% 22.3% Weighted-average discount rate 9.9% 9.1% 12.1% 9.7% 9.1% 12.1%
Schedule of fair value assumptions used to estimate the value of Mortgage Servicing Rights capitalized in current period	The key economic assumptions used in estimating the fair value of MSRs capitalized during the period are presented below: Year Ended December 31, 2017 2016 2015 Weighted-average life (in years) 7.3 6.1 5.9 Weighted-average constant prepayment rate 8.7% 11.0% 10.7% Weighted-average discount rate 9.8% 9.7% 9.7%
Schedule of the impact to fair value of an adverse change in key economic assumptions	The sensitivity analysis below presents the impact to current fair value of an immediate 50 basis point and 100 basis point adverse change in the key economic assumptions and presents the decline in fair value that would occur if the adverse change were realized. These sensitivities are hypothetical, with the effect of a variation in a particular assumption on the fair value of the mortgage servicing rights calculated independently without changing any other assumption. In reality, changes in one factor may result in changes in another (e.g., changes in interest rates, which drive changes in prepayment rates, could result in changes in the discount rates), which may amplify or counteract the sensitivities. The primary risk inherent in the Company’s MSRs is an increase in prepayments of the underlying mortgage loans serviced, which is dependent upon market movements of interest rates. December 31, (in millions) 2017 2016 Prepayment rate: Decline in fair value from a 50 basis point decrease in interest rates $22 $9 Decline in fair value from a 100 basis point decrease in interest rates 46 25 Weighted-average discount rate: Decline in fair value from a 50 basis point increase in weighted-average discount rate 4 3 Decline in fair value from a 100 basis point increase in weighted-average discount rate 8 6

GOODWILL (Tables)

GOODWILL (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	Changes in the carrying value of goodwill for the years ended December 31, 2017 and 2016 are presented below: (in millions) Consumer Banking Commercial Banking Total Balance at December 31, 2015 $2,136 $4,740 $6,876 Adjustments — — — Balance at December 31, 2016 $2,136 $4,740 $6,876 Business acquisition — 11 11 Adjustments — — — Balance at December 31, 2017 $2,136 $4,751 $6,887

VARIABLE INTEREST ENTITIES VARI

VARIABLE INTEREST ENTITIES VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities [Abstract]
Schedule of Variable Interest Entities	A summary of these investments is presented below: December 31, (in millions) 2017 2016 LIHTC investment included in other assets $951 $793 LIHTC unfunded commitments included in other liabilities 491 428 Renewable energy investments included in other assets 335 220
Schedule of Affordable Housing Tax Credit Investments	The following table presents other information related to the Company’s affordable housing tax credit investments: Year Ended December 31, (in millions) 2017 2016 Tax credits included in income tax expense $83 $59 Amortization expense included in income tax expense 94 59 Other tax benefits included in income tax expense 31 21

DEPOSITS (Tables)

DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of the major components of deposits	The major components of deposits are presented below: December 31, (in millions) 2017 2016 Demand $29,279 $28,472 Checking with interest 22,229 20,714 Regular savings 9,518 8,964 Money market accounts 37,454 38,176 Term deposits 16,609 13,478 Total deposits $115,089 $109,804
Schedule of maturity distribution of term deposits	The maturity distribution of term deposits as of December 31, 2017 is presented below: Year (in millions) 2018 $13,754 2019 1,985 2020 351 2021 452 2022 62 2023 and thereafter 5 Total $16,609
Schedule of maturities of term deposits greater than $100,000	The remaining maturities of these deposits are presented below: (in millions) Three months or less $4,948 After three months through six months 1,925 After six months through twelve months 3,040 After twelve months 1,453 Total term deposits $11,366

BORROWED FUNDS (Tables)

BORROWED FUNDS (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of short-term borrowed funds	A summary of the Company’s short-term borrowed funds is presented below: December 31, (in millions) 2017 2016 Federal funds purchased $460 $533 Securities sold under agreements to repurchase 355 615 Other short-term borrowed funds 1,856 3,211 Total short-term borrowed funds $2,671 $4,359 Key data related to short-term borrowed funds is presented in the following table: As of and for the Year Ended December 31, (in millions, except ratio data) 2017 2016 2015 Weighted-average interest rate at year-end: (1) Federal funds purchased and securities sold under agreements to repurchase 0.74 % 0.26 % 0.15 % Other short-term borrowed funds 1.72 0.94 0.44 Maximum amount outstanding at month-end during the year: Federal funds purchased and securities sold under agreements to repurchase (2) $1,174 $1,522 $5,375 Other short-term borrowed funds 3,508 5,461 7,004 Average amount outstanding during the year: Federal funds purchased and securities sold under agreements to repurchase (2) $776 $947 $3,364 Other short-term borrowed funds 2,321 3,207 5,865 Weighted-average interest rate during the year: (1) Federal funds purchased and securities sold under agreements to repurchase 0.36 % 0.09 % 0.22 % Other short-term borrowed funds 1.32 0.64 0.28 (1) Rates exclude certain hedging costs. (2) Balances are net of certain short-term receivables associated with reverse repurchase agreements, as applicable.
Schedule of long-term borrowed funds	A summary of the Company’s long-term borrowed funds is presented below: December 31, (in millions) 2017 2016 Parent Company: 2.375% fixed-rate senior unsecured debt, due 2021 $349 $348 4.150% fixed-rate subordinated debt, due 2022 348 347 5.158% fixed-to-floating rate subordinated debt, due 2023, converting to floating at 333 333 3.750% fixed-rate subordinated debt, due 2024 250 250 4.023% fixed-rate subordinated debt, due 2024 42 42 4.350% fixed-rate subordinated debt, due 2025 249 249 4.300% fixed-rate subordinated debt, due 2025 749 749 Banking Subsidiaries: 2.300% senior unsecured notes, due 2018 (1) (2) — 745 2.450% senior unsecured notes, due 2019 (1) 743 747 2.500% senior unsecured notes, due 2019 (1) 741 741 2.250% senior unsecured notes, due 2020 (1) 692 — Floating-rate senior unsecured notes, due 2020 (1) 299 — Floating-rate senior unsecured notes, due 2020 (1) 249 — 2.200% senior unsecured notes, due 2020 (1) 498 — 2.250% senior unsecured notes, due 2020 (1) 742 — 2.550% senior unsecured notes, due 2021 (1) 964 965 Floating-rate senior unsecured notes, due 2022 (1) 249 — 2.650% senior unsecured notes, due 2022 (1) 491 — Federal Home Loan advances due through 2033 3,761 7,264 Other 16 10 Total long-term borrowed funds $11,765 $12,790 (1) Issued under CBNA’s Global Bank Note Program. (2) Reclassified to short-term borrowed funds.
Schedule of maturities of long-term borrowed funds	A summary of maturities for the Company’s long-term borrowed funds at December 31, 2017 is presented below: (in millions) Parent Company Banking Subsidiaries Consolidated Year 2018 $— $— $— 2019 — 5,235 5,235 2020 — 2,492 2,492 2021 349 967 1,316 2022 348 744 1,092 2023 and thereafter 1,623 7 1,630 Total $2,320 $9,445 $11,765

DERIVATIVES (Tables)

DERIVATIVES (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of derivative instruments in consolidated balance sheets	The following table presents derivative instruments included on the Consolidated Balance Sheets in derivative assets and derivative liabilities: December 31, 2017 December 31, 2016 (in millions) Notional Amount (1) Derivative Assets (2) Derivative Liabilities (2) Notional Amount (1) Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate contracts $13,300 $— $— $13,350 $52 $193 Derivatives not designated as hedging instruments: Interest rate contracts 80,180 538 379 54,656 557 452 Foreign exchange contracts 9,882 148 149 8,039 134 126 Other contracts 1,039 7 5 1,498 16 7 Total derivatives not designated as hedging instruments 693 533 707 585 Gross derivative fair values 693 533 759 778 Less: Gross amounts offset in the Consolidated Balance Sheets (3) (72 ) (72 ) (106 ) (106 ) Less: Cash collateral applied (3) (4 ) (151 ) (26 ) (13 ) Total net derivative fair values presented in the Consolidated Balance Sheets $617 $310 $627 $659 (1) The notional or contractual amount of interest rate derivatives and foreign exchange contracts is the amount upon which interest and other payments under the contract are based. For interest rate contracts, the notional amount is typically not exchanged. Therefore, notional amounts should not be taken as the measure of credit or market risk, as they do not measure the true economic risk of these contracts. (2) Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives. (3) Amounts represent the impact of enforceable master netting agreements that allow the Company to net settle positive and negative positions.
Schedule of fair value hedges	The following table presents the effect on other income of fair value hedges described above, in millions: Amounts Recognized in Other Income for the Year Ended December 31, 2017 2016 2015 Derivative Hedged Item Hedge Ineffectiveness Derivative Hedged Item Hedge Ineffectiveness Derivative Hedged Item Hedge Ineffectiveness ($26 ) $27 $1 ($6 ) $5 ($1 ) ($2 ) $2 $—
Schedule of effect of cash flow hedges on net income and stockholders' equity	The following table presents the effect of cash flow hedges on net income and stockholders’ equity: Amounts Recognized for the Year Ended December 31, (in millions) 2017 2016 2015 Effective portion of (loss) gain recognized in OCI (1) ($23 ) ($100 ) $150 Amounts reclassified from OCI to interest income (2) 25 90 82 Amounts reclassified from OCI to interest expense (2) — (27 ) (59 ) Amounts reclassified from OCI to other income (3) — (5 ) — (1) The cumulative effective gains and losses on the Company’s cash flow hedging activities are included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets. (2) This amount includes both (a) the amortization of effective gains and losses associated with the Company’s terminated cash flow hedges and (b) the current reporting period’s interest settlements realized on the Company’s active cash flow hedges. Both (a) and (b) were previously included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets and were subsequently recorded as adjustments to the interest income or expense of the underlying hedged item. (3) This includes gains and losses attributable to previously hedged cash flows where the likelihood occurrence of those cash flows is no longer probable.
Schedule of effect of derivative Instruments on net income	The following table presents the effect of customer derivatives and economic hedges on noninterest income: Amounts Recognized in Noninterest Income for the Year Ended December 31, (in millions) 2017 2016 2015 Customer derivative contracts Customer interest rate contracts (1) $5 ($23 ) $140 Customer foreign exchange contracts (1) 172 (81 ) (18 ) Residential loan commitments (2) 2 (2 ) (4 ) Economic hedges Offsetting derivatives transactions to hedge interest rate risk on customer interest rate contracts (1) 46 70 (106 ) Offsetting derivatives transactions to hedge foreign exchange risk on customer foreign exchange contracts (1) (151 ) 95 19 Forward sale contracts (2) (8 ) 6 1 Total $66 $65 $32 (1) Reported in foreign exchange and interest rate products on the Consolidated Statements of Operations. (2) Reported in mortgage banking fees on the Consolidated Statements of Operations.

EMPLOYEE BENEFITS (Tables)

EMPLOYEE BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	The following table presents qualified pension plan assets measured at fair value within the fair value hierarchy: Fair Value Measurements as of December 31, 2017 (in millions) Total Level 1 Level 2 Level 3 Assets: Managed portfolio assets: U.S. government obligations 8 — 8 — Non-U.S. government obligations 2 — 2 — Municipal obligations 1 — 1 — Corporate bonds 102 — 102 — Asset-backed securities 1 — 1 — Total assets in the fair value hierarchy 114 — 114 — Investments measured at net asset value (1) 1,024 Assets at fair value at measurement date of December 31, 2017 $1,138 $— $114 $— (1) Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table presents qualified pension plan assets measured at fair value within the fair value hierarchy: Fair Value Measurements as of December 31, 2016 (in millions) Total Level 1 Level 2 Level 3 Assets: Managed portfolio assets Cash and money market funds 2 — 2 — U.S. government obligations 10 — 10 — Municipal obligations 2 — 2 — Corporate bonds 89 — 89 — Asset-backed securities 1 — 1 — Total assets in the fair value hierarchy 104 — 104 — Investments measured at net asset value (1) 918 Assets at fair value at measurement date of December 31, 2016 $1,022 $— $104 $— (1) Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	Changes in the fair value of defined benefit pension plan assets, projected benefit obligation, funded status, and accumulated benefit obligation are presented below: Year Ended December 31, Qualified Plan Non-Qualified Plan (in millions) 2017 2016 2017 2016 Fair value of plan assets as of January 1 $1,015 $917 $— $— Actual return on plan assets 185 82 — — Employer contributions — 75 8 8 Benefits and administrative expenses paid (61 ) (59 ) (8 ) (8 ) Fair value of plan assets as of December 31 1,139 1,015 — — Projected benefit obligation 1,089 1,024 106 105 Pension asset (obligation) $50 ($9 ) ($106 ) ($105 ) Accumulated benefit obligation $1,089 $1,024 $106 $105
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Other changes in plan assets and benefit obligations recognized in OCI (for the qualified, non-qualified and postretirement plans) are presented below: Year Ended December 31, (in millions) 2017 2016 2015 Net periodic pension income ($2 ) ($1 ) ($7 ) Net actuarial (gain) loss (31 ) 54 7 Amortization of prior service credit 1 1 — Amortization of net actuarial loss (18 ) (16 ) (15 ) Total recognized in other comprehensive income (loss) (48 ) 39 (8 ) Total recognized in net periodic pension cost and other comprehensive income (loss) ($50 ) $38 ($15 )
Schedule of net periodic (income) cost	The components of net periodic pension (income) cost for the Company's qualified and non-qualified plans are presented below: Year Ended December 31, Qualified Plan Non-Qualified Plan Total (in millions) 2017 2016 2015 2017 2016 2015 2017 2016 2015 Service cost $3 $3 $3 $— $— $— $3 $3 $3 Interest cost 42 44 44 4 4 4 46 48 48 Expected return on plan assets (69 ) (68 ) (74 ) — — — (69 ) (68 ) (74 ) Amortization of actuarial loss 16 14 13 2 2 2 18 16 15 Net periodic pension (income) cost ($8 ) ($7 ) ($14 ) $6 $6 $6 ($2 ) ($1 ) ($8 )
Schedule of Expected Benefit Payments	Expected future benefit payments for the qualified and non-qualified plans are presented below: (in millions) Expected benefit payments by fiscal year ending December 31, 2018 $65 December 31, 2019 66 December 31, 2020 66 December 31, 2021 67 December 31, 2022 68 December 31, 2023 - 2027 346
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share	The following table presents the unfunded commitments, redemption frequency and redemption notice period for Plan investments that utilize net asset value to determine fair value: Fair Value Estimated Using Net Asset Value per Share December 31, Unfunded Redemption Redemption Redemption Investment (dollars in millions) 2017 2016 Commitment Frequency Restrictions Notice Period Liquid Cash Fund $11 $9 $— Daily None Same day before 5:30pm ET Equity Mutual Fund (1) — 40 — Daily None 7 days Common and Collective Funds: Global equities funds 472 386 — Daily None 3 days Balanced funds 214 193 — Daily None 2 days Fixed income fund 150 133 — Daily None 3 days Managed Portfolio - Fixed Income Mutual Fund (2) 35 30 — Daily None 1 days Limited Partnerships: International equity fund 142 117 — Monthly None 3 days Offshore feeder fund — 10 — Monthly None 14 days Total $1,024 $918 $— (1) The equity mutual fund seeks to offer participants capital appreciation by primarily investing in common stocks via investments in several underlying funds of the same fund family. The principal investment objective is to generate positive total return. (2) The managed portfolio fixed income mutual fund seeks to outperform the Barclay’s U.S. Long Credit Index or similar benchmark.
Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Allocation of Plan Assets	The qualified plan’s allocation by asset category is presented below: Target Asset Allocation Actual Asset Allocation Asset Category 2017 2017 2016 Equity securities 48-58% 54.0 % 49.6 % Debt securities 41-51% 45.0 % 45.2 % Other 1.0 % 5.2 % Total 100.0 % 100.0 %
Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assumptions Used in Determining Benefit Obligations and Net Periodic Benefit Cost	Weighted-average rates assumed in determining the net periodic benefit cost of the postretirement benefits plan are as follows: For the Year Ended December 31, (dollars in millions) 2017 2016 Discount rate 3.530 % 3.930 % Rate of compensation increase N/A N/A Ultimate health care cost trend rate 5.000 % 5.000 % Effect on accumulated postretirement benefit obligation: One percent increase in assumed health care cost trend $— $— One percent decrease in assumed health care cost trend — —
Schedule of Expected Benefit Payments	Expected future benefit payments for the postretirement benefit plan are presented below: (in millions) Expected benefit payments by fiscal year ending December 31, 2018 $2 December 31, 2019 2 December 31, 2020 1 December 31, 2021 1 December 31, 2022 1 December 31, 2023 - 2027 5
Qualified and Non-Qualified Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assumptions Used in Determining Benefit Obligations and Net Periodic Benefit Cost	Weighted-average rates assumed in determining the actuarial present value of benefit obligations and net periodic benefit cost are presented below: As of and for the Year Ended December 31, 2017 2016 2015 Assumptions for benefit obligations Discount rate-qualified plan 3.670 % 4.190 % 4.640 % Discount rate-non-qualified plan 3.530 % 4.050 % 4.540 % Expected long-term rate of return on plan assets 7.000 % 7.500 % 7.500 % Assumptions for net periodic pension cost Discount rate-qualified plan 4.190 % 4.640 % 4.125 % Discount rate-non-qualified plan 4.050 % 4.540 % 3.875 % Expected long-term rate of return on plan assets 7.000 % 7.500 % 7.500 %

RECLASSIFICATIONS OUT OF ACCU49

RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of other comprehensive income	The following table presents the changes in the balances, net of income taxes, of each component of AOCI: (in millions) Net Unrealized (Losses) Gains on Derivatives Net Unrealized (Losses) Gains on Securities Employee Benefit Plans Total AOCI Balance at January 1, 2015 ($69 ) $74 ($377 ) ($372 ) Other comprehensive income before reclassifications 93 (66 ) — 27 Other-than-temporary impairment not recognized in earnings on securities — (22 ) — (22 ) Amounts reclassified from other comprehensive income (14 ) (14 ) 8 (20 ) Net other comprehensive loss 79 (102 ) 8 (15 ) Balance at December 31, 2015 $10 ($28 ) ($369 ) ($387 ) Other comprehensive income before reclassifications (62 ) (139 ) — (201 ) Other-than-temporary impairment not recognized in earnings on securities — (17 ) — (17 ) Amounts reclassified from other comprehensive income (36 ) (2 ) (25 ) (63 ) Net other comprehensive loss (98 ) (158 ) (25 ) (281 ) Balance at December 31, 2016 ($88 ) ($186 ) ($394 ) ($668 ) Other comprehensive income before reclassifications (14 ) (6 ) — (20 ) Amounts reclassified from other comprehensive income (16 ) (2 ) 31 13 Net other comprehensive loss (30 ) (8 ) 31 (7 ) Reclassification of tax effects resulting from the 2017 Tax Legislation (1) (25 ) (42 ) (78 ) (145 ) Balance at December 31, 2017 ($143 ) ($236 ) ($441 ) ($820 ) (1) As of December 31, 2017, the balance of AOCI reflects the retrospective adoption of FASB ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . For further discussion, see Note 22 “Income Taxes.”
Schedule of reclassification out of accumulated other comprehensive income	The following table reports the amounts reclassified out of each component of AOCI and into the Consolidated Statements of Operations: Year Ended December 31, (in millions) 2017 2016 2015 Details about AOCI Components Affected Line Item in the Consolidated Statements of Operations Reclassification adjustment for net derivative gains (losses) included in net income: $25 $90 $82 Interest income — (27 ) (59 ) Interest expense — (5 ) — Other income 25 58 23 Income before income tax expense 9 22 9 Income tax expense $16 $36 $14 Net income Reclassification of net securities gains (losses) to net income: $11 $16 $29 Securities gains, net (7 ) (12 ) (7 ) Net securities impairment losses recognized in earnings 4 4 22 Income before income tax expense 2 2 8 Income tax expense $2 $2 $14 Net income Reclassification of changes related to the employee benefit plan: ($48 ) $39 ($8 ) Salaries and employee benefits (48 ) 39 (8 ) Income before income tax expense (17 ) 14 — Income tax expense ($31 ) $25 ($8 ) Net income Total reclassification (losses) gains ($13 ) $63 $20 Net income The following table presents the effects to net income of the amounts reclassified out of AOCI: Year Ended December 31, (in millions) 2017 2016 2015 Net interest income (includes $25, $63 and $23 of AOCI reclassifications, respectively) $4,173 $3,758 $3,402 Provision for credit losses 321 369 302 Noninterest income (includes $4, ($1) and $22 of AOCI reclassifications, respectively) 1,534 1,497 1,422 Noninterest expense (includes $48, ($39) and $8 of AOCI reclassifications, respectively) 3,474 3,352 3,259 Income before income tax expense 1,912 1,534 1,263 Income tax expense (includes ($6), $38 and $17 income tax net expense from reclassification items, respectively) 260 489 423 Net income $1,652 $1,045 $840

SHARE-BASED COMPENSATION SHARE-

SHARE-BASED COMPENSATION SHARE-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2017
Citizens Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Share-Based Plans Activity	The following table presents the activity related to the Company’s share-based plans (excluding the ESPP) for the year ended December 31, 2017 : CFG Share Awards Shares Weighted-Average Grant Price Outstanding, January 1 2,909,029 $23.92 Granted 1,256,816 39.09 Vested & Distributed (1,426,850 ) 21.91 Forfeited (117,481 ) 32.12 Outstanding, December 31 2,621,514 $33.30

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of outstanding off balance sheet arrangements	A summary of outstanding off-balance sheet arrangements is presented below: December 31, (in millions) 2017 2016 Undrawn commitments to extend credit $62,959 $60,872 Financial standby letters of credit 2,036 1,892 Performance letters of credit 47 40 Commercial letters of credit 53 43 Marketing rights 41 44 Risk participation agreements 16 19 Residential mortgage loans sold with recourse 7 8 Total $65,159 $62,918

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Assets and liabilities measured on recurring basis	The following table presents assets and liabilities measured at fair value, including gross derivative assets and liabilities on a recurring basis at December 31, 2017 : (in millions) Total Level 1 Level 2 Level 3 Securities available for sale: Mortgage-backed securities $20,139 $— $20,139 $— State and political subdivisions 6 — 6 — U.S. Treasury and other 12 12 — — Total securities available for sale 20,157 12 20,145 — Loans held for sale, at fair value: Residential loans held for sale 326 — 326 — Commercial loans held for sale 171 — 171 — Total loans held for sale, at fair value 497 — 497 — Derivative assets (1) Interest rate swaps 538 — 538 — Foreign exchange contracts 148 — 148 — Other contracts 7 — 7 — Total derivative assets 693 — 693 — Other investment securities, at fair value: Money market mutual fund 165 165 — — Other investments 4 — 4 — Total other investment securities, at fair value 169 165 4 — Total assets $21,516 $177 $21,339 $— Derivative liabilities (1) Interest rate swaps $379 $— $379 $— Foreign exchange contracts 149 — 149 — Other contracts 5 — 5 — Total derivative liabilities 533 — 533 — Total liabilities $533 $— $533 $— (1) Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives. The following table presents assets and liabilities measured at fair value including gross derivative assets and liabilities on a recurring basis at December 31, 2016 : (in millions) Total Level 1 Level 2 Level 3 Securities available for sale: Mortgage-backed securities $19,446 $— $19,446 $— State and political subdivisions 8 — 8 — Equity securities 17 — 17 — U.S. Treasury 30 30 — — Total securities available for sale 19,501 30 19,471 — Loans held for sale, at fair value: Residential loans held for sale 504 — 504 — Commercial loans held for sale 79 — 79 — Total loans held for sale, at fair value 583 — 583 — Derivative assets: Interest rate swaps 609 — 609 — Foreign exchange contracts 134 — 134 — Other contracts 16 — 16 — Total derivative assets 759 — 759 — Other investment securities, at fair value: Money market mutual fund 91 91 — — Other investments 5 — 5 — Total other investment securities, at fair value 96 91 5 — Total assets $20,939 $121 $20,818 $— Derivative liabilities: Interest rate swaps $645 $— $645 $— Foreign exchange contracts 126 — 126 — Other contracts 7 — 7 — Total derivative liabilities 778 — 778 — Total liabilities $778 $— $778 $—
Summary of difference between aggregated fair value and unpaid principal balance of loans held for sale	The following table presents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans held for sale measured at fair value: December 31, 2017 December 31, 2016 (in millions) Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Aggregate Unpaid Principal Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Aggregate Unpaid Principal Residential mortgage loans held for sale, at fair value $326 $326 $— $504 $505 ($1 ) Commercial and commercial real estate loans held for sale, at fair value 171 171 — 79 79 —
Gains (losses) on assets and liabilities measured on a nonrecurring basis included in earnings	The following table presents gains (losses) on assets and liabilities measured at fair value on a nonrecurring basis and recorded in earnings: Year Ended December 31, (in millions) 2017 2016 2015 Impaired collateral-dependent loans ($35 ) ($33 ) ($32 ) MSRs 2 4 9 Foreclosed assets (3 ) (3 ) (3 ) Leased assets (15 ) 11 —
Fair value of assets and liabilities measured on a nonrecurring basis	The following table presents assets and liabilities measured at fair value on a nonrecurring basis: December 31, 2017 December 31, 2016 (in millions) Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Impaired collateral-dependent loans $393 $— $393 $— $355 $— $355 $— MSRs 218 — — 218 182 — — 182 Foreclosed assets 31 — 31 — 44 — 44 — Leased assets 112 — 112 — 158 — 158 —
Assets and liabilities measured at fair value	The following table presents the estimated fair value for financial instruments not recorded at fair value in the Consolidated Financial Statements. The carrying amounts are recorded in the Consolidated Balance Sheets under the indicated captions: December 31, 2017 Total Level 1 Level 2 Level 3 (in millions) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Securities held to maturity $4,685 $4,668 $— $— $4,685 $4,668 $— $— Other investment securities, at cost 722 722 — — 722 722 — — Other loans held for sale 221 221 — — — — 221 221 Loans and leases 110,617 111,168 — — 393 393 110,224 110,775 Financial Liabilities: Deposits 115,089 115,039 — — 115,089 115,039 — — Federal funds purchased and securities sold under agreements to repurchase 815 815 — — 815 815 — — Other short-term borrowed funds 1,856 1,856 — — 1,856 1,856 — — Long-term borrowed funds 11,765 11,891 — — 11,765 11,891 — — December 31, 2016 Total Level 1 Level 2 Level 3 (in millions) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Financial Assets: Securities held to maturity $5,071 $5,058 $— $— $5,071 $5,058 $— $— Other investment securities, at cost 942 942 — — 942 942 — — Other loans held for sale 42 42 — — — — 42 42 Loans and leases 107,669 107,537 — — 355 355 107,314 107,182 Financial Liabilities: Deposits 109,804 109,796 — — 109,804 109,796 — — Federal funds purchased and securities sold under agreements to repurchase 1,148 1,148 — — 1,148 1,148 — — Other short-term borrowed funds 3,211 3,211 — — 3,211 3,211 — — Long-term borrowed funds 12,790 12,849 — — 12,790 12,849 — —

OTHER INCOME (Tables)

OTHER INCOME (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Details of other income	The following table presents the details of other income: Year Ended December 31, (in millions) 2017 2016 2015 Bank-owned life insurance income $54 $54 $56 Other 37 105 50 Other income $91 $159 $106

OTHER OPERATING EXPENSE (Tables

OTHER OPERATING EXPENSE (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Schedule of other operating expense	The following table presents the details of other operating expense: Year Ended December 31, (in millions) 2017 2016 2015 Deposit insurance $137 $120 $115 Promotional expense 105 98 101 Settlements and operating losses 54 62 43 Other 251 246 271 Other operating expense $547 $526 $530

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Comprehensive Income Tax	Total income tax expense is presented below: Year Ended December 31, (in millions) 2017 2016 2015 Income tax expense $260 $489 $423 Tax effect of changes in OCI (7 ) (168 ) (12 ) Total comprehensive income tax expense $253 $321 $411
Schedule of Components of Income Tax Expense	Components of income tax expense are presented below: (in millions) Current Deferred Total Year Ended December 31, 2017 U.S. federal $376 ($142 ) $234 State and local 20 6 26 Total $396 ($136 ) $260 Year Ended December 31, 2016 U.S. federal $292 $159 $451 State and local 44 (6 ) 38 Total $336 $153 $489 Year Ended December 31, 2015 U.S. federal $162 $225 $387 State and local 12 24 36 Total $174 $249 $423
Schedule of Effective Income Tax Rate Reconciliation	The effective income tax rate differed from the U.S. federal income tax rate of 35% in 2017 , 2016 and 2015 as presented below: Year Ended December 31, 2017 2016 2015 (in millions, except ratio data) Amount Rate Amount Rate Amount Rate U.S. Federal income tax expense and tax rate $669 35.0 % $537 35.0 % $442 35.0 % Increase (decrease) resulting from: 2017 Tax Legislation (331 ) (17.3 %) — — — — State and local income taxes (net of federal benefit) 46 2.4 38 2.5 27 2.1 Bank-owned life insurance (19 ) (1.0 ) (19 ) (1.2 ) (20 ) (1.6 ) Tax-exempt interest (21 ) (1.1 ) (19 ) (1.3 ) (17 ) (1.3 ) Tax advantaged investments (including related credits) (51 ) (2.7 ) (31 ) (2.0 ) (16 ) (1.2 ) Other tax credits (3 ) (0.1 ) (14 ) (0.9 ) — — Adjustments for uncertain tax positions (23 ) (1.2 ) — — — — Non-deductible expenses — — — — 8 0.6 Other (7 ) (0.4 ) (3 ) (0.2 ) (1 ) (0.1 ) Total income tax expense and tax rate $260 13.6 % $489 31.9 % $423 33.5 %
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities are presented below: December 31, (in millions) 2017 2016 Deferred tax assets: Other comprehensive income $271 $409 Allowance for credit losses 310 471 State net operating loss carryforwards 88 75 Accrued expenses not currently deductible 40 129 Investment and other tax credit carryforwards 65 52 Deferred income — 22 Fair value adjustments 27 40 Other — 6 Total deferred tax assets 801 1,204 Valuation allowance (105 ) (107 ) Deferred tax assets, net of valuation allowance 696 1,097 Deferred tax liabilities: Leasing transactions 525 881 Amortization of intangibles 352 522 Depreciation 182 234 Pension and other employee compensation plans 110 103 Partnerships 37 22 Deferred Income 27 — MSRs 34 49 Total deferred tax liabilities 1,267 1,811 Net deferred tax liability $571 $714
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is presented below: December 31, (in millions) 2017 2016 2015 Balance at the beginning of the year $42 $62 $72 Gross decrease for tax positions related to prior years (27 ) (19 ) (6 ) Gross increase for tax positions related to prior years — 1 — Decreases for tax positions as a result of the lapse of the statutes of limitations (1 ) (2 ) (3 ) Decreases for tax positions related to settlements with taxing authorities (9 ) — (1 ) Balance at end of year $5 $42 $62

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of earnings per share	Year Ended December 31, (in millions, except share and per-share data) 2017 2016 2015 Numerator (basic and diluted): Net income $1,652 $1,045 $840 Less: Preferred stock dividends 14 14 7 Net income available to common stockholders $1,638 $1,031 $833 Denominator: Weighted-average common shares outstanding - basic 502,157,440 522,093,545 535,599,731 Dilutive common shares: share-based awards 1,527,651 1,837,173 2,621,167 Weighted-average common shares outstanding - diluted 503,685,091 523,930,718 538,220,898 Earnings per common share: Basic $3.26 $1.97 $1.55 Diluted 3.25 1.97 1.55

REGULATORY MATTERS (Tables)

REGULATORY MATTERS (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The following table presents the Company’s capital and capital ratios under U.S. Basel III Standardized Transitional rules. The Company has declared itself as an “AOCI opt-out” institution, which means the Company is not required to recognize in regulatory capital the impacts of net unrealized gains and losses included within AOCI for securities that are available for sale or held to maturity, accumulated net gains and losses on cash-flow hedges and certain defined benefit pension plan assets. Transitional Basel III FDIA Requirements Actual Minimum Capital Adequacy Classification as Well-capitalized (6) (in millions, except ratio data) Amount Ratio Amount Ratio (5) Amount Ratio As of December 31, 2017 Common equity tier 1 capital (1) $14,309 11.2 % $7,342 5.750 % $8,300 6.5 % Tier 1 capital (2) 14,556 11.4 9,258 7.250 10,215 8.0 Total capital (3) 17,781 13.9 11,812 9.250 12,769 10.0 Tier 1 leverage (4) 14,556 10.0 5,824 4.000 7,280 5.0 As of December 31, 2016 Common equity tier 1 capital (1) $13,822 11.2 % $6,348 5.125 % $8,051 6.5 % Tier 1 capital (2) 14,069 11.4 8,206 6.625 9,909 8.0 Total capital (3) 17,347 14.0 10,683 8.625 12,386 10.0 Tier 1 leverage (4) 14,069 9.9 5,667 4.000 7,084 5.0 (1) “Common equity tier 1 capital ratio” represents CET1 capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (2) “Tier 1 capital ratio” is tier 1 capital, which includes CET1 capital plus non-cumulative perpetual preferred equity that qualifies as additional tier 1 capital, divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (3) “Total capital ratio” is total capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach. (4) “Tier 1 leverage ratio” is tier 1 capital divided by quarterly average total assets as defined under U.S. Basel III Standardized approach. (5) “Minimum Capital ratio” includes capital conservation buffer of 1.250% for 2017 and 0.625% for 2016; N/A to Tier 1 leverage. (6) Presented for informational purposes. Prompt corrective action provisions apply only to the Company’s insured depository institutions - CBNA and CBPA.

BUSINESS OPERATING SEGMENTS (Ta

BUSINESS OPERATING SEGMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of segment reporting information	As of and for the Year Ended December 31, 2017 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,651 $1,411 $111 $4,173 Noninterest income 905 538 91 1,534 Total revenue 3,556 1,949 202 5,707 Noninterest expense 2,593 772 109 3,474 Profit before provision for credit losses 963 1,177 93 2,233 Provision for credit losses 265 19 37 321 Income before income tax expense (benefit) 698 1,158 56 1,912 Income tax expense (benefit) 246 384 (370 ) 260 Net income $452 $774 $426 $1,652 Total average assets $59,714 $49,747 $40,492 $149,953 As of and for the Year Ended December 31, 2016 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,443 $1,288 $27 $3,758 Noninterest income 883 466 148 1,497 Total revenue 3,326 1,754 175 5,255 Noninterest expense 2,547 741 64 3,352 Profit before provision for credit losses 779 1,013 111 1,903 Provision for credit losses 243 47 79 369 Income before income tax expense (benefit) 536 966 32 1,534 Income tax expense (benefit) 191 335 (37 ) 489 Net income $345 $631 $69 $1,045 Total average assets $56,388 $47,159 $39,636 $143,183 As of and for the Year Ended December 31, 2015 (in millions) Consumer Banking Commercial Banking Other Consolidated Net interest income $2,198 $1,162 $42 $3,402 Noninterest income 910 415 97 1,422 Total revenue 3,108 1,577 139 4,824 Noninterest expense 2,456 709 94 3,259 Profit before provision for credit losses 652 868 45 1,565 Provision for credit losses 252 (13 ) 63 302 Income (loss) before income tax expense (benefit) 400 881 (18 ) 1,263 Income tax expense (benefit) 138 302 (17 ) 423 Net income (loss) $262 $579 ($1 ) $840 Total average assets $52,848 $42,800 $39,422 $135,070

PARENT COMPANY FINANCIALS (Tabl

PARENT COMPANY FINANCIALS (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Statements of Operations	Condensed Statements of Operations Year Ended December 31, (in millions) 2017 2016 2015 OPERATING INCOME: Income from consolidated subsidiaries and excluding equity in undistributed earnings: Dividends from banking subsidiaries $1,055 $555 $345 Interest 43 53 54 Management and service fees 31 26 20 Income from nonbank subsidiaries and excluding equity in undistributed earnings: Dividends from nonbank subsidiaries 4 — — Interest 1 — — Equity securities gains 1 3 3 All other operating income 1 7 4 Total operating income 1,136 644 426 OPERATING EXPENSE: Salaries and employee benefits 40 37 15 Interest expense 97 99 108 All other expenses 22 15 38 Total operating expense 159 151 161 Income before taxes and undistributed income 977 493 265 Income taxes (10 ) (26 ) (29 ) Income before undistributed earnings of subsidiaries 987 519 294 Equity in undistributed earnings of subsidiaries: Bank 655 522 543 Nonbank 10 4 3 Net income $1,652 $1,045 $840 Other comprehensive (loss) income, net of income taxes: Net pension plan activity arising during the period ($1 ) ($2 ) $1 Net unrealized derivative instrument gains (losses) arising during the period 1 (8 ) 2 Net unrealized securities losses arising during the period — — (2 ) Other comprehensive (loss) income activity of the Parent Company, net of income taxes — (10 ) 1 Other comprehensive loss activity of Bank subsidiaries, net of income taxes (7 ) (271 ) (16 ) Total other comprehensive loss, net of income taxes (7 ) (281 ) (15 ) Total comprehensive income $1,645 $764 $825
Condensed Balance Sheets	Condensed Balance Sheets (in millions) December 31, 2017 December 31, 2016 ASSETS: Cash and due from banks $563 $671 Loans and advances to: Bank subsidiaries 1,160 1,156 Nonbank subsidiaries 70 20 Investments in subsidiaries: Bank subsidiaries 20,765 20,116 Nonbank subsidiaries 73 50 Other assets 125 128 TOTAL ASSETS $22,756 $22,141 LIABILITIES: Long-term borrowed funds due to: Unaffiliated companies $2,320 $2,318 Other liabilities 166 76 TOTAL LIABILITIES 2,486 2,394 TOTAL STOCKHOLDERS’ EQUITY 20,270 19,747 TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY $22,756 $22,141
Condensed Cash Flow Statements	Condensed Cash Flow Statements Year Ended December 31, (in millions) 2017 2016 2015 OPERATING ACTIVITIES Net income $1,652 $1,045 $840 Adjustments to reconcile net income to net cash provided by operating activities: Deferred income taxes (11 ) 5 49 Gain on sales of assets (1 ) (3 ) (3 ) Equity in undistributed earnings of subsidiaries (665 ) (526 ) (546 ) Increase (decrease) in other liabilities 99 (19 ) (48 ) Decrease (increase) in other assets 5 35 (16 ) Other operating, net (1 ) (4 ) 3 Total adjustments (574 ) (512 ) (561 ) Net cash provided by operating activities 1,078 533 279 INVESTING ACTIVITIES Proceeds from sales of securities available for sale — — 8 Investments in and advances to subsidiaries (230 ) (40 ) (215 ) Repayment of investments in and advances to subsidiaries 167 588 376 Other investing, net (1 ) (2 ) — Net cash (used) provided by investing activities (64 ) 546 169 FINANCING ACTIVITIES Proceeds from issuance of long-term borrowed funds — 349 1,000 Repayments of long-term borrowed funds — (625 ) (750 ) Proceeds from issuance of common stock 34 22 27 Treasury stock purchased (820 ) (430 ) (500 ) Net proceeds from issuance of preferred stock — — 247 Dividends declared and paid to common stockholders (322 ) (241 ) (214 ) Dividends declared and paid to preferred stockholders (14 ) (14 ) (7 ) Net cash used by financing activities (1,122 ) (939 ) (197 ) (Decrease) increase in cash and due from banks (108 ) 140 251 Cash and due from banks at beginning of year 671 531 280 Cash and due from banks at end of year $563 $671 $531

BASIS OF PRESENTATION Narrative

BASIS OF PRESENTATION Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Future minimum lease payments	$ 842
Reclassification of tax effects resulting from the 2017 Tax Legislation	$ 145

CASH AND DUE FROM BANKS (Detail

CASH AND DUE FROM BANKS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Interest-bearing cash and due from banks	$ 2,045	$ 2,749
Interest rate on FRB balances	1.50%
Interest earned on FRB balances	$ 16	$ 7	$ 4

SECURITIES - Narrative (Details

SECURITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Taxable interest income from investment securities	$ 625	$ 584	$ 621
Impaired debt securities sold	0	0	0
Pretax non-credit related losses were deferred in OCI	0	27	36
Available-for-sale Securities
Schedule of Available-for-sale Securities [Line Items]
Cumulative credit losses recognized in earnings	80	75	66	$ 62
Credit impairments recognized in earnings on securities that have been previously impaired	7	12	7
Available-for-sale Securities | Proprietary Internal Model
Schedule of Available-for-sale Securities [Line Items]
Credit impairments recognized in earnings on securities that have been previously impaired		5
Held-to-maturity Securities
Schedule of Available-for-sale Securities [Line Items]
Cumulative credit losses recognized in earnings	0	0	0
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Securitizations of mortgage loans	$ 134	$ 68	3
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Value of held-to-maturity security sold			73
Gain on other than temporary impairments			$ 2

SECURITIES - Schedule of Invest

SECURITIES - Schedule of Investments (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Securities Available-for-sale, Amortized Cost		$ 20,394	$ 19,713
Securities Available-for-sale, Gross Unrealized Gains		47	80
Securities Available-for-sale, Gross Unrealized Losses		(284)	(292)
Securities Available-for-sale, Fair Value	[1]	20,157	19,501
Securities Held-to-maturity, Amortized Cost		4,685	5,071
Securities Held-to-maturity, Gross Unrealized Gain		29	31
Securities Held-to-maturity, Gross Unrealized Losses		(46)	(44)
Securities held-to-maturity, Fair Value		4,668	5,058
Money market mutual fund, Amortized Cost		165	91
Money market mutual fund, Gross Unrealized Gains		0	0
Money market mutual fund, Gross Unrealized Losses		0	0
Money market mutual fund, Fair Value		165	91
Total other investment securities, at fair value, Amortized Cost		169	96
Total other investments securities, at fair value, Gross Unrealized Gains		0	0
Total other investments securities, at fair value, Gross Unrealized Losses		0	0
Total other investment securities, at fair value		169	96
Other Investment Securities, at Cost, Amortized Cost Basis		7	0
Other Investment Securities, at Cost, Accumulated Gross Unrealized Gain, before Tax		0	0
Other Investment Securities, at Cost, Accumulated Gross Unrealized Loss, before Tax		0	0
Other Investment Securities, at Cost		7	0
Total other investment securities, at cost		722	942
Total other investment securities, at cost, Gross Unrealized Gain		0	0
Total other investment securities, at cost, Gross Unrealized Losses		0	0
Total other investment securities, at cost, Fair Value		722	942
U.S. Treasury and other
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		12	30
Debt Securities Available-for-sale, Gross Unrealized Gains		0	0
Debt Securities Available-for-sale, Gross Unrealized Losses		0	0
Debt Securities Available-for-sale, Fair Value		12	30
State and political subdivisions
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		6	8
Debt Securities Available-for-sale, Gross Unrealized Gains		0	0
Debt Securities Available-for-sale, Gross Unrealized Losses		0	0
Debt Securities Available-for-sale, Fair Value		6	8
Federal agencies and U.S. government sponsored entities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		20,065	19,231
Debt Securities Available-for-sale, Gross Unrealized Gains		40	78
Debt Securities Available-for-sale, Gross Unrealized Losses		(277)	(264)
Debt Securities Available-for-sale, Fair Value		19,828	19,045
Securities Held-to-maturity, Amortized Cost		3,853	4,126
Securities Held-to-maturity, Gross Unrealized Gain		7	12
Securities Held-to-maturity, Gross Unrealized Losses		(46)	(44)
Securities held-to-maturity, Fair Value		3,814	4,094
Other/non-agency
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		311	427
Debt Securities Available-for-sale, Gross Unrealized Gains		7	2
Debt Securities Available-for-sale, Gross Unrealized Losses		(7)	(28)
Debt Securities Available-for-sale, Fair Value		311	401
Securities Held-to-maturity, Amortized Cost		832	945
Securities Held-to-maturity, Gross Unrealized Gain		22	19
Securities Held-to-maturity, Gross Unrealized Losses		0	0
Securities held-to-maturity, Fair Value		854	964
Total mortgage-backed securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		20,376	19,658
Debt Securities Available-for-sale, Gross Unrealized Gains		47	80
Debt Securities Available-for-sale, Gross Unrealized Losses		(284)	(292)
Debt Securities Available-for-sale, Fair Value		20,139	19,446
Total debt securities available for sale
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities Available-for-sale, Amortized Cost		20,394	19,696
Debt Securities Available-for-sale, Gross Unrealized Gains		47	80
Debt Securities Available-for-sale, Gross Unrealized Losses		(284)	(292)
Debt Securities Available-for-sale, Fair Value		20,157	19,484
Marketable equity securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Equity Securities Available-for-sale, Amortized Cost		0	5
Equity Securities Available-for-sale, Gross Unrealized Gains		0	0
Equity Securities Available-for-sale, Gross Unrealized Losses		0	0
Equity Securities Available-for-sale, Fair Value		0	5
Other equity securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Equity Securities Available-for-sale, Amortized Cost		0	12
Equity Securities Available-for-sale, Gross Unrealized Gains		0	0
Equity Securities Available-for-sale, Gross Unrealized Losses		0	0
Equity Securities Available-for-sale, Fair Value		0	12
Total equity securities available for sale
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Equity Securities Available-for-sale, Amortized Cost		0	17
Equity Securities Available-for-sale, Gross Unrealized Gains		0	0
Equity Securities Available-for-sale, Gross Unrealized Losses		0	0
Equity Securities Available-for-sale, Fair Value		0	17
Other investments
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Other investments, Amortized Cost		4	5
Other investments, Accumulated Gross Unrealized Gains		0	0
Other investments, Accumulated Gross Unrealized Losses		0	0
Other investments, Fair Value		4	5
Federal Reserve Bank stock
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Federal Reserve Bank stock, Amortized Cost		463	463
Federal Reserve Bank stock, Gross Unrealized Gains		0	0
Federal Reserve Bank stock, Gross Unrealized Losses		0	0
Federal Reserve Bank stock, Fair Value		463	463
Federal Home Loan Bank stock
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Federal Home Loan Bank stock, Amortized Cost		252	479
Federal Home Loan Bank stock, Gross Unrealized Gain		0	0
Federal Home Loan Bank stock, Gross Unrealized Losses		0	0
Federal Home Loan Bank stock, Fair Value		$ 252	$ 479
[1]	Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.

SECURITIES - Schedule of Availa

SECURITIES - Schedule of Available for Sale Securities Debt Maturities (Details) $ in Millions	Dec. 31, 2017USD ($)
Amortized Cost:
Amortized Cost, Debt securities available for sale, Maturity of 1 Year or Less	$ 13
Amortized Cost, Debt securities available for sale, Maturity of 1-5 Years	282
Amortized Cost, Debt securities available for sale, Maturity of 5-10 Years	1,067
Amortized Cost, Debt securities available for sale, Maturity After 10 Years	19,032
Amortized Cost, Debt securities available for sale, Total	20,394
Amortized Cost, Debt securities held to maturity, Maturity of 1 Year or Less	0
Amortized Cost, Debt securities held to maturity, Maturity of 1-5 Years	0
Amortized Cost, Debt securities held to maturity, Maturity of 5-10 Years	0
Amortized Cost, Debt securities held to maturity, Maturity After 10 Years	4,685
Amortized Cost, Debt securities held to maturity, Total	4,685
Total amortized cost of debt securities, Maturity of 1 Year or Less	13
Total amortized cost of debt securities, Maturity of 1-5 Years	282
Total amortized cost of debt securities, Maturity of 5-10 Years	1,067
Total amortized cost of debt securities, Maturity After 10 Years	23,717
Total amortized cost of debt securities, Total	25,079
Fair Value:
Fair Value, Debt securities available for sale, Maturity of 1 Year or Less	13
Fair Value, Debt securities available for sale, Maturity of 1-5 Years	282
Fair Value, Debt securities available for sale, Maturity of 5-10 Years	1,071
Fair Value, Debt securities available for sale, Maturity After 10 Years	18,791
Fair Value, Debt securities available for sale, Total	20,157
Fair Value, Debt securities held to maturity, Maturity of 1 Year or Less	0
Fair Value, Debt securities held to maturity, Maturity of 1-5 Years	0
Fair Value, Debt securities held to maturity, Maturity of 5-10 Years	0
Fair Value, Debt securities held to maturity, Maturity After 10 Years	4,668
Fair Value, Debt securities held to maturity, Total	4,668
Total fair value of debt securities, Maturity of 1 Year or Less	13
Total fair value of debt securities, Maturity of 1-5 Years	282
Total fair value of debt securities, Maturity of 5-10 Years	1,071
Total fair value of debt securities, Maturity After 10 Years	23,459
Total fair value of debt securities, Total	24,825
U.S. Treasury and other
Amortized Cost:
Amortized Cost, Debt securities available for sale, Maturity of 1 Year or Less	12
Amortized Cost, Debt securities available for sale, Maturity of 1-5 Years	0
Amortized Cost, Debt securities available for sale, Maturity of 5-10 Years	0
Amortized Cost, Debt securities available for sale, Maturity After 10 Years	0
Amortized Cost, Debt securities available for sale, Total	12
Fair Value:
Fair Value, Debt securities available for sale, Maturity of 1 Year or Less	12
Fair Value, Debt securities available for sale, Maturity of 1-5 Years	0
Fair Value, Debt securities available for sale, Maturity of 5-10 Years	0
Fair Value, Debt securities available for sale, Maturity After 10 Years	0
Fair Value, Debt securities available for sale, Total	12
State and political subdivisions
Amortized Cost:
Amortized Cost, Debt securities available for sale, Maturity of 1 Year or Less	0
Amortized Cost, Debt securities available for sale, Maturity of 1-5 Years	0
Amortized Cost, Debt securities available for sale, Maturity of 5-10 Years	0
Amortized Cost, Debt securities available for sale, Maturity After 10 Years	6
Amortized Cost, Debt securities available for sale, Total	6
Fair Value:
Fair Value, Debt securities available for sale, Maturity of 1 Year or Less	0
Fair Value, Debt securities available for sale, Maturity of 1-5 Years	0
Fair Value, Debt securities available for sale, Maturity of 5-10 Years	0
Fair Value, Debt securities available for sale, Maturity After 10 Years	6
Fair Value, Debt securities available for sale, Total	6
Federal agencies and U.S. government sponsored entities
Amortized Cost:
Amortized Cost, Debt securities available for sale, Maturity of 1 Year or Less	0
Amortized Cost, Debt securities available for sale, Maturity of 1-5 Years	261
Amortized Cost, Debt securities available for sale, Maturity of 5-10 Years	1,067
Amortized Cost, Debt securities available for sale, Maturity After 10 Years	18,737
Amortized Cost, Debt securities available for sale, Total	20,065
Amortized Cost, Debt securities held to maturity, Maturity of 1 Year or Less	0
Amortized Cost, Debt securities held to maturity, Maturity of 1-5 Years	0
Amortized Cost, Debt securities held to maturity, Maturity of 5-10 Years	0
Amortized Cost, Debt securities held to maturity, Maturity After 10 Years	3,853
Amortized Cost, Debt securities held to maturity, Total	3,853
Fair Value:
Fair Value, Debt securities available for sale, Maturity of 1 Year or Less	0
Fair Value, Debt securities available for sale, Maturity of 1-5 Years	261
Fair Value, Debt securities available for sale, Maturity of 5-10 Years	1,071
Fair Value, Debt securities available for sale, Maturity After 10 Years	18,496
Fair Value, Debt securities available for sale, Total	19,828
Fair Value, Debt securities held to maturity, Maturity of 1 Year or Less	0
Fair Value, Debt securities held to maturity, Maturity of 1-5 Years	0
Fair Value, Debt securities held to maturity, Maturity of 5-10 Years	0
Fair Value, Debt securities held to maturity, Maturity After 10 Years	3,814
Fair Value, Debt securities held to maturity, Total	3,814
Other/non-agency
Amortized Cost:
Amortized Cost, Debt securities available for sale, Maturity of 1 Year or Less	1
Amortized Cost, Debt securities available for sale, Maturity of 1-5 Years	21
Amortized Cost, Debt securities available for sale, Maturity of 5-10 Years	0
Amortized Cost, Debt securities available for sale, Maturity After 10 Years	289
Amortized Cost, Debt securities available for sale, Total	311
Amortized Cost, Debt securities held to maturity, Maturity of 1 Year or Less	0
Amortized Cost, Debt securities held to maturity, Maturity of 1-5 Years	0
Amortized Cost, Debt securities held to maturity, Maturity of 5-10 Years	0
Amortized Cost, Debt securities held to maturity, Maturity After 10 Years	832
Amortized Cost, Debt securities held to maturity, Total	832
Fair Value:
Fair Value, Debt securities available for sale, Maturity of 1 Year or Less	1
Fair Value, Debt securities available for sale, Maturity of 1-5 Years	21
Fair Value, Debt securities available for sale, Maturity of 5-10 Years	0
Fair Value, Debt securities available for sale, Maturity After 10 Years	289
Fair Value, Debt securities available for sale, Total	311
Fair Value, Debt securities held to maturity, Maturity of 1 Year or Less	0
Fair Value, Debt securities held to maturity, Maturity of 1-5 Years	0
Fair Value, Debt securities held to maturity, Maturity of 5-10 Years	0
Fair Value, Debt securities held to maturity, Maturity After 10 Years	854
Fair Value, Debt securities held to maturity, Total	$ 854

SECURITIES - Income Recognized

SECURITIES - Income Recognized from Investment Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Sale of Investments [Abstract]
Gains on sale of debt securities	$ 11	$ 18	$ 41
Losses on sale of debt securities	0	(2)	(12)
Debt securities gains, net	11	16	29
Equity securities gains	$ 1	$ 3	$ 3

SECURITIES - Schedule of Securi

SECURITIES - Schedule of Securities Pledged (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Pledged against repurchase agreements, Amortized Cost	$ 358	$ 631
Pledged against FHLB borrowed funds, Amortized Cost	839	953
Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law, Amortized Cost	3,113	3,575
Pledged against repurchase agreements, Fair Value	357	620
Pledged against FHLB borrowed funds, Fair Value	861	972
Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law, Fair Value	$ 3,082	$ 3,563

SECURITIES - Other than tempora

SECURITIES - Other than temporary impairment recognized in earnings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Total other-than-temporary impairment losses	$ (7)	$ (39)	$ (43)
Portions of loss recognized in other comprehensive income (before taxes)	0	27	36
Net securities impairment losses recognized in earnings	$ (7)	$ (12)	$ (7)

SECURITIES - Schedule of Inve68

SECURITIES - Schedule of Investments in Continuous Loss Positions (Details) $ in Millions	Dec. 31, 2017USD ($)Securities	Dec. 31, 2016USD ($)Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, number of issues | Securities	300	328
Less than 12 months, fair value	$ 10,218	$ 15,403
Less than 12 months, gross unrealized losses	$ (98)	$ (292)
12 months or longer, number of issues | Securities	162	45
12 months or longer, fair value	$ 8,145	$ 763
12 months or longer, gross unrealized losses	$ (232)	$ (44)
Total, number of issues | Securities	462	373
Total, fair value	$ 18,363	$ 16,166
Total, gross unrealized losses	$ (330)	$ (336)
State and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, number of issues | Securities		1
Less than 12 months, fair value		$ 8
Less than 12 months, gross unrealized losses		$ 0
12 months or longer, number of issues | Securities		0
12 months or longer, fair value		$ 0
12 months or longer, gross unrealized losses		$ 0
Total, number of issues | Securities		1
Total, fair value		$ 8
Total, gross unrealized losses		$ 0
Federal agencies and U.S. government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, number of issues | Securities	294	323
Less than 12 months, fair value	$ 10,163	$ 15,387
Less than 12 months, gross unrealized losses	$ (97)	$ (292)
12 months or longer, number of issues | Securities	152	25
12 months or longer, fair value	$ 8,061	$ 461
12 months or longer, gross unrealized losses	$ (226)	$ (16)
Total, number of issues | Securities	446	348
Total, fair value	$ 18,224	$ 15,848
Total, gross unrealized losses	$ (323)	$ (308)
Other/non-agency
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, number of issues | Securities	6	4
Less than 12 months, fair value	$ 55	$ 8
Less than 12 months, gross unrealized losses	$ (1)	$ 0
12 months or longer, number of issues | Securities	10	20
12 months or longer, fair value	$ 84	$ 302
12 months or longer, gross unrealized losses	$ (6)	$ (28)
Total, number of issues | Securities	16	24
Total, fair value	$ 139	$ 310
Total, gross unrealized losses	$ (7)	$ (28)
Total mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, number of issues | Securities	300	327
Less than 12 months, fair value	$ 10,218	$ 15,395
Less than 12 months, gross unrealized losses	$ (98)	$ (292)
12 months or longer, number of issues | Securities	162	45
12 months or longer, fair value	$ 8,145	$ 763
12 months or longer, gross unrealized losses	$ (232)	$ (44)
Total, number of issues | Securities	462	372
Total, fair value	$ 18,363	$ 16,158
Total, gross unrealized losses	$ (330)	$ (336)

SECURITIES - Schedule of Cumula

SECURITIES - Schedule of Cumulative Credit Losses Recognized in Earnings (Details) - Available-for-sale Securities - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Cumulative balance at beginning of period		$ 75	$ 66	$ 62
Credit impairments recognized in earnings on securities that have been previously impaired		7	12	7
Reductions due to increases in cash flow expectations on impaired securities (1)	[1]	(2)	(3)	(3)
Cumulative balance at end of period		$ 80	$ 75	$ 66
[1]	Reported in interest income from investment securities on the Consolidated Statements of Operations.

LOANS AND LEASES - Narrative (D

LOANS AND LEASES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Sales	$ 886	$ 901
Loans held for sale	497	583
Other loans held for sale	221	42
Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	497	583
Other loans held for sale	0	0
Level 2 | Residential loans held for sale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	326	504
Level 2 | Commercial loans held for sale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	171	79
TDR Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans sold	78	310
Gain (loss) on sales of loans	17	72
Residential mortgages | TDR Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans sold	49	255
Commercial | TDR Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans sold	6
Retail | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral for FHLB borrowed funds	24,900	24,000
Loans pledged as collateral to support the contingent ability to borrow at the FRB discount window	18,100	16,800
Retail | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Sales	254	699
Retail | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Sales	$ 29	$ 55

LOANS AND LEASES - Summary of L

LOANS AND LEASES - Summary of Loans and Leases Portfolio (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[1],[2]	$ 110,617	$ 107,669
Loans held for sale		718	625
Mortgage loans serviced for others | Banking Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		20,300	17,300
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		52,031	51,651
Commercial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		37,562	37,274
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		11,308	10,624
Commercial | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		3,161	3,753
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		58,586	56,018
Retail | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		17,045	15,115
Retail | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		1,392	1,858
Retail | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		13,483	14,100
Retail | Home equity loans serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		542	750
Retail | Home equity lines of credit serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		149	219
Retail | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		13,204	13,938
Retail | Education
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[3]	8,134	6,610
Retail | Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		1,848	1,691
Retail | Other retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		$ 2,789	$ 1,737
[1]	Excluded from the table above are loans held for sale totaling $718 million and $625 million as of December 31, 2017 and 2016, respectively.
[2]	Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $20.3 billion and $17.3 billion at December 31, 2017 and 2016, respectively.
[3]	During first quarter 2017, student loans were renamed “education” loans. Refer to Note 1 “Significant Accountant Policies” for more information.

LOANS AND LEASES - Loan Purchas

LOANS AND LEASES - Loan Purchases and Sales (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	$ 1,015	$ 2,458
Sales	886	901
Retail | Education
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	862	1,224
Sales	0	0
Retail | Automobile
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	153	695
Sales	0	0
Retail | Residential mortgages
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	0	539
Sales	254	699
Retail | Home equity loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	0	0
Sales	29	55
Commercial | Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchases	0	0
Sales	$ 603	$ 147

LOANS AND LEASES - Summary of I

LOANS AND LEASES - Summary of Investments in Leases (Details) - Leases - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Direct financing leases	$ 3,122	$ 3,670
Leveraged leases	39	83
Total leases	$ 3,161	$ 3,753

LOANS AND LEASES - Components o

LOANS AND LEASES - Components of Investments in Leases (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total future minimum lease rentals	$ 2,347
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total future minimum lease rentals	2,347	$ 2,922
Estimated residual value of leased equipment (non-guaranteed)	1,072	1,166
Initial direct costs	15	20
Unearned income on minimum lease rentals and estimated residual value of leased equipment	(273)	(355)
Total leases	$ 3,161	$ 3,753

LOANS AND LEASES - Future Minim

LOANS AND LEASES - Future Minimum Payments Receivable (Details) $ in Millions	Dec. 31, 2017USD ($)
Receivables [Abstract]
2,018	$ 602
2,019	553
2,020	399
2,021	300
2,022	201
Thereafter	292
Total	$ 2,347

ALLOWANCE FOR CREDIT LOSSES, 76

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses		$ 321		$ 369	$ 302
Minimum qualifying balance		3
Nonperforming assets, net of valuation allowance		36		49
Mortgage loans collateralized by OREO		$ 181		$ 177
High loan to value criteria (exceeds)		90.00%		90.00%
Allowance for loan and lease losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses		$ 305	[1]	$ 355	305
Allowance for loan and lease losses | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses		248	[1]	$ 242	$ 266
Scenario, Adjustment | Allowance for loan and lease losses | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses	[1]	$ (50)
[1]	Includes an increase of approximately $50 million to commercial and corresponding decrease to retail for the impact of the enhancement to the assessment of qualitative risks, factors and events that may not be measured in the modeled results.

ALLOWANCE FOR CREDIT LOSSES, 77

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Summary of Changes in Allowance for Credit Losses (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		$ 1,236
Provision charged to income		321		$ 369	$ 302
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		1,236		1,236
Allowance for loan and lease losses
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		1,236		1,216	1,195
Charge-offs		(512)		(536)	(480)
Recoveries		207		201	196
Net charge-offs		(305)		(335)	(284)
Provision charged to income		305	[1]	355	305
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		1,236		1,236	1,216
Reserve for unfunded lending commitments
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		72		58	61
Provision for unfunded lending commitments		16		14	(3)
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		88		72	58
Allowance for loan and lease losses and reserve for off-balance sheet activities, total
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		1,308		1,274
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		1,324		1,308	1,274
Commercial | Allowance for loan and lease losses
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		663		596	544
Charge-offs		(75)		(79)	(36)
Recoveries		40		33	49
Net charge-offs		(35)		(46)	13
Provision charged to income		57	[1]	113	39
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		685		663	596
Commercial | Reserve for unfunded lending commitments
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		72		58	61
Provision for unfunded lending commitments		16		14	(3)
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		88		72	58
Commercial | Allowance for loan and lease losses and reserve for off-balance sheet activities, total
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		735		654
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		773		735	654
Retail | Allowance for loan and lease losses
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		573		620	651
Charge-offs		(437)		(457)	(444)
Recoveries		167		168	147
Net charge-offs		(270)		(289)	(297)
Provision charged to income		248	[1]	242	266
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		551		573	620
Retail | Reserve for unfunded lending commitments
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		0		0	0
Provision for unfunded lending commitments		0		0	0
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		0		0	0
Retail | Allowance for loan and lease losses and reserve for off-balance sheet activities, total
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Beginning balance		573		620
Allowance for loan and lease losses / Reserve for unfunded lending commitments, Ending balance		551		$ 573	$ 620
Scenario, Adjustment | Commercial | Allowance for loan and lease losses
Allowance for Loan and Lease Losses [Roll Forward]
Provision charged to income	[1]	50
Scenario, Adjustment | Retail | Allowance for loan and lease losses
Allowance for Loan and Lease Losses [Roll Forward]
Provision charged to income	[1]	$ (50)
[1]	Includes an increase of approximately $50 million to commercial and corresponding decrease to retail for the impact of the enhancement to the assessment of qualitative risks, factors and events that may not be measured in the modeled results.

ALLOWANCE FOR CREDIT LOSSES, 78

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Recorded Investment in Loan and Leases (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated	$ 1,131	$ 1,223
Formula-based evaluation	109,486	106,446
Total	110,617	107,669
Commercial
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated	370	424
Formula-based evaluation	51,661	51,227
Total	52,031	51,651
Retail
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated	761	799
Formula-based evaluation	57,825	55,219
Total	$ 58,586	$ 56,018

ALLOWANCE FOR CREDIT LOSSES, 79

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Summary of Allowance for Credit Losses by Evaluation Method (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated	$ 81	$ 106
Formula-based evaluation	1,243	1,202
Allowance for credit losses	1,324	1,308
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated	47	63
Formula-based evaluation	726	672
Allowance for credit losses	773	735
Retail
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated	34	43
Formula-based evaluation	517	530
Allowance for credit losses	$ 551	$ 573

ALLOWANCE FOR CREDIT LOSSES, 80

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Recorded Investment in Commercial Loans and Leases by Regulatory Classification Ratings (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 110,617	$ 107,669
Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	52,031	51,651
Commercial | Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Total	52,031	51,651
Commercial | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	37,562	37,274
Commercial | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	11,308	10,624
Commercial | Leases
Financing Receivable, Recorded Investment [Line Items]
Total	3,161	3,753
Commercial | Pass | Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Total	49,205	48,739
Commercial | Pass | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	35,430	35,010
Commercial | Pass | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	10,706	10,146
Commercial | Pass | Leases
Financing Receivable, Recorded Investment [Line Items]
Total	3,069	3,583
Commercial | Special Mention | Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Total	1,716	1,437
Commercial | Special Mention | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	1,143	1,015
Commercial | Special Mention | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	500	370
Commercial | Special Mention | Leases
Financing Receivable, Recorded Investment [Line Items]
Total	73	52
Commercial | Substandard | Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Total	878	1,188
Commercial | Substandard | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	785	1,027
Commercial | Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	74	58
Commercial | Substandard | Leases
Financing Receivable, Recorded Investment [Line Items]
Total	19	103
Commercial | Doubtful | Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Total	232	287
Commercial | Doubtful | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total	204	222
Commercial | Doubtful | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	28	50
Commercial | Doubtful | Leases
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 15

ALLOWANCE FOR CREDIT LOSSES, 81

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Recorded Investment in Retail Loans by Delinquency Status (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 1,456	$ 1,465
Total	110,617	107,669
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	501	404
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	163	116
Financing Receivables, 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	792	945
Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	58,586	56,018
Retail | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	16,714	14,807
Past Due	184	200
Total	17,045	15,115
Retail | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,212	1,628
Past Due	78	103
Total	1,392	1,858
Retail | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	12,756	13,432
Past Due	289	272
Total	13,483	14,100
Retail | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	477	673
Past Due	36	36
Total	542	750
Retail | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	116	158
Past Due	12	36
Total	149	219
Retail | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,596	12,509
Past Due	335	252
Total	13,204	13,938
Retail | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,898	6,379
Past Due	76	80
Total	8,134	6,610
Retail | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,747	1,611
Past Due	38	37
Total	1,848	1,691
Retail | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,679	1,676
Past Due	42	16
Total	2,789	1,737
Retail | Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	55,195	52,873
Total	58,586	56,018
Retail | Financing Receivables, 1 to 29 Days Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	147	108
Retail | Financing Receivables, 1 to 29 Days Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	102	127
Retail | Financing Receivables, 1 to 29 Days Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	438	396
Retail | Financing Receivables, 1 to 29 Days Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	29	41
Retail | Financing Receivables, 1 to 29 Days Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	21	25
Retail | Financing Receivables, 1 to 29 Days Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,273	1,177
Retail | Financing Receivables, 1 to 29 Days Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	160	151
Retail | Financing Receivables, 1 to 29 Days Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	63	43
Retail | Financing Receivables, 1 to 29 Days Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	68	45
Retail | Financing Receivables, 1 to 29 Days Past Due | Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,301	2,113
Retail | Financing Receivables, 30 to 59 Days Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	46	53
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20	23
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	78	57
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10	14
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	3
Retail | Financing Receivables, 30 to 59 Days Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	220	172
Retail | Financing Receivables, 30 to 59 Days Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	23	24
Retail | Financing Receivables, 30 to 59 Days Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	12
Retail | Financing Receivables, 30 to 59 Days Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20	8
Retail | Financing Receivables, 30 to 59 Days Past Due | Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	433	366
Retail | Financing Receivables, 60 to 89 Days Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	18	12
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	7
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	23	20
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	5
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	2
Retail | Financing Receivables, 60 to 89 Days Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	55	38
Retail | Financing Receivables, 60 to 89 Days Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	13
Retail | Financing Receivables, 60 to 89 Days Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9	9
Retail | Financing Receivables, 60 to 89 Days Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	4
Retail | Financing Receivables, 60 to 89 Days Past Due | Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	138	110
Retail | Financing Receivables, 90 Days or More Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	120	135
Retail | Financing Receivables, 90 Days or More Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	54	73
Retail | Financing Receivables, 90 Days or More Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	188	195
Retail | Financing Receivables, 90 Days or More Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	22	17
Retail | Financing Receivables, 90 Days or More Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7	31
Retail | Financing Receivables, 90 Days or More Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	60	42
Retail | Financing Receivables, 90 Days or More Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	41	43
Retail | Financing Receivables, 90 Days or More Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	17	16
Retail | Financing Receivables, 90 Days or More Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10	4
Retail | Financing Receivables, 90 Days or More Past Due | Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 519	$ 556

ALLOWANCE FOR CREDIT LOSSES, 82

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Nonperforming Loans and Leases by Class (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	$ 871	$ 1,045
Loans accruing and 90 days or more past due		32	26
GNMA loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans sold with right to repurchase		30	32
Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans accruing and 90 days or more past due		15	18
Commercial | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	265	387
Loans accruing and 90 days or more past due		8	2
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	238	322
Loans accruing and 90 days or more past due		5	2
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	27	50
Loans accruing and 90 days or more past due		3	0
Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	0	15
Loans accruing and 90 days or more past due		0	0
Retail | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	606	658
Loans accruing and 90 days or more past due		24	24
Retail | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	128	144
Loans accruing and 90 days or more past due		16	18
Retail | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	72	98
Loans accruing and 90 days or more past due		0	0
Retail | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	233	243
Loans accruing and 90 days or more past due		0	0
Retail | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	25	32
Loans accruing and 90 days or more past due		0	0
Retail | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	18	33
Loans accruing and 90 days or more past due		0	0
Retail | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	70	50
Loans accruing and 90 days or more past due		0	0
Retail | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	38	38
Loans accruing and 90 days or more past due		3	5
Retail | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	17	16
Loans accruing and 90 days or more past due		0	0
Retail | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans	[1]	5	4
Loans accruing and 90 days or more past due		$ 5	$ 1
[1]	Nonperforming balances exclude first lien residential mortgage loans that are 100% guaranteed by the Federal Housing Administration. These loans, which are accruing and 90 days or more past due, totaled $15 million and $18 million as of December 31, 2017 and 2016, respectively. Nonperforming balances also exclude guaranteed residential mortgage loans sold to GNMA for which the Company has the right, but not the obligation, to repurchase. These loans totaled $30 million and $32 million as of December 31, 2017 and 2016, respectively. These loans are included in the Company’s Consolidated Balance Sheets.

ALLOWANCE FOR CREDIT LOSSES, 83

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Performance Indicators for Nonperforming Assets (Details)	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	0.79%	0.97%
Nonperforming assets as a percentage of total assets	0.60%	0.73%
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	0.24%	0.36%
Nonperforming assets as a percentage of total assets	0.17%	0.26%
Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	0.55%	0.61%
Nonperforming assets as a percentage of total assets	0.43%	0.47%

ALLOWANCE FOR CREDIT LOSSES, 84

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Accruing and Nonaccruing Past Due Amounts (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 1,456	$ 1,465
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	501	404
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	163	116
Financing Receivables, 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	792	945
Commercial | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	366	433
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	273	364
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	88	53
Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5	16
Commercial | Financing Receivables, 30 to 59 Days Past Due | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	68	38
Commercial | Financing Receivables, 30 to 59 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	26	36
Commercial | Financing Receivables, 30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	38	1
Commercial | Financing Receivables, 30 to 59 Days Past Due | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	1
Commercial | Financing Receivables, 60 to 89 Days Past Due | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	25	6
Commercial | Financing Receivables, 60 to 89 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	4
Commercial | Financing Receivables, 60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20	2
Commercial | Financing Receivables, 60 to 89 Days Past Due | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	0
Commercial | Financing Receivables, 90 Days or More Past Due | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	273	389
Commercial | Financing Receivables, 90 Days or More Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	243	324
Commercial | Financing Receivables, 90 Days or More Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	30	50
Commercial | Financing Receivables, 90 Days or More Past Due | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	15
Retail | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,090	1,032
Retail | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	184	200
Retail | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	78	103
Retail | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	289	272
Retail | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	36	36
Retail | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	36
Retail | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	335	252
Retail | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	76	80
Retail | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	38	37
Retail | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	42	16
Retail | Financing Receivables, 30 to 59 Days Past Due | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	433	366
Retail | Financing Receivables, 30 to 59 Days Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	46	53
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20	23
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	78	57
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10	14
Retail | Financing Receivables, 30 to 59 Days Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	3
Retail | Financing Receivables, 30 to 59 Days Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	220	172
Retail | Financing Receivables, 30 to 59 Days Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	23	24
Retail | Financing Receivables, 30 to 59 Days Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	12
Retail | Financing Receivables, 30 to 59 Days Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20	8
Retail | Financing Receivables, 60 to 89 Days Past Due | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	138	110
Retail | Financing Receivables, 60 to 89 Days Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	18	12
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	7
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	23	20
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	5
Retail | Financing Receivables, 60 to 89 Days Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	2
Retail | Financing Receivables, 60 to 89 Days Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	55	38
Retail | Financing Receivables, 60 to 89 Days Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	13
Retail | Financing Receivables, 60 to 89 Days Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9	9
Retail | Financing Receivables, 60 to 89 Days Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12	4
Retail | Financing Receivables, 90 Days or More Past Due | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	519	556
Retail | Financing Receivables, 90 Days or More Past Due | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	120	135
Retail | Financing Receivables, 90 Days or More Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	54	73
Retail | Financing Receivables, 90 Days or More Past Due | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	188	195
Retail | Financing Receivables, 90 Days or More Past Due | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	22	17
Retail | Financing Receivables, 90 Days or More Past Due | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7	31
Retail | Financing Receivables, 90 Days or More Past Due | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	60	42
Retail | Financing Receivables, 90 Days or More Past Due | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	41	43
Retail | Financing Receivables, 90 Days or More Past Due | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	17	16
Retail | Financing Receivables, 90 Days or More Past Due | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 10	$ 4

ALLOWANCE FOR CREDIT LOSSES, 85

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Impaired Loans by Class (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	$ 506	$ 634
Allowance on Impaired Loans	81	106
Impaired Loans Without a Related Allowance	625	589
Unpaid Contractual Balance	1,364	1,443
Total Recorded Investment in Impaired Loans	1,131	1,223
Commercial | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	208	286
Allowance on Impaired Loans	47	63
Impaired Loans Without a Related Allowance	162	138
Unpaid Contractual Balance	443	475
Total Recorded Investment in Impaired Loans	370	424
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	183	247
Allowance on Impaired Loans	42	55
Impaired Loans Without a Related Allowance	159	134
Unpaid Contractual Balance	403	431
Total Recorded Investment in Impaired Loans	342	381
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	25	39
Allowance on Impaired Loans	5	8
Impaired Loans Without a Related Allowance	3	4
Unpaid Contractual Balance	40	44
Total Recorded Investment in Impaired Loans	28	43
Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	0	0
Allowance on Impaired Loans	0	0
Impaired Loans Without a Related Allowance	0	0
Unpaid Contractual Balance	0	0
Total Recorded Investment in Impaired Loans	0	0
Retail | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	298	348
Allowance on Impaired Loans	34	43
Impaired Loans Without a Related Allowance	463	451
Unpaid Contractual Balance	921	968
Total Recorded Investment in Impaired Loans	761	799
Retail | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	25	37
Allowance on Impaired Loans	2	2
Impaired Loans Without a Related Allowance	126	141
Unpaid Contractual Balance	197	235
Total Recorded Investment in Impaired Loans	151	178
Retail | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	41	51
Allowance on Impaired Loans	4	3
Impaired Loans Without a Related Allowance	80	94
Unpaid Contractual Balance	162	191
Total Recorded Investment in Impaired Loans	121	145
Retail | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	16	23
Allowance on Impaired Loans	1	1
Impaired Loans Without a Related Allowance	181	173
Unpaid Contractual Balance	241	240
Total Recorded Investment in Impaired Loans	197	196
Retail | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	29	41
Allowance on Impaired Loans	2	4
Impaired Loans Without a Related Allowance	22	19
Unpaid Contractual Balance	67	70
Total Recorded Investment in Impaired Loans	51	60
Retail | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	2	2
Allowance on Impaired Loans	0	0
Impaired Loans Without a Related Allowance	7	7
Unpaid Contractual Balance	14	13
Total Recorded Investment in Impaired Loans	9	9
Retail | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	2	4
Allowance on Impaired Loans	0	0
Impaired Loans Without a Related Allowance	21	15
Unpaid Contractual Balance	30	25
Total Recorded Investment in Impaired Loans	23	19
Retail | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	154	154
Allowance on Impaired Loans	17	25
Impaired Loans Without a Related Allowance	21	1
Unpaid Contractual Balance	175	155
Total Recorded Investment in Impaired Loans	175	155
Retail | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	24	26
Allowance on Impaired Loans	7	6
Impaired Loans Without a Related Allowance	1	0
Unpaid Contractual Balance	25	26
Total Recorded Investment in Impaired Loans	25	26
Retail | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Loans With a Related Allowance	5	10
Allowance on Impaired Loans	1	2
Impaired Loans Without a Related Allowance	4	1
Unpaid Contractual Balance	10	13
Total Recorded Investment in Impaired Loans	$ 9	$ 11

ALLOWANCE FOR CREDIT LOSSES, 86

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Additional Impaired Loan Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	$ 35	$ 35	$ 47
Average Recorded Investment	1,130	1,102	1,283
Commercial | Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	4	5	5
Average Recorded Investment	417	351	179
Commercial | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	4	5	4
Average Recorded Investment	380	295	135
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	0	0	1
Average Recorded Investment	37	53	44
Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	0	0	0
Average Recorded Investment	0	3	0
Retail | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	31	30	42
Average Recorded Investment	713	751	1,104
Retail | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	4	4	15
Average Recorded Investment	136	161	415
Retail | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	6	7	9
Average Recorded Investment	121	144	222
Retail | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	6	6	4
Average Recorded Investment	176	178	173
Retail | Home equity loans serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	3	3	4
Average Recorded Investment	49	60	75
Retail | Home equity lines of credit serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	0	0	0
Average Recorded Investment	9	9	9
Retail | Automobile
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	1	0	0
Average Recorded Investment	18	14	11
Retail | Education
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	9	7	7
Average Recorded Investment	173	150	157
Retail | Credit cards
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	2	2	2
Average Recorded Investment	22	23	26
Retail | Other retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Interest Income Recognized	0	1	1
Average Recorded Investment	$ 9	$ 12	$ 16

ALLOWANCE FOR CREDIT LOSSES, 87

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - TDRs and Unfunded Commitments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded commitments tied to TDRs	$ 39	$ 42
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR balance	129	120
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR balance	$ 761	$ 799

ALLOWANCE FOR CREDIT LOSSES, 88

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Troubled Debt Restructuring (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		$ 1	$ 8	$ 4
Charge-offs Resulting from Modification		$ 5	$ 4	$ 7
Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	2,724	2,585	2,834
Pre-Modification Outstanding Recorded Investment	[1]	$ 34	$ 37	$ 73
Post-Modification Outstanding Recorded Investment	[1]	$ 36	$ 37	$ 73
Maturity Extension
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	386	348	421
Pre-Modification Outstanding Recorded Investment	[2]	$ 65	$ 54	$ 66
Post-Modification Outstanding Recorded Investment	[2]	$ 66	$ 55	$ 65
Other
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	2,562	2,501	3,261
Pre-Modification Outstanding Recorded Investment	[3]	$ 164	$ 150	$ 165
Post-Modification Outstanding Recorded Investment	[3]	161	146	159
Commercial
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		(1)	3	(1)
Charge-offs Resulting from Modification		0	0	1
Commercial | Commercial
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		(1)	3	(1)
Charge-offs Resulting from Modification		0	0	1
Commercial | Commercial real estate
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		0	0	0
Commercial | Leases
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		$ 0	$ 0	$ 0
Commercial | Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	7	13	26
Pre-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 19
Post-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 19
Commercial | Interest Rate Reduction | Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	7	12	25
Pre-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 19
Post-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 19
Commercial | Interest Rate Reduction | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	0	1	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Commercial | Interest Rate Reduction | Leases
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	0	0	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Commercial | Maturity Extension
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	46	82	161
Pre-Modification Outstanding Recorded Investment	[2]	$ 22	$ 25	$ 22
Post-Modification Outstanding Recorded Investment	[2]	$ 22	$ 26	$ 22
Commercial | Maturity Extension | Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	45	81	160
Pre-Modification Outstanding Recorded Investment	[2]	$ 22	$ 20	$ 22
Post-Modification Outstanding Recorded Investment	[2]	$ 22	$ 21	$ 22
Commercial | Maturity Extension | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	1	1	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 5	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 5	$ 0
Commercial | Maturity Extension | Leases
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	0	0	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Commercial | Other
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	16	14	17
Pre-Modification Outstanding Recorded Investment	[3]	$ 70	$ 48	$ 38
Post-Modification Outstanding Recorded Investment	[3]	$ 71	$ 48	$ 38
Commercial | Other | Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	15	14	16
Pre-Modification Outstanding Recorded Investment	[3]	$ 70	$ 48	$ 34
Post-Modification Outstanding Recorded Investment	[3]	$ 71	$ 48	$ 34
Commercial | Other | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	1	0	1
Pre-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 4
Post-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 4
Commercial | Other | Leases
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	0	0	0
Pre-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[3]	0	0	0
Retail
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		2	5	5
Charge-offs Resulting from Modification		5	4	6
Retail | Residential mortgages
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		(1)	(1)	(1)
Charge-offs Resulting from Modification		0	0	0
Retail | Home equity loans
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	(1)	0
Charge-offs Resulting from Modification		0	0	1
Retail | Home equity lines of credit
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		1	1	2
Retail | Home equity loans serviced by others
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		0	0	1
Retail | Home equity lines of credit serviced by others
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		0	0	0
Retail | Automobile
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		0	0	0
Charge-offs Resulting from Modification		4	3	2
Retail | Education
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		2	4	4
Charge-offs Resulting from Modification		0	0	0
Retail | Credit cards
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		3	3	2
Charge-offs Resulting from Modification		0	0	0
Retail | Other retail
Financing Receivable, Modifications [Line Items]
Net Change to ALLL Resulting from Modification		(2)	0	0
Charge-offs Resulting from Modification		$ 0	$ 0	$ 0
Retail | Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	2,717	2,572	2,808
Pre-Modification Outstanding Recorded Investment	[1]	$ 33	$ 36	$ 54
Post-Modification Outstanding Recorded Investment	[1]	$ 35	$ 36	$ 54
Retail | Interest Rate Reduction | Residential mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	71	71	153
Pre-Modification Outstanding Recorded Investment	[1]	$ 9	$ 10	$ 31
Post-Modification Outstanding Recorded Investment	[1]	$ 10	$ 10	$ 31
Retail | Interest Rate Reduction | Home equity loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	82	97	96
Pre-Modification Outstanding Recorded Investment	[1]	$ 5	$ 6	$ 5
Post-Modification Outstanding Recorded Investment	[1]	$ 6	$ 6	$ 5
Retail | Interest Rate Reduction | Home equity lines of credit
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	50	49	4
Pre-Modification Outstanding Recorded Investment	[1]	$ 3	$ 4	$ 1
Post-Modification Outstanding Recorded Investment	[1]	$ 3	$ 4	$ 1
Retail | Interest Rate Reduction | Home equity loans serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	15	18	29
Pre-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 2
Post-Modification Outstanding Recorded Investment	[1]	$ 1	$ 1	$ 2
Retail | Interest Rate Reduction | Home equity lines of credit serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	5	8	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Retail | Interest Rate Reduction | Automobile
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	130	138	108
Pre-Modification Outstanding Recorded Investment	[1]	$ 2	$ 3	$ 2
Post-Modification Outstanding Recorded Investment	[1]	$ 2	$ 3	$ 2
Retail | Interest Rate Reduction | Education
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	0	0	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Retail | Interest Rate Reduction | Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	2,363	2,187	2,413
Pre-Modification Outstanding Recorded Investment	[1]	$ 13	$ 12	$ 13
Post-Modification Outstanding Recorded Investment	[1]	$ 13	$ 12	$ 13
Retail | Interest Rate Reduction | Other retail
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[1]	1	4	3
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0
Retail | Maturity Extension
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	340	266	260
Pre-Modification Outstanding Recorded Investment	[2]	$ 43	$ 29	$ 44
Post-Modification Outstanding Recorded Investment	[2]	$ 44	$ 29	$ 43
Retail | Maturity Extension | Residential mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	73	60	40
Pre-Modification Outstanding Recorded Investment	[2]	$ 12	$ 10	$ 7
Post-Modification Outstanding Recorded Investment	[2]	$ 13	$ 10	$ 6
Retail | Maturity Extension | Home equity loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	1	39	191
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 4	$ 35
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 5	$ 35
Retail | Maturity Extension | Home equity lines of credit
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	235	121	23
Pre-Modification Outstanding Recorded Investment	[2]	$ 30	$ 13	$ 2
Post-Modification Outstanding Recorded Investment	[2]	$ 30	$ 12	$ 2
Retail | Maturity Extension | Home equity loans serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	0	0	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Retail | Maturity Extension | Home equity lines of credit serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	2	5	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 1	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 1	$ 0
Retail | Maturity Extension | Automobile
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	29	41	5
Pre-Modification Outstanding Recorded Investment	[2]	$ 1	$ 1	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 1	$ 1	$ 0
Retail | Maturity Extension | Education
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	0	0	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Retail | Maturity Extension | Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	0	0	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Retail | Maturity Extension | Other retail
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[2]	0	0	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[2]	$ 0	$ 0	$ 0
Retail | Other
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	2,546	2,487	3,244
Pre-Modification Outstanding Recorded Investment	[3]	$ 94	$ 102	$ 127
Post-Modification Outstanding Recorded Investment	[3]	$ 90	$ 98	$ 121
Retail | Other | Residential mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	171	247	275
Pre-Modification Outstanding Recorded Investment	[3]	$ 19	$ 26	$ 33
Post-Modification Outstanding Recorded Investment	[3]	$ 19	$ 26	$ 33
Retail | Other | Home equity loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	232	279	448
Pre-Modification Outstanding Recorded Investment	[3]	$ 13	$ 18	$ 28
Post-Modification Outstanding Recorded Investment	[3]	$ 13	$ 17	$ 28
Retail | Other | Home equity lines of credit
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	395	304	320
Pre-Modification Outstanding Recorded Investment	[3]	$ 27	$ 23	$ 21
Post-Modification Outstanding Recorded Investment	[3]	$ 27	$ 22	$ 19
Retail | Other | Home equity loans serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	52	60	124
Pre-Modification Outstanding Recorded Investment	[3]	$ 2	$ 2	$ 6
Post-Modification Outstanding Recorded Investment	[3]	$ 2	$ 2	$ 5
Retail | Other | Home equity lines of credit serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	26	24	41
Pre-Modification Outstanding Recorded Investment	[3]	$ 2	$ 1	$ 3
Post-Modification Outstanding Recorded Investment	[3]	$ 2	$ 1	$ 2
Retail | Other | Automobile
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	1,336	1,081	812
Pre-Modification Outstanding Recorded Investment	[3]	$ 24	$ 20	$ 14
Post-Modification Outstanding Recorded Investment	[3]	$ 20	$ 18	$ 12
Retail | Other | Education
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	329	479	1,204
Pre-Modification Outstanding Recorded Investment	[3]	$ 7	$ 12	$ 22
Post-Modification Outstanding Recorded Investment	[3]	$ 7	$ 12	$ 22
Retail | Other | Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	0	0	0
Pre-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 0
Retail | Other | Other retail
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	[3]	5	13	20
Pre-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[3]	$ 0	$ 0	$ 0
[1]	Includes modifications that consist of multiple concessions, one of which is an interest rate reduction.
[2]	Includes modifications that consist of multiple concessions, one of which is a maturity extension (unless one of the other concessions was an interest rate reduction).
[3]	Includes modifications other than interest rate reductions or maturity extensions, such as lowering scheduled payments for a specified period of time, principal forgiveness, and capitalizing arrearages. Also included are the following: deferrals, trial modifications, certain bankruptcies, loans in forbearance and prepayment plans. Modifications can include the deferral of accrued interest resulting in post modification balances being higher than pre-modification.

ALLOWANCE FOR CREDIT LOSSES, 89

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Default of Modified Debt Agreements (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1,116	1,074	1,288
Balance Defaulted | $	$ 50	$ 60	$ 52
Commercial | Commercial Banking
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	9	23	23
Balance Defaulted | $	$ 9	$ 13	$ 2
Commercial | Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	8	22	23
Balance Defaulted | $	$ 5	$ 13	$ 2
Commercial | Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1	1	0
Balance Defaulted | $	$ 4	$ 0	$ 0
Commercial | Leases
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0	0
Balance Defaulted | $	$ 0	$ 0	$ 0
Retail | Retail
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1,107	1,051	1,265
Balance Defaulted | $	$ 41	$ 47	$ 50
Retail | Residential mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	152	187	168
Balance Defaulted | $	$ 19	$ 24	$ 21
Retail | Home equity loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	43	50	184
Balance Defaulted | $	$ 2	$ 3	$ 13
Retail | Home equity lines of credit
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	200	155	131
Balance Defaulted | $	$ 14	$ 13	$ 7
Retail | Home equity loans serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	23	37	43
Balance Defaulted | $	$ 0	$ 1	$ 1
Retail | Home equity lines of credit serviced by others
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	10	17	22
Balance Defaulted | $	$ 1	$ 0	$ 1
Retail | Automobile
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	140	110	87
Balance Defaulted | $	$ 1	$ 2	$ 1
Retail | Education
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	44	59	171
Balance Defaulted | $	$ 1	$ 1	$ 3
Retail | Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	491	433	455
Balance Defaulted | $	$ 3	$ 3	$ 3
Retail | Other retail
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	4	3	4
Balance Defaulted | $	$ 0	$ 0	$ 0

ALLOWANCE FOR CREDIT LOSSES, 90

ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Loans with Indicators of High Credit Risk (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 110,617	$ 107,669
High loan-to-value
Financing Receivable, Recorded Investment [Line Items]
Total	796	1,592
High loan-to-value | Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total	366	566
High loan-to-value | Home Equity Loans and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Total	166	550
High loan-to-value | Home Equity Products Serviced by Others
Financing Receivable, Recorded Investment [Line Items]
Total	264	476
High loan-to-value | Credit Cards
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
High loan-to-value | Education
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Interest only/negative amortization
Financing Receivable, Recorded Investment [Line Items]
Total	1,764	1,583
Interest only/negative amortization | Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total	1,763	1,582
Interest only/negative amortization | Home Equity Loans and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Interest only/negative amortization | Home Equity Products Serviced by Others
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Interest only/negative amortization | Credit Cards
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Interest only/negative amortization | Education
Financing Receivable, Recorded Investment [Line Items]
Total	1	1
Low introductory rate
Financing Receivable, Recorded Investment [Line Items]
Total	197	112
Low introductory rate | Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Low introductory rate | Home Equity Loans and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Low introductory rate | Home Equity Products Serviced by Others
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Low introductory rate | Credit Cards
Financing Receivable, Recorded Investment [Line Items]
Total	197	112
Low introductory rate | Education
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Multiple characteristics and other
Financing Receivable, Recorded Investment [Line Items]
Total	1	3
Multiple characteristics and other | Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total	1	3
Multiple characteristics and other | Home Equity Loans and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Multiple characteristics and other | Home Equity Products Serviced by Others
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Multiple characteristics and other | Credit Cards
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Multiple characteristics and other | Education
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Credit risk, loans with increased credit exposure
Financing Receivable, Recorded Investment [Line Items]
Total	2,758	3,290
Credit risk, loans with increased credit exposure | Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total	2,130	2,151
Credit risk, loans with increased credit exposure | Home Equity Loans and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Total	166	550
Credit risk, loans with increased credit exposure | Home Equity Products Serviced by Others
Financing Receivable, Recorded Investment [Line Items]
Total	264	476
Credit risk, loans with increased credit exposure | Credit Cards
Financing Receivable, Recorded Investment [Line Items]
Total	197	112
Credit risk, loans with increased credit exposure | Education
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1	$ 1

PREMISES, EQUIPMENT, AND SOFT91

PREMISES, EQUIPMENT, AND SOFTWARE - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Capital Leases of Lessee [Abstract]
Book value of capital leased assets	$ 30	$ 45
Capital leased assets accumulated depreciation	20	30
Depreciation expense	124	130	$ 116
Capitalized Software
Capitalized software, gross	1,700	1,500
Capitalized software, accumulated amortization	869	691
Amortization of software	180	170	$ 146
Assets subject to operating leases	$ 112	$ 158

PREMISES, EQUIPMENT, AND SOFT92

PREMISES, EQUIPMENT, AND SOFTWARE - Schedule of Premises and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total premises and equipment, gross	$ 2,590	$ 2,445
Less: accumulated depreciation	(1,905)	(1,844)
Total premises and equipment, net	$ 685	601
Land and land improvements
Property, Plant and Equipment [Line Items]
Useful life	10 years
Total premises and equipment, gross	$ 47	47
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Total premises and equipment, gross	$ 719	684
Buildings and leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Buildings and leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life	40 years
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total premises and equipment, gross	$ 1,824	$ 1,714
Furniture, fixtures and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture, fixtures and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	15 years

PREMISES, EQUIPMENT, AND SOFT93

PREMISES, EQUIPMENT, AND SOFTWARE - Schedule of Amortization (Details) $ in Millions	Dec. 31, 2017USD ($)
Capitalized Software, Expected Future Amortization Expense [Abstract]
2,018	$ 171
2,019	141
2,020	109
2,021	71
2,022	36
Thereafter	92
Total	620	[1]
In-process software	$ 178
[1]	Excluded from this balance is $178 million of in-process software at December 31, 2017.

LEASE COMMITMENTS - Aggregate M

LEASE COMMITMENTS - Aggregate Minimum Rental Commitments (Details) $ in Millions	Dec. 31, 2017USD ($)
Operating Leases
2,018	$ 171
2,019	148
2,020	130
2,021	111
2,022	81
Thereafter	201
Total minimum lease payments	842
Capital Leases
2,018	3
2,019	2
2,020	2
2,021	2
2,022	1
Thereafter	8
Total minimum lease payments	18
Amounts representing interest	(8)
Present value of net minimum lease payments	$ 10

LEASE COMMITMENTS - Narrative (

LEASE COMMITMENTS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Rent expense for operating leases and capital leases	$ 211	$ 208	$ 205

MORTGAGE BANKING - Residential

MORTGAGE BANKING - Residential Mortgage Loans (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan sale proceeds		$ 3,161	$ 2,652	$ 2,381
Valuation recoveries		2	4	9
Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residential mortgage loan sale proceeds	[1]	3,161	2,652	2,667
Gain on sales		35	69	51
Mortgage servicing fees		53	51	55
Repurchased residential mortgages		3	6	10
Valuation recoveries		$ (2)	$ (4)	$ (9)
[1]	Represents the unpaid principal balance at the time of the sale.

MORTGAGE BANKING - Changes Rela

MORTGAGE BANKING - Changes Related to MSRs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation allowance for servicing assets
Valuation recoveries	$ 2	$ 4	$ 9
Residential mortgages
MSRs
Balance as of beginning of period	167	173
Amount capitalized	37	29
Purchases	28	0
Amortization	(31)	(35)
Carrying amount before valuation allowance	201	167	173
Valuation allowance for servicing assets
Balance as of beginning of period	5	9
Valuation recoveries	(2)	(4)	(9)
Balance at end of period	3	5	$ 9
Net carrying value of MSRs	$ 198	$ 162

MORTGAGE BANKING - Economic Ass

MORTGAGE BANKING - Economic Assumptions Used to Estimate Value of MSRs (Details) - Residential mortgages - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Fair value	$ 218	$ 182
Weighted-average life (in years)	5 years 10 months 24 days	5 years 8 months 12 days
Weighted-average constant prepayment rate	10.00%	10.80%
Weighted-average discount rate	9.90%	9.70%
Minimum
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Weighted-average life (in years)	2 years 3 months 18 days	2 years 7 months 6 days
Weighted-average constant prepayment rate	6.60%	8.80%
Weighted-average discount rate	9.10%	9.10%
Maximum
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Weighted-average life (in years)	8 years 4 months 24 days	7 years 3 months 18 days
Weighted-average constant prepayment rate	20.10%	22.30%
Weighted-average discount rate	12.10%	12.10%

MORTGAGE BANKING - Economic A99

MORTGAGE BANKING - Economic Assumptions Used to Estimate Value of MSRs Capitalized (Details) - Residential mortgages	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Servicing Assets at Fair Value [Line Items]
Weighted-average life (in years)	7 years 3 months 18 days	6 years 1 month 6 days	5 years 10 months 24 days
Weighted-average constant prepayment rate	8.70%	11.00%	10.70%
Weighted-average discount rate	9.80%	9.70%	9.70%

MORTGAGE BANKING - Sensitivity

MORTGAGE BANKING - Sensitivity Analysis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Prepayment rate
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Decline in fair value from a 50 basis point decrease in interest rates	$ 22	$ 9
Decline in fair value from a 100 basis point decrease in interest rates	46	25
Weighted average discount rate
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Decline in fair value from a 50 basis point increase in weighted-average discount rate	4	3
Decline in fair value from a 100 basis point increase in weighted-average discount rate	$ 8	$ 6
Minimum
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Adverse change in basis points	0.50%	0.50%
Maximum
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Adverse change in basis points	1.00%	1.00%

GOODWILL - Narrative (Details)

GOODWILL - Narrative (Details)	12 Months Ended			360 Months Ended
	Dec. 31, 2017USD ($)reporting_unitsegment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)business
Goodwill [Line Items]
Number of segments | segment	2
Number of reporting units | reporting_unit	2
Number of acquisitions of banks or assets of banks | business				25
Goodwill acquired during period	$ 11,000,000
Goodwill impairment	0	$ 0	$ 0
Consumer Banking
Goodwill [Line Items]
Goodwill acquired during period	0
Goodwill accumulated impairment loss	5,900,000,000	5,900,000,000		$ 5,900,000,000
Commercial Banking
Goodwill [Line Items]
Goodwill acquired during period	11,000,000
Goodwill accumulated impairment loss	50,000,000	$ 50,000,000		$ 50,000,000
Western Reserve Partners, LLC
Goodwill [Line Items]
Goodwill acquired during period	$ 11,000,000

GOODWILL - Goodwill Rollforward

GOODWILL - Goodwill Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance	$ 6,876	$ 6,876
Business acquisition	11
Adjustments	0	0
Ending balance	6,887	6,876
Consumer Banking
Goodwill [Roll Forward]
Beginning balance	2,136	2,136
Business acquisition	0
Adjustments	0	0
Ending balance	2,136	2,136
Commercial Banking
Goodwill [Roll Forward]
Beginning balance	4,740	4,740
Business acquisition	11
Adjustments	0	0
Ending balance	$ 4,751	$ 4,740

VARIABLE INTEREST ENTITIES - Na

VARIABLE INTEREST ENTITIES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
LIHTC Investments
Variable Interest Entity [Line Items]
Net impairment losses recognized in earnings	$ 0	$ 0

VARIABLE INTEREST ENTITIES - Sc

VARIABLE INTEREST ENTITIES - Schedule of Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
LIHTC Investments
Variable Interest Entity [Line Items]
LIHTC investment included in other assets	$ 951	$ 793
LIHTC unfunded commitments included in other liabilities	491	428
Renewable Energy
Variable Interest Entity [Line Items]
Renewable energy investments included in other assets	$ 335	$ 220

VARIABLE INTEREST ENTITIES -105

VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - LIHTC Investments - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Tax credits included in income tax expense	$ 83	$ 59
Amortization expense included in income tax expense	94	59
Other tax benefits included in income tax expense	$ 31	$ 21

DEPOSITS - Narrative (Details)

DEPOSITS - Narrative (Details) $ in Millions	Dec. 31, 2017USD ($)
Banking and Thrift [Abstract]
Time deposits of $100,000 or more	$ 11,366

DEPOSITS - Major Components of

DEPOSITS - Major Components of Deposits (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deposits, by Type [Abstract]
Demand	$ 29,279	$ 28,472
Checking with interest	22,229	20,714
Regular savings	9,518	8,964
Money market accounts	37,454	38,176
Term deposits	16,609	13,478
Total deposits	$ 115,089	$ 109,804

DEPOSITS - Maturities of Term D

DEPOSITS - Maturities of Term Deposits (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Time Deposits, Fiscal Year Maturity [Abstract]
2,018	$ 13,754
2,019	1,985
2,020	351
2,021	452
2,022	62
2023 and thereafter	5
Total	$ 16,609	$ 13,478

DEPOSITS - Maturities of Ter109

DEPOSITS - Maturities of Term Deposits Greater than $100,000 (Details) $ in Millions	Dec. 31, 2017USD ($)
Contractual Maturities, Time Deposits, $100,000 or More [Abstract]
Three months or less	$ 4,948
After three months through six months	1,925
After six months through twelve months	3,040
After twelve months	1,453
Total term deposits	$ 11,366

BORROWED FUNDS - Narrative (Det

BORROWED FUNDS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017		Dec. 31, 2016
Debt Instrument [Line Items]
Hedging basis adjustments	$ 693	[1]	$ 759
Short-term borrowed funds	2,671		4,359
FHLB advances and letters of credit | Secured Debt
Debt Instrument [Line Items]
Short-term borrowed funds	9,400		13,400
FHLB advances
Debt Instrument [Line Items]
Available borrowing capacity	8,000		2,800
FRB advances
Debt Instrument [Line Items]
Available borrowing capacity	41,200
Parent company
Debt Instrument [Line Items]
Principal balance	2,300		2,300
Unamortized deferred issuance costs and/or discounts	(5)		(7)
Banking Subsidiaries
Debt Instrument [Line Items]
Principal balance	9,500		10,500
Unamortized deferred issuance costs and/or discounts	(19)		(12)
Hedging basis adjustments	$ (63)		$ (40)
[1]	Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives.

BORROWED FUNDS - Short Term Deb

BORROWED FUNDS - Short Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Total short-term borrowed funds	$ 2,671	$ 4,359
Federal funds purchased
Short-term Debt [Line Items]
Total short-term borrowed funds	460	533
Securities sold under agreements to repurchase
Short-term Debt [Line Items]
Total short-term borrowed funds	355	615
Other short-term borrowed funds
Short-term Debt [Line Items]
Total short-term borrowed funds	$ 1,856	$ 3,211

BORROWED FUNDS - Short Term Bor

BORROWED FUNDS - Short Term Borrowed Debt Key Data (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal funds purchased and securities sold under agreements to repurchase
Short-term Debt [Line Items]
Weighted-average interest rate at period end	[1]	0.74%	0.26%	0.15%
Maximum amount outstanding at month-end during the period	[2]	$ 1,174	$ 1,522	$ 5,375
Average amount outstanding during the period	[2]	$ 776	$ 947	$ 3,364
Weighted-average interest rate during the period	[1]	0.36%	0.09%	0.22%
Other short-term borrowed funds
Short-term Debt [Line Items]
Weighted-average interest rate at period end	[1]	1.72%	0.94%	0.44%
Maximum amount outstanding at month-end during the period		$ 3,508	$ 5,461	$ 7,004
Average amount outstanding during the period		$ 2,321	$ 3,207	$ 5,865
Weighted-average interest rate during the period	[1]	1.32%	0.64%	0.28%
[1]	Rates exclude certain hedging costs.
[2]	Balances are net of certain short-term receivables associated with reverse repurchase agreements, as applicable.

BORROWED FUNDS - Long Term Debt

BORROWED FUNDS - Long Term Debt (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term borrowed funds		$ 11,765	$ 12,790
Banking Subsidiaries
Debt Instrument [Line Items]
Long-term borrowed funds		9,445
Citizens Financial Group, Inc.
Debt Instrument [Line Items]
Long-term borrowed funds		$ 2,320
Senior Unsecured Notes | Banking Subsidiaries | 2.300% senior unsecured notes, due 2018
Debt Instrument [Line Items]
Interest rate		2.30%
Long-term borrowed funds	[1],[2]	$ 0	745
Senior Unsecured Notes | Banking Subsidiaries | 2.450% senior unsecured notes, due 2019
Debt Instrument [Line Items]
Interest rate		2.45%
Long-term borrowed funds	[1]	$ 743	747
Senior Unsecured Notes | Banking Subsidiaries | 2.500% senior unsecured notes, due 2019
Debt Instrument [Line Items]
Interest rate		2.50%
Long-term borrowed funds	[1]	$ 741	741
Senior Unsecured Notes | Banking Subsidiaries | 2.250% senior unsecured notes, due 2020 (1)
Debt Instrument [Line Items]
Interest rate		2.25%
Long-term borrowed funds	[1]	$ 692	0
Senior Unsecured Notes | Banking Subsidiaries | Floating rate senior unsecured notes, due 2020
Debt Instrument [Line Items]
Long-term borrowed funds	[1]	299	0
Senior Unsecured Notes | Banking Subsidiaries | Floating rate senior unsecured notes, due 2020
Debt Instrument [Line Items]
Long-term borrowed funds	[1]	$ 249	0
Senior Unsecured Notes | Banking Subsidiaries | 2.200% senior unsecured notes, due 2020
Debt Instrument [Line Items]
Interest rate		2.20%
Long-term borrowed funds	[1]	$ 498	0
Senior Unsecured Notes | Banking Subsidiaries | 2.250% senior unsecured notes, due 2020
Debt Instrument [Line Items]
Interest rate		2.25%
Long-term borrowed funds	[1]	$ 742	0
Senior Unsecured Notes | Banking Subsidiaries | 2.550% senior unsecured notes, due 2021
Debt Instrument [Line Items]
Interest rate		2.55%
Long-term borrowed funds	[1]	$ 964	965
Senior Unsecured Notes | Banking Subsidiaries | Floating-rate senior unsecured notes, due 2022
Debt Instrument [Line Items]
Long-term borrowed funds	[1]	$ 249	0
Senior Unsecured Notes | Banking Subsidiaries | 2.650% senior unsecured notes, due 2022
Debt Instrument [Line Items]
Interest rate		2.65%
Long-term borrowed funds	[1]	$ 491	0
Senior Unsecured Notes | Citizens Financial Group, Inc. | 2.375% fixed rate senior unsecured debt, due 2021
Debt Instrument [Line Items]
Interest rate		2.375%
Long-term borrowed funds		$ 349	348
Subordinated Debt | Citizens Financial Group, Inc. | 4.150% fixed rate subordinated debt, due 2022
Debt Instrument [Line Items]
Interest rate		4.15%
Long-term borrowed funds		$ 348	347
Subordinated Debt | Citizens Financial Group, Inc. | 5.158% fixed-to-floating rate subordinated debt, (LIBOR 3.56%) callable, due 2023
Debt Instrument [Line Items]
Interest rate		5.158%
Long-term borrowed funds		$ 333	333
Subordinated Debt | Citizens Financial Group, Inc. | 3.750% fixed rate subordinated debt due 2024
Debt Instrument [Line Items]
Interest rate		3.75%
Long-term borrowed funds		$ 250	250
Subordinated Debt | Citizens Financial Group, Inc. | 4.023% fixed rate subordinated debt, due 2024
Debt Instrument [Line Items]
Interest rate		4.023%
Long-term borrowed funds		$ 42	42
Subordinated Debt | Citizens Financial Group, Inc. | 4.350% fixed rate subordinated debt, due 2025
Debt Instrument [Line Items]
Interest rate		4.35%
Long-term borrowed funds		$ 249	249
Subordinated Debt | Citizens Financial Group, Inc. | 4.300% fixed rate subordinated debt, due 2025
Debt Instrument [Line Items]
Interest rate		4.30%
Long-term borrowed funds		$ 749	749
Subordinated Debt | Citizens Financial Group, Inc. | LIBOR | 5.158% fixed-to-floating rate subordinated debt, (LIBOR 3.56%) callable, due 2023
Debt Instrument [Line Items]
Interest rate		3.56%
Federal Home Loan advances | Banking Subsidiaries
Debt Instrument [Line Items]
Long-term borrowed funds		$ 3,761	7,264
Other | Banking Subsidiaries
Debt Instrument [Line Items]
Long-term borrowed funds		$ 16	$ 10
[1]	Issued under CBNA’s Global Bank Note Program
[2]	Reclassified to short-term borrowed funds.

BORROWED FUNDS - Maturities of

BORROWED FUNDS - Maturities of Long-term Borrowed Funds (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
2,018	$ 0
2,019	5,235
2,020	2,492
2,021	1,316
2,022	1,092
2023 and thereafter	1,630
Total	11,765	$ 12,790
Banking Subsidiaries
Debt Instrument [Line Items]
2,018	0
2,019	5,235
2,020	2,492
2,021	967
2,022	744
2023 and thereafter	7
Total	9,445
Citizens Financial Group, Inc.
Debt Instrument [Line Items]
2,018	0
2,019	0
2,020	0
2,021	349
2,022	348
2023 and thereafter	1,623
Total	$ 2,320

DERIVATIVES - Narrative (Detail

DERIVATIVES - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Derivative [Line Items]
Net gain (pre-tax) on derivatives expected to be reclassified in next 12 months	$ 1
Derivative Financial Instruments, Liabilities
Derivative [Line Items]
Change in derivative liability balance	(349)
Derivative Financial Instruments, Assets
Derivative [Line Items]
Change in derivative asset value	$ (10)

DERIVATIVES - Schedule of Deriv

DERIVATIVES - Schedule of Derivative Instruments (Details) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016
Derivative Assets
Derivative assets		$ 693	[1]	$ 759
Less: Gross amounts offset in the Consolidated Balance Sheets	[2]	(72)	[1]	(106)
Less: Cash collateral applied	[2]	(4)	[1]	(26)
Total net derivative fair values presented in the Consolidated Balance Sheets		617	[1]	627
Derivative Liabilities
Derivative Liabilities		533	[1]	778
Less: Gross amounts offset in the Consolidated Balance Sheets	[2]	(72)	[1]	(106)
Less: Cash collateral applied	[2]	(151)	[1]	(13)
Total net derivative fair values presented in the Consolidated Balance Sheets		310	[1]	659
Derivatives not designated as hedging instruments:
Derivative Assets
Derivative assets		693	[1]	707
Derivative Liabilities
Derivative Liabilities		533	[1]	585
Interest rate swaps
Derivative Assets
Derivative assets		538		609
Derivative Liabilities
Derivative Liabilities		379		645
Interest rate swaps | Derivatives designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Notional amount	[3]	13,300		13,350
Derivative Assets
Derivative assets		0	[1]	52
Derivative Liabilities
Derivative Liabilities		0	[1]	193
Interest rate swaps | Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Notional amount	[3]	80,180		54,656
Derivative Assets
Derivative assets		538	[1]	557
Derivative Liabilities
Derivative Liabilities		379	[1]	452
Foreign exchange contracts
Derivative Assets
Derivative assets		148		134
Derivative Liabilities
Derivative Liabilities		149		126
Foreign exchange contracts | Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Notional amount	[3]	9,882		8,039
Derivative Assets
Derivative assets		148	[1]	134
Derivative Liabilities
Derivative Liabilities		149	[1]	126
Other contracts
Derivative Assets
Derivative assets		7		16
Derivative Liabilities
Derivative Liabilities		5		7
Other contracts | Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Notional amount	[3]	1,039		1,498
Derivative Assets
Derivative assets		7	[1]	16
Derivative Liabilities
Derivative Liabilities		$ 5	[1]	$ 7
[1]	Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives.
[2]	Amounts represent the impact of enforceable master netting agreements that allow the Company to net settle positive and negative positions.
[3]	The notional or contractual amount of interest rate derivatives and foreign exchange contracts is the amount upon which interest and other payments under the contract are based. For interest rate contracts, the notional amount is typically not exchanged. Therefore, notional amounts should not be taken as the measure of credit or market risk, as they do not measure the true economic risk of these contracts.

DERIVATIVES - Schedule of Fair

DERIVATIVES - Schedule of Fair Value Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	$ 66	$ 65	$ 32
Hedge of interest rate risk | Other Income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	(26)	(6)	(2)
Hedged Item	27	5	2
Hedge Ineffectiveness	$ 1	$ (1)	$ 0

DERIVATIVES - Effect of Derivat

DERIVATIVES - Effect of Derivative Instruments on Net Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI to interest expense		$ (747)	$ (508)	$ (452)
Amount Reclassified from AOCI
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion of (loss) gain recognized in OCI	[1]	(23)	(100)	150
Amount Reclassified from AOCI | Net Unrealized (Losses) Gains on Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI to interest income	[2]	25	90	82
Amounts reclassified from OCI to interest expense	[2]	0	(27)	(59)
Amounts reclassified from OCI to other income	[3]	$ 0	$ (5)	$ 0
[1]	The cumulative effective gains and losses on the Company’s cash flow hedging activities are included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets.
[2]	This amount includes both (a) the amortization of effective gains and losses associated with the Company’s terminated cash flow hedges and (b) the current reporting period’s interest settlements realized on the Company’s active cash flow hedges. Both (a) and (b) were previously included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets and were subsequently recorded as adjustments to the interest income or expense of the underlying hedged item.
[3]	This includes gains and losses attributable to previously hedged cash flows where the likelihood occurrence of those cash flows is no longer probable.

DERIVATIVES - Effect of Custome

DERIVATIVES - Effect of Customer Derivatives and Economic Hedges on Net Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income		$ 66	$ 65	$ 32
Customer derivative contracts | Foreign exchange and trade finance fees | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[1]	5	(23)	140
Customer derivative contracts | Foreign exchange and trade finance fees | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[1]	172	(81)	(18)
Customer derivative contracts | Mortgage banking fees | Residential loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[2]	2	(2)	(4)
Economic hedges | Foreign exchange and trade finance fees | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[1]	46	70	(106)
Economic hedges | Foreign exchange and trade finance fees | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[1]	(151)	95	19
Economic hedges | Mortgage banking fees | Forward sale contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	[2]	$ (8)	$ 6	$ 1
[1]	Reported in foreign exchange and interest rate products on the Consolidated Statements of Operations.
[2]	Reported in mortgage banking fees on the Consolidated Statements of Operations.

EMPLOYEE BENEFITS - Narrative (

EMPLOYEE BENEFITS - Narrative (Details) - USD ($)	Sep. 07, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Years of service used in determining benefits		5 years
Net actuarial loss recorded in AOCI expected to be recognized during 2017		$ 17,000,000
401(k) Plan
Employer matching contribution, time of service required		1 year
Employer matching contribution percentage				100.00%		100.00%
Employer matching contribution, Percent of employees' pay				4.00%	5.00%	5.00%
Employer matching contribution, addition		2.00%
Employer contribution amount		$ 61,000,000	$ 55,000,000	$ 52,000,000
Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial losses		585,000,000
Employer contributions	$ 75,000,000	0	$ 75,000,000
Expected contribution		$ 0
Discount rate		3.67%	4.19%	4.64%
Non-Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial losses			$ 634,000,000
Employer contributions		$ 8,000,000	$ 8,000,000
Expected contribution		$ 8,000,000
Discount rate		3.53%	4.05%	4.54%
Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contribution		$ 2,000,000
Discount rate		3.20%	3.53%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Assumed annual rate of increase in the per capita cost of covered health care benefits		7.00%	7.00%
Ultimate health care cost trend rate		5.00%	5.00%

EMPLOYEE BENEFITS - Allocation

EMPLOYEE BENEFITS - Allocation of Plan Assets (Details)	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations	54.00%	49.60%
Equity securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Minimum target asset allocation	48.00%
Equity securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Minimum target asset allocation	58.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations	45.00%	45.20%
Debt securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Minimum target asset allocation	41.00%
Debt securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Minimum target asset allocation	51.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations	1.00%	5.20%

EMPLOYEE BENEFITS - Changes in

EMPLOYEE BENEFITS - Changes in the Fair Value of Pension Plan Assets, Projected Benefit Obligation, Funded Status, and Accumulated Benefit Obligation (Details) - USD ($) $ in Millions	Sep. 07, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets as of January 1		$ 104
Fair value of plan assets as of December 31		114	$ 104
Qualified Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets as of January 1		1,015	917
Actual return on plan assets		185	82
Employer contributions	$ 75	0	75
Benefits and administrative expenses paid		(61)	(59)
Fair value of plan assets as of December 31		1,139	1,015
Projected benefit obligation		1,089	1,024
Pension asset (obligation)		50	(9)
Accumulated benefit obligation		1,089	1,024
Non-Qualified Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets as of January 1		0	0
Actual return on plan assets		0	0
Employer contributions		8	8
Benefits and administrative expenses paid		(8)	(8)
Fair value of plan assets as of December 31		0	0
Projected benefit obligation		106	105
Pension asset (obligation)		(106)	(105)
Accumulated benefit obligation		$ 106	$ 105

EMPLOYEE BENEFITS - Plan Amount

EMPLOYEE BENEFITS - Plan Amounts Recognized in OCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Net periodic pension income	$ (2)	$ (1)	$ (7)
Net actuarial (gain) loss	(31)	54	7
Amortization of prior service credit	1	1	0
Amortization of net actuarial loss	(18)	(16)	(15)
Total recognized in other comprehensive income (loss)	(48)	39	(8)
Total recognized in net periodic pension cost and other comprehensive income (loss)	$ (50)	$ 38	$ (15)

EMPLOYEE BENEFITS - Schedule of

EMPLOYEE BENEFITS - Schedule of Net Periodic (Income) Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 3	$ 3
Interest cost	46	48	48
Expected return on plan assets	(69)	(68)	(74)
Amortization of actuarial loss	18	16	15
Net periodic pension (income) cost	(2)	(1)	(8)
Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3
Interest cost	42	44	44
Expected return on plan assets	(69)	(68)	(74)
Amortization of actuarial loss	16	14	13
Net periodic pension (income) cost	(8)	(7)	(14)
Non-Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	4	4	4
Expected return on plan assets	0	0	0
Amortization of actuarial loss	2	2	2
Net periodic pension (income) cost	$ 6	$ 6	$ 6

EMPLOYEE BENEFITS - Assumptions

EMPLOYEE BENEFITS - Assumptions Used in Determining Actuarial Present Value of Benefit Obligations and Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assumptions for benefit obligations
Expected long-term rate of return on plan assets	7.00%	7.50%	7.50%
Assumptions for net periodic pension cost
Expected long-term rate of return on plan assets	7.00%	7.50%	7.50%
Qualified Plan
Assumptions for benefit obligations
Discount rate	3.67%	4.19%	4.64%
Assumptions for net periodic pension cost
Discount rate	4.19%	4.64%	4.125%
Non-Qualified Plan
Assumptions for benefit obligations
Discount rate	3.53%	4.05%	4.54%
Assumptions for net periodic pension cost
Discount rate	4.05%	4.54%	3.875%

EMPLOYEE BENEFITS - Expected Fu

EMPLOYEE BENEFITS - Expected Future Benefit Payments (Details) $ in Millions	Dec. 31, 2017USD ($)
Qualified and Non-Qualified Plans
Expected benefit payments by fiscal year ended
December 31, 2018	$ 65
December 31, 2019	66
December 31, 2020	66
December 31, 2021	67
December 31, 2022	68
December 31, 2023 - 2027	346
Postretirement Benefit Plan
Expected benefit payments by fiscal year ended
December 31, 2018	2
December 31, 2019	2
December 31, 2020	1
December 31, 2021	1
December 31, 2022	1
December 31, 2023 - 2027	$ 5

EMPLOYEE BENEFITS - Fair Value

EMPLOYEE BENEFITS - Fair Value of Plan Assets (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		$ 114	$ 104
Investments measured at net asset value	[1]	1,024	918
Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			2
Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		8	10
Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		2
Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	2
Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		102	89
Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	1
Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			0
Level 1 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0
Level 1 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		114	104
Level 2 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			2
Level 2 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		8	10
Level 2 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		2
Level 2 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	2
Level 2 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		102	89
Level 2 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	1
Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			0
Level 3 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0
Level 3 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Investment
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		$ 1,138	$ 1,022
[1]	Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.

EMPLOYEE BENEFITS - Fair Val128

EMPLOYEE BENEFITS - Fair Value Estimated Using Net Asset Value per Share (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value	[1]	$ 1,024	$ 918
Unfunded commitments		0
Mutual funds | Liquid Cash Fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		11	9
Unfunded commitments		0
Mutual funds | Equity Mutual Fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value	[2]	0	40
Unfunded commitments	[2]	$ 0
Redemption notice period	[2]	7 days
Common and collective funds | Global equities funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		$ 472	386
Unfunded commitments		$ 0
Redemption notice period		3 days
Common and collective funds | Balanced funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		$ 214	193
Unfunded commitments		$ 0
Redemption notice period		2 days
Common and collective funds | Fixed income fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		$ 150	133
Unfunded commitments		$ 0
Redemption notice period		3 days
Managed portfolio, fixed income mutual fund | Managed Portfolio, Fixed Income Mutual Fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value	[3]	$ 35	30
Unfunded commitments	[3]	$ 0
Redemption notice period	[3]	1 day
Limited partnerships | International equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		$ 142	117
Unfunded commitments		$ 0
Redemption notice period		3 days
Limited partnerships | Offshore feeder fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments measured at net asset value		$ 0	$ 10
Unfunded commitments		$ 0
Redemption notice period		14 days
[1]	Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.
[2]	The equity mutual fund seeks to offer participants capital appreciation by primarily investing in common stocks via investments in several underlying funds of the same fund family. The principal investment objective is to generate positive total return.
[3]	The managed portfolio fixed income mutual fund seeks to outperform the Barclay’s U.S. Long Credit Index or similar benchmark.

EMPLOYEE BENEFITS - Assumpti129

EMPLOYEE BENEFITS - Assumptions Used in Determining the Net Periodic Benefit Cost of the Postretirement Benefits Plan (Details) - Postretirement Benefit Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.53%	3.93%
Ultimate health care cost trend rate	5.00%	5.00%
Effect on accumulated postretirement benefit obligation: One percent increase in assumed health care cost trend	$ 0	$ 0
Effect on accumulated postretirement benefit obligation: One percent decrease in assumed health care cost trend	$ 0	$ 0

RECLASSIFICATIONS OUT OF ACC130

RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		$ 19,747	$ 19,646	$ 19,268
Other-than-temporary impairment not recognized in earnings on securities		0	(17)	(22)
Reclassification of tax effects resulting from the 2017 Tax Legislation		145
Ending balance		20,270	19,747	19,646
Net Unrealized (Losses) Gains on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(88)	10	(69)
Other comprehensive income before reclassifications		(14)	(62)	93
Other-than-temporary impairment not recognized in earnings on securities			0	0
Amounts reclassified from other comprehensive income		(16)	(36)	(14)
Net other comprehensive loss		(30)	(98)	79
Reclassification of tax effects resulting from the 2017 Tax Legislation	[1]	(25)
Ending balance		(143)	(88)	10
Net Unrealized (Losses) Gains on Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(186)	(28)	74
Other comprehensive income before reclassifications		(6)	(139)	(66)
Other-than-temporary impairment not recognized in earnings on securities			(17)	(22)
Amounts reclassified from other comprehensive income		(2)	(2)	(14)
Net other comprehensive loss		(8)	(158)	(102)
Reclassification of tax effects resulting from the 2017 Tax Legislation	[1]	(42)
Ending balance		(236)	(186)	(28)
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(394)	(369)	(377)
Other comprehensive income before reclassifications		0	0	0
Other-than-temporary impairment not recognized in earnings on securities			0	0
Amounts reclassified from other comprehensive income		31	(25)	8
Net other comprehensive loss		31	(25)	8
Reclassification of tax effects resulting from the 2017 Tax Legislation	[1]	(78)
Ending balance		(441)	(394)	(369)
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(668)	(387)	(372)
Other comprehensive income before reclassifications		(20)	(201)	27
Other-than-temporary impairment not recognized in earnings on securities			(17)	(22)
Amounts reclassified from other comprehensive income		13	(63)	(20)
Net other comprehensive loss		(7)	(281)	(15)
Reclassification of tax effects resulting from the 2017 Tax Legislation	[1]	(145)
Ending balance		$ (820)	$ (668)	$ (387)
[1]	As of December 31, 2017, the balance of AOCI reflects the retrospective adoption of FASB ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. For further discussion, see Note 22 “Income Taxes.”

RECLASSIFICATIONS OUT OF ACC131

RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassifications out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense		$ (747)	$ (508)	$ (452)
Net securities impairment losses recognized in earnings		(7)	(12)	(7)
Salaries and employee benefits		(1,761)	(1,709)	(1,636)
Income before income tax expense		1,912	1,534	1,263
Income tax expense		260	489	423
NET INCOME		1,652	1,045	840
Amount Reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense		(6)	38	17
NET INCOME		(13)	63	20
Reclassification adjustment for net derivative gains (losses) included in net income: | Amount Reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	[1]	25	90	82
Interest expense	[1]	0	(27)	(59)
Other income		0	(5)	0
Income before income tax expense		25	58	23
Income tax expense		9	22	9
NET INCOME		16	36	14
Reclassification of net securities gains (losses) to net income: | Amount Reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Securities gains, net		11	16	29
Net securities impairment losses recognized in earnings		(7)	(12)	(7)
Income before income tax expense		4	4	22
Income tax expense		2	2	8
NET INCOME		2	2	14
Reclassification of changes related to the employee benefit plan: | Amount Reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and employee benefits		(48)	39	(8)
Income before income tax expense		(48)	39	(8)
Income tax expense		(17)	14	0
NET INCOME		$ (31)	$ 25	$ (8)
[1]	This amount includes both (a) the amortization of effective gains and losses associated with the Company’s terminated cash flow hedges and (b) the current reporting period’s interest settlements realized on the Company’s active cash flow hedges. Both (a) and (b) were previously included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets and were subsequently recorded as adjustments to the interest income or expense of the underlying hedged item.

RECLASSIFICATIONS OUT OF ACC132

RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE LOSS - Effects to Net Income of Amounts Reclassified Out of OCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net interest income	$ 4,173	$ 3,758	$ 3,402
Provision for credit losses	321	369	302
Noninterest income	1,534	1,497	1,422
Noninterest expense	3,474	3,352	3,259
Income before income tax expense	1,912	1,534	1,263
Income tax expense	260	489	423
NET INCOME	1,652	1,045	840
Amount Reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net interest income	25	63	23
Noninterest income	4	(1)	22
Noninterest expense	48	(39)	8
Income tax expense	(6)	38	17
NET INCOME	$ (13)	$ 63	$ 20

STOCKHOLDERS' EQUITY (Details)

STOCKHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 06, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Preferred Stock
Preferred stock, authorized (in shares)		100,000,000	100,000,000
Preferred stock, outstanding (in shares)		250,000	250,000
Preferred stock, par value (in dollars per share)		$ 25	$ 25
Preferred stock, redemption notice period		90 days
Treasury Stock
Cost of stock repurchase		$ 820	$ 430	$ 500
Treasury stock purchased (in shares)		22,362,401	17,332,684
Treasury stock purchased, price per share (in dollars per share)		$ 36.67	$ 24.81
Treasury stock purchased - increase (decrease) in treasury stock account		$ (820)	$ (430)	(500)
Deferred compensation, share-based payments
Treasury Stock
Shares repurchased (in shares)		0	0
Treasury Stock, at Cost
Treasury Stock
Treasury stock purchased - increase (decrease) in treasury stock account		$ (845)	$ (405)	$ (500)
Additional Paid-in Capital
Treasury Stock
Treasury stock purchased - increase (decrease) in treasury stock account		$ 25	$ (25)
Series A Preferred Stock
Preferred Stock
Preferred stock, authorized (in shares)		250,000	250,000
Preferred stock, par value (in dollars per share)	$ 25	$ 25	$ 25
Preferred stock, issued	$ 250
Preferred stock, issued (in shares)	250,000	250,000	250,000
Preferred stock, dividend rate	5.50%
Preferred stock, liquidation preference (in dollars per share)	$ 1,000	$ 1,000	$ 1,000
Net proceeds from issuance of stock	$ 247
Preferred stock, redemption price per share (in dollars per share)		$ 1,000
Series A Preferred Stock | LIBOR
Preferred Stock
Preferred stock, dividend payment rate, basis spread on variable rate, beginning after April 6, 2020	3.96%

SHARE-BASED COMPENSATION - Narr

SHARE-BASED COMPENSATION - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee discount on company stock	10.00%
Maximum employee salary contribution percentage - ESPP	10.00%
Maximum employee contribution amount - ESPP	$ 25,000
Number of shares available for grant (in shares)	57,543,638
Compensation expense related to share-based plans	$ 39,000,000	$ 23,000,000	$ 24,000,000
Share-based compensation not yet recognized	$ 47,000,000
Unrecognized compensation expense, weighted-average period of recognition	2 years
Tax benefit recognized in earnings for share-based compensation arrangements	$ 9,000,000	$ 8,000,000	$ 5,000,000
2010 Long Term Incentive Plan | Restricted stock units | Vested March 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%
2010 Long Term Incentive Plan | Restricted stock units | Vesting March 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%
2014 Omnibus Incentive Plan | Time-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2014 Omnibus Incentive Plan | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Citizens Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	1,256,816	1,552,416	1,315,572
Weighted average grant price (in dollars per share)	$ 39.09	$ 24.53	$ 25.18
Awards vested (in shares)	1,426,850	1,762,655	2,496,092
Weighted average grant price of awards vested (in dollars per share)	$ 21.91	$ 22.14	$ 22.15

SHARE-BASED COMPENSATION - Shar

SHARE-BASED COMPENSATION - Share-based Compensation Activity (Details) - Citizens Share Awards - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares Underlying Awards
Nonvested, Beginning of period (in shares)	2,909,029
Granted (in shares)	1,256,816	1,552,416	1,315,572
Vested (in shares)	(1,426,850)	(1,762,655)	(2,496,092)
Forfeited (in shares)	(117,481)
Nonvested, End of period (in shares)	2,621,514	2,909,029
Weighted Average Grant Price
Nonvested, Beginning of period (in dollars per share)	$ 23.92
Granted (in dollars per share)	39.09	$ 24.53	$ 25.18
Vested (in dollars per share)	21.91	22.14	$ 22.15
Forfeited (in dollars per share)	32.12
Nonvested, End of period (in dollars per share)	$ 33.30	$ 23.92

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)counterparty	Dec. 31, 2016USD ($)	Dec. 31, 2003
Letters of Credit [Abstract]
Letters of credit outstanding	$ 3	$ 3
Risk Participation Agreements [Abstract]
Risk participation agreements	$ 16	19
Risk participation agreements number of counterparties | counterparty	88
Risk participation agreements, Maximum term	9 years
Commercial loans held for sale | Purchase commitment
Commitments [Abstract]
Unsettled commercial loan trade purchases	$ 65	127
Unsettled commercial loan trade sales	$ 132	177
Minimum
Risk Participation Agreements [Abstract]
Risk participation agreements, Average term	1 year
Maximum
Risk Participation Agreements [Abstract]
Risk participation agreements, Average term	5 years
Marketing rights
Marketing Rights [Abstract]
Commitment period			25 years
Payments made	$ 3	$ 3
Remaining obligation due	$ 41
Financial standby letters of credit
Letters of Credit [Abstract]
Letters of credit terms	10 years
Commercial letters of credit
Letters of Credit [Abstract]
Letters of credit terms	1 year

COMMITMENTS AND CONTINGENCIE137

COMMITMENTS AND CONTINGENCIES - Schedule of Outstanding Off-balance sheet Arrangements (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Commitment amount	$ 65,159	$ 62,918
Undrawn commitments to extend credit
Other Commitments [Line Items]
Commitment amount	62,959	60,872
Financial standby letters of credit
Other Commitments [Line Items]
Commitment amount	2,036	1,892
Performance letters of credit
Other Commitments [Line Items]
Commitment amount	47	40
Commercial letters of credit
Other Commitments [Line Items]
Commitment amount	53	43
Marketing rights
Other Commitments [Line Items]
Commitment amount	41	44
Risk participation agreements
Other Commitments [Line Items]
Commitment amount	16	19
Residential mortgage loans sold with recourse
Other Commitments [Line Items]
Commitment amount	$ 7	$ 8

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other income	$ 91	$ 159	$ 106
Commercial loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other income	4	4	3
Mortgage banking fees | Residential loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Changes in fair value for loans accounted for under fair value option	$ 6	$ (5)	$ (2)

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements (Details) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016
Assets
Securities available for sale	[1]	$ 20,157		$ 19,501
Loans held for sale		497		583
Derivative assets		693	[2]	759
Other investment securities, at fair value:
Money market mutual fund		165		91
Other investments		4		5
Total other investment securities, at fair value		169		96
Total assets		21,516		20,939
Liabilities
Total derivative liabilities		533	[2]	778
Total liabilities		533		778
Interest rate swaps
Assets
Derivative assets		538		609
Liabilities
Total derivative liabilities		379		645
Foreign exchange contracts
Assets
Derivative assets		148		134
Liabilities
Total derivative liabilities		149		126
Other contracts
Assets
Derivative assets		7		16
Liabilities
Total derivative liabilities		5		7
Mortgage-backed securities
Assets
Securities available for sale		20,139		19,446
State and political subdivisions
Assets
Securities available for sale		6		8
Equity securities
Assets
Securities available for sale				17
U.S. Treasury and other
Assets
Securities available for sale		12		30
Residential loans held for sale
Assets
Loans held for sale		326		504
Commercial loans held for sale
Assets
Loans held for sale		171		79
Level 1
Assets
Securities available for sale		12		30
Loans held for sale		0		0
Derivative assets		0		0
Other investment securities, at fair value:
Money market mutual fund		165		91
Other investments		0		0
Total other investment securities, at fair value		165		91
Total assets		177		121
Liabilities
Total derivative liabilities		0		0
Total liabilities		0		0
Level 1 | Interest rate swaps
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 1 | Foreign exchange contracts
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 1 | Other contracts
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 1 | Mortgage-backed securities
Assets
Securities available for sale		0		0
Level 1 | State and political subdivisions
Assets
Securities available for sale		0		0
Level 1 | Equity securities
Assets
Securities available for sale				0
Level 1 | U.S. Treasury and other
Assets
Securities available for sale		12		30
Level 1 | Residential loans held for sale
Assets
Loans held for sale		0		0
Level 1 | Commercial loans held for sale
Assets
Loans held for sale		0		0
Level 2
Assets
Securities available for sale		20,145		19,471
Loans held for sale		497		583
Derivative assets		693		759
Other investment securities, at fair value:
Money market mutual fund		0		0
Other investments		4		5
Total other investment securities, at fair value		4		5
Total assets		21,339		20,818
Liabilities
Total derivative liabilities		533		778
Total liabilities		533		778
Level 2 | Interest rate swaps
Assets
Derivative assets		538		609
Liabilities
Total derivative liabilities		379		645
Level 2 | Foreign exchange contracts
Assets
Derivative assets		148		134
Liabilities
Total derivative liabilities		149		126
Level 2 | Other contracts
Assets
Derivative assets		7		16
Liabilities
Total derivative liabilities		5		7
Level 2 | Mortgage-backed securities
Assets
Securities available for sale		20,139		19,446
Level 2 | State and political subdivisions
Assets
Securities available for sale		6		8
Level 2 | Equity securities
Assets
Securities available for sale				17
Level 2 | U.S. Treasury and other
Assets
Securities available for sale		0		0
Level 2 | Residential loans held for sale
Assets
Loans held for sale		326		504
Level 2 | Commercial loans held for sale
Assets
Loans held for sale		171		79
Level 3
Assets
Securities available for sale		0		0
Loans held for sale		0		0
Derivative assets		0		0
Other investment securities, at fair value:
Money market mutual fund		0		0
Other investments		0		0
Total other investment securities, at fair value		0		0
Total assets		0		0
Liabilities
Total derivative liabilities		0		0
Total liabilities		0		0
Level 3 | Interest rate swaps
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 3 | Foreign exchange contracts
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 3 | Other contracts
Assets
Derivative assets		0		0
Liabilities
Total derivative liabilities		0		0
Level 3 | Mortgage-backed securities
Assets
Securities available for sale		0		0
Level 3 | State and political subdivisions
Assets
Securities available for sale		0		0
Level 3 | Equity securities
Assets
Securities available for sale				0
Level 3 | U.S. Treasury and other
Assets
Securities available for sale		0		0
Level 3 | Residential loans held for sale
Assets
Loans held for sale		0		0
Level 3 | Commercial loans held for sale
Assets
Loans held for sale		$ 0		$ 0
[1]	Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.
[2]	Amounts reflect changes in the treatment of variation margin on certain centrally cleared derivatives.

FAIR VALUE MEASUREMENTS - Resid

FAIR VALUE MEASUREMENTS - Residential and Commercial Mortgage Loans Held For Sale (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Aggregate Fair Value	$ 497	$ 583
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Aggregate Fair Value	497	583
Level 2 | Residential loans held for sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Aggregate Fair Value	326	504
Aggregate Unpaid Principal	326	505
Aggregate Fair Value Less Aggregate Unpaid Principal	0	(1)
Level 2 | Commercial loans held for sale
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Aggregate Fair Value	171	79
Aggregate Unpaid Principal	171	79
Aggregate Fair Value Less Aggregate Unpaid Principal	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Sc141

FAIR VALUE MEASUREMENTS - Schedule of Gain (Loss) on Assets and Liabilities Measured on Nonrecurring Basis Included in Earnings (Details) - Nonrecurring measurement basis - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Impaired collateral-dependent loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) included in earnings on assets measured on a nonrecurring basis	$ (35)	$ (33)	$ (32)
MSRs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) included in earnings on assets measured on a nonrecurring basis	2	4	9
Foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) included in earnings on assets measured on a nonrecurring basis	(3)	(3)	(3)
Leased assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) included in earnings on assets measured on a nonrecurring basis	$ (15)	$ 11	$ 0

FAIR VALUE MEASUREMENTS - Sc142

FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements on a Nonrecurring Basis (Details) - Nonrecurring measurement basis - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired collateral-dependent loans	$ 393	$ 355
MSRs	218	182
Foreclosed assets	31	44
Leased assets	112	158
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired collateral-dependent loans	0	0
MSRs	0	0
Foreclosed assets	0	0
Leased assets	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired collateral-dependent loans	393	355
MSRs	0	0
Foreclosed assets	31	44
Leased assets	112	158
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired collateral-dependent loans	0	0
MSRs	218	182
Foreclosed assets	0	0
Leased assets	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Sc143

FAIR VALUE MEASUREMENTS - Schedule of Financial Instruments not Recorded at Fair Value (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Financial Assets:
Securities held to maturity, carrying value		$ 4,685	$ 5,071
Securities held-to-maturity, fair value		4,668	5,058
Other investment securities, at cost, carrying value		722	942
Other investment securities, at cost, estimated fair value		722	942
Other loans held for sale, carrying value		221	42
Other loans held for sale, fair value		221	42
Loans and leases, carrying value	[1],[2]	110,617	107,669
Loans and leases, fair value		111,168	107,537
Financial Liabilities:
Deposits, carrying value		115,089	109,804
Deposits, fair value		115,039	109,796
Federal funds purchased and securities sold under agreements to repurchase, carrying value		815	1,148
Federal funds purchased and securities sold under agreements to repurchase, fair value		815	1,148
Other short-term borrowed funds, carrying value		1,856	3,211
Other short-term borrowed funds, fair value		1,856	3,211
Long-term borrowed funds, carrying value		11,765	12,790
Long-term borrowed funds, fair value		11,891	12,849
Level 1
Financial Assets:
Securities held to maturity, carrying value		0	0
Securities held-to-maturity, fair value		0	0
Other investment securities, at cost, carrying value		0	0
Other investment securities, at cost, estimated fair value		0	0
Other loans held for sale, carrying value		0	0
Other loans held for sale, fair value		0	0
Loans and leases, carrying value		0	0
Loans and leases, fair value		0	0
Financial Liabilities:
Deposits, carrying value		0	0
Deposits, fair value		0	0
Federal funds purchased and securities sold under agreements to repurchase, carrying value		0	0
Federal funds purchased and securities sold under agreements to repurchase, fair value		0	0
Other short-term borrowed funds, carrying value		0	0
Other short-term borrowed funds, fair value		0	0
Long-term borrowed funds, carrying value		0	0
Long-term borrowed funds, fair value		0	0
Level 2
Financial Assets:
Securities held to maturity, carrying value		4,685	5,071
Securities held-to-maturity, fair value		4,668	5,058
Other investment securities, at cost, carrying value		722	942
Other investment securities, at cost, estimated fair value		722	942
Other loans held for sale, carrying value		0	0
Other loans held for sale, fair value		0	0
Loans and leases, carrying value		393	355
Loans and leases, fair value		393	355
Financial Liabilities:
Deposits, carrying value		115,089	109,804
Deposits, fair value		115,039	109,796
Federal funds purchased and securities sold under agreements to repurchase, carrying value		815	1,148
Federal funds purchased and securities sold under agreements to repurchase, fair value		815	1,148
Other short-term borrowed funds, carrying value		1,856	3,211
Other short-term borrowed funds, fair value		1,856	3,211
Long-term borrowed funds, carrying value		11,765	12,790
Long-term borrowed funds, fair value		11,891	12,849
Level 3
Financial Assets:
Securities held to maturity, carrying value		0	0
Securities held-to-maturity, fair value		0	0
Other investment securities, at cost, carrying value		0	0
Other investment securities, at cost, estimated fair value		0	0
Other loans held for sale, carrying value		221	42
Other loans held for sale, fair value		221	42
Loans and leases, carrying value		110,224	107,314
Loans and leases, fair value		110,775	107,182
Financial Liabilities:
Deposits, carrying value		0	0
Deposits, fair value		0	0
Federal funds purchased and securities sold under agreements to repurchase, carrying value		0	0
Federal funds purchased and securities sold under agreements to repurchase, fair value		0	0
Other short-term borrowed funds, carrying value		0	0
Other short-term borrowed funds, fair value		0	0
Long-term borrowed funds, carrying value		0	0
Long-term borrowed funds, fair value		$ 0	$ 0
[1]	Excluded from the table above are loans held for sale totaling $718 million and $625 million as of December 31, 2017 and 2016, respectively.
[2]	Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $20.3 billion and $17.3 billion at December 31, 2017 and 2016, respectively.

OTHER INCOME (Details)

OTHER INCOME (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Bank-owned life insurance income	$ 54	$ 54	$ 56
Other	37	105	50
Other income	$ 91	$ 159	$ 106

OTHER OPERATING EXPENSE (Detail

OTHER OPERATING EXPENSE (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Deposit insurance	$ 137	$ 120	$ 115
Promotional expense	105	98	101
Settlements and operating losses	54	62	43
Other	251	246	271
Other operating expense	$ 547	$ 526	$ 530

INCOME TAXES - Income Tax Expen

INCOME TAXES - Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax expense	$ 260	$ 489	$ 423
Tax effect of changes in OCI	(7)	(168)	(12)
Total comprehensive income tax expense	$ 253	$ 321	$ 411

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
U.S. federal	$ 376	$ 292	$ 162
State and local	20	44	12
Total	396	336	174
Deferred
U.S. federal	(142)	159	225
State and local	6	(6)	24
Total	(136)	153	249
U.S. federal	234	451	387
State and local	26	38	36
Income tax expense	$ 260	$ 489	$ 423

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amount
U.S. Federal income tax expense	$ 669	$ 537	$ 442
Increase (decrease) resulting from:
2017 Tax Legislation	(331)	0	0
State and local income taxes (net of federal benefit)	46	38	27
Bank-owned life insurance	(19)	(19)	(20)
Tax-exempt interest	(21)	(19)	(17)
Tax advantaged investments (including related credits)	(51)	(31)	(16)
Other tax credits	(3)	(14)	0
Adjustments for uncertain tax positions	(23)	0	0
Non-deductible expenses	0	0	8
Other	(7)	(3)	(1)
Income tax expense	$ 260	$ 489	$ 423
Rate
U.S. Federal income tax rate	35.00%	35.00%	35.00%
Increase (decrease) resulting from:
2017 Tax Legislation	(17.30%)	0.00%	0.00%
State and local income taxes (net of federal benefit)	2.40%	2.50%	2.10%
Bank-owned life insurance	(1.00%)	(1.20%)	(1.60%)
Tax-exempt interest	(1.10%)	(1.30%)	(1.30%)
Tax advantaged investments (including related credits)	(2.70%)	(2.00%)	(1.20%)
Other tax credits	(0.10%)	(0.90%)	(0.00%)
Adjustments for uncertain tax positions	(1.20%)	0.00%	0.00%
Non-deductible expenses	0.00%	0.00%	0.60%
Other	(0.40%)	(0.20%)	(0.10%)
Total income tax expense and tax rate	13.60%	31.90%	33.50%

INCOME TAXES - Deferred Income

INCOME TAXES - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Other comprehensive income	$ 271	$ 409
Allowance for credit losses	310	471
State net operating loss carryforwards	88	75
Accrued expenses not currently deductible	40	129
Investment and other tax credit carryforwards	65	52
Deferred income	0	22
Fair value adjustments	27	40
Other	0	6
Total deferred tax assets	801	1,204
Valuation allowance	(105)	(107)
Deferred tax assets, net of valuation allowance	696	1,097
Deferred tax liabilities:
Leasing transactions	525	881
Amortization of intangibles	352	522
Depreciation	182	234
Pension and other employee compensation plans	110	103
Partnerships	37	22
Deferred Income	27	0
MSRs	34	49
Total deferred tax liabilities	1,267	1,811
Net deferred tax liability	$ 571	$ 714

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
U.S. Federal income tax rate	35.00%	35.00%	35.00%
State operating loss carryforwards	$ 1,400,000,000
Deferred tax asset valuation allowance	105,000,000	$ 107,000,000
Decrease in deferred tax asset valuation allowance	2,000,000
Unrecognized tax benefits that would impact effective tax rate	5,000,000
Interest on unrecognized tax benefits accrued (released) during period	(8,000,000)	8,000,000	$ 1,000,000
Accrued interest on unrecognized tax benefits	1,000,000	22,000,000	14,000,000
Penalties accrued income tax examination	0	0	0
Penalties expense income tax examination	0	$ 0	$ 0
Revaluation of deferred tax liability - net tax benefit from 2017 Tax Legislation	331,000,000
Revaluation of deferred tax asset - net tax expense from 2017 Tax Legislation	145,000,000
Reclassification between AOCI and retained earnings for tax effects of 2017 Tax Legislation	145,000,000
Tax Years Ended Prior to 1988
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Base year loan loss reserves attributable to prior years	$ 557,000,000

INCOME TAXES - Unrecognized Tax

INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	$ 42	$ 62	$ 72
Gross decrease for tax positions related to prior years	(27)	(19)	(6)
Gross increase for tax positions related to prior years	0	1	0
Decreases for tax positions as a result of the lapse of the statutes of limitations	(1)	(2)	(3)
Decreases for tax positions related to settlements with taxing authorities	(9)	0	(1)
Balance at end of year	$ 5	$ 42	$ 62

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator (basic and diluted):
Net income	$ 1,652	$ 1,045	$ 840
Less: Preferred stock dividends	14	14	7
Net income available to common stockholders	$ 1,638	$ 1,031	$ 833
Denominator:
Weighted-average common shares outstanding - basic (in shares)	502,157,440	522,093,545	535,599,731
Dilutive common shares: share-based awards (in shares)	1,527,651	1,837,173	2,621,167
Weighted-average common shares outstanding - diluted (in shares)	503,685,091	523,930,718	538,220,898
Earnings per common share:
Basic (in dollars per share)	$ 3.26	$ 1.97	$ 1.55
Diluted (in dollars per share)	$ 3.25	$ 1.97	$ 1.55
Antidilutive securities (in shares)	533	0	0

REGULATORY MATTERS - Narrative

REGULATORY MATTERS - Narrative (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018$ / shares	Dec. 31, 2017USD ($)subsidiary$ / shares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Revaluation of deferred tax liability - net tax benefit from 2017 Tax Legislation		$ 331
Revaluation of deferred tax asset - net tax expense from 2017 Tax Legislation		145
Reclassification of tax effects resulting from the 2017 Tax Legislation		$ 145
Common stock dividends (in dollars per share) | $ / shares		$ 0.18
Dividends		$ 322	$ 241
Treasury stock purchased		820	430	$ 500
Repayments of long-term borrowed funds		12,751	8,429	766
Preferred stock dividends		$ 14	14	$ 7
Subordinated Debt
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Repayments of long-term borrowed funds			$ 625
Forecast
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock dividends (in dollars per share) | $ / shares	$ 0.22
Bank subsidiaries
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Number of financial subsidiaries | subsidiary		2

REGULATORY MATTERS - Capital an

REGULATORY MATTERS - Capital and Capital Ratio Information (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Common Equity Tier 1 to Risk-Weighted Assets (Amount)
Actual	[1]	$ 14,309	$ 13,822
Minimum Capital Adequacy	[1]	7,342	6,348
Classification as Well-capitalized	[1],[2]	$ 8,300	$ 8,051
Common Equity Tier 1 to Risk-Weighted Assets (Ratio)
Actual	[1]	11.20%	11.20%
Minimum Capital Adequacy	[1],[3]	5.75%	5.125%
Classification as Well-capitalized	[1],[2]	6.50%	6.50%
Tier 1 Capital to Risk-Weighted Assets (Amount)
Actual	[4]	$ 14,556	$ 14,069
Minimum Capital Adequacy	[4]	9,258	8,206
Classification as Well-capitalized	[2],[4]	$ 10,215	$ 9,909
Tier 1 Capital to Risk-Weighted Assets (Ratio)
Actual	[4]	11.40%	11.40%
Minimum Capital Adequacy	[3],[4]	7.25%	6.625%
Classification as Well-capitalized	[2],[4]	8.00%	8.00%
Total Capital to Risk-Weighted Assets (Amount)
Actual	[5]	$ 17,781	$ 17,347
Minimum Capital Adequacy	[5]	11,812	10,683
Classification as Well-capitalized	[2],[5]	$ 12,769	$ 12,386
Total Capital to Risk-Weighted Assets (Ratio)
Actual	[5]	13.90%	14.00%
Minimum Capital Adequacy	[3],[5]	9.25%	8.625%
Classification as Well-capitalized	[2],[5]	10.00%	10.00%
Tier 1 Capital to Average Assets (Leverage) (Amount)
Actual	[6]	$ 14,556	$ 14,069
Minimum Capital Adequacy	[6]	5,824	5,667
Classification as Well-capitalized	[2],[6]	$ 7,280	$ 7,084
Tier 1 Capital to Average Assets (Leverage) (Ratio)
Actual	[6]	10.00%	9.90%
Minimum Capital Adequacy	[3],[6]	4.00%	4.00%
Classification as Well-capitalized	[2],[6]	5.00%	5.00%
Capital conservation buffer		1.25%	0.625%
[1]	“Common equity tier 1 capital ratio” represents CET1 capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach.
[2]	Presented for informational purposes. Prompt corrective action provisions apply only to the Company’s insured depository institutions - CBNA and CBPA.
[3]	“Minimum Capital ratio” includes capital conservation buffer of 1.250% for 2017 and 0.625% for 2016; N/A to Tier 1 leverage.
[4]	“Tier 1 capital ratio” is tier 1 capital, which includes CET1 capital plus non-cumulative perpetual preferred equity that qualifies as additional tier 1 capital, divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach.
[5]	“Total capital ratio” is total capital divided by total risk-weighted assets as defined under U.S. Basel III Standardized approach.
[6]	“Tier 1 leverage ratio” is tier 1 capital divided by quarterly average total assets as defined under U.S. Basel III Standardized approach.

BUSINESS OPERATING SEGMENTS - N

BUSINESS OPERATING SEGMENTS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of segments | segment	2
Revenues	$ 5,707	$ 5,255	$ 4,824
Consumer Banking | Maximum
Segment Reporting Information [Line Items]
Revenues	25
Commercial Banking | Minimum
Segment Reporting Information [Line Items]
Revenues	25
Commercial Banking | Maximum
Segment Reporting Information [Line Items]
Revenues	$ 2,500

BUSINESS OPERATING SEGMENTS (De

BUSINESS OPERATING SEGMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income	$ 4,173	$ 3,758	$ 3,402
Noninterest income	1,534	1,497	1,422
Total revenue	5,707	5,255	4,824
Noninterest expense	3,474	3,352	3,259
Profit (loss) before provision for credit losses	2,233	1,903	1,565
Provision for credit losses	321	369	302
Income before income tax expense	1,912	1,534	1,263
Income tax expense	260	489	423
NET INCOME	1,652	1,045	840
Total average assets	149,953	143,183	135,070
Operating Segments | Consumer Banking
Segment Reporting Information [Line Items]
Net interest income	2,651	2,443	2,198
Noninterest income	905	883	910
Total revenue	3,556	3,326	3,108
Noninterest expense	2,593	2,547	2,456
Profit (loss) before provision for credit losses	963	779	652
Provision for credit losses	265	243	252
Income before income tax expense	698	536	400
Income tax expense	246	191	138
NET INCOME	452	345	262
Total average assets	59,714	56,388	52,848
Operating Segments | Commercial Banking
Segment Reporting Information [Line Items]
Net interest income	1,411	1,288	1,162
Noninterest income	538	466	415
Total revenue	1,949	1,754	1,577
Noninterest expense	772	741	709
Profit (loss) before provision for credit losses	1,177	1,013	868
Provision for credit losses	19	47	(13)
Income before income tax expense	1,158	966	881
Income tax expense	384	335	302
NET INCOME	774	631	579
Total average assets	49,747	47,159	42,800
Other
Segment Reporting Information [Line Items]
Net interest income	111	27	42
Noninterest income	91	148	97
Total revenue	202	175	139
Noninterest expense	109	64	94
Profit (loss) before provision for credit losses	93	111	45
Provision for credit losses	37	79	63
Income before income tax expense	56	32	(18)
Income tax expense	(370)	(37)	(17)
NET INCOME	426	69	(1)
Total average assets	$ 40,492	$ 39,636	$ 39,422

PARENT COMPANY FINANCIALS - Con

PARENT COMPANY FINANCIALS - Condensed Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Income
Total interest income	$ 4,920	$ 4,266	$ 3,854
Operating expense
Salaries and employee benefits	1,761	1,709	1,636
Interest expense	747	508	452
All other expenses	547	526	530
Income taxes	260	489	423
NET INCOME	1,652	1,045	840
Other comprehensive (loss) income, net of income taxes
Net unrealized derivative instrument gains (losses) arising during the period	(14)	(62)	93
Net unrealized securities losses arising during the period	(6)	(139)	(66)
Total other comprehensive loss, net of income taxes	(7)	(281)	(15)
Total comprehensive income	1,645	764	825
Payments of ordinary common stock dividends	322	241	214
Dividends to preferred stockholders	14	14	7
Parent company
Operating Income
Dividends from banking subsidiaries	1,055	555	345
Interest income	43	53	54
Management and service fees	31	26	20
Equity securities gains	1	3	3
All other operating income	1	7	4
Total interest income	1,136	644	426
Operating expense
Salaries and employee benefits	40	37	15
Interest expense	97	99	108
All other expenses	22	15	38
Total operating expense	159	151	161
Income before taxes and undistributed income	977	493	265
Income taxes	(10)	(26)	(29)
Income before undistributed income of subsidiaries and associated companies	987	519	294
Equity in undistributed income (losses) of subsidiaries and associated companies	665	526	546
NET INCOME	1,652	1,045	840
Other comprehensive (loss) income, net of income taxes
Net pension plan activity arising during the period	(1)	(2)	1
Net unrealized derivative instrument gains (losses) arising during the period	1	(8)	2
Net unrealized securities losses arising during the period	0	0	(2)
Net other comprehensive loss	0	(10)	1
Other comprehensive income (loss) activity of Bank subsidiaries, net of income taxes	(7)	(271)	(16)
Total other comprehensive loss, net of income taxes	(7)	(281)	(15)
Total comprehensive income	1,645	764	825
Nonbank subsidiaries | Parent company
Operating Income
Interest income	1	0	0
Dividends from nonbank subsidiaries	4	0	0
Operating expense
Equity in undistributed income (losses) of subsidiaries and associated companies	10	4	3
Bank subsidiaries | Parent company
Operating expense
Equity in undistributed income (losses) of subsidiaries and associated companies	$ 655	$ 522	$ 543

PARENT COMPANY FINANCIALS - 158

PARENT COMPANY FINANCIALS - Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS:
Cash and due from banks	$ 987	$ 955
Other assets	3,429	2,993
TOTAL ASSETS	152,336	149,520
LIABILITIES:
Long-term borrowed funds	11,765	12,790
Other liabilities	1,660	1,447
TOTAL LIABILITIES	132,066	129,773
TOTAL STOCKHOLDERS’ EQUITY	20,270	19,747	$ 19,646	$ 19,268
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	152,336	149,520
Parent company
ASSETS:
Cash and due from banks	563	671
Other assets	125	128
TOTAL ASSETS	22,756	22,141
LIABILITIES:
Other liabilities	166	76
TOTAL LIABILITIES	2,486	2,394
TOTAL STOCKHOLDERS’ EQUITY	20,270	19,747
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	22,756	22,141
Bank subsidiaries | Parent company
ASSETS:
Loans and advances	1,160	1,156
Investments in subsidiaries	20,765	20,116
Unaffiliated companies | Parent company
LIABILITIES:
Long-term borrowed funds	2,320	2,318
Nonbank subsidiaries | Parent company
ASSETS:
Loans and advances	70	20
Investments in subsidiaries	$ 73	$ 50

PARENT COMPANY FINANCIALS - 159

PARENT COMPANY FINANCIALS - Condensed Cash Flow Statements (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income		$ 1,652	$ 1,045	$ 840
Deferred income taxes		(136)	153	249
Increase (decrease) in other liabilities		(119)	(59)	(161)
Decrease (increase) in other assets		(502)	(274)	(467)
Net cash provided by operating activities		1,883	1,490	1,229
INVESTING ACTIVITIES
Net cash used in investing activities		(3,984)	(11,326)	(5,905)
FINANCING ACTIVITIES
Proceeds from issuance of long-term borrowed funds		15,363	15,144	6,750
Repayments of long-term borrowed funds		(12,751)	(8,429)	(766)
Treasury stock purchased		(820)	(430)	(500)
Net proceeds from issuance of preferred stock		0	0	247
Dividends declared and paid to common stockholders		(322)	(241)	(214)
Dividends declared and paid to preferred stockholders		(14)	(14)	(7)
Net cash provided by financing activities		1,429	10,455	4,485
(Decrease) increase in cash and cash equivalents	[1]	(672)	619	(191)
Cash and cash equivalents at beginning of period	[1]	3,704	3,085	3,276
Cash and cash equivalents at end of period	[1]	3,032	3,704	3,085
Parent company
OPERATING ACTIVITIES
Net income		1,652	1,045	840
Deferred income taxes		(11)	5	49
Gain on sales of assets		(1)	(3)	(3)
Equity in undistributed earnings of subsidiaries		(665)	(526)	(546)
Increase (decrease) in other liabilities		99	(19)	(48)
Decrease (increase) in other assets		5	35	(16)
Other operating, net		(1)	(4)	3
Total adjustments		(574)	(512)	(561)
Net cash provided by operating activities		1,078	533	279
INVESTING ACTIVITIES
Proceeds from sales of securities available for sale		0	0	8
Investments in and advances to subsidiaries		(230)	(40)	(215)
Repayment of investments in and advances to subsidiaries		167	588	376
Other investing, net		(1)	(2)	0
Net cash used in investing activities		(64)	546	169
FINANCING ACTIVITIES
Proceeds from issuance of long-term borrowed funds		0	349	1,000
Repayments of long-term borrowed funds		0	(625)	(750)
Proceeds from issuance of common stock		34	22	27
Treasury stock purchased		(820)	(430)	(500)
Net proceeds from issuance of preferred stock		0	0	247
Dividends declared and paid to common stockholders		(322)	(241)	(214)
Dividends declared and paid to preferred stockholders		(14)	(14)	(7)
Net cash provided by financing activities		(1,122)	(939)	(197)
(Decrease) increase in cash and cash equivalents		(108)	140	251
Cash and cash equivalents at beginning of period		671	531	280
Cash and cash equivalents at end of period		$ 563	$ 671	$ 531
[1]	Cash and cash equivalents includes cash and due from banks and interest-bearing cash and due from banks as reflected on the Consolidated Balance Sheets.