Comerica (CMA) 10-Q 1 Nov 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 24, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Amendment Flag	false
Entity Registrant Name	Comerica INC /NEW/
Entity Central Index Key	28,412
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		172,262,981
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks		$ 1,292	$ 1,157
Interest-bearing deposits with banks		6,748	4,990
Other short-term investments		92	113
Investment securities available-for-sale	[1]	10,789	10,519
Investment securities held-to-maturity		1,695	1,981
Commercial loans		31,152	31,659
Real estate construction loans		2,743	2,001
Commercial mortgage loans		9,013	8,977
Lease financing		648	724
International loans		1,303	1,368
Residential mortgage loans		1,874	1,870
Consumer loans		2,541	2,485
Total loans		49,274	49,084
Less allowance for loan losses		(727)	(634)
Net loans		48,547	48,450
Premises and equipment		528	550
Accrued income and other assets		4,433	4,117
Total assets		74,124	71,877
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing deposits		31,776	30,839
Money market and interest-bearing checking deposits		22,436	23,532
Savings deposits		2,052	1,898
Customer certificates of deposit		2,967	3,552
Foreign office time deposits		30	32
Total interest-bearing deposits		27,485	29,014
Total deposits		59,261	59,853
Short-term borrowings		12	23
Accrued expenses and other liabilities		1,234	1,383
Medium- and long-term debt		5,890	3,058
Total liabilities		66,397	64,317
Common stock - $5 par value: Authorized - 325,000,000 shares; Issued - 228,164,824 shares		1,141	1,141
Capital surplus		2,174	2,173
Accumulated other comprehensive loss		(292)	(429)
Retained earnings		7,262	7,084
Less cost of common stock in treasury - 56,096,416 shares at 9/30/16 and 52,457,113 shares at 12/31/15		(2,558)	(2,409)
Total shareholders' equity		7,727	7,560
Total liabilities and shareholders' equity		$ 74,124	$ 71,877
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common stock, par value	$ 5	$ 5
Common stock, authorized shares	325,000,000	325,000,000
Common stock, issued shares	228,164,824	228,164,824
Shares in treasury	56,096,416	52,457,113

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
INTEREST INCOME
Interest and fees on loans	$ 411	$ 390	$ 1,223	$ 1,156
Interest on investment securities	61	54	185	160
Interest on short-term investments	8	4	17	11
Total interest income	480	448	1,425	1,327
INTEREST EXPENSE
Interest on deposits	10	11	30	33
Interest on medium- and long-term debt	20	15	53	38
Total interest expense	30	26	83	71
Net interest income	450	422	1,342	1,256
Provision for credit losses	16	26	213	87
Net interest income after provision for credit losses	434	396	1,129	1,169
NONINTEREST INCOME
Card fees	76	71	224	203
Service charges on deposit accounts	55	57	165	168
Fiduciary income	47	47	142	142
Commercial lending fees	26	22	68	69
Letter of credit fees	12	13	38	39
Bank-owned life insurance	12	10	30	29
Foreign exchange income	10	10	31	29
Brokerage fees	5	5	14	13
Net securities losses	0	0	(3)	(2)
Other noninterest income	29	25	75	79
Total noninterest income	272	260	784	769
NONINTEREST EXPENSES
Salaries and benefits expense	247	243	742	747
Outside processing fee expense	86	83	247	239
Net occupancy expense	40	41	117	118
Equipment expense	13	13	40	39
Restructuring charges	20	0	73	0
Software expense	31	26	90	73
FDIC insurance expense	14	9	39	27
Advertising expense	5	6	15	17
Litigation-related expense	0	(3)	0	(32)
Other noninterest expenses	37	39	106	117
Total noninterest expenses	493	457	1,469	1,345
Income before income taxes	213	199	444	593
Provision for income taxes	64	63	131	188
Net Income	149	136	313	405
Less income allocated to participating securities	1	2	3	5
Net income attributable to common shares	$ 148	$ 134	$ 310	$ 400
Basic earnings per common share	$ 0.87	$ 0.76	$ 1.80	$ 2.27
Diluted earnings per common share	$ 0.84	$ 0.74	$ 1.76	$ 2.20
Comprehensive income	$ 152	$ 187	$ 450	$ 472
Cash dividends declared on common stock	$ 40	$ 37	$ 115	$ 110
Cash dividends declared per common share	$ 0.23	$ 0.21	$ 0.66	$ 0.62

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital Surplus	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury Stock
BALANCE at Dec. 31, 2014	$ 7,402	$ 1,141	$ 2,188	$ (412)	$ 6,744	$ (2,259)
BALANCE (in shares) at Dec. 31, 2014		179
Net income	405				405
Other comprehensive income, net of tax	67			67
Cash dividends declared on common stock	(110)				(110)
Purchase of common stock	(175)					(175)
Purchase of common stock (in shares)		(3.8)
Purchase and retirement of warrants	(10)		(10)
Net issuance of common stock under employee stock plans	14		(21)		(10)	45
Net issuance of common stock under employee stock plans (in shares)		1
Net issuance of common stock for warrants	0		(21)		(22)	43
Net issuance of common stock for warrants (in shares)		1
Share-based compensation	29		29
BALANCE at Sep. 30, 2015	7,622	$ 1,141	2,165	(345)	7,007	(2,346)
BALANCE (in shares) at Sep. 30, 2015		177.2
BALANCE at Dec. 31, 2015	7,560	$ 1,141	2,173	(429)	7,084	(2,409)
BALANCE (in shares) at Dec. 31, 2015		175.7
Net income	313				313
Other comprehensive income, net of tax	137			137
Cash dividends declared on common stock	(115)				(115)
Purchase of common stock	(211)					(211)
Purchase of common stock (in shares)		(5)
Net issuance of common stock under employee stock plans	13		(29)		(20)	62
Net issuance of common stock under employee stock plans (in shares)		1.4
Share-based compensation	30		30
BALANCE at Sep. 30, 2016	$ 7,727	$ 1,141	$ 2,174	$ (292)	$ 7,262	$ (2,558)
BALANCE (in shares) at Sep. 30, 2016		172.1

Consolidated Statements Of Cha6

Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Cash dividends declared on common stock, per share	$ 0.23	$ 0.21	$ 0.66	$ 0.62

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
OPERATING ACTIVITIES
Net income	$ 313	$ 405
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	213	87
Benefit for deferred income taxes	(74)	(52)
Depreciation and amortization	91	90
Net periodic defined benefit cost	11	34
Share-based compensation expense	30	29
Net amortization of securities	7	11
Accretion of loan purchase discount	(4)	(6)
Net securities losses	3	2
Net gains on sales of foreclosed property	(3)	(2)
Excess tax benefits from share-based compensation arrangements	(1)	(3)
Net change in accrued income receivable	(8)	(9)
Net change in accrued expenses payable	71	(70)
Other, net	(252)	147
Net cash provided by operating activities	397	663
INVESTING ACTIVITIES
Maturities and redemptions of investment securities available-for-sale	1,259	1,333
Purchases of investment securities available-for-sale	(1,396)	(1,933)
Maturities and redemptions of investment securities held-to-maturity	288	244
Purchases of investment securities held-to-maturity	0	(166)
Net change in loans	(290)	(436)
Proceeds from sales of foreclosed property	15	8
Net increase in premises and equipment	(71)	(78)
Purchases of Federal Home Loan Bank stock	(115)	0
Other, net	3	5
Net cash used in investing activities	(307)	(1,023)
FINANCING ACTIVITIES
Net change in deposits	(686)	1,361
Net change in short-term borrowings	(11)	(7)
Maturities of medium- and long-term debt	0	(606)
Issuances of medium- and long-term debt	2,800	1,016
Repurchases of common stock	(211)	(175)
Cash dividends paid on common stock	(112)	(109)
Issuances of common stock under employee stock plans	25	21
Purchase and retirement of warrants	0	(10)
Excess tax benefits from share-based compensation arrangements	1	3
Other, net	(3)	(5)
Net cash provided by financing activities	1,803	1,489
Net increase in cash and cash equivalents	1,893	1,129
Cash and cash equivalents at beginning of period	6,147	6,071
Cash and cash equivalents at end of period	8,040	7,200
Interest paid	75	64
Income tax paid	66	46
Noncash investing and financing activities:
Loans transferred to other real estate	21	9
Loans transferred from portfolio to held-for-sale	0	19
Loans transferred from held-for-sale to portfolio	17	0
Lease residual transferred to other assets	$ 0	$ 16

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	BASIS OF PRESENTATION AND ACCOUNTING POLICIES Organization The accompanying unaudited consolidated financial statements were prepared in accordance with United States (U.S.) generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation were included. The results of operations for the nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . Certain items in prior periods were reclassified to conform to the current presentation. For further information, refer to the consolidated financial statements and footnotes thereto included in the Annual Report of Comerica Incorporated and Subsidiaries (the Corporation) on Form 10-K for the year ended December 31, 2015 . Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842),” (ASU 2016-02), to increase the transparency and comparability of lease recognition and disclosure. The update requires lessees to recognize lease contracts with a term greater than one year on the balance sheet, while recognizing expenses on the income statement in a manner similar to current guidance. For lessors, the update makes targeted changes to the classification criteria and the lessor accounting model to align the guidance with the new lessee model and revenue guidance. ASU 2016-02 is effective for the Corporation on January 1, 2019 and must be applied using the modified retrospective approach. Early adoption is permitted. The Corporation is currently evaluating the impact of adopting ASU 2016-02. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payments Accounting,” (ASU 2016-09), which intends to simplify accounting for share based payment transactions, including the income tax consequences and classification of awards. Among other items, the update requires excess tax benefits and deficiencies to be recognized as a component of income taxes within the income statement rather than other comprehensive income as required in current guidance. ASU 2016-09 is effective for the Corporation on January 1, 2017. The recognition of excess tax benefits and deficiencies in the income statement must be adopted prospectively. The method of transition required will differ for other items being amended. Early adoption is permitted. The impact to the Corporation upon adoption is dependent on the market value per share of the Corporation's common stock at option expiration dates and restricted stock vesting dates. In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments," (ASU 2016-13), which addresses concerns regarding the perceived delay in recognition of credit losses under the existing incurred loss model. The amendment introduces a new, single model for recognizing credit losses on all financial instruments presented on cost basis. Under the new model, entities must estimate current expected credit losses by considering all available relevant information, including historical and current information, as well as reasonable and supportable forecasts of future events. The update also requires additional qualitative and quantitative information to allow users to better understand the credit risk within the portfolio and the methodologies for determining allowance. ASU 2016-13 is effective for the Corporation on January 1, 2020 and must be applied using the modified retrospective approach with limited exceptions. Early adoption is permitted. The Corporation is currently evaluating the impact of adopting ASU 2016-13. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” (ASU 2016-15), which reduces diversity in the presentation of several categories of transactions in the cash flow statement. Among other things, the update clarifies the appropriate classification for proceeds from settlement of bank owned life insurance (BOLI) policies. Based on preliminary assessments, the Corporation expects to change the classification of proceeds from settlement of BOLI policies from operating activities to investing activities. Proceeds from settlement of BOLI policies totaled $10 million and $6 million for the nine-month periods ended September 30, 2016 and 2015, respectively, and $12 million for the year ended December 31, 2015. Other changes in classification resulting from this update are not expected to be significant. ASU 2016-15 is effective for the Corporation on January 1, 2018 and must be applied using the retrospective approach. Early adoption is permitted.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Corporation utilizes fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. The determination of fair values of financial instruments often requires the use of estimates. In cases where quoted market values in an active market are not available, the Corporation uses present value techniques and other valuation methods to estimate the fair values of its financial instruments. These valuation methods require considerable judgment and the resulting estimates of fair value can be significantly affected by the assumptions made and methods used. Trading securities, investment securities available-for-sale, derivatives and deferred compensation plan liabilities are recorded at fair value on a recurring basis. Additionally, from time to time, the Corporation may be required to record other assets and liabilities at fair value on a nonrecurring basis, such as impaired loans, other real estate (primarily foreclosed property), nonmarketable equity securities and certain other assets and liabilities. These nonrecurring fair value adjustments typically involve write-downs of individual assets or application of lower of cost or fair value accounting. Refer to Note 1 to the consolidated financial statements in the Corporation's Annual Report on Form 10-K for the year ended December 31, 2015 for further information about the fair value hierarchy, descriptions of the valuation methodologies and key inputs used to measure financial assets and liabilities recorded at fair value, as well as a description of the methods and significant assumptions used to estimate fair value disclosures for financial instruments not recorded at fair value in their entirety on a recurring basis. ASSETS AND LIABLILITIES RECORDED AT FAIR VALUE ON A RECURRING BASIS The following tables present the recorded amount of assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 . (in millions) Total Level 1 Level 2 Level 3 September 30, 2016 Trading securities: Deferred compensation plan assets $ 88 $ 88 $ — $ — Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities 2,826 2,826 — — Residential mortgage-backed securities (a) 7,828 — 7,828 — State and municipal securities 8 — — 8 (b) Equity and other non-debt securities 127 81 — 46 (b) Total investment securities available-for-sale 10,789 2,907 7,828 54 Derivative assets: Interest rate contracts 389 — 362 27 Energy derivative contracts 192 — 192 — Foreign exchange contracts 39 — 39 — Warrants 2 — — 2 Total derivative assets 622 — 593 29 Total assets at fair value $ 11,499 $ 2,995 $ 8,421 $ 83 Derivative liabilities: Interest rate contracts $ 170 $ — $ 170 $ — Energy derivative contracts 190 — 190 — Foreign exchange contracts 30 — 30 — Total derivative liabilities 390 — 390 — Deferred compensation plan liabilities 88 88 — — Total liabilities at fair value $ 478 $ 88 $ 390 $ — (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Auction-rate securities. (in millions) Total Level 1 Level 2 Level 3 December 31, 2015 Trading securities: Deferred compensation plan assets $ 89 $ 89 $ — $ — Equity and other non-debt securities 3 3 $ — $ — Total trading securities 92 92 — — Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities 2,763 2,763 — — Residential mortgage-backed securities (a) 7,545 — 7,545 — State and municipal securities 9 — — 9 (b) Corporate debt securities 1 — — 1 (b) Equity and other non-debt securities 201 134 — 67 (b) Total investment securities available-for-sale 10,519 2,897 7,545 77 Derivative assets: Interest rate contracts 286 — 277 9 Energy derivative contracts 475 — 475 — Foreign exchange contracts 57 — 57 — Warrants 2 — — 2 Total derivative assets 820 — 809 11 Total assets at fair value $ 11,431 $ 2,989 $ 8,354 $ 88 Derivative liabilities: Interest rate contracts $ 92 $ — $ 92 $ — Energy derivative contracts 472 — 472 — Foreign exchange contracts 46 — 46 — Total derivative liabilities 610 — 610 — Deferred compensation plan liabilities 89 89 — — Total liabilities at fair value $ 699 $ 89 $ 610 $ — (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Auction-rate securities. There were no transfers of assets or liabilities recorded at fair value on a recurring basis into or out of Level 1, Level 2 and Level 3 fair value measurements during each of the three- and nine-month periods ended September 30, 2016 and 2015 . The following table summarizes the changes in Level 3 assets and liabilities measured at fair value on a recurring basis for the three- and nine-month periods ended September 30, 2016 and 2015 . Net Realized/Unrealized Gains (Losses) (Pretax) Balance at Beginning of Period Recorded in Earnings Recorded in Other Comprehensive Income Balance at End of Period (in millions) Realized Unrealized Redemptions Sales Three Months Ended September 30, 2016 Investment securities available-for-sale: State and municipal securities (a) $ 8 $ — $ — $ — $ — $ — $ 8 Corporate debt securities (a) 1 — — — (1 ) — — Equity and other non-debt securities (a) 48 — — 1 (c) (3 ) — 46 Total investment securities available-for-sale 57 — — 1 (c) (4 ) — 54 Derivative assets: Interest rate contracts 27 — — — — — 27 Warrants 2 3 (b) — — — (3 ) 2 Three Months Ended September 30, 2015 Investment securities available-for-sale: State and municipal securities (a) $ 23 $ — $ — $ — $ (14 ) $ — $ 9 Corporate debt securities (a) 1 — — — — — 1 Equity and other non-debt securities (a) 71 — — (1 ) (c) (1 ) — 69 Total investment securities available-for-sale 95 — — (1 ) (c) (15 ) — 79 Derivative assets: Interest rate contracts 2 — 9 (b) — — — 11 Warrants 3 5 (b) — — — (5 ) 3 Nine Months Ended September 30, 2016 Investment securities available-for-sale: State and municipal securities (a) $ 9 $ — $ — $ — $ (1 ) $ — $ 8 Corporate debt securities (a) 1 — — — (1 ) — — Equity and other non-debt securities (a) 67 — — (3 ) (c) (18 ) — 46 Total investment securities available-for-sale 77 — — (3 ) (c) (20 ) — 54 Derivative assets: Interest rate contracts 9 — 18 (b) — — — 27 Warrants 2 4 (b) — — — (4 ) 2 Nine Months Ended September 30, 2015 Investment securities available-for-sale: State and municipal securities (a) $ 23 $ — $ — $ — $ (14 ) $ — $ 9 Corporate debt securities (a) 1 — — — — — 1 Equity and other non-debt securities (a) 112 (2 ) (d) — — (41 ) — 69 Total investment securities available-for-sale 136 (2 ) (d) — — (55 ) — 79 Derivative assets: Interest rate contracts — — 11 (b) — — — 11 Warrants 4 6 (b) (1 ) (b) — — (6 ) 3 (a) Auction-rate securities. (b) Realized and unrealized gains and losses due to changes in fair value recorded in "other noninterest income" on the consolidated statements of comprehensive income. (c) Recorded in "net unrealized gains (losses) on investment securities available-for-sale" in other comprehensive income (loss). (d) Realized and unrealized gains and losses due to changes in fair value recorded in "net securities losses" on the consolidated statements of comprehensive income. ASSETS AND LIABILITIES RECORDED AT FAIR VALUE ON A NONRECURRING BASIS The Corporation may be required, from time to time, to record certain assets and liabilities at fair value on a nonrecurring basis. These include assets that are recorded at the lower of cost or fair value that were recognized at fair value below cost at the end of the period. The following table presents assets recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 . No liabilities were recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 . (in millions) Total Level 2 Level 3 September 30, 2016 Loans: Commercial 313 7 306 Commercial mortgage 7 — 7 International 15 — 15 Total assets at fair value $ 335 $ 7 $ 328 December 31, 2015 Loans held-for-sale: Commercial $ 8 $ 8 $ — Loans: Commercial 134 — 134 Commercial mortgage 11 — 11 International 8 — 8 Total loans 153 — 153 Other real estate 2 — 2 Total assets at fair value excluding investments recorded at net asset value 163 8 155 Other investments recorded at net asset value: Nonmarketable equity securities (a) 1 Total assets at fair value $ 164 (a) Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. Level 3 assets recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 included loans for which a specific allowance was established based on the fair value of collateral and other real estate for which fair value of the properties was less than the cost basis. For both asset classes, the unobservable inputs were the additional adjustments applied by management to the appraised values to reflect such factors as non-current appraisals and revisions to estimated time to sell. These adjustments are determined based on qualitative judgments made by management on a case-by-case basis and are not quantifiable inputs, although they are used in the determination of fair value. The Corporation's Level 3 recurring fair value measurements primarily include auction-rate securities where fair value is determined using an income approach based on a discounted cash flow model and certain interest rate derivative contracts where credit valuation adjustments are significant to the overall fair value of the derivative. The inputs in the table below reflect management's expectation of continued illiquidity in the secondary auction-rate securities market due to a lack of market activity for the issuers remaining in the portfolio, a lack of market incentives for issuer redemptions, and the expectation for a continuing low interest rate environment. The September 30, 2016 workout periods reflect the view that short-term interest rates could rise at a slower pace in 2016 than was expected at December 31, 2015 . Discounted Cash Flow Model Unobservable Input Fair Value (in millions) Discount Rate Workout Period (in years) September 30, 2016 State and municipal securities (a) $ 8 4% - 5% 1 - 3 Equity and other non-debt securities (a) 46 6% - 9% 1 - 2 December 31, 2015 State and municipal securities (a) $ 9 3% - 8% 1 - 2 Equity and other non-debt securities (a) 67 4% - 9% 1 (a) Auction-rate securities. ESTIMATED FAIR VALUES OF FINANCIAL INSTRUMENTS NOT RECORDED AT FAIR VALUE ON A RECURRING BASIS The Corporation typically holds the majority of its financial instruments until maturity and thus does not expect to realize many of the estimated fair value amounts disclosed. The disclosures also do not include estimated fair value amounts for items that are not defined as financial instruments, but which have significant value. These include such items as core deposit intangibles, the future earnings potential of significant customer relationships and the value of trust operations and other fee generating businesses. The Corporation believes the imprecision of an estimate could be significant. The carrying amount and estimated fair value of financial instruments not recorded at fair value in their entirety on a recurring basis on the Corporation’s consolidated balance sheets are as follows: Carrying Amount Estimated Fair Value (in millions) Total Level 1 Level 2 Level 3 September 30, 2016 Assets Cash and due from banks $ 1,292 $ 1,292 $ 1,292 $ — $ — Interest-bearing deposits with banks 6,748 6,748 6,748 — — Investment securities held-to-maturity 1,695 1,713 — 1,713 — Loans held-for-sale 4 4 — 4 — Total loans, net of allowance for loan losses (a) 48,547 48,483 — 7 48,476 Customers’ liability on acceptances outstanding 2 2 2 — — Restricted equity investments 207 207 207 — — Nonmarketable equity securities (b) 9 17 Liabilities Demand deposits (noninterest-bearing) 31,776 31,776 — 31,776 — Interest-bearing deposits 24,518 24,518 — 24,518 — Customer certificates of deposit 2,967 2,952 — 2,952 — Total deposits 59,261 59,246 — 59,246 — Short-term borrowings 12 12 12 — — Acceptances outstanding 2 2 2 — — Medium- and long-term debt 5,890 5,857 — 5,857 — Credit-related financial instruments (80 ) (80 ) — — (80 ) December 31, 2015 Assets Cash and due from banks $ 1,157 $ 1,157 $ 1,157 $ — $ — Interest-bearing deposits with banks 4,990 4,990 4,990 — — Investment securities held-to-maturity 1,981 1,973 — 1,973 — Loans held-for-sale (c) 21 21 — 21 — Total loans, net of allowance for loan losses (a) 48,450 48,269 — — 48,269 Customers’ liability on acceptances outstanding 5 5 5 — — Restricted equity investments 92 92 92 — — Nonmarketable equity securities (b) (d) 10 18 Liabilities Demand deposits (noninterest-bearing) 30,839 30,839 — 30,839 — Interest-bearing deposits 25,462 25,462 — 25,462 — Customer certificates of deposit 3,552 3,536 — 3,536 — Total deposits 59,853 59,837 — 59,837 — Short-term borrowings 23 23 23 — — Acceptances outstanding 5 5 5 — — Medium- and long-term debt 3,058 3,032 — 3,032 — Credit-related financial instruments (83 ) (83 ) — — (83 ) (a) Included $335 million and $153 million of impaired loans recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 , respectively. (b) Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (c) Included $8 million impaired loans held-for-sale recorded at fair value on a nonrecurring basis at December 31, 2015 . (d) Included $1 million of nonmarketable equity securities recorded at fair value on a nonrecurring basis at December 31, 2015 .

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES A summary of the Corporation’s investment securities follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2016 Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities $ 2,771 $ 55 $ — $ 2,826 Residential mortgage-backed securities (a) 7,714 121 7 7,828 State and municipal securities 8 — — 8 Equity and other non-debt securities 128 1 2 127 Total investment securities available-for-sale (b) $ 10,621 $ 177 $ 9 $ 10,789 Investment securities held-to-maturity (c): Residential mortgage-backed securities (a) $ 1,695 $ 18 $ — $ 1,713 December 31, 2015 Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities $ 2,769 $ 1 $ 7 $ 2,763 Residential mortgage-backed securities (a) 7,513 76 44 7,545 State and municipal securities 9 — — 9 Corporate debt securities 1 — — 1 Equity and other non-debt securities 199 2 — 201 Total investment securities available-for-sale (b) $ 10,491 $ 79 $ 51 $ 10,519 Investment securities held-to-maturity (c): Residential mortgage-backed securities (a) $ 1,981 $ 2 $ 10 $ 1,973 (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Included auction-rate securities at amortized cost and fair value of $56 million and $54 million , respectively as of September 30, 2016 and $76 million and $77 million , respectively, as of December 31, 2015 . (c) The amortized cost of investment securities held-to-maturity included net unrealized losses of $13 million at September 30, 2016 and $15 million at December 31, 2015 related to securities transferred from available-for-sale, which are included in accumulated other comprehensive loss. A summary of the Corporation’s investment securities in an unrealized loss position as of September 30, 2016 and December 31, 2015 follows: Temporarily Impaired Less than 12 Months 12 Months or more Total (in millions) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses September 30, 2016 Residential mortgage-backed securities (a) $ 573 $ 1 $ 1,244 $ 15 $ 1,817 $ 16 State and municipal securities (b) — — 7 — (c) 7 — (c) Equity and other non-debt securities (b) 36 1 10 1 46 2 Total temporarily impaired securities $ 609 $ 2 $ 1,261 $ 16 $ 1,870 $ 18 December 31, 2015 U.S. Treasury and other U.S. government agency securities $ 2,265 $ 7 $ — $ — $ 2,265 $ 7 Residential mortgage-backed securities (a) 2,665 21 1,976 51 4,641 72 State and municipal securities (b) — — 9 — (c) 9 — (c) Corporate debt securities (b) — — 1 — (c) 1 — (c) Equity and other non-debt securities (b) 14 — (c) — — 14 — (c) Total temporarily impaired securities $ 4,944 $ 28 $ 1,986 $ 51 $ 6,930 $ 79 (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Primarily auction-rate securities. (c) Unrealized losses less than $0.5 million. At September 30, 2016 , the Corporation had 95 securities in an unrealized loss position with no credit impairment, including 52 residential mortgage-backed securities, 28 auction-rate preferred securities and 15 state and municipal auction-rate securities. As of September 30, 2016 , approximately 96 percent of the aggregate par value of auction-rate securities have been redeemed or sold since acquisition, of which approximately 90 percent were redeemed at or above cost. The unrealized losses for these securities resulted from changes in market interest rates and liquidity. The Corporation ultimately expects full collection of the carrying amount of these securities, does not intend to sell the securities in an unrealized loss position, and it is not more-likely-than-not that the Corporation will be required to sell the securities in an unrealized loss position prior to recovery of amortized cost. The Corporation does not consider these securities to be other-than-temporarily impaired at September 30, 2016 . Sales, calls and write-downs of investment securities available-for-sale are recorded in “net securities losses” on the consolidated statements of comprehensive income, computed based on the adjusted cost of the specific security. The Corporation recognized no gains or losses for both the three-month periods ended September 30, 2016 and 2015 and no gains and $3 million and $2 million of losses for the nine-month periods ended September 30, 2016 and 2015 , respectively. The following table summarizes the amortized cost and fair values of debt securities by contractual maturity. Securities with multiple maturity dates are classified in the period of final maturity. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. (in millions) Available-for-sale Held-to-maturity September 30, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Contractual maturity Within one year $ 10 $ 10 $ — $ — After one year through five years 3,000 3,056 — — After five years through ten years 1,401 1,450 25 25 After ten years 6,082 6,146 1,670 1,688 Subtotal 10,493 10,662 1,695 1,713 Equity and other non-debt securities 128 127 Total investment securities $ 10,621 $ 10,789 $ 1,695 $ 1,713 Included in the contractual maturity distribution in the table above were residential mortgage-backed securities available-for-sale with total amortized cost and fair value of $7.7 billion and $7.8 billion , respectively, and residential mortgage-backed securities held-to-maturity with a total amortized cost and fair value of $1.7 billion . The actual cash flows of mortgage-backed securities may differ from contractual maturity as the borrowers of the underlying loans may exercise prepayment options. At September 30, 2016 , investment securities with a carrying value of $1.5 billion were pledged where permitted or required by law to secure $990 million of liabilities, primarily public and other deposits of state and local government agencies and derivative instruments.

Credit Quality And Allowance Fo

Credit Quality And Allowance For Credit Losses	9 Months Ended
	Sep. 30, 2016
Credit Quality And Allowance For Credit Losses [Abstract]
Credit Quality And Allowance For Credit Losses	CREDIT QUALITY AND ALLOWANCE FOR CREDIT LOSSES The following table presents an aging analysis of the recorded balance of loans. Loans Past Due and Still Accruing (in millions) 30-59 Days 60-89 Days 90 Days or More Total Nonaccrual Loans Current Loans Total Loans September 30, 2016 Business loans: Commercial $ 68 $ 17 $ 21 $ 106 $ 508 $ 30,538 $ 31,152 Real estate construction: Commercial Real Estate business line (a) 12 — — 12 — 2,370 2,382 Other business lines (b) 11 — — 11 — 350 361 Total real estate construction 23 — — 23 — 2,720 2,743 Commercial mortgage: Commercial Real Estate business line (a) 5 1 — 6 8 2,171 2,185 Other business lines (b) 15 8 6 29 36 6,763 6,828 Total commercial mortgage 20 9 6 35 44 8,934 9,013 Lease financing — — — — 6 642 648 International 1 — — 1 19 1,283 1,303 Total business loans 112 26 27 165 577 44,117 44,859 Retail loans: Residential mortgage 13 1 9 23 23 1,828 1,874 Consumer: Home equity 6 2 — 8 27 1,757 1,792 Other consumer 1 — 12 13 4 732 749 Total consumer 7 2 12 21 31 2,489 2,541 Total retail loans 20 3 21 44 54 4,317 4,415 Total loans $ 132 $ 29 $ 48 $ 209 $ 631 $ 48,434 $ 49,274 December 31, 2015 Business loans: Commercial $ 46 $ 12 $ 13 $ 71 $ 238 $ 31,350 $ 31,659 Real estate construction: Commercial Real Estate business line (a) 5 — — 5 — 1,676 1,681 Other business lines (b) 3 — — 3 1 316 320 Total real estate construction 8 — — 8 1 1,992 2,001 Commercial mortgage: Commercial Real Estate business line (a) 7 — 1 8 16 2,080 2,104 Other business lines (b) 7 5 3 15 44 6,814 6,873 Total commercial mortgage 14 5 4 23 60 8,894 8,977 Lease financing — — — — 6 718 724 International 2 — — 2 8 1,358 1,368 Total business loans 70 17 17 104 313 44,312 44,729 Retail loans: Residential mortgage 26 1 — 27 27 1,816 1,870 Consumer: Home equity 5 3 — 8 27 1,685 1,720 Other consumer 7 — — 7 — 758 765 Total consumer 12 3 — 15 27 2,443 2,485 Total retail loans 38 4 — 42 54 4,259 4,355 Total loans $ 108 $ 21 $ 17 $ 146 $ 367 $ 48,571 $ 49,084 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. The following table presents loans by credit quality indicator, based on internal risk ratings assigned to each business loan at the time of approval and subjected to subsequent reviews, generally at least annually, and to pools of retail loans with similar risk characteristics. Internally Assigned Rating (in millions) Pass (a) Special Mention (b) Substandard (c) Nonaccrual (d) Total September 30, 2016 Business loans: Commercial $ 28,406 $ 965 $ 1,273 $ 508 $ 31,152 Real estate construction: Commercial Real Estate business line (e) 2,382 — — — 2,382 Other business lines (f) 358 3 — — 361 Total real estate construction 2,740 3 — — 2,743 Commercial mortgage: Commercial Real Estate business line (e) 2,141 16 20 8 2,185 Other business lines (f) 6,529 136 127 36 6,828 Total commercial mortgage 8,670 152 147 44 9,013 Lease financing 625 11 6 6 648 International 1,230 20 34 19 1,303 Total business loans 41,671 1,151 1,460 577 44,859 Retail loans: Residential mortgage 1,838 3 10 23 1,874 Consumer: Home equity 1,760 2 3 27 1,792 Other consumer 744 1 — 4 749 Total consumer 2,504 3 3 31 2,541 Total retail loans 4,342 6 13 54 4,415 Total loans $ 46,013 $ 1,157 $ 1,473 $ 631 $ 49,274 December 31, 2015 Business loans: Commercial $ 29,117 $ 1,293 $ 1,011 $ 238 $ 31,659 Real estate construction: Commercial Real Estate business line (e) 1,681 — — — 1,681 Other business lines (f) 318 1 — 1 320 Total real estate construction 1,999 1 — 1 2,001 Commercial mortgage: Commercial Real Estate business line (e) 2,031 31 26 16 2,104 Other business lines (f) 6,536 172 121 44 6,873 Total commercial mortgage 8,567 203 147 60 8,977 Lease financing 693 17 8 6 724 International 1,245 59 56 8 1,368 Total business loans 41,621 1,573 1,222 313 44,729 Retail loans: Residential mortgage 1,828 2 13 27 1,870 Consumer: Home equity 1,687 1 5 27 1,720 Other consumer 755 3 7 — 765 Total consumer 2,442 4 12 27 2,485 Total retail loans 4,270 6 25 54 4,355 Total loans $ 45,891 $ 1,579 $ 1,247 $ 367 $ 49,084 (a) Includes all loans not included in the categories of special mention, substandard or nonaccrual. (b) Special mention loans are accruing loans that have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date. (c) Substandard loans are accruing loans that have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans also are distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. This category is generally consistent with the "substandard" category as defined by regulatory authorities. (d) Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to the Nonperforming Assets subheading in Note 1 - Basis of Presentation and Accounting Policies - on page F-58 in the Corporation's 2015 Annual Report. A significant majority of nonaccrual loans are generally consistent with the "substandard" category and the remainder are generally consistent with the "doubtful" category as defined by regulatory authorities. (e) Primarily loans to real estate developers. (f) Primarily loans secured by owner-occupied real estate. The following table summarizes nonperforming assets. (in millions) September 30, 2016 December 31, 2015 Nonaccrual loans $ 631 $ 367 Reduced-rate loans (a) 8 12 Total nonperforming loans 639 379 Foreclosed property (b) 21 12 Total nonperforming assets $ 660 $ 391 (a) There were no reduced-rate business loans at both September 30, 2016 and December 31, 2015 . Reduced-rate retail loans were $8 million and $12 million at September 30, 2016 and December 31, 2015 , respectively. (b) Included $5 million and $9 million of foreclosed residential real estate properties at September 30, 2016 and December 31, 2015 , respectively. There were no retail loans secured by residential real estate properties in process of foreclosure included in nonaccrual loans at September 30, 2016 compared to $1 million at December 31, 2015 . Allowance for Credit Losses The following table details the changes in the allowance for loan losses and related loan amounts. 2016 2015 (in millions) Business Loans Retail Loans Total Business Loans Retail Loans Total Three Months Ended September 30 Allowance for loan losses: Balance at beginning of period $ 682 $ 47 $ 729 $ 563 $ 55 $ 618 Loan charge-offs (34 ) (1 ) (35 ) (31 ) (3 ) (34 ) Recoveries on loans previously charged-off 18 1 19 10 1 11 Net loan charge-offs (16 ) — (16 ) (21 ) (2 ) (23 ) Provision for loan losses 12 2 14 25 3 28 Foreign currency translation adjustment — — — (1 ) — (1 ) Balance at end of period $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 Nine Months Ended September 30 Allowance for loan losses: Balance at beginning of period $ 579 $ 55 $ 634 $ 534 $ 60 $ 594 Loan charge-offs (161 ) (5 ) (166 ) (83 ) (9 ) (92 ) Recoveries on loans previously charged-off 53 3 56 38 5 43 Net loan charge-offs (108 ) (2 ) (110 ) (45 ) (4 ) (49 ) Provision for loan losses 206 (4 ) 202 79 — 79 Foreign currency translation adjustment 1 — 1 (2 ) — (2 ) Balance at end of period $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 As a percentage of total loans 1.51 % 1.10 % 1.48 % 1.27 % 1.29 % 1.27 % September 30 Allowance for loan losses: Individually evaluated for impairment $ 115 $ 1 $ 116 $ 47 $ — $ 47 Collectively evaluated for impairment 563 48 611 519 56 575 Total allowance for loan losses $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 Loans: Individually evaluated for impairment $ 677 $ 29 $ 706 $ 338 $ 51 $ 389 Collectively evaluated for impairment 44,182 4,386 48,568 44,233 4,318 48,551 Purchased credit impaired (PCI) loans (a) — — — — 2 2 Total loans evaluated for impairment $ 44,859 $ 4,415 $ 49,274 $ 44,571 $ 4,371 $ 48,942 (a) No allowance for loan losses was required for PCI loans at September 30, 2015 . Changes in the allowance for credit losses on lending-related commitments, included in "accrued expenses and other liabilities" on the consolidated balance sheets, are summarized in the following table. Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Balance at beginning of period $ 43 $ 50 $ 45 $ 41 Charge-offs on lending related commitments (a) — — (11 ) (1 ) Provision for credit losses on lending-related commitments 2 (2 ) 11 8 Balance at end of period $ 45 $ 48 $ 45 $ 48 (a) Charge-offs result from the sale of unfunded lending-related commitments. Individually Evaluated Impaired Loans The following table presents additional information regarding individually evaluated impaired loans. Recorded Investment In: (in millions) Impaired Loans with No Related Allowance Impaired Loans with Related Allowance Total Impaired Loans Unpaid Principal Balance Related Allowance for Loan Losses September 30, 2016 Business loans: Commercial $ 141 $ 482 $ 623 $ 704 $ 106 Commercial mortgage: Commercial Real Estate business line (a) — 6 6 15 1 Other business lines (b) 4 25 29 43 3 Total commercial mortgage 4 31 35 58 4 International 3 16 19 26 5 Total business loans 148 529 677 788 115 Retail loans: Residential mortgage 12 — 12 13 — Consumer: Home equity 12 — 12 16 — Other consumer 2 3 5 6 1 Total consumer 14 3 17 22 1 Total retail loans (c) 26 3 29 35 1 Total individually evaluated impaired loans $ 174 $ 532 $ 706 $ 823 $ 116 December 31, 2015 Business loans: Commercial $ 82 $ 252 $ 334 $ 398 $ 45 Commercial mortgage: Commercial Real Estate business line (a) 7 8 15 38 1 Other business lines (b) 2 32 34 55 5 Total commercial mortgage 9 40 49 93 6 International — 10 10 17 2 Total business loans 91 302 393 508 53 Retail loans: Residential mortgage 13 — 13 13 — Consumer: Home equity 12 — 12 16 — Other consumer 6 — 6 10 — Total consumer 18 — 18 26 — Total retail loans (c) 31 — 31 39 — Total individually evaluated impaired loans $ 122 $ 302 $ 424 $ 547 $ 53 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. (c) Individually evaluated retail loans generally have no related allowance for loan losses, primarily due to policy which results in direct write-downs of most restructured retail loans. The following table presents information regarding average individually evaluated impaired loans and the related interest recognized. Interest income recognized for the period primarily related to performing restructured loans. Individually Evaluated Impaired Loans 2016 2015 (in millions) Average Balance for the Period Interest Income Recognized for the Period Average Balance for the Period Interest Income Recognized for the Period Three Months Ended September 30 Business loans: Commercial $ 606 $ 2 $ 236 $ 1 Commercial mortgage: Commercial Real Estate business line (a) 7 — 15 — Other business lines (b) 30 — 37 1 Total commercial mortgage 37 — 52 1 International 19 — 10 — Total business loans 662 2 298 2 Retail loans: Residential mortgage 11 — 23 — Consumer loans: Home equity 12 — 12 — Other consumer 4 — 7 — Total consumer 16 — 19 — Total retail loans 27 — 42 — Total individually evaluated impaired loans $ 689 $ 2 $ 340 $ 2 Nine Months Ended September 30 Business loans: Commercial $ 559 $ 8 $ 172 $ 3 Commercial mortgage: Commercial Real Estate business line (a) 9 — 17 — Other business lines (b) 31 — 41 1 Total commercial mortgage 40 — 58 1 International 19 — 5 — Total business loans 618 8 235 4 Retail loans: Residential mortgage 12 — 23 — Consumer: Home equity 12 — 12 — Other consumer 4 — 6 — Total consumer 16 — 18 — Total retail loans 28 — 41 — Total individually evaluated impaired loans $ 646 $ 8 $ 276 $ 4 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. Troubled Debt Restructurings The following tables detail the recorded balance at September 30, 2016 and 2015 of loans considered to be troubled debt restructurings (TDRs) that were restructured during the three- and nine-month periods ended September 30, 2016 and 2015 , by type of modification. In cases of loans with more than one type of modification, the loans were categorized based on the most significant modification. 2016 2015 Type of Modification Type of Modification (in millions) Principal Deferrals (a) Interest Rate Reductions AB Note Restructures (b) Total Modifications Principal Deferrals (a) Interest Rate Reductions Total Modifications Three Months Ended September 30 Business loans: Commercial $ 70 $ — $ 40 $ 110 $ 100 $ — $ 100 Commercial mortgage: Commercial Real Estate business line (c) — — — — 7 — 7 Other business lines (d) — — — — 3 — 3 Total commercial mortgage — — — — 10 — 10 International — — — — 2 — 2 Total business loans 70 — 40 110 112 — 112 Retail loans: Residential mortgage — — — — 18 — 18 Consumer: Home equity — — — — 1 1 2 Total retail loans — — — — 19 1 20 Total loans $ 70 $ — $ 40 $ 110 $ 131 $ 1 $ 132 Nine Months Ended September 30 Business loans: Commercial $ 150 $ — $ 49 $ 199 $ 102 $ — $ 102 Commercial mortgage: Commercial Real Estate business line (c) — — — — 9 — 9 Other business lines (d) 2 — — 2 7 — 7 Total commercial mortgage 2 — — 2 16 — 16 International — — 3 3 2 — 2 Total business loans 152 — 52 204 120 — 120 Retail loans: Residential mortgage — — — — 18 — 18 Consumer: Home equity 1 1 — 2 1 1 2 Total retail loans 1 1 — 2 19 1 20 Total loans $ 153 $ 1 $ 52 $ 206 $ 139 $ 1 $ 140 (a) Primarily represents loan balances where terms were extended 90 days or more at or above contractual interest rates. (b) Loan restructurings whereby the original loan is restructured into two notes: an "A" note, which generally reflects the portion of the modified loan which is expected to be collected; and a "B" note, which is generally fully charged off. (c) Primarily loans to real estate developers. (d) Primarily loans secured by owner-occupied real estate. Commitments to lend additional funds to borrowers whose terms have been modified in TDRs were $37 million at September 30, 2016 and $6 million at December 31, 2015 . The majority of the modifications considered to be TDRs that occurred during the nine months ended September 30, 2016 and 2015 were principal deferrals. The Corporation charges interest on principal balances outstanding during deferral periods. Additionally, none of the modifications involved forgiveness of principal. As a result, the current and future financial effects of the recorded balance of loans considered to be TDRs that were restructured during the nine months ended September 30, 2016 and 2015 were insignificant. On an ongoing basis, the Corporation monitors the performance of modified loans to their restructured terms. In the event of a subsequent default, the allowance for loan losses continues to be reassessed on the basis of an individual evaluation of the loan. The following table presents information regarding the recorded balance at September 30, 2016 and 2015 of loans modified by principal deferral during the twelve-month periods ended September 30, 2016 and 2015 , and those principal deferrals which experienced a subsequent default during the three- and nine-month periods ended September 30, 2016 and 2015 . For principal deferrals, incremental deterioration in the credit quality of the loan, represented by a downgrade in the risk rating of the loan, for example, due to missed interest payments or a reduction of collateral value, is considered a subsequent default. 2016 2015 (in millions) Balance at September 30 Subsequent Default in the Three Months Ended September 30 Subsequent Default in the Nine Months Ended September 30 Balance at September 30 Subsequent Default in the Three Months Ended September 30 Subsequent Default in the Nine Months Ended September 30 Principal deferrals: Business loans: Commercial $ 229 $ — $ 13 $ 108 $ 1 $ 3 Commercial mortgage: Commercial Real Estate business line (a) — — — 9 — — Other business lines (b) 4 — 1 7 — 1 Total commercial mortgage 4 — 1 16 — 1 International — — — 2 — — Total business loans 233 — 14 126 1 4 Retail loans: Residential mortgage — — — 18 (c) — — Consumer: Home equity 1 (c) — — 1 (c) — — Total retail loans 1 — — 19 — — Total principal deferrals $ 234 $ — $ 14 $ 145 $ 1 $ 4 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. (c) Includes bankruptcy loans for which the court has discharged the borrower's obligation and the borrower has not reaffirmed the debt. During the twelve-month periods ended September 30, 2016 and 2015 , loans with a carrying value of $4 million and $2 million , respectively, were modified by interest rate reduction. During the twelve-month period ended September 30, 2016 , loans with a carrying value of $52 million were restructured into two notes (AB note restructures). For reduced-rate loans and AB Note restructures, a subsequent payment default is defined in terms of delinquency, when a principal or interest payment is 90 days past due. There were no subsequent payment defaults of reduced-rate loans or AB note restructures during the three- and nine-month periods ended September 30, 2016 and 2015 .

Derivative And Credit-Related F

Derivative And Credit-Related Financial Instruments	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative And Credit-Related Financial Instruments	DERIVATIVE AND CREDIT-RELATED FINANCIAL INSTRUMENTS In the normal course of business, the Corporation enters into various transactions involving derivative and credit-related financial instruments to manage exposure to fluctuations in interest rate, foreign currency and other market risks and to meet the financing needs of customers (customer-initiated derivatives). These financial instruments involve, to varying degrees, elements of market and credit risk. Market and credit risk are included in the determination of fair value. Market risk is the potential loss that may result from movements in interest rates, foreign currency exchange rates or energy commodity prices that cause an unfavorable change in the value of a financial instrument. The Corporation manages this risk by establishing monetary exposure limits and monitoring compliance with those limits. Market risk inherent in interest rate and energy contracts entered into on behalf of customers is mitigated by taking offsetting positions, except in those circumstances when the amount, tenor and/or contract rate level results in negligible economic risk, whereby the cost of purchasing an offsetting contract is not economically justifiable. The Corporation mitigates most of the inherent market risk in foreign exchange contracts entered into on behalf of customers by taking offsetting positions and manages the remainder through individual foreign currency position limits and aggregate value-at-risk limits. These limits are established annually and reviewed quarterly. Market risk inherent in derivative instruments held or issued for risk management purposes is typically offset by changes in the fair value of the assets or liabilities being hedged. Credit risk is the possible loss that may occur in the event of nonperformance by the counterparty to a financial instrument. The Corporation attempts to minimize credit risk arising from customer-initiated derivatives by evaluating the creditworthiness of each customer, adhering to the same credit approval process used for traditional lending activities and obtaining collateral as deemed necessary. Derivatives with dealer counterparties are either cleared through a clearinghouse or settled directly with a single counterparty. For derivatives settled directly with dealer counterparties, the Corporation utilizes counterparty risk limits and monitoring procedures as well as master netting arrangements and bilateral collateral agreements to facilitate the management of credit risk. Master netting arrangements effectively reduce credit risk by permitting settlement of positive and negative positions and offset cash collateral held with the same counterparty on a net basis. Bilateral collateral agreements require daily exchange of cash or highly rated securities issued by the U.S. Treasury or other U.S. government entities to collateralize amounts due to either party beyond certain risk limits. At September 30, 2016 , counterparties with bilateral collateral agreements had pledged $34 million of marketable investment securities and deposited $147 million of cash with the Corporation to secure the fair value of contracts in an unrealized gain position, and the Corporation had pledged $44 million of marketable investment securities and posted $10 million of cash as collateral for contracts in an unrealized loss position. For those counterparties not covered under bilateral collateral agreements, collateral is obtained, if deemed necessary, based on the results of management’s credit evaluation of the counterparty. Collateral varies, but may include cash, investment securities, accounts receivable, equipment or real estate. Included in the fair value of derivative instruments are credit valuation adjustments reflecting counterparty credit risk. These adjustments are determined by applying a credit spread for the counterparty or the Corporation, as appropriate, to the total expected exposure of the derivative. There were no derivative instruments with credit-risk-related contingent features that were in a liability position at September 30, 2016 . Derivative Instruments Derivative instruments utilized by the Corporation are negotiated over-the-counter and primarily include swaps, caps and floors, forward contracts and options, each of which may relate to interest rates, energy commodity prices or foreign currency exchange rates. Swaps are agreements in which two parties periodically exchange cash payments based on specified indices applied to a specified notional amount until a stated maturity. Caps and floors are agreements which entitle the buyer to receive cash payments based on the difference between a specified reference rate or price and an agreed strike rate or price, applied to a specified notional amount until a stated maturity. Forward contracts are over-the-counter agreements to buy or sell an asset at a specified future date and price. Options are similar to forward contracts except the purchaser has the right, but not the obligation, to buy or sell the asset during a specified period or at a specified future date. Over-the-counter contracts are tailored to meet the needs of the counterparties involved and, therefore, contain a greater degree of credit risk and liquidity risk than exchange-traded contracts, which have standardized terms and readily available price information. The Corporation reduces exposure to market and liquidity risks from over-the-counter derivative instruments entered into for risk management purposes, and transactions entered into to mitigate the market risk associated with customer-initiated transactions, by conducting hedging transactions with investment grade domestic and foreign financial institutions and subjecting counterparties to credit approvals, limits and collateral monitoring procedures similar to those used in making other extensions of credit. In addition, certain derivative contracts executed bilaterally with a dealer counterparty in the over-the-counter market are cleared through a clearinghouse, whereby the clearinghouse becomes the counterparty to the transaction. The following table presents the composition of the Corporation’s derivative instruments held or issued for risk management purposes or in connection with customer-initiated and other activities at September 30, 2016 and December 31, 2015 . The table excludes commitments and warrants accounted for as derivatives. September 30, 2016 December 31, 2015 Fair Value Fair Value (in millions) Notional/ Contract Amount (a) Gross Derivative Assets Gross Derivative Liabilities Notional/ Contract Amount (a) Gross Derivative Assets Gross Derivative Liabilities Risk management purposes Derivatives designated as hedging instruments Interest rate contracts: Swaps - fair value - receive fixed/pay floating $ 2,525 $ 172 $ — $ 2,525 $ 147 $ — Derivatives used as economic hedges Foreign exchange contracts: Spot, forwards and swaps 720 — 1 593 3 — Total risk management purposes 3,245 172 1 3,118 150 — Customer-initiated and other activities Interest rate contracts: Caps and floors written 386 — — 253 — — Caps and floors purchased 386 — — 253 — — Swaps 12,481 217 170 11,722 139 92 Total interest rate contracts 13,253 217 170 12,228 139 92 Energy contracts: Caps and floors written 471 1 41 536 — 85 Caps and floors purchased 471 41 — 536 85 — Swaps 1,236 150 149 2,055 390 387 Total energy contracts 2,178 192 190 3,127 475 472 Foreign exchange contracts: Spot, forwards, options and swaps 1,760 39 29 2,291 54 46 Total customer-initiated and other activities 17,191 448 389 17,646 668 610 Total gross derivatives $ 20,436 620 390 $ 20,764 818 610 Amounts offset in the consolidated balance sheets: Netting adjustment - Offsetting derivative assets/liabilities (108 ) (108 ) (127 ) (127 ) Netting adjustment - Cash collateral received/posted (85 ) (8 ) (291 ) (3 ) Net derivatives included in the consolidated balance sheets (b) 427 274 400 480 Amounts not offset in the consolidated balance sheets: Marketable securities pledged under bilateral collateral agreements (32 ) (41 ) (137 ) (3 ) Net derivatives after deducting amounts not offset in the consolidated balance sheets $ 395 $ 233 $ 263 $ 477 (a) Notional or contractual amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the consolidated balance sheets. (b) Net derivative assets are included in “accrued income and other assets” and net derivative liabilities are included in “accrued expenses and other liabilities” on the consolidated balance sheets. Included in the fair value of net derivative assets and net derivative liabilities are credit valuation adjustments reflecting counterparty credit risk and credit risk of the Corporation. The fair value of net derivative assets included credit valuation adjustments for counterparty credit risk of $11 million and $5 million at September 30, 2016 and December 31, 2015 , respectively. Risk Management As an end-user, the Corporation employs a variety of financial instruments for risk management purposes, including cash instruments, such as investment securities, as well as derivative instruments. Activity related to these instruments is centered predominantly in the interest rate markets and mainly involves interest rate swaps. Various other types of instruments also may be used to manage exposures to market risks, including interest rate caps and floors, total return swaps, foreign exchange forward contracts and foreign exchange swap agreements. The Corporation has entered into interest rate swap agreements for interest rate risk management purposes. These interest rate swap agreements effectively modify the Corporation’s exposure to interest rate risk by converting fixed-rate debt to a floating rate. These agreements involve the receipt of fixed-rate interest amounts in exchange for floating-rate interest payments over the life of the agreement, without an exchange of the underlying principal amount. Risk management fair value interest rate swaps generated net interest income of $15 million and $18 million for the three months ended September 30, 2016 and 2015 , respectively, and $48 million and $52 million for the nine months ended September 30, 2016 and 2015 , respectively. The Corporation recognized $1 million and $3 million of net gains for the three months ended September 30, 2016 and 2015 , respectively, and $4 million and $2 million of net gains for the nine months ended September 30, 2016 and 2015 , respectively, for the ineffective portion of risk management derivative instruments designated as fair value hedges of fixed-rate debt, included in "other noninterest income" in the consolidated statements of comprehensive income. Foreign exchange rate risk arises from changes in the value of certain assets and liabilities denominated in foreign currencies. The Corporation employs spot and forward contracts in addition to swap contracts to manage exposure to these and other risks. There were no significant net gains or losses on risk management derivative instruments used as economic hedges in any period presented in the consolidated statements of comprehensive income. Net gains or losses on these instruments are included in "other noninterest income". The following table summarizes the expected weighted average remaining maturity of the notional amount of risk management interest rate swaps and the weighted average interest rates associated with amounts expected to be received or paid on interest rate swap agreements as of September 30, 2016 and December 31, 2015 . Weighted Average (dollar amounts in millions) Notional Amount Remaining Maturity (in years) Receive Rate Pay Rate (a) September 30, 2016 Swaps - fair value - receive fixed/pay floating rate Medium- and long-term debt designation $ 2,525 4.3 3.89 % 1.59 % December 31, 2015 Swaps - fair value - receive fixed/pay floating rate Medium- and long-term debt designation 2,525 5.1 3.89 1.11 (a) Variable rates paid on receive fixed swaps are based on six-month LIBOR rates in effect at September 30, 2016 and December 31, 2015 . Management believes these hedging strategies achieve the desired relationship between the rate maturities of assets and funding sources which, in turn, reduce the overall exposure of net interest income to interest rate risk, although there can be no assurance that such strategies will be successful. Customer-Initiated and Other The Corporation enters into derivative transactions at the request of customers and generally takes offsetting positions with dealer counterparties to mitigate the inherent market risk. Income primarily results from the spread between the customer derivative and the offsetting dealer position. For customer-initiated foreign exchange contracts where offsetting positions have not been taken, the Corporation manages the remaining inherent market risk through individual foreign currency position limits and aggregate value-at-risk limits. These limits are established annually and reviewed quarterly. For those customer-initiated derivative contracts which were not offset or where the Corporation holds a position within the limits described above, the Corporation recognized an insignificant amount of net gains in “other noninterest income” in the consolidated statements of comprehensive income for both the three-month periods ended September 30, 2016 and 2015 , and $1 million of net gains for both the nine-month periods ended September 30, 2016 and 2015 . Fair values of customer-initiated and other derivative instruments represent the net unrealized gains or losses on such contracts and are recorded in the consolidated balance sheets. Changes in fair value are recognized in the consolidated statements of comprehensive income. The net gains recognized in income on customer-initiated derivative instruments, net of the impact of offsetting positions, were as follows . Three Months Ended September 30, Nine Months Ended September 30, (in millions) Location of Gain 2016 2015 2016 2015 Interest rate contracts Other noninterest income $ 6 $ 4 $ 14 $ 11 Energy contracts Other noninterest income — 1 1 2 Foreign exchange contracts Foreign exchange income 11 9 30 27 Total $ 17 $ 14 $ 45 $ 40 Credit-Related Financial Instruments The Corporation issues off-balance sheet financial instruments in connection with commercial and consumer lending activities. The Corporation’s credit risk associated with these instruments is represented by the contractual amounts indicated in the following table. (in millions) September 30, 2016 December 31, 2015 Unused commitments to extend credit: Commercial and other $ 24,115 $ 26,115 Bankcard, revolving check credit and home equity loan commitments 2,638 2,414 Total unused commitments to extend credit $ 26,753 $ 28,529 Standby letters of credit $ 3,757 $ 3,985 Commercial letters of credit 33 41 The Corporation maintains an allowance to cover probable credit losses inherent in lending-related commitments, including unused commitments to extend credit, letters of credit and financial guarantees. The allowance for credit losses on lending-related commitments, included in “accrued expenses and other liabilities” on the consolidated balance sheets, was $45 million at both September 30, 2016 and December 31, 2015 . Unused Commitments to Extend Credit Commitments to extend credit are legally binding agreements to lend to a customer, provided there is no violation of any condition established in the contract. These commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many commitments expire without being drawn upon, the total contractual amount of commitments does not necessarily represent future cash requirements of the Corporation. Commercial and other unused commitments are primarily variable rate commitments. The allowance for credit losses on lending-related commitments included $30 million and $33 million at September 30, 2016 and December 31, 2015 , respectively, for probable credit losses inherent in the Corporation’s unused commitments to extend credit. Standby and Commercial Letters of Credit Standby letters of credit represent conditional obligations of the Corporation which guarantee the performance of a customer to a third party. Standby letters of credit are primarily issued to support public and private borrowing arrangements, including commercial paper, bond financing and similar transactions. Commercial letters of credit are issued to finance foreign or domestic trade transactions. These contracts expire in decreasing amounts through the year 2023 . The Corporation may enter into participation arrangements with third parties that effectively reduce the maximum amount of future payments which may be required under standby and commercial letters of credit. These risk participations covered $282 million and $287 million , respectively, of the $3.8 billion and $4.0 billion standby and commercial letters of credit outstanding at September 30, 2016 and December 31, 2015 , respectively. The carrying value of the Corporation’s standby and commercial letters of credit, included in “accrued expenses and other liabilities” on the consolidated balance sheets, totaled $50 million at September 30, 2016 , including $35 million in deferred fees and $15 million in the allowance for credit losses on lending-related commitments. At December 31, 2015 , the comparable amounts were $49 million , $37 million and $12 million , respectively. The following table presents a summary of criticized standby and commercial letters of credit at September 30, 2016 and December 31, 2015 . The Corporation's criticized list is generally consistent with the Special mention, Substandard and Doubtful categories defined by regulatory authorities. The Corporation manages credit risk through underwriting, periodically reviewing and approving its credit exposures using Board committee approved credit policies and guidelines. (dollar amounts in millions) September 30, 2016 December 31, 2015 Total criticized standby and commercial letters of credit $ 136 $ 110 As a percentage of total outstanding standby and commercial letters of credit 3.6 % 2.7 % Other Credit-Related Financial Instruments The Corporation enters into credit risk participation agreements, under which the Corporation assumes credit exposure associated with a borrower’s performance related to certain interest rate derivative contracts. The Corporation is not a party to the interest rate derivative contracts and only enters into these credit risk participation agreements in instances in which the Corporation is also a party to the related loan participation agreement for such borrowers. The Corporation manages its credit risk on the credit risk participation agreements by monitoring the creditworthiness of the borrowers, which is based on the normal credit review process had it entered into the derivative instruments directly with the borrower. The notional amount of such credit risk participation agreement reflects the pro-rata share of the derivative instrument, consistent with its share of the related participated loan. As of September 30, 2016 and December 31, 2015 , the total notional amount of the credit risk participation agreements was approximately $514 million and $559 million , respectively, and the fair value, included in customer-initiated interest rate contracts recorded in "accrued expenses and other liabilities" on the consolidated balance sheets, was insignificant at both September 30, 2016 and December 31, 2015 . The maximum estimated exposure to these agreements, as measured by projecting a maximum value of the guaranteed derivative instruments, assuming 100 percent default by all obligors on the maximum values, was approximately $9 million and $5 million at September 30, 2016 and December 31, 2015 , respectively. In the event of default, the lead bank has the ability to liquidate the assets of the borrower, in which case the lead bank would be required to return a percentage of the recouped assets to the participating banks. As of September 30, 2016 , the weighted average remaining maturity of outstanding credit risk participation agreements was 2.4 years.

Variable Interest Entities (VIE

Variable Interest Entities (VIEs)	9 Months Ended
	Sep. 30, 2016
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Variable Interest Entities (VIEs)	VARIABLE INTEREST ENTITIES (VIEs) The Corporation evaluates its interest in certain entities to determine if these entities meet the definition of a VIE and whether the Corporation is the primary beneficiary and should consolidate the entity based on the variable interests it held both at inception and when there is a change in circumstances that requires a reconsideration. The Corporation holds ownership interests in funds in the form of limited partnerships or limited liability companies (LLCs) investing in affordable housing projects that qualify for the low-income housing tax credit (LIHTC). The Corporation also directly invests in limited partnerships and LLCs which invest in community development projects which generate similar tax credits to investors. As an investor, the Corporation obtains income tax credits and deductions from the operating losses of these tax credit entities. These tax credit entities meet the definition of a VIE; however, the Corporation is not the primary beneficiary of the entities, as it does not have both the power to direct the activities that most significantly impact the economic performance of the entities and the obligation to absorb losses or the right to receive benefits that could be significant to the entities. While the partnership/LLC agreements allow the limited partners/investor members, through a majority vote, to remove the general partner/managing member, this right is not deemed to be substantive. The Corporation accounts for its interests in LIHTC entities using the proportional amortization method. Exposure to loss as a result of the Corporation’s involvement with LIHTC entities at September 30, 2016 was limited to approximately $406 million . Ownership interests in other community development projects which generate similar tax credits to investors (other tax credit entities) are accounted for under either the cost or equity method. Exposure to loss as a result of the Corporation's involvement in other tax credit entities at September 30, 2016 was limited to approximately $8 million . Investment balances, including all legally binding commitments to fund future investments, are included in “accrued income and other assets” on the consolidated balance sheets. A liability is recognized in “accrued expenses and other liabilities” on the consolidated balance sheets for all legally binding unfunded commitments to fund tax credit entities ( $150 million at September 30, 2016 ). Amortization and other write-downs of LIHTC investments are presented on a net basis as a component of the "provision for income taxes" on the consolidated statements of comprehensive income, while amortization and write-downs of other tax credit investments are recorded in “other noninterest income." The income tax credits and deductions are recorded as a reduction of income tax expense and a reduction of federal income taxes payable. The Corporation provided no financial or other support that was not contractually required to any of the above VIEs during the nine months ended September 30, 2016 and 2015 . The following table summarizes the impact of these tax credit entities on line items on the Corporation’s consolidated statements of comprehensive income. Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Other noninterest income: Amortization of other tax credit investments $ (1 ) $ — $ (1 ) $ 1 Provision for income taxes: Amortization of LIHTC investments 17 15 49 45 Low income housing tax credits (16 ) (15 ) (47 ) (45 ) Other tax benefits related to tax credit entities (7 ) (5 ) (19 ) (15 ) Total provision for income taxes $ (6 ) $ (5 ) (17 ) (15 ) For further information on the Corporation’s consolidation policy, see Note 1 to the consolidated financial statements in the Corporation's 2015 Annual Report.

Medium- And Long-Term Debt

Medium- And Long-Term Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Medium- And Long-Term Debt	MEDIUM- AND LONG-TERM DEBT Medium- and long-term debt is summarized as follows: (in millions) September 30, 2016 December 31, 2015 Parent company Subordinated notes: 3.80% subordinated notes due 2026 (a) 274 259 Medium-term notes: 2.125% notes due 2019 (a) 352 349 Total parent company 626 608 Subsidiaries Subordinated notes: 5.75% subordinated notes due 2016 (a) (b) 651 659 5.20% subordinated notes due 2017 (a) 516 530 4.00% subordinated notes due 2025 (a) 370 351 7.875% subordinated notes due 2026 (a) 230 223 Total subordinated notes 1,767 1,763 Medium-term notes: 2.50% notes due 2020 (a) 681 671 Federal Home Loan Bank (FHLB) advances: Floating-rate based on FHLB auction rate due 2026 2,800 — Other notes: 6.0% - 6.4% fixed-rate notes due 2020 16 16 Total subsidiaries 5,264 2,450 Total medium- and long-term debt $ 5,890 $ 3,058 (a) The fixed interest rates on these notes have been swapped to a variable rate and designated in a hedging relationship. Accordingly, carrying value has been adjusted to reflect the change in the fair value of the debt as a result of changes in the benchmark rate. (b) The fixed interest rate on $250 million of $650 million total par value of these notes have been swapped to a variable rate. The remaining amount is not swapped. Subordinated notes with remaining maturities greater than one year qualify as Tier 2 capital. Comerica Bank (the Bank), a wholly-owned subsidiary of the Corporation, is a member of the FHLB, which provides short- and long-term funding to its members through advances collateralized by real estate-related assets. Actual borrowing capacity is contingent on the amount of collateral available to be pledged to the FHLB. At September 30, 2016 , $15.3 billion of real estate-related loans were pledged to the FHLB as blanket collateral for potential future borrowings of approximately $3.8 billion . In the second quarter 2016, the Bank borrowed $2.8 billion of 10-year, floating-rate FHLB advances due 2026 . The interest rate on each of eight notes resets every four weeks, based on the FHLB auction rate, with the reset date of each note scheduled at one-week intervals. At September 30, 2016 the weighted-average rate on these advances was 0.4045% . Each note may be prepaid in full, without penalty, at each scheduled reset date. Proceeds were used for general corporate purposes. Unamortized debt issuance costs deducted from the carrying amount of medium- and long-term debt totaled $7 million at September 30, 2016 and $8 million at December 31, 2015 .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table presents a reconciliation of the changes in the components of accumulated other comprehensive loss and details the components of other comprehensive income (loss) for the nine months ended September 30, 2016 and 2015 , including the amount of income tax expense (benefit) allocated to each component of other comprehensive income (loss). Nine Months Ended September 30, (in millions) 2016 2015 Accumulated net unrealized gains on investment securities: Balance at beginning of period, net of tax $ 9 $ 37 Net unrealized holding gains arising during the period 140 44 Less: Provision for income taxes 51 16 Net unrealized holding gains arising during the period, net of tax 89 28 Less: Net realized losses included in net securities losses — (2 ) Less: Benefit for income taxes — (1 ) Reclassification adjustment for net securities losses included in net income, net of tax — (1 ) Less: Net losses realized as a yield adjustment in interest on investment securities (2 ) (6 ) Less: Benefit for income taxes (1 ) (2 ) Reclassification adjustment for net losses realized as a yield adjustment included in net income, net of tax (1 ) (4 ) Change in net unrealized gains on investment securities, net of tax 90 33 Balance at end of period, net of tax $ 99 $ 70 Accumulated defined benefit pension and other postretirement plans adjustment: Balance at beginning of period, net of tax $ (438 ) $ (449 ) Actuarial loss arising during the period (191 ) — Prior service credit arising during the period 235 — Net defined benefit pension and other postretirement adjustment arising during the period 44 — Less: Provision for income taxes 16 — Net defined benefit pension and other postretirement plans adjustment arising during the period, net of tax 28 — Amortization of actuarial net loss recognized in salaries and benefits expense 29 53 Less: Provision for income taxes 10 19 Adjustment for amounts recognized as components of net periodic benefit cost during the period, net of tax 19 34 Change in defined benefit pension and other postretirement plans adjustment, net of tax 47 34 Balance at end of period, net of tax $ (391 ) $ (415 ) Total accumulated other comprehensive loss at end of period, net of tax $ (292 ) $ (345 ) For additional information regarding the net defined benefit pension and other postretirement adjustment arising during the period ended September 30, 2016, refer to Note 10.

Net Income Per Common Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Income Per Common Share	NET INCOME PER COMMON SHARE Basic and diluted net income per common share are presented in the following table. Three Months Ended September 30, Nine Months Ended September 30, (in millions, except per share data) 2016 2015 2016 2015 Basic and diluted Net income $ 149 $ 136 $ 313 $ 405 Less: Income allocated to participating securities 1 2 3 5 Net income attributable to common shares $ 148 $ 134 $ 310 $ 400 Basic average common shares 171 176 173 176 Basic net income per common share $ 0.87 $ 0.76 $ 1.80 $ 2.27 Basic average common shares 171 176 173 176 Dilutive common stock equivalents: Net effect of the assumed exercise of stock options 2 2 1 2 Net effect of the assumed exercise of warrants 3 3 2 4 Diluted average common shares 176 181 176 182 Diluted net income per common share $ 0.84 $ 0.74 $ 1.76 $ 2.20 The following average shares related to outstanding options to purchase shares of common stock were not included in the computation of diluted net income per common share because the options were anti-dilutive for the period. Three Months Ended September 30, Nine Months Ended September 30, (shares in millions) 2016 2015 2016 2015 Average outstanding options 2.6 4.6 4.0 5.4 Range of exercise prices $46.68 - $59.86 $46.68 - $60.82 $37.26 - $59.86 $46.68 - $60.82

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Net periodic benefit costs are charged to "employee benefits expense" on the consolidated statements of comprehensive income. The components of net periodic benefit cost for the Corporation's qualified pension plan, non-qualified pension plan and postretirement benefit plan are as follows. Qualified Defined Benefit Pension Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Service cost $ 8 $ 9 $ 24 $ 27 Interest cost 23 22 69 66 Expected return on plan assets (39 ) (40 ) (120 ) (120 ) Amortization of prior service cost 1 1 3 3 Amortization of net loss 7 15 23 44 Net periodic defined benefit cost $ — $ 7 $ (1 ) $ 20 Non-Qualified Defined Benefit Pension Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Service cost $ — $ 1 $ 2 $ 3 Interest cost 3 2 8 7 Amortization of prior service credit (1 ) (1 ) (3 ) (3 ) Amortization of net loss 2 3 5 8 Net periodic defined benefit cost $ 4 $ 5 $ 12 $ 15 Postretirement Benefit Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Interest cost $ — $ 1 $ 2 $ 2 Expected return on plan assets (1 ) (1 ) (3 ) (3 ) Amortization of net loss 1 — 1 1 Net periodic postretirement benefit cost $ — $ — $ — $ — In October 2016, the Corporation modified the tax-qualified defined benefit retirement plan (the pension plan) to freeze final average pay benefits as of December 31, 2016, other than for participants who are 60 or older as of December 31, 2016, and added a cash balance plan provision, effective January 1, 2017. In October 2016, the Corporation also modified the non-qualified retirement benefit plan (the non-qualified pension plan) to effectively adjust the final average pay benefit under that plan so that only compensation and service prior to December 31, 2016 is taken into account, other than for active participants on December 31, 2016 who are 60 or older as of that date. Any final average pay benefit that would have been earned under the non-qualified pension plan based on compensation and service after December 31, 2016 will be effectively frozen (other than for active participants age 60 or older). Most active pension plan participants will be converted to a cash balance formula effective January 1, 2017. Generally, active pension plan participants 60 years or older as of December 31, 2016 remain covered by the final average pay formula. Eligible employees currently participating in the retirement account plan, a defined contribution plan covering employees not accruing a benefit in the pension plan, will also be converted to the cash balance pension plan effective January 1, 2017. Final retirement account plan balances will be transferred to the Corporation's 401(k) plan in the first quarter of 2017. Contributions to the retirement account plan will cease for periods beginning after December 31, 2016. As a result of the plan modifications, the Corporation remeasured the pension plan and the non-qualified pension plan as of September 30, 2016. The Corporation updated its significant actuarial assumptions used for the remeasurements including the discount rate, which decreased to 3.64 percent . The fair value of pension plan assets as of the remeasurement date was $2.6 billion . The remeasurement increased the qualified defined benefit pension plan asset by $41 million , including a prior service credit of $201 million and an actuarial loss of $160 million . The non-qualified defined benefit pension plan liability decreased by $3 million , including a prior service credit of $34 million and an actuarial loss of $31 million . For further information on the Corporation's employee benefit plans, refer to Note 17 to the consolidated financial statements in the Corporation's 2015 Annual Report.

Income Taxes And Tax-Related It

Income Taxes And Tax-Related Items	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes and Tax-Related Items	INCOME TAXES AND TAX-RELATED ITEMS At September 30, 2016 , net unrecognized tax benefits were $15 million , compared to $22 million at December 31, 2015 . The decrease in net unrecognized tax benefits of $7 million was primarily due to the recognition of federal settlements. The Corporation anticipates that it is reasonably possible that final settlement of federal and state tax issues will result in a decrease in net unrecognized tax benefits of $1 million within the next twelve months. Included in "accrued expense and other liabilities" on the consolidated balance sheets was an $8 million liability for tax-related interest and penalties at September 30, 2016 compared to $3 million at December 31, 2015 . Net deferred tax assets were $187 million at September 30, 2016 , compared to $199 million at December 31, 2015 . The decrease of $12 million in net deferred tax assets resulted primarily from an increase in deferred tax liabilities related to unrealized gains on investment securities available-for-sale and the September 30, 2016 remeasurement of the Corporation's defined benefit pension plans as well as a reversal of deferred tax assets related to expired stock options, partially offset by restructuring charges and an increase in the allowance for loan losses. Included in deferred tax assets at both September 30, 2016 and December 31, 2015 were $5 million of state net operating loss carryforwards, which expire between 2016 and 2026 . The Corporation believes that it is more likely than not that the benefit from certain of these state net operating loss carryforwards will not be realized and, accordingly, maintained a valuation allowance of $3 million at both September 30, 2016 and December 31, 2015 . The determination regarding valuation allowance was based on evidence of loss carryback capacity, projected future reversals of existing taxable temporary differences to absorb the deferred tax assets and assumptions made regarding future events. In the ordinary course of business, the Corporation enters into certain transactions that have tax consequences. From time to time, the Internal Revenue Service (IRS) or other tax jurisdictions may review and/or challenge specific interpretive tax positions taken by the Corporation with respect to those transactions. The Corporation believes that its tax returns were filed based upon applicable statutes, regulations and case law in effect at the time of the transactions. The IRS or other tax jurisdictions, an administrative authority or a court, if presented with the transactions, could disagree with the Corporation’s interpretation of the tax law. Based on current knowledge and probability assessment of various potential outcomes, the Corporation believes that current tax reserves are adequate, and the amount of any potential incremental liability arising is not expected to have a material adverse effect on the Corporation’s consolidated financial condition or results of operations. Probabilities and outcomes are reviewed as events unfold, and adjustments to the reserves are made when necessary.

Contingent Liabilities

Contingent Liabilities	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	CONTINGENT LIABILITIES Legal Proceedings As previously reported in the Corporation's Form 10-K for the year ended December 31, 2015 and Form 10-Q for the periods ended March 31, 2016, and June 30, 2016, Comerica Bank, a wholly owned subsidiary of the Corporation, was named in November 2011 as a third-party defendant in Butte Local Development v. Masters Group v. Comerica Bank (“the case”), for lender liability. The case was tried in January 2014, in the Montana Second District Judicial Court for Silver Bow County in Butte, Montana. On January 17, 2014 , a jury awarded Masters $52 million against the Bank. On July 1, 2015, after an appeal filed by the Corporation, the Montana Supreme Court ("the court") reversed the judgment against the Corporation and remanded the case for a new trial with instructions that Michigan law should apply. The court also reversed punitive and consequential damages previously awarded by the jury. The Corporation believes it has meritorious defenses to the remaining claims in this case and intends to continue to defend itself vigorously. Management believes that current reserves related to this case are adequate in the event of a negative outcome. The Corporation and certain of its subsidiaries are subject to various other pending or threatened legal proceedings arising out of the normal course of business or operations. The Corporation believes it has meritorious defenses to the claims asserted against it in its other currently outstanding legal proceedings and, with respect to such legal proceedings, intends to continue to defend itself vigorously, litigating or settling cases according to management’s judgment as to what is in the best interests of the Corporation and its shareholders. Settlement may result from the Corporation's determination that it may be more prudent financially to settle, rather than litigate, and should not be regarded as an admission of liability. On at least a quarterly basis, the Corporation assesses its potential liabilities and contingencies in connection with outstanding legal proceedings utilizing the latest information available. On a case-by-case basis, reserves are established for those legal claims for which it is probable that a loss will be incurred either as a result of a settlement or judgment, and the amount of such loss can be reasonably estimated. The actual costs of resolving these claims may be substantially higher or lower than the amounts reserved. Based on current knowledge, and after consultation with legal counsel, management believes that current reserves are adequate, and the amount of any incremental liability arising from these matters is not expected to have a material adverse effect on the Corporation’s consolidated financial condition, consolidated results of operations or consolidated cash flows. Legal fees of $4 million and $5 million were included in "other noninterest expenses" on the consolidated statements of income for the three months ended September 30, 2016 and 2015 , respectively, and $14 million and $15 million for the nine months ended September 30, 2016 and 2015 , respectively. For matters where a loss is not probable, the Corporation has not established legal reserves. The Corporation believes the estimate of the aggregate range of reasonably possible losses, in excess of reserves established, for all legal proceedings in which it is involved is from zero to approximately $32 million at September 30, 2016 . This estimated aggregate range of reasonably possible losses is based upon currently available information for those proceedings in which the Corporation is involved, taking into account the Corporation’s best estimate of such losses for those cases for which such estimate can be made. For certain cases, the Corporation does not believe that an estimate can currently be made. The Corporation’s estimate involves significant judgment, given the varying stages of the proceedings (including the fact that many are currently in preliminary stages), the existence in certain proceedings of multiple defendants (including the Corporation) whose share of liability has yet to be determined, the numerous yet-unresolved issues in many of the proceedings (including issues regarding class certification and the scope of many of the claims) and the attendant uncertainty of the various potential outcomes of such proceedings. Accordingly, the Corporation’s estimate will change from time to time, and actual losses may be more or less than the current estimate. In the event of unexpected future developments, it is possible that the ultimate resolution of these matters may be material to the Corporation's consolidated financial condition, consolidated results of operations or consolidated cash flows. For information regarding income tax contingencies, refer to Note 11 .

Restructuring Charges

Restructuring Charges	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring Charges	RESTRUCTURING CHARGES The Corporation approved and launched an initiative in the second quarter 2016 designed to reduce overhead and increase revenue (the GEAR Up initiative). The actions in the initiative include, but are not limited to, a reduction in workforce, a new retirement program, streamlining operational processes, real estate optimization including consolidating 38 banking centers as well as reducing office and operations space, selective outsourcing of technology functions and reduction of technology system applications. Certain actions associated with the GEAR Up initiative result in restructuring charges. Generally, costs associated with or incurred to generate revenue as part of the initiative are recorded according to the nature of the cost and are not included in restructuring charges. The Corporation considers the following costs associated with the initiative to be restructuring charges: • Employee costs: Primarily severance costs in accordance with the Corporation’s severance plan. • Facilities costs: Costs pertaining to consolidating banking centers and other facilities, such as lease termination costs and decommissioning costs. Also includes accelerated depreciation and impairment of owned property to be sold. • Technology costs: Impairment and other costs associated with optimizing technology infrastructure and reducing the number of applications. • Other costs: Includes primarily professional fees, as well as other contract termination fees and legal fees incurred in the execution of the initiative. See Note 10 for further information concerning the Corporation's retirement benefit plans. Restructuring charges are recorded as a component of noninterest expenses on the consolidated statements of comprehensive income. The following table presents changes in restructuring reserves, cumulative charges incurred to date and total expected restructuring charges: (in millions) Employee Costs Facilities Costs Technology Costs Other Costs Total Three Months Ended September 30, 2016 Balance at beginning of period $ 46 $ — $ — $ 4 $ 50 Restructuring charges 4 5 — 11 20 Payments (12 ) (1 ) — (8 ) (21 ) Adjustments for non-cash charges (a) 2 (4 ) — — (2 ) Balance at end of period $ 40 $ — $ — $ 7 $ 47 Nine Months Ended September 30, 2016 Balance at beginning of period $ — $ — $ — $ — $ — Restructuring charges 50 5 — 18 73 Payments (12 ) (1 ) — (11 ) (24 ) Adjustments for non-cash charges (a) 2 (4 ) — — (2 ) Balance at end of period $ 40 $ — $ — $ 7 $ 47 Total restructuring charges incurred to date $ 50 $ 5 $ — $ 18 $ 73 Total expected restructuring charges (b) $65 - $70 $35 - $40 $10 - $15 $30 - $35 $140 - $160 (a) Adjustments for non-cash charges include the benefit from forfeitures of nonvested stock compensation in Employee Costs and accelerated depreciation expense in Facilities Costs. (b) Restructuring activities are expected to be substantially completed by 12/31/2018 . Restructuring charges directly attributable to a business segment are assigned to that business segment. Restructuring charges incurred by areas whose services support the overall Corporation are allocated based on the methodology described in Note 22 to the consolidated financial statements in the Corporation's 2015 Annual Report. Total restructuring charges assigned to the Business Bank, Retail Bank and Wealth Management were $10 million , $8 million and $2 million , respectively, for the three months ended September 30, 2016 and $36 million , $27 million and $10 million , respectively, for the nine months ended September 30, 2016 . Remaining expected restructuring charges will be assigned to the business segments using the same methodology. Facilities costs pertaining to the consolidation of banking centers are expected to impact primarily the Retail Bank.

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Business Segment Information	BUSINESS SEGMENT INFORMATION The Corporation has strategically aligned its operations into three major business segments: the Business Bank, the Retail Bank and Wealth Management. These business segments are differentiated based on the type of customer and the related products and services provided. In addition to the three major business segments, the Finance Division is also reported as a segment. Business segment results are produced by the Corporation’s internal management accounting system. This system measures financial results based on the internal business unit structure of the Corporation. The performance of the business segments is not comparable with the Corporation's consolidated results and is not necessarily comparable with similar information for any other financial institution. Additionally, because of the interrelationships of the various segments, the information presented is not indicative of how the segments would perform if they operated as independent entities. The management accounting system assigns balance sheet and income statement items to each business segment using certain methodologies, which are regularly reviewed and refined. From time to time, the Corporation may make reclassifications among the segments to more appropriately reflect management's current view of the segments, and methodologies may be modified as the management accounting system is enhanced and changes occur in the organizational structure and/or product lines. For comparability purposes, amounts in all periods are based on business unit structure and methodologies in effect at September 30, 2016 . Effective January 1, 2016, in conjunction with the effective date for regulatory Liquidity Coverage Ratio (LCR) requirements, the Corporation prospectively implemented an additional funds transfer pricing (FTP) charge, primarily for the cost of maintaining liquid assets to support potential draws on unfunded loan commitments and for the long-term economic cost of holding collateral for secured deposits. For further information about the Corporation's FTP methodology, refer to Note 22 to the consolidated financial statements in the Corporation's Annual Report on Form 10-K for the year ended December 31, 2015. The following discussion provides information about the activities of each business segment. A discussion of the financial results and the factors impacting performance can be found in the section entitled "Business Segments" in the financial review. The Business Bank meets the needs of middle market businesses, multinational corporations and governmental entities by offering various products and services, including commercial loans and lines of credit, deposits, cash management, capital market products, international trade finance, letters of credit, foreign exchange management services and loan syndication services. The Retail Bank includes small business banking and personal financial services, consisting of consumer lending, consumer deposit gathering and mortgage loan origination. In addition to a full range of financial services provided to small business customers, this business segment offers a variety of consumer products, including deposit accounts, installment loans, credit cards, student loans, home equity lines of credit and residential mortgage loans. Wealth Management offers products and services consisting of fiduciary services, private banking, retirement services, investment management and advisory services, investment banking and brokerage services. This business segment also offers the sale of annuity products, as well as life, disability and long-term care insurance products. The Finance segment includes the Corporation’s securities portfolio and asset and liability management activities. This segment is responsible for managing the Corporation’s funding, liquidity and capital needs, performing interest sensitivity analysis and executing various strategies to manage the Corporation’s exposure to liquidity, interest rate risk and foreign exchange risk. The Other category includes discontinued operations, the income and expense impact of equity and cash, tax benefits not assigned to specific business segments, charges of an unusual or infrequent nature that are not reflective of the normal operations of the business segments and miscellaneous other expenses of a corporate nature. For further information on the methodologies which form the basis for these results refer to Note 22 to the consolidated financial statements in the Corporation's 2015 Annual Report. Business segment financial results are as follows: (dollar amounts in millions) Business Retail Wealth Management Finance Other Total Three Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 361 $ 156 $ 41 $ (114 ) $ 6 $ 450 Provision for credit losses 2 10 (1 ) — 5 16 Noninterest income 145 50 61 13 3 272 Noninterest expenses 215 195 75 (1 ) 9 493 Provision (benefit) for income taxes 97 — 10 (39 ) (4 ) 64 Net income (loss) $ 192 $ 1 $ 18 $ (61 ) $ (1 ) $ 149 Net credit-related charge-offs $ 14 $ 3 $ (1 ) $ — $ — $ 16 Selected average balances: Assets $ 39,618 $ 6,544 $ 5,283 $ 14,144 $ 7,320 $ 72,909 Loans 38,243 5,871 5,092 — — 49,206 Deposits 30,019 23,654 4,030 98 264 58,065 Statistical data: Return on average assets (a) 1.94 % 0.01 % 1.39 % N/M N/M 0.82 % Efficiency ratio (b) 42.38 94.57 73.07 N/M N/M 68.15 (dollar amounts in millions) Business Retail Wealth Management Finance Other Total Three Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 378 $ 158 $ 45 $ (163 ) $ 4 $ 422 Provision for credit losses 30 2 (3 ) — (3 ) 26 Noninterest income 144 49 59 12 (4 ) 260 Noninterest expenses 198 185 75 — (1 ) 457 Provision (benefit) for income taxes 99 7 11 (57 ) 3 63 Net income (loss) $ 195 $ 13 $ 21 $ (94 ) $ 1 $ 136 Net credit-related charge-offs (recoveries) $ 23 $ 1 $ (1 ) $ — $ — $ 23 Selected average balances: Assets $ 39,768 $ 6,518 $ 5,228 $ 11,761 $ 8,058 $ 71,333 Loans 38,113 5,835 5,024 — — 48,972 Deposits 31,405 23,079 4,188 203 265 59,140 Statistical data: Return on average assets (a) 1.96 % 0.23 % 1.62 % N/M N/M 0.76 % Efficiency ratio (b) 37.98 89.33 71.12 N/M N/M 66.87 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful (dollar amounts in millions) Business Bank Retail Bank Wealth Management Finance Other Total Nine Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 1,077 $ 466 $ 128 $ (346 ) $ 17 $ 1,342 Provision for credit losses 200 13 (3 ) — 3 213 Noninterest income 426 141 181 33 3 784 Noninterest expenses 644 579 229 (3 ) 20 1,469 Provision (benefit) for income taxes 217 5 30 (119 ) (2 ) 131 Net income (loss) $ 442 $ 10 $ 53 $ (191 ) $ (1 ) $ 313 Net credit-related charge-offs $ 113 $ 6 $ 2 $ — $ — $ 121 Selected average balances: Assets $ 39,589 $ 6,548 $ 5,220 $ 13,955 $ 5,630 $ 70,942 Loans 38,126 5,872 5,025 — — 49,023 Deposits 29,195 23,438 4,137 81 251 57,102 Statistical data: Return on average assets (a) 1.49 % 0.06 % 1.37 % N/M N/M 0.59 % Efficiency ratio (b) 42.70 94.87 74.09 N/M N/M 68.88 (dollar amounts in millions) Business Bank Retail Bank Wealth Management Finance Other Total Nine Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 1,117 $ 466 $ 133 $ (471 ) $ 11 $ 1,256 Provision for credit losses 116 (14 ) (13 ) — (2 ) 87 Noninterest income 426 136 177 32 (2 ) 769 Noninterest expenses 572 542 225 (2 ) 8 1,345 Provision (benefit) for income taxes 289 26 35 (163 ) 1 188 Net income (loss) $ 566 $ 48 $ 63 $ (274 ) $ 2 $ 405 Net credit-related charge-offs (recoveries) $ 55 $ 3 $ (8 ) $ — $ — $ 50 Selected average balances: Assets $ 39,567 $ 6,449 $ 5,137 $ 11,593 $ 6,942 $ 69,688 Loans 37,950 5,767 4,938 — — 48,655 Deposits 30,607 22,746 4,082 146 270 57,851 Statistical data: Return on average assets (a) 1.91 % 0.28 % 1.64 % N/M N/M 0.78 % Efficiency ratio (b) 37.00 89.91 71.98 N/M N/M 66.25 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful The Corporation operates in three primary markets - Texas, California, and Michigan, as well as in Arizona and Florida, with select businesses operating in several other states, and in Canada and Mexico. The Corporation produces market segment results for the Corporation’s three primary geographic markets as well as Other Markets. Other Markets includes Florida, Arizona, the International Finance division and businesses with a national perspective. The Finance & Other category includes the Finance segment and the Other category as previously described. Market segment results are provided as supplemental information to the business segment results and may not meet all operating segment criteria as set forth in GAAP. For comparability purposes, amounts in all periods are based on market segments and methodologies in effect at September 30, 2016 . A discussion of the financial results and the factors impacting performance can be found in the section entitled "Market Segments" in the financial review. Market segment financial results are as follows: (dollar amounts in millions) Michigan California Texas Other Finance Total Three Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 169 $ 181 $ 118 $ 90 $ (108 ) $ 450 Provision for credit losses 13 (4 ) (3 ) 5 5 16 Noninterest income 82 44 33 97 16 272 Noninterest expenses 161 110 102 112 8 493 Provision (benefit) for income taxes 26 44 19 18 (43 ) 64 Net income (loss) $ 51 $ 75 $ 33 $ 52 $ (62 ) $ 149 Net credit-related charge-offs (recoveries) $ 1 $ — $ 10 $ 5 $ — $ 16 Selected average balances: Assets $ 13,174 $ 17,933 $ 11,014 $ 9,324 $ 21,464 $ 72,909 Loans 12,488 17,637 10,566 8,515 — 49,206 Deposits 21,944 17,674 9,860 8,225 362 58,065 Statistical data: Return on average assets (a) 0.90 % 1.61 % 1.18 % 2.23 % N/M 0.82 % Efficiency ratio (b) 64.10 48.56 67.29 59.87 N/M 68.15 (dollar amounts in millions) Michigan California Texas Other Finance Total Three Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 179 $ 186 $ 129 $ 87 $ (159 ) $ 422 Provision for credit losses 6 24 10 (11 ) (3 ) 26 Noninterest income 84 38 34 96 8 260 Noninterest expenses 152 101 97 108 (1 ) 457 Provision (benefit) for income taxes 35 37 20 25 (54 ) 63 Net income (loss) $ 70 $ 62 $ 36 $ 61 $ (93 ) $ 136 Net credit-related charge-offs (recoveries) $ 9 $ 10 $ 4 $ — $ — $ 23 Selected average balances: Assets $ 13,856 $ 17,060 $ 11,578 $ 9,020 $ 19,819 $ 71,333 Loans 13,223 16,789 10,997 7,963 — 48,972 Deposits 21,946 18,371 10,753 7,602 468 59,140 Statistical data: Return on average assets (a) 1.23 % 1.27 % 1.16 % 2.70 % N/M 0.76 % Efficiency ratio (b) 57.42 45.19 59.48 59.00 N/M 66.87 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful (dollar amounts in millions) Michigan California Texas Other Markets Finance & Other Total Nine Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 509 $ 537 $ 360 $ 265 $ (329 ) $ 1,342 Provision for credit losses 10 8 199 (7 ) 3 213 Noninterest income 240 120 95 293 36 784 Noninterest expenses 471 333 316 332 17 1,469 Provision (benefit) for income taxes 90 118 (20 ) 64 (121 ) 131 Net income (loss) $ 178 $ 198 $ (40 ) $ 169 $ (192 ) $ 313 Net credit-related charge-offs (recoveries) $ 6 $ 25 $ 88 $ 2 $ — $ 121 Selected average balances: Assets $ 13,291 $ 17,824 $ 11,198 $ 9,044 $ 19,585 $ 70,942 Loans 12,640 17,544 10,722 8,117 — 49,023 Deposits 21,731 17,089 10,095 7,855 332 57,102 Statistical data: Return on average assets (a) 1.06 % 1.46 % (0.45 )% 2.48 % N/M 0.59 % Efficiency ratio (b) 62.60 50.63 69.16 59.36 N/M 68.88 (dollar amounts in millions) Michigan California Texas Other Markets Finance & Other Total Nine Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 533 $ 542 $ 390 $ 251 $ (460 ) $ 1,256 Provision for credit losses (15 ) 24 74 6 (2 ) 87 Noninterest income 249 109 99 282 30 769 Noninterest expenses 433 298 286 322 6 1,345 Provision (benefit) for income taxes 122 123 48 57 (162 ) 188 Net income (loss) $ 242 $ 206 $ 81 $ 148 $ (272 ) $ 405 Net credit-related charge-offs (recoveries) $ 10 $ 16 $ 13 $ 11 $ — $ 50 Selected average balances: Assets $ 13,815 $ 16,741 $ 11,880 $ 8,717 $ 18,535 $ 69,688 Loans 13,245 16,473 11,260 7,677 — 48,655 Deposits 21,788 17,500 10,907 7,240 416 57,851 Statistical data: Return on average assets (a) 1.42 % 1.47 % 0.87 % 2.26 % N/M 0.78 % Efficiency ratio (b) 55.18 45.74 58.32 60.23 N/M 66.25 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful

Basis of Presentation and Acc22

Basis of Presentation and Accounting Policies Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842),” (ASU 2016-02), to increase the transparency and comparability of lease recognition and disclosure. The update requires lessees to recognize lease contracts with a term greater than one year on the balance sheet, while recognizing expenses on the income statement in a manner similar to current guidance. For lessors, the update makes targeted changes to the classification criteria and the lessor accounting model to align the guidance with the new lessee model and revenue guidance. ASU 2016-02 is effective for the Corporation on January 1, 2019 and must be applied using the modified retrospective approach. Early adoption is permitted. The Corporation is currently evaluating the impact of adopting ASU 2016-02. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payments Accounting,” (ASU 2016-09), which intends to simplify accounting for share based payment transactions, including the income tax consequences and classification of awards. Among other items, the update requires excess tax benefits and deficiencies to be recognized as a component of income taxes within the income statement rather than other comprehensive income as required in current guidance. ASU 2016-09 is effective for the Corporation on January 1, 2017. The recognition of excess tax benefits and deficiencies in the income statement must be adopted prospectively. The method of transition required will differ for other items being amended. Early adoption is permitted. The impact to the Corporation upon adoption is dependent on the market value per share of the Corporation's common stock at option expiration dates and restricted stock vesting dates. In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments," (ASU 2016-13), which addresses concerns regarding the perceived delay in recognition of credit losses under the existing incurred loss model. The amendment introduces a new, single model for recognizing credit losses on all financial instruments presented on cost basis. Under the new model, entities must estimate current expected credit losses by considering all available relevant information, including historical and current information, as well as reasonable and supportable forecasts of future events. The update also requires additional qualitative and quantitative information to allow users to better understand the credit risk within the portfolio and the methodologies for determining allowance. ASU 2016-13 is effective for the Corporation on January 1, 2020 and must be applied using the modified retrospective approach with limited exceptions. Early adoption is permitted. The Corporation is currently evaluating the impact of adopting ASU 2016-13. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” (ASU 2016-15), which reduces diversity in the presentation of several categories of transactions in the cash flow statement. Among other things, the update clarifies the appropriate classification for proceeds from settlement of bank owned life insurance (BOLI) policies. Based on preliminary assessments, the Corporation expects to change the classification of proceeds from settlement of BOLI policies from operating activities to investing activities. Proceeds from settlement of BOLI policies totaled $10 million and $6 million for the nine-month periods ended September 30, 2016 and 2015, respectively, and $12 million for the year ended December 31, 2015. Other changes in classification resulting from this update are not expected to be significant. ASU 2016-15 is effective for the Corporation on January 1, 2018 and must be applied using the retrospective approach. Early adoption is permitted.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Assets And Liabilities Recorded At Fair Value On A Recurring Basis	The following tables present the recorded amount of assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 . (in millions) Total Level 1 Level 2 Level 3 September 30, 2016 Trading securities: Deferred compensation plan assets $ 88 $ 88 $ — $ — Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities 2,826 2,826 — — Residential mortgage-backed securities (a) 7,828 — 7,828 — State and municipal securities 8 — — 8 (b) Equity and other non-debt securities 127 81 — 46 (b) Total investment securities available-for-sale 10,789 2,907 7,828 54 Derivative assets: Interest rate contracts 389 — 362 27 Energy derivative contracts 192 — 192 — Foreign exchange contracts 39 — 39 — Warrants 2 — — 2 Total derivative assets 622 — 593 29 Total assets at fair value $ 11,499 $ 2,995 $ 8,421 $ 83 Derivative liabilities: Interest rate contracts $ 170 $ — $ 170 $ — Energy derivative contracts 190 — 190 — Foreign exchange contracts 30 — 30 — Total derivative liabilities 390 — 390 — Deferred compensation plan liabilities 88 88 — — Total liabilities at fair value $ 478 $ 88 $ 390 $ — (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Auction-rate securities. (in millions) Total Level 1 Level 2 Level 3 December 31, 2015 Trading securities: Deferred compensation plan assets $ 89 $ 89 $ — $ — Equity and other non-debt securities 3 3 $ — $ — Total trading securities 92 92 — — Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities 2,763 2,763 — — Residential mortgage-backed securities (a) 7,545 — 7,545 — State and municipal securities 9 — — 9 (b) Corporate debt securities 1 — — 1 (b) Equity and other non-debt securities 201 134 — 67 (b) Total investment securities available-for-sale 10,519 2,897 7,545 77 Derivative assets: Interest rate contracts 286 — 277 9 Energy derivative contracts 475 — 475 — Foreign exchange contracts 57 — 57 — Warrants 2 — — 2 Total derivative assets 820 — 809 11 Total assets at fair value $ 11,431 $ 2,989 $ 8,354 $ 88 Derivative liabilities: Interest rate contracts $ 92 $ — $ 92 $ — Energy derivative contracts 472 — 472 — Foreign exchange contracts 46 — 46 — Total derivative liabilities 610 — 610 — Deferred compensation plan liabilities 89 89 — — Total liabilities at fair value $ 699 $ 89 $ 610 $ — (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Auction-rate securities.
Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis	The following table summarizes the changes in Level 3 assets and liabilities measured at fair value on a recurring basis for the three- and nine-month periods ended September 30, 2016 and 2015 . Net Realized/Unrealized Gains (Losses) (Pretax) Balance at Beginning of Period Recorded in Earnings Recorded in Other Comprehensive Income Balance at End of Period (in millions) Realized Unrealized Redemptions Sales Three Months Ended September 30, 2016 Investment securities available-for-sale: State and municipal securities (a) $ 8 $ — $ — $ — $ — $ — $ 8 Corporate debt securities (a) 1 — — — (1 ) — — Equity and other non-debt securities (a) 48 — — 1 (c) (3 ) — 46 Total investment securities available-for-sale 57 — — 1 (c) (4 ) — 54 Derivative assets: Interest rate contracts 27 — — — — — 27 Warrants 2 3 (b) — — — (3 ) 2 Three Months Ended September 30, 2015 Investment securities available-for-sale: State and municipal securities (a) $ 23 $ — $ — $ — $ (14 ) $ — $ 9 Corporate debt securities (a) 1 — — — — — 1 Equity and other non-debt securities (a) 71 — — (1 ) (c) (1 ) — 69 Total investment securities available-for-sale 95 — — (1 ) (c) (15 ) — 79 Derivative assets: Interest rate contracts 2 — 9 (b) — — — 11 Warrants 3 5 (b) — — — (5 ) 3 Nine Months Ended September 30, 2016 Investment securities available-for-sale: State and municipal securities (a) $ 9 $ — $ — $ — $ (1 ) $ — $ 8 Corporate debt securities (a) 1 — — — (1 ) — — Equity and other non-debt securities (a) 67 — — (3 ) (c) (18 ) — 46 Total investment securities available-for-sale 77 — — (3 ) (c) (20 ) — 54 Derivative assets: Interest rate contracts 9 — 18 (b) — — — 27 Warrants 2 4 (b) — — — (4 ) 2 Nine Months Ended September 30, 2015 Investment securities available-for-sale: State and municipal securities (a) $ 23 $ — $ — $ — $ (14 ) $ — $ 9 Corporate debt securities (a) 1 — — — — — 1 Equity and other non-debt securities (a) 112 (2 ) (d) — — (41 ) — 69 Total investment securities available-for-sale 136 (2 ) (d) — — (55 ) — 79 Derivative assets: Interest rate contracts — — 11 (b) — — — 11 Warrants 4 6 (b) (1 ) (b) — — (6 ) 3 (a) Auction-rate securities. (b) Realized and unrealized gains and losses due to changes in fair value recorded in "other noninterest income" on the consolidated statements of comprehensive income. (c) Recorded in "net unrealized gains (losses) on investment securities available-for-sale" in other comprehensive income (loss). (d) Realized and unrealized gains and losses due to changes in fair value recorded in "net securities losses" on the consolidated statements of comprehensive income.
Assets And Liabilities Recorded At Fair Value On A Nonrecurring Basis	The following table presents assets recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 . No liabilities were recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 . (in millions) Total Level 2 Level 3 September 30, 2016 Loans: Commercial 313 7 306 Commercial mortgage 7 — 7 International 15 — 15 Total assets at fair value $ 335 $ 7 $ 328 December 31, 2015 Loans held-for-sale: Commercial $ 8 $ 8 $ — Loans: Commercial 134 — 134 Commercial mortgage 11 — 11 International 8 — 8 Total loans 153 — 153 Other real estate 2 — 2 Total assets at fair value excluding investments recorded at net asset value 163 8 155 Other investments recorded at net asset value: Nonmarketable equity securities (a) 1 Total assets at fair value $ 164 (a) Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
Quantitative Information About Level 3 Measurements	The Corporation's Level 3 recurring fair value measurements primarily include auction-rate securities where fair value is determined using an income approach based on a discounted cash flow model and certain interest rate derivative contracts where credit valuation adjustments are significant to the overall fair value of the derivative. The inputs in the table below reflect management's expectation of continued illiquidity in the secondary auction-rate securities market due to a lack of market activity for the issuers remaining in the portfolio, a lack of market incentives for issuer redemptions, and the expectation for a continuing low interest rate environment. The September 30, 2016 workout periods reflect the view that short-term interest rates could rise at a slower pace in 2016 than was expected at December 31, 2015 . Discounted Cash Flow Model Unobservable Input Fair Value (in millions) Discount Rate Workout Period (in years) September 30, 2016 State and municipal securities (a) $ 8 4% - 5% 1 - 3 Equity and other non-debt securities (a) 46 6% - 9% 1 - 2 December 31, 2015 State and municipal securities (a) $ 9 3% - 8% 1 - 2 Equity and other non-debt securities (a) 67 4% - 9% 1 (a) Auction-rate securities.
Estimated Fair Values Of Financial Instruments Not Recorded At Fair Value In Their Entirety On A Recurring Basis	The carrying amount and estimated fair value of financial instruments not recorded at fair value in their entirety on a recurring basis on the Corporation’s consolidated balance sheets are as follows: Carrying Amount Estimated Fair Value (in millions) Total Level 1 Level 2 Level 3 September 30, 2016 Assets Cash and due from banks $ 1,292 $ 1,292 $ 1,292 $ — $ — Interest-bearing deposits with banks 6,748 6,748 6,748 — — Investment securities held-to-maturity 1,695 1,713 — 1,713 — Loans held-for-sale 4 4 — 4 — Total loans, net of allowance for loan losses (a) 48,547 48,483 — 7 48,476 Customers’ liability on acceptances outstanding 2 2 2 — — Restricted equity investments 207 207 207 — — Nonmarketable equity securities (b) 9 17 Liabilities Demand deposits (noninterest-bearing) 31,776 31,776 — 31,776 — Interest-bearing deposits 24,518 24,518 — 24,518 — Customer certificates of deposit 2,967 2,952 — 2,952 — Total deposits 59,261 59,246 — 59,246 — Short-term borrowings 12 12 12 — — Acceptances outstanding 2 2 2 — — Medium- and long-term debt 5,890 5,857 — 5,857 — Credit-related financial instruments (80 ) (80 ) — — (80 ) December 31, 2015 Assets Cash and due from banks $ 1,157 $ 1,157 $ 1,157 $ — $ — Interest-bearing deposits with banks 4,990 4,990 4,990 — — Investment securities held-to-maturity 1,981 1,973 — 1,973 — Loans held-for-sale (c) 21 21 — 21 — Total loans, net of allowance for loan losses (a) 48,450 48,269 — — 48,269 Customers’ liability on acceptances outstanding 5 5 5 — — Restricted equity investments 92 92 92 — — Nonmarketable equity securities (b) (d) 10 18 Liabilities Demand deposits (noninterest-bearing) 30,839 30,839 — 30,839 — Interest-bearing deposits 25,462 25,462 — 25,462 — Customer certificates of deposit 3,552 3,536 — 3,536 — Total deposits 59,853 59,837 — 59,837 — Short-term borrowings 23 23 23 — — Acceptances outstanding 5 5 5 — — Medium- and long-term debt 3,058 3,032 — 3,032 — Credit-related financial instruments (83 ) (83 ) — — (83 ) (a) Included $335 million and $153 million of impaired loans recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 , respectively. (b) Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets. (c) Included $8 million impaired loans held-for-sale recorded at fair value on a nonrecurring basis at December 31, 2015 . (d) Included $1 million of nonmarketable equity securities recorded at fair value on a nonrecurring basis at December 31, 2015 .

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Summary Of Investment Securities	A summary of the Corporation’s investment securities follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2016 Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities $ 2,771 $ 55 $ — $ 2,826 Residential mortgage-backed securities (a) 7,714 121 7 7,828 State and municipal securities 8 — — 8 Equity and other non-debt securities 128 1 2 127 Total investment securities available-for-sale (b) $ 10,621 $ 177 $ 9 $ 10,789 Investment securities held-to-maturity (c): Residential mortgage-backed securities (a) $ 1,695 $ 18 $ — $ 1,713 December 31, 2015 Investment securities available-for-sale: U.S. Treasury and other U.S. government agency securities $ 2,769 $ 1 $ 7 $ 2,763 Residential mortgage-backed securities (a) 7,513 76 44 7,545 State and municipal securities 9 — — 9 Corporate debt securities 1 — — 1 Equity and other non-debt securities 199 2 — 201 Total investment securities available-for-sale (b) $ 10,491 $ 79 $ 51 $ 10,519 Investment securities held-to-maturity (c): Residential mortgage-backed securities (a) $ 1,981 $ 2 $ 10 $ 1,973 (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Included auction-rate securities at amortized cost and fair value of $56 million and $54 million , respectively as of September 30, 2016 and $76 million and $77 million , respectively, as of December 31, 2015 . (c) The amortized cost of investment securities held-to-maturity included net unrealized losses of $13 million at September 30, 2016 and $15 million at December 31, 2015 related to securities transferred from available-for-sale, which are included in accumulated other comprehensive loss.
Summary Of Investment Securities In Unrealized Loss Positions	A summary of the Corporation’s investment securities in an unrealized loss position as of September 30, 2016 and December 31, 2015 follows: Temporarily Impaired Less than 12 Months 12 Months or more Total (in millions) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses September 30, 2016 Residential mortgage-backed securities (a) $ 573 $ 1 $ 1,244 $ 15 $ 1,817 $ 16 State and municipal securities (b) — — 7 — (c) 7 — (c) Equity and other non-debt securities (b) 36 1 10 1 46 2 Total temporarily impaired securities $ 609 $ 2 $ 1,261 $ 16 $ 1,870 $ 18 December 31, 2015 U.S. Treasury and other U.S. government agency securities $ 2,265 $ 7 $ — $ — $ 2,265 $ 7 Residential mortgage-backed securities (a) 2,665 21 1,976 51 4,641 72 State and municipal securities (b) — — 9 — (c) 9 — (c) Corporate debt securities (b) — — 1 — (c) 1 — (c) Equity and other non-debt securities (b) 14 — (c) — — 14 — (c) Total temporarily impaired securities $ 4,944 $ 28 $ 1,986 $ 51 $ 6,930 $ 79 (a) Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. (b) Primarily auction-rate securities. (c) Unrealized losses less than $0.5 million.
Contractual Maturity Distribution Of Debt Securities	The following table summarizes the amortized cost and fair values of debt securities by contractual maturity. Securities with multiple maturity dates are classified in the period of final maturity. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. (in millions) Available-for-sale Held-to-maturity September 30, 2016 Amortized Cost Fair Value Amortized Cost Fair Value Contractual maturity Within one year $ 10 $ 10 $ — $ — After one year through five years 3,000 3,056 — — After five years through ten years 1,401 1,450 25 25 After ten years 6,082 6,146 1,670 1,688 Subtotal 10,493 10,662 1,695 1,713 Equity and other non-debt securities 128 127 Total investment securities $ 10,621 $ 10,789 $ 1,695 $ 1,713

Credit Quality And Allowance 25

Credit Quality And Allowance For Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2016
Credit Quality And Allowance For Credit Losses [Abstract]
Aging Analysis Of Loans	The following table presents an aging analysis of the recorded balance of loans. Loans Past Due and Still Accruing (in millions) 30-59 Days 60-89 Days 90 Days or More Total Nonaccrual Loans Current Loans Total Loans September 30, 2016 Business loans: Commercial $ 68 $ 17 $ 21 $ 106 $ 508 $ 30,538 $ 31,152 Real estate construction: Commercial Real Estate business line (a) 12 — — 12 — 2,370 2,382 Other business lines (b) 11 — — 11 — 350 361 Total real estate construction 23 — — 23 — 2,720 2,743 Commercial mortgage: Commercial Real Estate business line (a) 5 1 — 6 8 2,171 2,185 Other business lines (b) 15 8 6 29 36 6,763 6,828 Total commercial mortgage 20 9 6 35 44 8,934 9,013 Lease financing — — — — 6 642 648 International 1 — — 1 19 1,283 1,303 Total business loans 112 26 27 165 577 44,117 44,859 Retail loans: Residential mortgage 13 1 9 23 23 1,828 1,874 Consumer: Home equity 6 2 — 8 27 1,757 1,792 Other consumer 1 — 12 13 4 732 749 Total consumer 7 2 12 21 31 2,489 2,541 Total retail loans 20 3 21 44 54 4,317 4,415 Total loans $ 132 $ 29 $ 48 $ 209 $ 631 $ 48,434 $ 49,274 December 31, 2015 Business loans: Commercial $ 46 $ 12 $ 13 $ 71 $ 238 $ 31,350 $ 31,659 Real estate construction: Commercial Real Estate business line (a) 5 — — 5 — 1,676 1,681 Other business lines (b) 3 — — 3 1 316 320 Total real estate construction 8 — — 8 1 1,992 2,001 Commercial mortgage: Commercial Real Estate business line (a) 7 — 1 8 16 2,080 2,104 Other business lines (b) 7 5 3 15 44 6,814 6,873 Total commercial mortgage 14 5 4 23 60 8,894 8,977 Lease financing — — — — 6 718 724 International 2 — — 2 8 1,358 1,368 Total business loans 70 17 17 104 313 44,312 44,729 Retail loans: Residential mortgage 26 1 — 27 27 1,816 1,870 Consumer: Home equity 5 3 — 8 27 1,685 1,720 Other consumer 7 — — 7 — 758 765 Total consumer 12 3 — 15 27 2,443 2,485 Total retail loans 38 4 — 42 54 4,259 4,355 Total loans $ 108 $ 21 $ 17 $ 146 $ 367 $ 48,571 $ 49,084 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate.
Loans By Credit Quality Indicator	The following table presents loans by credit quality indicator, based on internal risk ratings assigned to each business loan at the time of approval and subjected to subsequent reviews, generally at least annually, and to pools of retail loans with similar risk characteristics. Internally Assigned Rating (in millions) Pass (a) Special Mention (b) Substandard (c) Nonaccrual (d) Total September 30, 2016 Business loans: Commercial $ 28,406 $ 965 $ 1,273 $ 508 $ 31,152 Real estate construction: Commercial Real Estate business line (e) 2,382 — — — 2,382 Other business lines (f) 358 3 — — 361 Total real estate construction 2,740 3 — — 2,743 Commercial mortgage: Commercial Real Estate business line (e) 2,141 16 20 8 2,185 Other business lines (f) 6,529 136 127 36 6,828 Total commercial mortgage 8,670 152 147 44 9,013 Lease financing 625 11 6 6 648 International 1,230 20 34 19 1,303 Total business loans 41,671 1,151 1,460 577 44,859 Retail loans: Residential mortgage 1,838 3 10 23 1,874 Consumer: Home equity 1,760 2 3 27 1,792 Other consumer 744 1 — 4 749 Total consumer 2,504 3 3 31 2,541 Total retail loans 4,342 6 13 54 4,415 Total loans $ 46,013 $ 1,157 $ 1,473 $ 631 $ 49,274 December 31, 2015 Business loans: Commercial $ 29,117 $ 1,293 $ 1,011 $ 238 $ 31,659 Real estate construction: Commercial Real Estate business line (e) 1,681 — — — 1,681 Other business lines (f) 318 1 — 1 320 Total real estate construction 1,999 1 — 1 2,001 Commercial mortgage: Commercial Real Estate business line (e) 2,031 31 26 16 2,104 Other business lines (f) 6,536 172 121 44 6,873 Total commercial mortgage 8,567 203 147 60 8,977 Lease financing 693 17 8 6 724 International 1,245 59 56 8 1,368 Total business loans 41,621 1,573 1,222 313 44,729 Retail loans: Residential mortgage 1,828 2 13 27 1,870 Consumer: Home equity 1,687 1 5 27 1,720 Other consumer 755 3 7 — 765 Total consumer 2,442 4 12 27 2,485 Total retail loans 4,270 6 25 54 4,355 Total loans $ 45,891 $ 1,579 $ 1,247 $ 367 $ 49,084 (a) Includes all loans not included in the categories of special mention, substandard or nonaccrual. (b) Special mention loans are accruing loans that have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date. (c) Substandard loans are accruing loans that have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans also are distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. This category is generally consistent with the "substandard" category as defined by regulatory authorities. (d) Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to the Nonperforming Assets subheading in Note 1 - Basis of Presentation and Accounting Policies - on page F-58 in the Corporation's 2015 Annual Report. A significant majority of nonaccrual loans are generally consistent with the "substandard" category and the remainder are generally consistent with the "doubtful" category as defined by regulatory authorities. (e) Primarily loans to real estate developers. (f) Primarily loans secured by owner-occupied real estate.
Schedule Of Nonaccrual, Reduced-Rate Loans And Foreclosed Property	The following table summarizes nonperforming assets. (in millions) September 30, 2016 December 31, 2015 Nonaccrual loans $ 631 $ 367 Reduced-rate loans (a) 8 12 Total nonperforming loans 639 379 Foreclosed property (b) 21 12 Total nonperforming assets $ 660 $ 391 (a) There were no reduced-rate business loans at both September 30, 2016 and December 31, 2015 . Reduced-rate retail loans were $8 million and $12 million at September 30, 2016 and December 31, 2015 , respectively. (b) Included $5 million and $9 million of foreclosed residential real estate properties at September 30, 2016 and December 31, 2015 , respectively.
Changes In The Allowance For Loan Losses And Related Loan Amounts	The following table details the changes in the allowance for loan losses and related loan amounts. 2016 2015 (in millions) Business Loans Retail Loans Total Business Loans Retail Loans Total Three Months Ended September 30 Allowance for loan losses: Balance at beginning of period $ 682 $ 47 $ 729 $ 563 $ 55 $ 618 Loan charge-offs (34 ) (1 ) (35 ) (31 ) (3 ) (34 ) Recoveries on loans previously charged-off 18 1 19 10 1 11 Net loan charge-offs (16 ) — (16 ) (21 ) (2 ) (23 ) Provision for loan losses 12 2 14 25 3 28 Foreign currency translation adjustment — — — (1 ) — (1 ) Balance at end of period $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 Nine Months Ended September 30 Allowance for loan losses: Balance at beginning of period $ 579 $ 55 $ 634 $ 534 $ 60 $ 594 Loan charge-offs (161 ) (5 ) (166 ) (83 ) (9 ) (92 ) Recoveries on loans previously charged-off 53 3 56 38 5 43 Net loan charge-offs (108 ) (2 ) (110 ) (45 ) (4 ) (49 ) Provision for loan losses 206 (4 ) 202 79 — 79 Foreign currency translation adjustment 1 — 1 (2 ) — (2 ) Balance at end of period $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 As a percentage of total loans 1.51 % 1.10 % 1.48 % 1.27 % 1.29 % 1.27 % September 30 Allowance for loan losses: Individually evaluated for impairment $ 115 $ 1 $ 116 $ 47 $ — $ 47 Collectively evaluated for impairment 563 48 611 519 56 575 Total allowance for loan losses $ 678 $ 49 $ 727 $ 566 $ 56 $ 622 Loans: Individually evaluated for impairment $ 677 $ 29 $ 706 $ 338 $ 51 $ 389 Collectively evaluated for impairment 44,182 4,386 48,568 44,233 4,318 48,551 Purchased credit impaired (PCI) loans (a) — — — — 2 2 Total loans evaluated for impairment $ 44,859 $ 4,415 $ 49,274 $ 44,571 $ 4,371 $ 48,942 (a) No allowance for loan losses was required for PCI loans at September 30, 2015 .
Changes In the Allowance For Credit Losses On Lending-Related Commitments	Changes in the allowance for credit losses on lending-related commitments, included in "accrued expenses and other liabilities" on the consolidated balance sheets, are summarized in the following table. Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Balance at beginning of period $ 43 $ 50 $ 45 $ 41 Charge-offs on lending related commitments (a) — — (11 ) (1 ) Provision for credit losses on lending-related commitments 2 (2 ) 11 8 Balance at end of period $ 45 $ 48 $ 45 $ 48 (a) Charge-offs result from the sale of unfunded lending-related commitments.
Individually Evaluated Impaired Loans	The following table presents additional information regarding individually evaluated impaired loans. Recorded Investment In: (in millions) Impaired Loans with No Related Allowance Impaired Loans with Related Allowance Total Impaired Loans Unpaid Principal Balance Related Allowance for Loan Losses September 30, 2016 Business loans: Commercial $ 141 $ 482 $ 623 $ 704 $ 106 Commercial mortgage: Commercial Real Estate business line (a) — 6 6 15 1 Other business lines (b) 4 25 29 43 3 Total commercial mortgage 4 31 35 58 4 International 3 16 19 26 5 Total business loans 148 529 677 788 115 Retail loans: Residential mortgage 12 — 12 13 — Consumer: Home equity 12 — 12 16 — Other consumer 2 3 5 6 1 Total consumer 14 3 17 22 1 Total retail loans (c) 26 3 29 35 1 Total individually evaluated impaired loans $ 174 $ 532 $ 706 $ 823 $ 116 December 31, 2015 Business loans: Commercial $ 82 $ 252 $ 334 $ 398 $ 45 Commercial mortgage: Commercial Real Estate business line (a) 7 8 15 38 1 Other business lines (b) 2 32 34 55 5 Total commercial mortgage 9 40 49 93 6 International — 10 10 17 2 Total business loans 91 302 393 508 53 Retail loans: Residential mortgage 13 — 13 13 — Consumer: Home equity 12 — 12 16 — Other consumer 6 — 6 10 — Total consumer 18 — 18 26 — Total retail loans (c) 31 — 31 39 — Total individually evaluated impaired loans $ 122 $ 302 $ 424 $ 547 $ 53 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. (c) Individually evaluated retail loans generally have no related allowance for loan losses, primarily due to policy which results in direct write-downs of most restructured retail loans.
Average Individually Evaluated Impaired Loans And Related Interest Recognized	The following table presents information regarding average individually evaluated impaired loans and the related interest recognized. Interest income recognized for the period primarily related to performing restructured loans. Individually Evaluated Impaired Loans 2016 2015 (in millions) Average Balance for the Period Interest Income Recognized for the Period Average Balance for the Period Interest Income Recognized for the Period Three Months Ended September 30 Business loans: Commercial $ 606 $ 2 $ 236 $ 1 Commercial mortgage: Commercial Real Estate business line (a) 7 — 15 — Other business lines (b) 30 — 37 1 Total commercial mortgage 37 — 52 1 International 19 — 10 — Total business loans 662 2 298 2 Retail loans: Residential mortgage 11 — 23 — Consumer loans: Home equity 12 — 12 — Other consumer 4 — 7 — Total consumer 16 — 19 — Total retail loans 27 — 42 — Total individually evaluated impaired loans $ 689 $ 2 $ 340 $ 2 Nine Months Ended September 30 Business loans: Commercial $ 559 $ 8 $ 172 $ 3 Commercial mortgage: Commercial Real Estate business line (a) 9 — 17 — Other business lines (b) 31 — 41 1 Total commercial mortgage 40 — 58 1 International 19 — 5 — Total business loans 618 8 235 4 Retail loans: Residential mortgage 12 — 23 — Consumer: Home equity 12 — 12 — Other consumer 4 — 6 — Total consumer 16 — 18 — Total retail loans 28 — 41 — Total individually evaluated impaired loans $ 646 $ 8 $ 276 $ 4 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate.
Troubled Debt Restructurings By Type Of Modification	The following tables detail the recorded balance at September 30, 2016 and 2015 of loans considered to be troubled debt restructurings (TDRs) that were restructured during the three- and nine-month periods ended September 30, 2016 and 2015 , by type of modification. In cases of loans with more than one type of modification, the loans were categorized based on the most significant modification. 2016 2015 Type of Modification Type of Modification (in millions) Principal Deferrals (a) Interest Rate Reductions AB Note Restructures (b) Total Modifications Principal Deferrals (a) Interest Rate Reductions Total Modifications Three Months Ended September 30 Business loans: Commercial $ 70 $ — $ 40 $ 110 $ 100 $ — $ 100 Commercial mortgage: Commercial Real Estate business line (c) — — — — 7 — 7 Other business lines (d) — — — — 3 — 3 Total commercial mortgage — — — — 10 — 10 International — — — — 2 — 2 Total business loans 70 — 40 110 112 — 112 Retail loans: Residential mortgage — — — — 18 — 18 Consumer: Home equity — — — — 1 1 2 Total retail loans — — — — 19 1 20 Total loans $ 70 $ — $ 40 $ 110 $ 131 $ 1 $ 132 Nine Months Ended September 30 Business loans: Commercial $ 150 $ — $ 49 $ 199 $ 102 $ — $ 102 Commercial mortgage: Commercial Real Estate business line (c) — — — — 9 — 9 Other business lines (d) 2 — — 2 7 — 7 Total commercial mortgage 2 — — 2 16 — 16 International — — 3 3 2 — 2 Total business loans 152 — 52 204 120 — 120 Retail loans: Residential mortgage — — — — 18 — 18 Consumer: Home equity 1 1 — 2 1 1 2 Total retail loans 1 1 — 2 19 1 20 Total loans $ 153 $ 1 $ 52 $ 206 $ 139 $ 1 $ 140 (a) Primarily represents loan balances where terms were extended 90 days or more at or above contractual interest rates. (b) Loan restructurings whereby the original loan is restructured into two notes: an "A" note, which generally reflects the portion of the modified loan which is expected to be collected; and a "B" note, which is generally fully charged off. (c) Primarily loans to real estate developers. (d) Primarily loans secured by owner-occupied real estate.
Troubled Debt Restructuring Subsequent Default	The following table presents information regarding the recorded balance at September 30, 2016 and 2015 of loans modified by principal deferral during the twelve-month periods ended September 30, 2016 and 2015 , and those principal deferrals which experienced a subsequent default during the three- and nine-month periods ended September 30, 2016 and 2015 . For principal deferrals, incremental deterioration in the credit quality of the loan, represented by a downgrade in the risk rating of the loan, for example, due to missed interest payments or a reduction of collateral value, is considered a subsequent default. 2016 2015 (in millions) Balance at September 30 Subsequent Default in the Three Months Ended September 30 Subsequent Default in the Nine Months Ended September 30 Balance at September 30 Subsequent Default in the Three Months Ended September 30 Subsequent Default in the Nine Months Ended September 30 Principal deferrals: Business loans: Commercial $ 229 $ — $ 13 $ 108 $ 1 $ 3 Commercial mortgage: Commercial Real Estate business line (a) — — — 9 — — Other business lines (b) 4 — 1 7 — 1 Total commercial mortgage 4 — 1 16 — 1 International — — — 2 — — Total business loans 233 — 14 126 1 4 Retail loans: Residential mortgage — — — 18 (c) — — Consumer: Home equity 1 (c) — — 1 (c) — — Total retail loans 1 — — 19 — — Total principal deferrals $ 234 $ — $ 14 $ 145 $ 1 $ 4 (a) Primarily loans to real estate developers. (b) Primarily loans secured by owner-occupied real estate. (c) Includes bankruptcy loans for which the court has discharged the borrower's obligation and the borrower has not reaffirmed the debt.

Derivative And Credit-Related26

Derivative And Credit-Related Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Of Derivative Instruments	The following table presents the composition of the Corporation’s derivative instruments held or issued for risk management purposes or in connection with customer-initiated and other activities at September 30, 2016 and December 31, 2015 . The table excludes commitments and warrants accounted for as derivatives. September 30, 2016 December 31, 2015 Fair Value Fair Value (in millions) Notional/ Contract Amount (a) Gross Derivative Assets Gross Derivative Liabilities Notional/ Contract Amount (a) Gross Derivative Assets Gross Derivative Liabilities Risk management purposes Derivatives designated as hedging instruments Interest rate contracts: Swaps - fair value - receive fixed/pay floating $ 2,525 $ 172 $ — $ 2,525 $ 147 $ — Derivatives used as economic hedges Foreign exchange contracts: Spot, forwards and swaps 720 — 1 593 3 — Total risk management purposes 3,245 172 1 3,118 150 — Customer-initiated and other activities Interest rate contracts: Caps and floors written 386 — — 253 — — Caps and floors purchased 386 — — 253 — — Swaps 12,481 217 170 11,722 139 92 Total interest rate contracts 13,253 217 170 12,228 139 92 Energy contracts: Caps and floors written 471 1 41 536 — 85 Caps and floors purchased 471 41 — 536 85 — Swaps 1,236 150 149 2,055 390 387 Total energy contracts 2,178 192 190 3,127 475 472 Foreign exchange contracts: Spot, forwards, options and swaps 1,760 39 29 2,291 54 46 Total customer-initiated and other activities 17,191 448 389 17,646 668 610 Total gross derivatives $ 20,436 620 390 $ 20,764 818 610 Amounts offset in the consolidated balance sheets: Netting adjustment - Offsetting derivative assets/liabilities (108 ) (108 ) (127 ) (127 ) Netting adjustment - Cash collateral received/posted (85 ) (8 ) (291 ) (3 ) Net derivatives included in the consolidated balance sheets (b) 427 274 400 480 Amounts not offset in the consolidated balance sheets: Marketable securities pledged under bilateral collateral agreements (32 ) (41 ) (137 ) (3 ) Net derivatives after deducting amounts not offset in the consolidated balance sheets $ 395 $ 233 $ 263 $ 477 (a) Notional or contractual amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the consolidated balance sheets. (b) Net derivative assets are included in “accrued income and other assets” and net derivative liabilities are included in “accrued expenses and other liabilities” on the consolidated balance sheets. Included in the fair value of net derivative assets and net derivative liabilities are credit valuation adjustments reflecting counterparty credit risk and credit risk of the Corporation. The fair value of net derivative assets included credit valuation adjustments for counterparty credit risk of $11 million and $5 million at September 30, 2016 and December 31, 2015 , respectively.
Schedule Of Weighted Average Maturity And Interest Rates On Risk Management Interest Rate Swaps	The following table summarizes the expected weighted average remaining maturity of the notional amount of risk management interest rate swaps and the weighted average interest rates associated with amounts expected to be received or paid on interest rate swap agreements as of September 30, 2016 and December 31, 2015 . Weighted Average (dollar amounts in millions) Notional Amount Remaining Maturity (in years) Receive Rate Pay Rate (a) September 30, 2016 Swaps - fair value - receive fixed/pay floating rate Medium- and long-term debt designation $ 2,525 4.3 3.89 % 1.59 % December 31, 2015 Swaps - fair value - receive fixed/pay floating rate Medium- and long-term debt designation 2,525 5.1 3.89 1.11 (a) Variable rates paid on receive fixed swaps are based on six-month LIBOR rates in effect at September 30, 2016 and December 31, 2015 .
Schedule Of Net Gains Recognized In Income On Customer-Initiated Derivatives	The net gains recognized in income on customer-initiated derivative instruments, net of the impact of offsetting positions, were as follows . Three Months Ended September 30, Nine Months Ended September 30, (in millions) Location of Gain 2016 2015 2016 2015 Interest rate contracts Other noninterest income $ 6 $ 4 $ 14 $ 11 Energy contracts Other noninterest income — 1 1 2 Foreign exchange contracts Foreign exchange income 11 9 30 27 Total $ 17 $ 14 $ 45 $ 40
Schedule Of Financial Instruments With Off-Balance Sheet Credit Risk	The Corporation’s credit risk associated with these instruments is represented by the contractual amounts indicated in the following table. (in millions) September 30, 2016 December 31, 2015 Unused commitments to extend credit: Commercial and other $ 24,115 $ 26,115 Bankcard, revolving check credit and home equity loan commitments 2,638 2,414 Total unused commitments to extend credit $ 26,753 $ 28,529 Standby letters of credit $ 3,757 $ 3,985 Commercial letters of credit 33 41
Summary Of Criticized Letters Of Credit	The following table presents a summary of criticized standby and commercial letters of credit at September 30, 2016 and December 31, 2015 . The Corporation's criticized list is generally consistent with the Special mention, Substandard and Doubtful categories defined by regulatory authorities. The Corporation manages credit risk through underwriting, periodically reviewing and approving its credit exposures using Board committee approved credit policies and guidelines. (dollar amounts in millions) September 30, 2016 December 31, 2015 Total criticized standby and commercial letters of credit $ 136 $ 110 As a percentage of total outstanding standby and commercial letters of credit 3.6 % 2.7 %

Variable Interest Entities (V27

Variable Interest Entities (VIEs) (Tables)	9 Months Ended
	Sep. 30, 2016
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Impact Of VIEs On The Consolidated Statements Of Comprehensive Income	The following table summarizes the impact of these tax credit entities on line items on the Corporation’s consolidated statements of comprehensive income. Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Other noninterest income: Amortization of other tax credit investments $ (1 ) $ — $ (1 ) $ 1 Provision for income taxes: Amortization of LIHTC investments 17 15 49 45 Low income housing tax credits (16 ) (15 ) (47 ) (45 ) Other tax benefits related to tax credit entities (7 ) (5 ) (19 ) (15 ) Total provision for income taxes $ (6 ) $ (5 ) (17 ) (15 )

Medium- And Long-Term Debt (Tab

Medium- And Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule Of Medium- And Long-Term Debt	Medium- and long-term debt is summarized as follows: (in millions) September 30, 2016 December 31, 2015 Parent company Subordinated notes: 3.80% subordinated notes due 2026 (a) 274 259 Medium-term notes: 2.125% notes due 2019 (a) 352 349 Total parent company 626 608 Subsidiaries Subordinated notes: 5.75% subordinated notes due 2016 (a) (b) 651 659 5.20% subordinated notes due 2017 (a) 516 530 4.00% subordinated notes due 2025 (a) 370 351 7.875% subordinated notes due 2026 (a) 230 223 Total subordinated notes 1,767 1,763 Medium-term notes: 2.50% notes due 2020 (a) 681 671 Federal Home Loan Bank (FHLB) advances: Floating-rate based on FHLB auction rate due 2026 2,800 — Other notes: 6.0% - 6.4% fixed-rate notes due 2020 16 16 Total subsidiaries 5,264 2,450 Total medium- and long-term debt $ 5,890 $ 3,058 (a) The fixed interest rates on these notes have been swapped to a variable rate and designated in a hedging relationship. Accordingly, carrying value has been adjusted to reflect the change in the fair value of the debt as a result of changes in the benchmark rate. (b) The fixed interest rate on $250 million of $650 million total par value of these notes have been swapped to a variable rate. The remaining amount is not swapped.

Accumulated Other Comprehensi29

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule Of Accumulated Other Comprehensive Loss	The following table presents a reconciliation of the changes in the components of accumulated other comprehensive loss and details the components of other comprehensive income (loss) for the nine months ended September 30, 2016 and 2015 , including the amount of income tax expense (benefit) allocated to each component of other comprehensive income (loss). Nine Months Ended September 30, (in millions) 2016 2015 Accumulated net unrealized gains on investment securities: Balance at beginning of period, net of tax $ 9 $ 37 Net unrealized holding gains arising during the period 140 44 Less: Provision for income taxes 51 16 Net unrealized holding gains arising during the period, net of tax 89 28 Less: Net realized losses included in net securities losses — (2 ) Less: Benefit for income taxes — (1 ) Reclassification adjustment for net securities losses included in net income, net of tax — (1 ) Less: Net losses realized as a yield adjustment in interest on investment securities (2 ) (6 ) Less: Benefit for income taxes (1 ) (2 ) Reclassification adjustment for net losses realized as a yield adjustment included in net income, net of tax (1 ) (4 ) Change in net unrealized gains on investment securities, net of tax 90 33 Balance at end of period, net of tax $ 99 $ 70 Accumulated defined benefit pension and other postretirement plans adjustment: Balance at beginning of period, net of tax $ (438 ) $ (449 ) Actuarial loss arising during the period (191 ) — Prior service credit arising during the period 235 — Net defined benefit pension and other postretirement adjustment arising during the period 44 — Less: Provision for income taxes 16 — Net defined benefit pension and other postretirement plans adjustment arising during the period, net of tax 28 — Amortization of actuarial net loss recognized in salaries and benefits expense 29 53 Less: Provision for income taxes 10 19 Adjustment for amounts recognized as components of net periodic benefit cost during the period, net of tax 19 34 Change in defined benefit pension and other postretirement plans adjustment, net of tax 47 34 Balance at end of period, net of tax $ (391 ) $ (415 ) Total accumulated other comprehensive loss at end of period, net of tax $ (292 ) $ (345 )

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Basic And Diluted Net Income Per Common Share	Basic and diluted net income per common share are presented in the following table. Three Months Ended September 30, Nine Months Ended September 30, (in millions, except per share data) 2016 2015 2016 2015 Basic and diluted Net income $ 149 $ 136 $ 313 $ 405 Less: Income allocated to participating securities 1 2 3 5 Net income attributable to common shares $ 148 $ 134 $ 310 $ 400 Basic average common shares 171 176 173 176 Basic net income per common share $ 0.87 $ 0.76 $ 1.80 $ 2.27 Basic average common shares 171 176 173 176 Dilutive common stock equivalents: Net effect of the assumed exercise of stock options 2 2 1 2 Net effect of the assumed exercise of warrants 3 3 2 4 Diluted average common shares 176 181 176 182 Diluted net income per common share $ 0.84 $ 0.74 $ 1.76 $ 2.20
Schedule of Average Shares Excluded From Diluted Net Income Per Common Share Computation	The following average shares related to outstanding options to purchase shares of common stock were not included in the computation of diluted net income per common share because the options were anti-dilutive for the period. Three Months Ended September 30, Nine Months Ended September 30, (shares in millions) 2016 2015 2016 2015 Average outstanding options 2.6 4.6 4.0 5.4 Range of exercise prices $46.68 - $59.86 $46.68 - $60.82 $37.26 - $59.86 $46.68 - $60.82

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Components of Net Periodic Benefit Cost	The components of net periodic benefit cost for the Corporation's qualified pension plan, non-qualified pension plan and postretirement benefit plan are as follows. Qualified Defined Benefit Pension Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Service cost $ 8 $ 9 $ 24 $ 27 Interest cost 23 22 69 66 Expected return on plan assets (39 ) (40 ) (120 ) (120 ) Amortization of prior service cost 1 1 3 3 Amortization of net loss 7 15 23 44 Net periodic defined benefit cost $ — $ 7 $ (1 ) $ 20 Non-Qualified Defined Benefit Pension Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Service cost $ — $ 1 $ 2 $ 3 Interest cost 3 2 8 7 Amortization of prior service credit (1 ) (1 ) (3 ) (3 ) Amortization of net loss 2 3 5 8 Net periodic defined benefit cost $ 4 $ 5 $ 12 $ 15 Postretirement Benefit Plan Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2016 2015 2016 2015 Interest cost $ — $ 1 $ 2 $ 2 Expected return on plan assets (1 ) (1 ) (3 ) (3 ) Amortization of net loss 1 — 1 1 Net periodic postretirement benefit cost $ — $ — $ — $ —

Restructuring Charges (Tables)

Restructuring Charges (Tables)	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	The following table presents changes in restructuring reserves, cumulative charges incurred to date and total expected restructuring charges: (in millions) Employee Costs Facilities Costs Technology Costs Other Costs Total Three Months Ended September 30, 2016 Balance at beginning of period $ 46 $ — $ — $ 4 $ 50 Restructuring charges 4 5 — 11 20 Payments (12 ) (1 ) — (8 ) (21 ) Adjustments for non-cash charges (a) 2 (4 ) — — (2 ) Balance at end of period $ 40 $ — $ — $ 7 $ 47 Nine Months Ended September 30, 2016 Balance at beginning of period $ — $ — $ — $ — $ — Restructuring charges 50 5 — 18 73 Payments (12 ) (1 ) — (11 ) (24 ) Adjustments for non-cash charges (a) 2 (4 ) — — (2 ) Balance at end of period $ 40 $ — $ — $ 7 $ 47 Total restructuring charges incurred to date $ 50 $ 5 $ — $ 18 $ 73 Total expected restructuring charges (b) $65 - $70 $35 - $40 $10 - $15 $30 - $35 $140 - $160 (a) Adjustments for non-cash charges include the benefit from forfeitures of nonvested stock compensation in Employee Costs and accelerated depreciation expense in Facilities Costs. (b) Restructuring activities are expected to be substantially completed by 12/31/2018 .

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Business Segment Financial Results	Business segment financial results are as follows: (dollar amounts in millions) Business Retail Wealth Management Finance Other Total Three Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 361 $ 156 $ 41 $ (114 ) $ 6 $ 450 Provision for credit losses 2 10 (1 ) — 5 16 Noninterest income 145 50 61 13 3 272 Noninterest expenses 215 195 75 (1 ) 9 493 Provision (benefit) for income taxes 97 — 10 (39 ) (4 ) 64 Net income (loss) $ 192 $ 1 $ 18 $ (61 ) $ (1 ) $ 149 Net credit-related charge-offs $ 14 $ 3 $ (1 ) $ — $ — $ 16 Selected average balances: Assets $ 39,618 $ 6,544 $ 5,283 $ 14,144 $ 7,320 $ 72,909 Loans 38,243 5,871 5,092 — — 49,206 Deposits 30,019 23,654 4,030 98 264 58,065 Statistical data: Return on average assets (a) 1.94 % 0.01 % 1.39 % N/M N/M 0.82 % Efficiency ratio (b) 42.38 94.57 73.07 N/M N/M 68.15 (dollar amounts in millions) Business Retail Wealth Management Finance Other Total Three Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 378 $ 158 $ 45 $ (163 ) $ 4 $ 422 Provision for credit losses 30 2 (3 ) — (3 ) 26 Noninterest income 144 49 59 12 (4 ) 260 Noninterest expenses 198 185 75 — (1 ) 457 Provision (benefit) for income taxes 99 7 11 (57 ) 3 63 Net income (loss) $ 195 $ 13 $ 21 $ (94 ) $ 1 $ 136 Net credit-related charge-offs (recoveries) $ 23 $ 1 $ (1 ) $ — $ — $ 23 Selected average balances: Assets $ 39,768 $ 6,518 $ 5,228 $ 11,761 $ 8,058 $ 71,333 Loans 38,113 5,835 5,024 — — 48,972 Deposits 31,405 23,079 4,188 203 265 59,140 Statistical data: Return on average assets (a) 1.96 % 0.23 % 1.62 % N/M N/M 0.76 % Efficiency ratio (b) 37.98 89.33 71.12 N/M N/M 66.87 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful (dollar amounts in millions) Business Bank Retail Bank Wealth Management Finance Other Total Nine Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 1,077 $ 466 $ 128 $ (346 ) $ 17 $ 1,342 Provision for credit losses 200 13 (3 ) — 3 213 Noninterest income 426 141 181 33 3 784 Noninterest expenses 644 579 229 (3 ) 20 1,469 Provision (benefit) for income taxes 217 5 30 (119 ) (2 ) 131 Net income (loss) $ 442 $ 10 $ 53 $ (191 ) $ (1 ) $ 313 Net credit-related charge-offs $ 113 $ 6 $ 2 $ — $ — $ 121 Selected average balances: Assets $ 39,589 $ 6,548 $ 5,220 $ 13,955 $ 5,630 $ 70,942 Loans 38,126 5,872 5,025 — — 49,023 Deposits 29,195 23,438 4,137 81 251 57,102 Statistical data: Return on average assets (a) 1.49 % 0.06 % 1.37 % N/M N/M 0.59 % Efficiency ratio (b) 42.70 94.87 74.09 N/M N/M 68.88 (dollar amounts in millions) Business Bank Retail Bank Wealth Management Finance Other Total Nine Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 1,117 $ 466 $ 133 $ (471 ) $ 11 $ 1,256 Provision for credit losses 116 (14 ) (13 ) — (2 ) 87 Noninterest income 426 136 177 32 (2 ) 769 Noninterest expenses 572 542 225 (2 ) 8 1,345 Provision (benefit) for income taxes 289 26 35 (163 ) 1 188 Net income (loss) $ 566 $ 48 $ 63 $ (274 ) $ 2 $ 405 Net credit-related charge-offs (recoveries) $ 55 $ 3 $ (8 ) $ — $ — $ 50 Selected average balances: Assets $ 39,567 $ 6,449 $ 5,137 $ 11,593 $ 6,942 $ 69,688 Loans 37,950 5,767 4,938 — — 48,655 Deposits 30,607 22,746 4,082 146 270 57,851 Statistical data: Return on average assets (a) 1.91 % 0.28 % 1.64 % N/M N/M 0.78 % Efficiency ratio (b) 37.00 89.91 71.98 N/M N/M 66.25 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful
Market Segment Financial Results	Market segment financial results are as follows: (dollar amounts in millions) Michigan California Texas Other Finance Total Three Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 169 $ 181 $ 118 $ 90 $ (108 ) $ 450 Provision for credit losses 13 (4 ) (3 ) 5 5 16 Noninterest income 82 44 33 97 16 272 Noninterest expenses 161 110 102 112 8 493 Provision (benefit) for income taxes 26 44 19 18 (43 ) 64 Net income (loss) $ 51 $ 75 $ 33 $ 52 $ (62 ) $ 149 Net credit-related charge-offs (recoveries) $ 1 $ — $ 10 $ 5 $ — $ 16 Selected average balances: Assets $ 13,174 $ 17,933 $ 11,014 $ 9,324 $ 21,464 $ 72,909 Loans 12,488 17,637 10,566 8,515 — 49,206 Deposits 21,944 17,674 9,860 8,225 362 58,065 Statistical data: Return on average assets (a) 0.90 % 1.61 % 1.18 % 2.23 % N/M 0.82 % Efficiency ratio (b) 64.10 48.56 67.29 59.87 N/M 68.15 (dollar amounts in millions) Michigan California Texas Other Finance Total Three Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 179 $ 186 $ 129 $ 87 $ (159 ) $ 422 Provision for credit losses 6 24 10 (11 ) (3 ) 26 Noninterest income 84 38 34 96 8 260 Noninterest expenses 152 101 97 108 (1 ) 457 Provision (benefit) for income taxes 35 37 20 25 (54 ) 63 Net income (loss) $ 70 $ 62 $ 36 $ 61 $ (93 ) $ 136 Net credit-related charge-offs (recoveries) $ 9 $ 10 $ 4 $ — $ — $ 23 Selected average balances: Assets $ 13,856 $ 17,060 $ 11,578 $ 9,020 $ 19,819 $ 71,333 Loans 13,223 16,789 10,997 7,963 — 48,972 Deposits 21,946 18,371 10,753 7,602 468 59,140 Statistical data: Return on average assets (a) 1.23 % 1.27 % 1.16 % 2.70 % N/M 0.76 % Efficiency ratio (b) 57.42 45.19 59.48 59.00 N/M 66.87 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful (dollar amounts in millions) Michigan California Texas Other Markets Finance & Other Total Nine Months Ended September 30, 2016 Earnings summary: Net interest income (expense) $ 509 $ 537 $ 360 $ 265 $ (329 ) $ 1,342 Provision for credit losses 10 8 199 (7 ) 3 213 Noninterest income 240 120 95 293 36 784 Noninterest expenses 471 333 316 332 17 1,469 Provision (benefit) for income taxes 90 118 (20 ) 64 (121 ) 131 Net income (loss) $ 178 $ 198 $ (40 ) $ 169 $ (192 ) $ 313 Net credit-related charge-offs (recoveries) $ 6 $ 25 $ 88 $ 2 $ — $ 121 Selected average balances: Assets $ 13,291 $ 17,824 $ 11,198 $ 9,044 $ 19,585 $ 70,942 Loans 12,640 17,544 10,722 8,117 — 49,023 Deposits 21,731 17,089 10,095 7,855 332 57,102 Statistical data: Return on average assets (a) 1.06 % 1.46 % (0.45 )% 2.48 % N/M 0.59 % Efficiency ratio (b) 62.60 50.63 69.16 59.36 N/M 68.88 (dollar amounts in millions) Michigan California Texas Other Markets Finance & Other Total Nine Months Ended September 30, 2015 Earnings summary: Net interest income (expense) $ 533 $ 542 $ 390 $ 251 $ (460 ) $ 1,256 Provision for credit losses (15 ) 24 74 6 (2 ) 87 Noninterest income 249 109 99 282 30 769 Noninterest expenses 433 298 286 322 6 1,345 Provision (benefit) for income taxes 122 123 48 57 (162 ) 188 Net income (loss) $ 242 $ 206 $ 81 $ 148 $ (272 ) $ 405 Net credit-related charge-offs (recoveries) $ 10 $ 16 $ 13 $ 11 $ — $ 50 Selected average balances: Assets $ 13,815 $ 16,741 $ 11,880 $ 8,717 $ 18,535 $ 69,688 Loans 13,245 16,473 11,260 7,677 — 48,655 Deposits 21,788 17,500 10,907 7,240 416 57,851 Statistical data: Return on average assets (a) 1.42 % 1.47 % 0.87 % 2.26 % N/M 0.78 % Efficiency ratio (b) 55.18 45.74 58.32 60.23 N/M 66.25 (a) Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity. (b) Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains. N/M – not meaningful

Basis of Presentation and Acc34

Basis of Presentation and Accounting Policies Basis of Presentation and Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Proceeds from settlement of BOLI policies	$ 10	$ 6	$ 12

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Recurring
Transfers into or out of Level 1 or Level 2 or Level 3	$ 0	$ 0	$ 0	$ 0
Total liabilities at fair value	478		478		$ 699
Nonrecurring
Total liabilities at fair value	$ 0		$ 0		$ 0

Fair Value Measurements (Assets

Fair Value Measurements (Assets And Liabilities Recorded At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	$ 10,789	$ 10,519
Derivative assets		620	818
Derivative liabilities	[2]	274	480
Equity and other non-debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		127	201
U.S. Treasury and other U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,826	2,763
Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[3]	7,828	7,545
State and municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		8	9
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale			1
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			92
Investment securities available-for-sale		10,789	10,519
Derivative assets		622	820
Total assets at fair value		11,499	11,431
Derivative liabilities		390	610
Deferred compensation plan liabilities		88	89
Total liabilities at fair value		478	699
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			92
Investment securities available-for-sale		2,907	2,897
Derivative assets		0	0
Total assets at fair value		2,995	2,989
Derivative liabilities		0	0
Deferred compensation plan liabilities		88	89
Total liabilities at fair value		88	89
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			0
Investment securities available-for-sale		7,828	7,545
Derivative assets		593	809
Total assets at fair value		8,421	8,354
Derivative liabilities		390	610
Deferred compensation plan liabilities		0	0
Total liabilities at fair value		390	610
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			0
Investment securities available-for-sale		54	77
Derivative assets		29	11
Total assets at fair value		83	88
Derivative liabilities		0	0
Deferred compensation plan liabilities		0	0
Total liabilities at fair value		0	0
Recurring | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		389	286
Derivative liabilities		170	92
Recurring | Interest rate contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Interest rate contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		362	277
Derivative liabilities		170	92
Recurring | Interest rate contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		27	9
Derivative liabilities		0	0
Recurring | Energy derivative contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		192	475
Derivative liabilities		190	472
Recurring | Energy derivative contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Energy derivative contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		192	475
Derivative liabilities		190	472
Recurring | Energy derivative contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		39	57
Derivative liabilities		30	46
Recurring | Foreign exchange contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Foreign exchange contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		39	57
Derivative liabilities		30	46
Recurring | Foreign exchange contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		2	2
Recurring | Warrants | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Recurring | Warrants | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Recurring | Warrants | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		2	2
Recurring | Deferred compensation plan assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		88	89
Recurring | Deferred compensation plan assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		88	89
Recurring | Deferred compensation plan assets | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Recurring | Deferred compensation plan assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0	0
Recurring | Equity and other non-debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			3
Investment securities available-for-sale		127	201
Recurring | Equity and other non-debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			3
Investment securities available-for-sale		81	134
Recurring | Equity and other non-debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			0
Investment securities available-for-sale		0	0
Recurring | Equity and other non-debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities			0
Investment securities available-for-sale	[4]	46	67
Recurring | U.S. Treasury and other U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,826	2,763
Recurring | U.S. Treasury and other U.S. government agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,826	2,763
Recurring | U.S. Treasury and other U.S. government agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Recurring | U.S. Treasury and other U.S. government agency securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Recurring | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[5]	7,828	7,545
Recurring | Residential mortgage-backed securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[5]	0	0
Recurring | Residential mortgage-backed securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[5]	7,828	7,545
Recurring | Residential mortgage-backed securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[5]	0	0
Recurring | State and municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		8	9
Recurring | State and municipal securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Recurring | State and municipal securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		$ 0	0
Recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale			1
Recurring | Corporate debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale			0
Recurring | Corporate debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale			0
Recurring | Corporate debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[4]		$ 1
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.
[2]	Net derivative assets are included in “accrued income and other assets” and net derivative liabilities are included in “accrued expenses and other liabilities” on the consolidated balance sheets. Included in the fair value of net derivative assets and net derivative liabilities are credit valuation adjustments reflecting counterparty credit risk and credit risk of the Corporation. The fair value of net derivative assets included credit valuation adjustments for counterparty credit risk of $11 million and $5 million at September 30, 2016 and December 31, 2015, respectively.
[3]	Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.
[4]	Auction-rate securities.
[5]	Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.

Fair Value Measurements (Change

Fair Value Measurements (Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015
Interest rate contracts
Balance at beginning of period		$ 27		$ 2		$ 9		$ 0
Realized gains (losses) recorded in earnings		0		0		0		0
Unrealized gains (losses) recorded in earnings		0		9	[1]	18	[1]	11	[1]
Gains (losses) recorded in other comprehensive income		0		0		0		0
Redemptions		0		0		0		0
Sales		0		0		0		0
Balance at end of period		27		11		27		11
Warrants
Balance at beginning of period		2		3		2		4
Realized gains (losses) recorded in earnings	[1]	3		5		4		6
Unrealized gains (losses) recorded in earnings		0		0		0		(1)	[1]
Gains (losses) recorded in other comprehensive income		0		0		0		0
Redemptions		0		0		0		0
Sales		(3)		(5)		(4)		(6)
Balance at end of period		2		3		2		3
Investment Securities Available-For-Sale
Balance at beginning of period		57		95		77		136
Realized gains (losses) recorded in earnings		0		0		0		(2)	[2]
Unrealized gains (losses) recorded in earnings		0		0		0		0
Gains (losses) recorded in other comprehensive income		1	[3]	(1)	[3]	(3)	[3]	0
Redemptions		(4)		(15)		(20)		(55)
Sales		0		0		0		0
Balance at end of period		54		79		54		79
State and municipal securities | Investment Securities Available-For-Sale
Balance at beginning of period	[4]	8		23		9		23
Realized gains (losses) recorded in earnings	[4]	0		0		0		0
Unrealized gains (losses) recorded in earnings	[4]	0		0		0		0
Gains (losses) recorded in other comprehensive income	[4]	0		0		0		0
Redemptions	[4]	0		(14)		(1)		(14)
Sales	[4]	0		0		0		0
Balance at end of period	[4]	8		9		8		9
Corporate debt securities | Investment Securities Available-For-Sale
Balance at beginning of period	[4]	1		1		1		1
Realized gains (losses) recorded in earnings	[4]	0		0		0		0
Unrealized gains (losses) recorded in earnings	[4]	0		0		0		0
Gains (losses) recorded in other comprehensive income	[4]	0		0		0		0
Redemptions	[4]	(1)		0		(1)		0
Sales	[4]	0		0		0		0
Balance at end of period	[4]	0		1		0		1
Equity and other non-debt securities | Investment Securities Available-For-Sale
Balance at beginning of period	[4]	48		71		67		112
Realized gains (losses) recorded in earnings	[4]	0		0		0		(2)	[2]
Unrealized gains (losses) recorded in earnings	[4]	0		0		0		0
Gains (losses) recorded in other comprehensive income	[4]	1	[3]	(1)	[3]	(3)	[3]	0
Redemptions	[4]	(3)		(1)		(18)		(41)
Sales	[4]	0		0		0		0
Balance at end of period	[4]	$ 46		$ 69		$ 46		$ 69
[1]	Realized and unrealized gains and losses due to changes in fair value recorded in "other noninterest income" on the consolidated statements of comprehensive income.
[2]	Realized and unrealized gains and losses due to changes in fair value recorded in "net securities losses" on the consolidated statements of comprehensive income.
[3]	Recorded in "net unrealized gains (losses) on investment securities available-for-sale" in other comprehensive income (loss).
[4]	Auction-rate securities.

Fair Value Measurements (Asse38

Fair Value Measurements (Assets And Liabilities Recorded At Fair Value On A Nonrecurring Basis) (Details) - Nonrecurring - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans			$ 153
Other real estate			2
Total assets at fair value excluding investments recorded at net asset value			163
Nonmarketable equity securities	[1]		1
Total assets at fair value		$ 335	164
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans			0
Other real estate			0
Total assets at fair value		7	8
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans			153
Other real estate			2
Total assets at fair value		328	155
Commercial borrower | Domestic loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale			8
Loans		313	134
Commercial borrower | Domestic loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale			8
Loans		7	0
Commercial borrower | Domestic loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale			0
Loans		306	134
Commercial borrower | International loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		15	8
Commercial borrower | International loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		0	0
Commercial borrower | International loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		15	8
Commercial borrower | Commercial Mortgage Loans | Domestic loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		7	11
Commercial borrower | Commercial Mortgage Loans | Domestic loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		0	0
Commercial borrower | Commercial Mortgage Loans | Domestic loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		$ 7	$ 11
[1]	Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Information About Level 3 Measurements) (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investment securities available-for-sale	[1]	$ 10,789	$ 10,519
Recurring
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investment securities available-for-sale		10,789	10,519
Recurring | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investment securities available-for-sale		54	77
Recurring | State and municipal securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investment securities available-for-sale	[2]	$ 8	$ 9
Recurring | State and municipal securities | Minimum | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable input, discount rate	[3]	4.00%	3.00%
Unobservable input, workout period	[3]	1 year	1 year
Recurring | State and municipal securities | Maximum | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable input, discount rate	[3]	5.00%	8.00%
Unobservable input, workout period	[3]	3 years	2 years
Recurring | Equity and other non-debt securities | Minimum | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable input, discount rate	[3]	6.00%	4.00%
Unobservable input, workout period	[3]	1 year	1 year
Recurring | Equity and other non-debt securities | Maximum | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable input, discount rate	[3]	9.00%	9.00%
Unobservable input, workout period	[3]	2 years	1 year
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.
[2]	Auction-rate securities.
[3]	Auction-rate securities.

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Values Of Financial Instruments Not Recorded At Fair Value In Their Entirety On A Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Cash and due from banks		$ 1,292	$ 1,157
Interest-bearing deposits with banks		6,748	4,990
Investment securities held-to-maturity		1,695	1,981
Total loans, net of allowance for loan losses		48,547	48,450
Demand deposits (noninterest-bearing)		31,776	30,839
Customer certificates of deposit		2,967	3,552
Total deposits		59,261	59,853
Short-term borrowings		12	23
Medium- and long-term debt		5,890	3,058
Carrying Amount
Cash and due from banks		1,292	1,157
Interest-bearing deposits with banks		6,748	4,990
Investment securities held-to-maturity		1,695	1,981
Loans held-for-sale		4	21	[1]
Total loans, net of allowance for loan losses	[2]	48,547	48,450
Customers' liability on acceptances outstanding		2	5
Restricted equity investments		207	92
Nonmarketable equity securities	[3]	9	10	[4]
Demand deposits (noninterest-bearing)		31,776	30,839
Interest-bearing deposits		24,518	25,462
Customer certificates of deposit		2,967	3,552
Total deposits		59,261	59,853
Short-term borrowings		12	23
Acceptances outstanding		2	5
Medium- and long-term debt		5,890	3,058
Credit-related financial instruments		(80)	(83)
Estimated Fair Value
Cash and due from banks		1,292	1,157
Interest-bearing deposits with banks		6,748	4,990
Investment securities held-to-maturity		1,713	1,973
Loans held-for-sale		4	21	[1]
Total loans, net of allowance for loan losses	[2]	48,483	48,269
Customers' liability on acceptances outstanding		2	5
Restricted equity investments		207	92
Nonmarketable equity securities	[3]	17	18	[4]
Demand deposits (noninterest-bearing)		31,776	30,839
Interest-bearing deposits		24,518	25,462
Customer certificates of deposit		2,952	3,536
Total deposits		59,246	59,837
Short-term borrowings		12	23
Acceptances outstanding		2	5
Medium- and long-term debt		5,857	3,032
Credit-related financial instruments		(80)	(83)
Level 1 | Estimated Fair Value
Cash and due from banks		1,292	1,157
Interest-bearing deposits with banks		6,748	4,990
Investment securities held-to-maturity		0	0
Loans held-for-sale		0	0	[1]
Total loans, net of allowance for loan losses	[2]	0	0
Customers' liability on acceptances outstanding		2	5
Restricted equity investments		207	92
Demand deposits (noninterest-bearing)		0	0
Interest-bearing deposits		0	0
Customer certificates of deposit		0	0
Total deposits		0	0
Short-term borrowings		12	23
Acceptances outstanding		2	5
Medium- and long-term debt		0	0
Credit-related financial instruments		0	0
Level 2 | Estimated Fair Value
Cash and due from banks		0	0
Interest-bearing deposits with banks		0	0
Investment securities held-to-maturity		1,713	1,973
Loans held-for-sale		4	21	[1]
Total loans, net of allowance for loan losses	[2]	7	0
Customers' liability on acceptances outstanding		0	0
Restricted equity investments		0	0
Demand deposits (noninterest-bearing)		31,776	30,839
Interest-bearing deposits		24,518	25,462
Customer certificates of deposit		2,952	3,536
Total deposits		59,246	59,837
Short-term borrowings		0	0
Acceptances outstanding		0	0
Medium- and long-term debt		5,857	3,032
Credit-related financial instruments		0	0
Level 3 | Estimated Fair Value
Cash and due from banks		0	0
Interest-bearing deposits with banks		0	0
Investment securities held-to-maturity		0	0
Loans held-for-sale		0	0	[1]
Total loans, net of allowance for loan losses	[2]	48,476	48,269
Customers' liability on acceptances outstanding		0	0
Restricted equity investments		0	0
Demand deposits (noninterest-bearing)		0	0
Interest-bearing deposits		0	0
Customer certificates of deposit		0	0
Total deposits		0	0
Short-term borrowings		0	0
Acceptances outstanding		0	0
Medium- and long-term debt		0	0
Credit-related financial instruments		(80)	(83)
Nonrecurring
Loans held-for-sale			8
Total loans, net of allowance for loan losses		$ 335	153
Nonmarketable equity securities	[5]		$ 1
[1]	Included $8 million impaired loans held-for-sale recorded at fair value on a nonrecurring basis at December 31, 2015.
[2]	Included $335 million and $153 million of impaired loans recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015, respectively.
[3]	Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
[4]	Included $1 million of nonmarketable equity securities recorded at fair value on a nonrecurring basis at December 31, 2015.
[5]	Certain investments that are measured at fair value using the net asset value have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016USD ($)Security	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)Security	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Securities with no credit impairment in unrealized loss position | Security		95		95
Securities gains		$ 0	$ 0	$ 0	$ 0
Securities losses		0	$ 0	3	$ 2
Investment securities available-for-sale, Amortized Cost	[1]	10,621		10,621		$ 10,491
Investment securities available-for-sale, Fair Value	[1]	10,789		10,789		10,519
Investment securities held-to-maturity, Amortized Cost		1,695		1,695		1,981
Investment securities held-to-maturity, Fair Value		1,713		1,713
Carrying value of securities pledged		1,500		1,500
Liabilities secured by pledged collateral		$ 1,000		$ 1,000
Residential mortgage-backed securities
Securities with no credit impairment in unrealized loss position | Security		52		52
Investment securities available-for-sale, Amortized Cost	[2]	$ 7,714		$ 7,714		7,513
Investment securities available-for-sale, Fair Value	[2]	7,828		7,828		7,545
Investment securities held-to-maturity, Amortized Cost	[2],[3]	1,695		1,695		1,981
Investment securities held-to-maturity, Fair Value	[2],[3]	$ 1,713		$ 1,713		1,973
Auction Rate Preferred Securities
Securities with no credit impairment in unrealized loss position		28		28
Auction-Rate State And Municipal Securities
Securities with no credit impairment in unrealized loss position		15		15
Auction-rate securities
ARS portfolio redeemed or sold since acquisition				96.00%
ARS portfolio redeemed or sold since acquisition at or above cost				90.00%
Investment securities available-for-sale, Amortized Cost		$ 56		$ 56		76
Investment securities available-for-sale, Fair Value		54		54		$ 77
Prepayment options | Residential mortgage-backed securities
Investment securities available-for-sale, Amortized Cost		7,700		7,700
Investment securities available-for-sale, Fair Value		7,800		7,800
Investment securities held-to-maturity, Amortized Cost		1,700		1,700
Investment securities held-to-maturity, Fair Value		$ 1,700		$ 1,700
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.
[2]	Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.
[3]	The amortized cost of investment securities held-to-maturity included net unrealized losses of $13 million at September 30, 2016 and $15 million at December 31, 2015 related to securities transferred from available-for-sale, which are included in accumulated other comprehensive loss.

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities Available-For-Sale) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Investment securities available-for-sale, Amortized Cost	[1]	$ 10,621	$ 10,491
Investment securities available-for-sale securities, Gross Unrealized Gains	[1]	177	79
Investment securities available-for-sale securities, Gross Unrealized Losses	[1]	9	51
Investment securities available-for-sale, Fair Value	[1]	10,789	10,519
Investment securities held-to-maturity, Amortized Cost		1,695	1,981
Investment securities held-to-maturity, Fair Value		1,713
Net unrealized losses on available-for-sale securities transferred to held-to-maturity		13	15
U.S. Treasury and other U.S. government agency securities
Investment securities available-for-sale, Amortized Cost		2,771	2,769
Investment securities available-for-sale securities, Gross Unrealized Gains		55	1
Investment securities available-for-sale securities, Gross Unrealized Losses		0	7
Investment securities available-for-sale, Fair Value		2,826	2,763
Residential mortgage-backed securities
Investment securities available-for-sale, Amortized Cost	[2]	7,714	7,513
Investment securities available-for-sale securities, Gross Unrealized Gains	[2]	121	76
Investment securities available-for-sale securities, Gross Unrealized Losses	[2]	7	44
Investment securities available-for-sale, Fair Value	[2]	7,828	7,545
Investment securities held-to-maturity, Amortized Cost	[2],[3]	1,695	1,981
Investment securities held-to-maturity, Gross Unrealized Gains	[2],[3]	18	2
Investment securities held-to-maturity, Gross Unrealized Losses	[2],[3]	0	10
Investment securities held-to-maturity, Fair Value	[2],[3]	1,713	1,973
State and municipal securities
Investment securities available-for-sale, Amortized Cost		8	9
Investment securities available-for-sale securities, Gross Unrealized Gains		0	0
Investment securities available-for-sale securities, Gross Unrealized Losses		0	0
Investment securities available-for-sale, Fair Value		8	9
Corporate debt securities
Investment securities available-for-sale, Amortized Cost			1
Investment securities available-for-sale securities, Gross Unrealized Gains			0
Investment securities available-for-sale securities, Gross Unrealized Losses			0
Investment securities available-for-sale, Fair Value			1
Equity and other non-debt securities
Investment securities available-for-sale, Amortized Cost		128	199
Investment securities available-for-sale securities, Gross Unrealized Gains		1	2
Investment securities available-for-sale securities, Gross Unrealized Losses		2	0
Investment securities available-for-sale, Fair Value		127	201
Auction-rate securities
Investment securities available-for-sale, Amortized Cost		56	76
Investment securities available-for-sale, Fair Value		$ 54	$ 77
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.
[2]	Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.
[3]	The amortized cost of investment securities held-to-maturity included net unrealized losses of $13 million at September 30, 2016 and $15 million at December 31, 2015 related to securities transferred from available-for-sale, which are included in accumulated other comprehensive loss.

Investment Securities (Summar43

Investment Securities (Summary Of Investment Securities Available-For-Sale In Unrealized Loss Positions) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Temporarily Impaired Less than 12 months, Fair Value		$ 609	$ 4,944
Temporarily Impaired Less than 12 Months, Unrealized Losses		2	28
Temporarily Impaired 12 months or more, Fair Value		1,261	1,986
Temporarily Impaired 12 Months or more, Unrealized Losses		16	51
Temporarily Impaired Total, Fair Value		1,870	6,930
Temporarily Impaired Total, Unrealized Losses		18	79
U.S. Treasury and other U.S. government agency securities
Temporarily Impaired Less than 12 months, Fair Value			2,265
Temporarily Impaired Less than 12 Months, Unrealized Losses			7
Temporarily Impaired 12 months or more, Fair Value			0
Temporarily Impaired 12 Months or more, Unrealized Losses			0
Temporarily Impaired Total, Fair Value			2,265
Temporarily Impaired Total, Unrealized Losses			7
Residential mortgage-backed securities
Temporarily Impaired Less than 12 months, Fair Value	[1]	573	2,665
Temporarily Impaired Less than 12 Months, Unrealized Losses	[1]	1	21
Temporarily Impaired 12 months or more, Fair Value	[1]	1,244	1,976
Temporarily Impaired 12 Months or more, Unrealized Losses	[1]	15	51
Temporarily Impaired Total, Fair Value	[1]	1,817	4,641
Temporarily Impaired Total, Unrealized Losses	[1]	16	72
State and municipal securities
Temporarily Impaired Less than 12 months, Fair Value	[2]	0	0
Temporarily Impaired Less than 12 Months, Unrealized Losses	[2]	0	0
Temporarily Impaired 12 months or more, Fair Value	[2]	7	9
Temporarily Impaired 12 Months or more, Unrealized Losses	[2],[3]	0	0
Temporarily Impaired Total, Fair Value	[2]	7	9
Temporarily Impaired Total, Unrealized Losses	[2],[3]	0	0
Corporate debt securities
Temporarily Impaired Less than 12 months, Fair Value	[2]		0
Temporarily Impaired Less than 12 Months, Unrealized Losses	[2]		0
Temporarily Impaired 12 months or more, Fair Value	[2]		1
Temporarily Impaired 12 Months or more, Unrealized Losses	[2],[3]		0
Temporarily Impaired Total, Fair Value	[2]		1
Temporarily Impaired Total, Unrealized Losses	[2],[3]		0
Equity and other non-debt securities
Temporarily Impaired Less than 12 months, Fair Value	[2]	36	14
Temporarily Impaired Less than 12 Months, Unrealized Losses	[2]	1	0	[3]
Temporarily Impaired 12 months or more, Fair Value	[2]	10	0
Temporarily Impaired 12 Months or more, Unrealized Losses	[2]	1	0
Temporarily Impaired Total, Fair Value	[2]	46	14
Temporarily Impaired Total, Unrealized Losses	[2]	$ 2	$ 0	[3]
[1]	Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises
[2]	Primarily auction-rate securities.
[3]	Unrealized losses less than $0.5 million.

Investment Securities (Contract

Investment Securities (Contractual Maturity Distribution Of Debt Securities) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Available-for-sale, Within one year, Amortized Cost		$ 10
Available-for-sale, After one year through five years, Amortized Cost		3,000
Available-for-sale, After five years through ten years, Amortized Cost		1,401
Available-for-sale, After ten years, Amortized Cost		6,082
Available-for-sale, Subtotal, Amortized Cost		10,493
Available-for-sale, Within one year, Fair Value		10
Available-for-sale, After one year through five years, Fair Value		3,056
Available-for-sale, After five years through ten years, Fair Value		1,450
Available-for-sale, After ten years, Fair Value		6,146
Available-for-sale, Subtotal, Fair Value		10,662
Investment securities available-for-sale, Amortized Cost	[1]	10,621	$ 10,491
Investment securities available-for-sale, Fair Value	[1]	10,789	10,519
Held-to-maturity, Within one year, Amortized Cost		0
Held-to-maturity, After one year through five years, Amortized Cost		0
Held-to-maturity, After five years through ten years, Amortized Cost		25
Held-to-maturities, After ten years, Amortized Cost		1,670
Held-to-maturity Securities		1,695	1,981
Held-to-maturity, Within one year, Fair Value		0
Held-to-maturity Securities, After one year through five years, Fair Value		0
Held-to-maturity Securities, After five years through ten years, Fair Value		25
Held-to-maturity Securities, After ten years, Fair Value		1,688
Held-to-maturity Securities, Fair Value		1,713
Equity and other non-debt securities
Investment securities available-for-sale, Amortized Cost		128	199
Investment securities available-for-sale, Fair Value		$ 127	$ 201
[1]	Included auction-rate securities at amortized cost and fair value of $56 million and $54 million, respectively as of September 30, 2016 and $76 million and $77 million, respectively, as of December 31, 2015.

Credit Quality And Allowance 45

Credit Quality And Allowance For Credit Losses (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Retail loans secured by residential real estate in process of foreclosure	$ 0		$ 0		$ 1
Commitments to lend additional funds to TDR borrowers	37		$ 37		$ 6
Interest Rate Reductions
Days past due defined as subsequent default			90 days	90 days
Balance	4	$ 2	$ 4	$ 2
Subsequent default during period	0	0	$ 0	0
AB Note Restructures
Days past due defined as subsequent default			90 days
Balance	52		$ 52
Subsequent default during period	$ 0	$ 0	$ 0	$ 0

Credit Quality And Allowance 46

Credit Quality And Allowance For Credit Losses (Aging Analysis Of Loans) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		$ 209	$ 146
Nonaccrual loans		631	367
Current loans		48,434	48,571
Total loans		49,274	49,084
30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		132	108
60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		29	21
90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		48	17
Business loans | Commercial borrower
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		165	104
Nonaccrual loans		577	313
Current loans		44,117	44,312
Total loans		44,859	44,729
Business loans | Commercial borrower | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		112	70
Business loans | Commercial borrower | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		26	17
Business loans | Commercial borrower | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		27	17
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		106	71
Nonaccrual loans		508	238
Current loans		30,538	31,350
Total loans		31,152	31,659
Business loans | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		68	46
Business loans | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		17	12
Business loans | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		21	13
Business loans | Commercial borrower | International loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		1	2
Nonaccrual loans		19	8
Current loans		1,283	1,358
Total loans		1,303	1,368
Business loans | Commercial borrower | International loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		1	2
Business loans | Commercial borrower | International loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Commercial borrower | International loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		23	8
Nonaccrual loans		0	1
Current loans		2,720	1,992
Total loans		2,743	2,001
Business loans | Real estate construction | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		23	8
Business loans | Real estate construction | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	12	5
Nonaccrual loans	[1]	0	0
Current loans	[1]	2,370	1,676
Total loans	[1],[2]	2,382	1,681
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	12	5
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	11	3
Nonaccrual loans	[3]	0	1
Current loans	[3]	350	316
Total loans	[3],[4]	361	320
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	11	3
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	0	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		35	23
Nonaccrual loans		44	60
Current loans		8,934	8,894
Total loans		9,013	8,977
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		20	14
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		9	5
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		6	4
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	6	8
Nonaccrual loans	[1]	8	16
Current loans	[1]	2,171	2,080
Total loans	[1],[2]	2,185	2,104
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	5	7
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	1	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[1]	0	1
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	29	15
Nonaccrual loans	[3]	36	44
Current loans	[3]	6,763	6,814
Total loans	[3],[4]	6,828	6,873
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	15	7
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	8	5
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing	[3]	6	3
Business loans | Lease financing | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Nonaccrual loans		6	6
Current loans		642	718
Total loans		648	724
Business loans | Lease financing | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Lease financing | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Lease financing | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		44	42
Nonaccrual loans		54	54
Current loans		4,317	4,259
Total loans		4,415	4,355
Retail loans | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		20	38
Retail loans | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		3	4
Retail loans | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		21	0
Retail loans | Consumer borrower
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		21	15
Nonaccrual loans		31	27
Current loans		2,489	2,443
Total loans		2,541	2,485
Retail loans | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		7	12
Retail loans | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		2	3
Retail loans | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		12	0
Retail loans | Real estate mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		23	27
Nonaccrual loans		23	27
Current loans		1,828	1,816
Total loans		1,874	1,870
Retail loans | Real estate mortgage | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		13	26
Retail loans | Real estate mortgage | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		1	1
Retail loans | Real estate mortgage | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		9	0
Retail loans | Home equity | Consumer borrower
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		8	8
Nonaccrual loans		27	27
Current loans		1,757	1,685
Total loans		1,792	1,720
Retail loans | Home equity | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		6	5
Retail loans | Home equity | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		2	3
Retail loans | Home equity | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		13	7
Nonaccrual loans		4	0
Current loans		732	758
Total loans		749	765
Retail loans | Other consumer | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		1	7
Retail loans | Other consumer | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans | Other consumer | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans past due and still accruing		$ 12	$ 0
[1]	Primarily loans to real estate developers.
[2]	Primarily loans to real estate developers.
[3]	Primarily loans secured by owner-occupied real estate.
[4]	Primarily loans secured by owner-occupied real estate.

Credit Quality And Allowance 47

Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total loans		$ 49,274	$ 49,084
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	46,013	45,891
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1,157	1,579
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,473	1,247
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	631	367
Business loans | Commercial borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		44,859	44,729
Business loans | Commercial borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	41,671	41,621
Business loans | Commercial borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1,151	1,573
Business loans | Commercial borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,460	1,222
Business loans | Commercial borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	577	313
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		31,152	31,659
Business loans | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	28,406	29,117
Business loans | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	965	1,293
Business loans | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,273	1,011
Business loans | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	508	238
Business loans | Commercial borrower | International loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,303	1,368
Business loans | Commercial borrower | International loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,230	1,245
Business loans | Commercial borrower | International loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	20	59
Business loans | Commercial borrower | International loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	34	56
Business loans | Commercial borrower | International loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	19	8
Business loans | Real estate construction | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		2,743	2,001
Business loans | Real estate construction | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	2,740	1,999
Business loans | Real estate construction | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	3	1
Business loans | Real estate construction | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	0	1
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[5],[6]	2,382	1,681
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[6]	2,382	1,681
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[6]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[6]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[6]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[7],[8]	361	320
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[8]	358	318
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[8]	3	1
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[8]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[8]	0	1
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		9,013	8,977
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	8,670	8,567
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	152	203
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	147	147
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	44	60
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[5],[6]	2,185	2,104
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[6]	2,141	2,031
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[6]	16	31
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[6]	20	26
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[6]	8	16
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[7],[8]	6,828	6,873
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[8]	6,529	6,536
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[8]	136	172
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[8]	127	121
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[8]	36	44
Business loans | Lease financing | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		648	724
Business loans | Lease financing | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	625	693
Business loans | Lease financing | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	11	17
Business loans | Lease financing | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	6	8
Business loans | Lease financing | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	6	6
Retail loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		4,415	4,355
Retail loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	4,342	4,270
Retail loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	6	6
Retail loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	13	25
Retail loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	54	54
Retail loans | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		2,541	2,485
Retail loans | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	2,504	2,442
Retail loans | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	3	4
Retail loans | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	3	12
Retail loans | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	31	27
Retail loans | Real estate mortgage
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,874	1,870
Retail loans | Real estate mortgage | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,838	1,828
Retail loans | Real estate mortgage | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	3	2
Retail loans | Real estate mortgage | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	10	13
Retail loans | Real estate mortgage | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	23	27
Retail loans | Home equity | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,792	1,720
Retail loans | Home equity | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,760	1,687
Retail loans | Home equity | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	2	1
Retail loans | Home equity | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	3	5
Retail loans | Home equity | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	27	27
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		749	765
Retail loans | Other consumer | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	744	755
Retail loans | Other consumer | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1	3
Retail loans | Other consumer | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	0	7
Retail loans | Other consumer | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	$ 4	$ 0
[1]	Includes all loans not included in the categories of special mention, substandard or nonaccrual.
[2]	Special mention loans are accruing loans that have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date.
[3]	Substandard loans are accruing loans that have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans also are distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. This category is generally consistent with the "substandard" category as defined by regulatory authorities.
[4]	Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to the Nonperforming Assets subheading in Note 1 - Basis of Presentation and Accounting Policies - on page F-58 in the Corporation's 2015 Annual Report. A significant majority of nonaccrual loans are generally consistent with the "substandard" category and the remainder are generally consistent with the "doubtful" category as defined by regulatory authorities.
[5]	Primarily loans to real estate developers.
[6]	Primarily loans to real estate developers.
[7]	Primarily loans secured by owner-occupied real estate.
[8]	Primarily loans secured by owner-occupied real estate.

Credit Quality And Allowance 48

Credit Quality And Allowance For Credit Losses (Schedule Of Nonaccrual, Reduced-Rate Loans And Foreclosed Property) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Nonaccrual loans		$ 631	$ 367
Reduced-rate loans	[1]	8	12
Total nonperforming loans		639	379
Foreclosed property	[2]	21	12
Total nonperforming assets		660	391
Residential Real Estate
Foreclosed property		5	9
Business loans
Reduced-rate loans		0	0
Retail loans
Nonaccrual loans		54	54
Reduced-rate loans		$ 8	$ 12
[1]	There were no reduced-rate business loans at both September 30, 2016 and December 31, 2015. Reduced-rate retail loans were $8 million and $12 million at September 30, 2016 and December 31, 2015, respectively.
[2]	Included $5 million and $9 million of foreclosed residential real estate properties at September 30, 2016 and December 31, 2015, respectively.

Credit Quality And Allowance 49

Credit Quality And Allowance For Credit Losses (Changes In The Allowance For Loan Losses And Related Loan Amounts) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan losses		$ 16	$ 26	$ 213	$ 87
Total loans						$ 49,274	$ 49,084
Allowance for loan losses on PCI loans						$ 0		$ 0
Financing Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period		729	618	634	594
Loan charge-offs		(35)	(34)	(166)	(92)
Recoveries on loans previously charged-off		19	11	56	43
Net loan charge-offs (recoveries)		(16)	(23)	(110)	(49)
Provision for loan losses		14	28	202	79
Foreign currency translation adjustment		0	(1)	1	(2)
Balance at end of period		727	622	727	622
As a percentage of total loans						1.48%		1.27%
Allowance for loan losses individually evaluated for impairment						$ 116		$ 47
Allowance for loan losses collectively evaluated for impairment						611		575
Total allowance for loan losses		729	618	634	594	727	634	622
Loans individually evaluated for impairment						706		389
Loans collectively evaluated for impairment						48,568		48,551
Purchased credit impaired (PCI) loans	[1]					0		2
Total loans						$ 49,274		$ 48,942
Business loans | Financing Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period		682	563	579	534
Loan charge-offs		(34)	(31)	(161)	(83)
Recoveries on loans previously charged-off		18	10	53	38
Net loan charge-offs (recoveries)		(16)	(21)	(108)	(45)
Provision for loan losses		12	25	206	79
Foreign currency translation adjustment		0	(1)	1	(2)
Balance at end of period		678	566	678	566
As a percentage of total loans						1.51%		1.27%
Allowance for loan losses individually evaluated for impairment						$ 115		$ 47
Allowance for loan losses collectively evaluated for impairment						563		519
Total allowance for loan losses		682	563	579	534	678	579	566
Loans individually evaluated for impairment						677		338
Loans collectively evaluated for impairment						44,182		44,233
Purchased credit impaired (PCI) loans	[1]					0		0
Total loans						44,859		$ 44,571
Retail loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans						$ 4,415	4,355
Retail loans | Financing Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period		47	55	55	60
Loan charge-offs		(1)	(3)	(5)	(9)
Recoveries on loans previously charged-off		1	1	3	5
Net loan charge-offs (recoveries)		0	(2)	(2)	(4)
Provision for loan losses		2	3	(4)	0
Foreign currency translation adjustment		0	0	0	0
Balance at end of period		49	56	49	56
As a percentage of total loans						1.10%		1.29%
Allowance for loan losses individually evaluated for impairment						$ 1		$ 0
Allowance for loan losses collectively evaluated for impairment						48		56
Total allowance for loan losses		$ 47	$ 55	$ 55	$ 60	49	$ 55	56
Loans individually evaluated for impairment						29		51
Loans collectively evaluated for impairment						4,386		4,318
Purchased credit impaired (PCI) loans	[1]					0		2
Total loans						$ 4,415		$ 4,371
[1]	No allowance for loan losses was required for PCI loans at September 30, 2015.

Credit Quality And Allowance 50

Credit Quality And Allowance For Credit Losses (Changes In The Allowance For Credit Losses On Lending-Related Commitments) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for credit losses		$ 16	$ 26	$ 213	$ 87
Lending-related commitments
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period		43	50	45	41
Charge-offs on lending related commitments	[1]	0	0	(11)	(1)
Provision for credit losses		2	(2)	11	8
Balance at end of period		$ 45	$ 48	$ 45	$ 48
[1]	Charge-offs result from the sale of unfunded lending-related commitments.

Credit Quality And Allowance 51

Credit Quality And Allowance For Credit Losses (Individually Evaluated Impaired Loans) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		$ 174	$ 122
Recorded investment in impaired loans with related allowance		532	302
Recorded investment total impaired loans		706	424
Unpaid principal balance		823	547
Related allowance for loan losses		116	53
Business loans | Commercial borrower
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		148	91
Recorded investment in impaired loans with related allowance		529	302
Recorded investment total impaired loans		677	393
Unpaid principal balance		788	508
Related allowance for loan losses		115	53
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		141	82
Recorded investment in impaired loans with related allowance		482	252
Recorded investment total impaired loans		623	334
Unpaid principal balance		704	398
Related allowance for loan losses		106	45
Business loans | Commercial borrower | International loans
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		3	0
Recorded investment in impaired loans with related allowance		16	10
Recorded investment total impaired loans		19	10
Unpaid principal balance		26	17
Related allowance for loan losses		5	2
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		4	9
Recorded investment in impaired loans with related allowance		31	40
Recorded investment total impaired loans		35	49
Unpaid principal balance		58	93
Related allowance for loan losses		4	6
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance	[1]	0	7
Recorded investment in impaired loans with related allowance	[1]	6	8
Recorded investment total impaired loans	[1]	6	15
Unpaid principal balance	[1]	15	38
Related allowance for loan losses	[1]	1	1
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance	[2]	4	2
Recorded investment in impaired loans with related allowance	[2]	25	32
Recorded investment total impaired loans	[2]	29	34
Unpaid principal balance	[2]	43	55
Related allowance for loan losses	[2]	3	5
Retail loans
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance	[3]	26	31
Recorded investment in impaired loans with related allowance	[3]	3	0
Recorded investment total impaired loans	[3]	29	31
Unpaid principal balance	[3]	35	39
Related allowance for loan losses	[3]	1	0
Retail loans | Consumer borrower
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		14	18
Recorded investment in impaired loans with related allowance		3	0
Recorded investment total impaired loans		17	18
Unpaid principal balance		22	26
Related allowance for loan losses		1	0
Retail loans | Real estate mortgage
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		12	13
Recorded investment in impaired loans with related allowance		0	0
Recorded investment total impaired loans		12	13
Unpaid principal balance		13	13
Related allowance for loan losses		0	0
Retail loans | Home equity | Consumer borrower
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		12	12
Recorded investment in impaired loans with related allowance		0	0
Recorded investment total impaired loans		12	12
Unpaid principal balance		16	16
Related allowance for loan losses		0	0
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Impaired [Line Items]
Recorded investment in impaired loans with no related allowance		2	6
Recorded investment in impaired loans with related allowance		3	0
Recorded investment total impaired loans		5	6
Unpaid principal balance		6	10
Related allowance for loan losses		$ 1	$ 0
[1]	Primarily loans to real estate developers.
[2]	Primarily loans secured by owner-occupied real estate.
[3]	Individually evaluated retail loans generally have no related allowance for loan losses, primarily due to policy which results in direct write-downs of most restructured retail loans.

Credit Quality And Allowance 52

Credit Quality And Allowance For Credit Losses (Average Individually Evaluated Impaired Loans And Related Interest Recognized) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		$ 689	$ 340	$ 646	$ 276
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		2	2	8	4
Business loans | Commercial borrower
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		662	298	618	235
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		2	2	8	4
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		606	236	559	172
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		2	1	8	3
Business loans | Commercial borrower | International loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		19	10	19	5
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	0	0	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		37	52	40	58
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	1	0	1
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period	[1]	7	15	9	17
Individually Evaluated Impaired Loans Interest Income Recognized for the Period	[1]	0	0	0	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period	[2]	30	37	31	41
Individually Evaluated Impaired Loans Interest Income Recognized for the Period	[2]	0	1	0	1
Retail loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		27	42	28	41
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	0	0	0
Retail loans | Consumer borrower
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		16	19	16	18
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	0	0	0
Retail loans | Real estate mortgage
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		11	23	12	23
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	0	0	0
Retail loans | Home equity | Consumer borrower
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		12	12	12	12
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		0	0	0	0
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Impaired [Line Items]
Individually Evaluated Impaired Loans Average Balance for the Period		4	7	4	6
Individually Evaluated Impaired Loans Interest Income Recognized for the Period		$ 0	$ 0	$ 0	$ 0
[1]	Primarily loans to real estate developers.
[2]	Primarily loans secured by owner-occupied real estate.

Credit Quality And Allowance 53

Credit Quality And Allowance For Credit Losses (Troubled Debt Restructurings By Type Of Modification) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		$ 110	$ 132	$ 206	$ 140
Business loans | Commercial borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		110	112	204	120
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		110	100	199	102
Business loans | Commercial borrower | International loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	2	3	2
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	10	2	16
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[1]	0	7	0	9
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[2]	0	3	2	7
Retail loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	20	2	20
Retail loans | Real estate mortgage
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	18	0	18
Retail loans | Home equity | Consumer borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	2	2	2
Principal Deferrals
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	70	131	$ 153	$ 139
Minimum period loan terms were extended				90 days	90 days
Principal Deferrals | Business loans | Commercial borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	70	112	$ 152	$ 120
Principal Deferrals | Business loans | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	70	100	150	102
Principal Deferrals | Business loans | Commercial borrower | International loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	0	2	0	2
Principal Deferrals | Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	0	10	2	16
Principal Deferrals | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[1],[3]	0	7	0	9
Principal Deferrals | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[2],[3]	0	3	2	7
Principal Deferrals | Retail loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	0	19	1	19
Principal Deferrals | Retail loans | Real estate mortgage
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	0	18	0	18
Principal Deferrals | Retail loans | Home equity | Consumer borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[3]	0	1	1	1
Interest Rate Reductions
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	1	1	1
Interest Rate Reductions | Business loans | Commercial borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	0	0	0
Interest Rate Reductions | Business loans | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	0	0	0
Interest Rate Reductions | Business loans | Commercial borrower | International loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	0	0	0
Interest Rate Reductions | Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	0	0	0
Interest Rate Reductions | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[1]	0	0	0	0
Interest Rate Reductions | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[2]	0	0	0	0
Interest Rate Reductions | Retail loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	1	1	1
Interest Rate Reductions | Retail loans | Real estate mortgage
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	0	0	0
Interest Rate Reductions | Retail loans | Home equity | Consumer borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period		0	$ 1	1	$ 1
AB Note Restructures
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	40		52
AB Note Restructures | Business loans | Commercial borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	40		52
AB Note Restructures | Business loans | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	40		49
AB Note Restructures | Business loans | Commercial borrower | International loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	0		3
AB Note Restructures | Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	0		0
AB Note Restructures | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[1],[4]	0		0
AB Note Restructures | Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[2],[4]	0		0
AB Note Restructures | Retail loans
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	0		0
AB Note Restructures | Retail loans | Real estate mortgage
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	0		0
AB Note Restructures | Retail loans | Home equity | Consumer borrower
Financing Receivable, Modifications [Line Items]
Recorded balance of troubled debt restructuring modified during the period	[4]	$ 0		$ 0
[1]	Primarily loans to real estate developers.
[2]	Primarily loans secured by owner-occupied real estate.
[3]	Primarily represents loan balances where terms were extended 90 days or more at or above contractual interest rates.
[4]	Loan restructurings whereby the original loan is restructured into two notes: an "A" note, which generally reflects the portion of the modified loan which is expected to be collected; and a "B" note, which is generally fully charged off.

Credit Quality And Allowance 54

Credit Quality And Allowance For Credit Losses Credit Quality And Allowance For Credit Losses (Troubled Debt Restructuring Subsequent Default) (Details) - Principal Deferrals - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015		Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Modifications [Line Items]
Balance		$ 234	$ 145		$ 234	$ 145
Subsequent default during period		0	1		14	4
Business loans | Commercial borrower
Financing Receivable, Modifications [Line Items]
Balance		233	126		233	126
Subsequent default during period		0	1		14	4
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Balance		229	108		229	108
Subsequent default during period		0	1		13	3
Business loans | Commercial borrower | International loans
Financing Receivable, Modifications [Line Items]
Balance		0	2		0	2
Subsequent default during period		0	0		0	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans
Financing Receivable, Modifications [Line Items]
Balance		4	16		4	16
Subsequent default during period		0	0		1	1
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Modifications [Line Items]
Balance	[1]	0	9		0	9
Subsequent default during period	[1]	0	0		0	0
Business loans | Real estate mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Modifications [Line Items]
Balance	[2]	4	7		4	7
Subsequent default during period	[2]	0	0		1	1
Retail loans
Financing Receivable, Modifications [Line Items]
Balance		1	19		1	19
Subsequent default during period		0	0		0	0
Retail loans | Home equity | Consumer borrower
Financing Receivable, Modifications [Line Items]
Balance	[3]	1	1		1	1
Subsequent default during period		0	0		0	0
Retail loans | Real estate mortgage
Financing Receivable, Modifications [Line Items]
Balance		0	18	[3]	0	18	[3]
Subsequent default during period		$ 0	$ 0		$ 0	$ 0
[1]	Primarily loans to real estate developers.
[2]	Primarily loans secured by owner-occupied real estate.
[3]	Includes bankruptcy loans for which the court has discharged the borrower's obligation and the borrower has not reaffirmed the debt.

Derivative And Credit-Related55

Derivative And Credit-Related Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of securities held as collateral for derivative assets	$ 34		$ 34
Cash received as collateral for derivative assets	147		147
Fair value of securities pledged as collateral for derivative liabilities	44		44
Cash posted as collateral for derivative liabilities	10		10
Aggregate fair value of all derivative instruments with credit-risk contingent features that were in a liability position	0		0
Net interest income generated by risk management fair value interest rate swaps	15	$ 18	48	$ 52
Net gain (loss) on interest rate fair value hedge ineffectiveness	1	(3)	4	(2)
Gain (loss) on foreign currency derivatives used as economic hedges	0	0	0	0
Net gain on open foreign currency positions		$ 1		$ 1
Allowance for credit losses on lending-related commitments	45		45		$ 45
Allowance for credit losses on lending-related commitments, amount related to unused commitments to extend credit	30		$ 30		33
Final year of expiration for outstanding letters of credit			2,023
Risk participation agreements covering standby and commercial letters of credit	282		$ 282		287
Standby and commercial letters of credit	3,800		3,800		4,000
Carrying value of standby and commercial letters of credit included in accrued expenses and other liabilities	50		50		49
Deferred fees on standby and commercial letters of credit included in accrued expenses and other liabilities	35		35		37
Allowance for credit losses on lending-related commitments, amount related to standby and commercial letters of credit	15		15		12
Notional amount of derivative credit risk participation agreements	514		514		559
Maximum estimated exposure to credit risk participation agreements assuming 100% default	$ 9		$ 9		$ 5
Weighted average remaining maturity of credit risk participation agreements, in years			2 years 4 months 20 days

Derivative And Credit-Related56

Derivative And Credit-Related Financial Instruments (Schedule Of Derivative Instruments) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	$ 20,436	$ 20,764
Fair Value of Gross Derivative Assets		620	818
Fair Value of Gross Derivative Liabilities		390	610
Derivative assets, Netting adjustment - Offsetting derivative liabilities		(108)	(127)
Derivative liabilities, Netting adjustment - Offsetting derivative assets		(108)	(127)
Derivative assets, Netting adjustment - Cash collateral received		(85)	(291)
Derivative liabilities, Netting adjustment, Cash collateral posted		(8)	(3)
Net derivative assets included in the consolidated balance sheets	[2]	427	400
Net derivative liabilities included in the consolidated balance sheets	[2]	274	480
Derivative asset, securities pledged as collateral		(32)	(137)
Derivative liability, securities pledged as collateral		(41)	(3)
Net derivative assets after deducting amounts not offset in the consolidated balance sheets		395	263
Net derivative liabilities after deducting amounts not offset in the consolidated balance sheets		233	477
Credit valuation adjustments for counterparty credit risk		11	5
Risk management purposes
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	3,245	3,118
Fair Value of Gross Derivative Assets		172	150
Fair Value of Gross Derivative Liabilities		1	0
Risk management purposes | Derivatives designated as hedging instruments | Fair Value Hedging | Interest rate swap
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	2,525	2,525
Fair Value of Gross Derivative Assets		172	147
Fair Value of Gross Derivative Liabilities		0	0
Risk management purposes | Derivatives used as economic hedges | Foreign exchange spot, forwards and swaps
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	720	593
Fair Value of Gross Derivative Assets		0	3
Fair Value of Gross Derivative Liabilities		1	0
Customer-initiated and other activities
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	17,191	17,646
Fair Value of Gross Derivative Assets		448	668
Fair Value of Gross Derivative Liabilities		389	610
Customer-initiated and other activities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	13,253	12,228
Fair Value of Gross Derivative Assets		217	139
Fair Value of Gross Derivative Liabilities		170	92
Customer-initiated and other activities | Interest rate caps and floors written
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	386	253
Fair Value of Gross Derivative Assets		0	0
Fair Value of Gross Derivative Liabilities		0	0
Customer-initiated and other activities | Interest rate caps and floors purchased
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	386	253
Fair Value of Gross Derivative Assets		0	0
Fair Value of Gross Derivative Liabilities		0	0
Customer-initiated and other activities | Interest rate swap
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	12,481	11,722
Fair Value of Gross Derivative Assets		217	139
Fair Value of Gross Derivative Liabilities		170	92
Customer-initiated and other activities | Energy contracts
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	2,178	3,127
Fair Value of Gross Derivative Assets		192	475
Fair Value of Gross Derivative Liabilities		190	472
Customer-initiated and other activities | Energy caps and floors written
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	471	536
Fair Value of Gross Derivative Assets		1	0
Fair Value of Gross Derivative Liabilities		41	85
Customer-initiated and other activities | Energy caps and floors purchased
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	471	536
Fair Value of Gross Derivative Assets		41	85
Fair Value of Gross Derivative Liabilities		0	0
Customer-initiated and other activities | Energy swaps
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	1,236	2,055
Fair Value of Gross Derivative Assets		150	390
Fair Value of Gross Derivative Liabilities		149	387
Customer-initiated and other activities | Foreign exchange spot, options and swaps
Derivatives, Fair Value [Line Items]
Notional/Contract Amount	[1]	1,760	2,291
Fair Value of Gross Derivative Assets		39	54
Fair Value of Gross Derivative Liabilities		$ 29	$ 46
[1]	Notional or contractual amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the consolidated balance sheets.
[2]	Net derivative assets are included in “accrued income and other assets” and net derivative liabilities are included in “accrued expenses and other liabilities” on the consolidated balance sheets. Included in the fair value of net derivative assets and net derivative liabilities are credit valuation adjustments reflecting counterparty credit risk and credit risk of the Corporation. The fair value of net derivative assets included credit valuation adjustments for counterparty credit risk of $11 million and $5 million at September 30, 2016 and December 31, 2015, respectively.

Derivative And Credit-Related57

Derivative And Credit-Related Financial Instruments (Schedule Of Weighted Average Maturity And Interest Rates On Risk Management Interest Rate Swaps) (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Notional Amount	[1]	$ 20,436	$ 20,764
Risk management purposes
Notional Amount	[1]	3,245	3,118
Medium- and long-term debt | Swaps - fair value - receive fixed/pay floating | Risk management purposes | Interest rate swap
Notional Amount		$ 2,525	$ 2,525
Weighted Average Remaining Maturity		4 years 7 months 3 days	5 years 27 days
Weighted Average Receive Rate		3.89%	3.89%
Weighted Average Pay Rate	[2]	1.59%	1.11%
[1]	Notional or contractual amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the consolidated balance sheets.
[2]	Variable rates paid on receive fixed swaps are based on six-month LIBOR rates in effect at September 30, 2016 and December 31, 2015.

Derivative And Credit-Related58

Derivative And Credit-Related Financial Instruments (Schedule Of Net Gains Recognized In Income On Customer-Initiated Derivatives) (Details) - Customer-initiated and other activities - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 17	$ 14	$ 45	$ 40
Interest rate contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	6	4	14	11
Energy contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	0	1	1	2
Foreign exchange contracts | Foreign exchange income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 11	$ 9	$ 30	$ 27

Derivative And Credit-Related59

Derivative And Credit-Related Financial Instruments (Schedule Of Financial Instruments With Off-Balance Sheet Credit Risk) (Details) - Maximum - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Unused Commitments to Extend Credit
Loss contingency, estimate of possible loss, maximum	$ (26,753)	$ (28,529)
Commercial And Other | Unused Commitments to Extend Credit
Loss contingency, estimate of possible loss, maximum	(24,115)	(26,115)
Bankcard, Revolving Check Credit And Home Equity Loan Commitments | Unused Commitments to Extend Credit
Loss contingency, estimate of possible loss, maximum	(2,638)	(2,414)
Standby Letters Of Credit
Loss contingency, estimate of possible loss, maximum	(3,757)	(3,985)
Commercial Letters Of Credit
Loss contingency, estimate of possible loss, maximum	$ (33)	$ (41)

Derivative And Credit-Related60

Derivative And Credit-Related Financial Instruments (Summary Of Internally Classified Watch List Letters Of Credit) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Total criticized standby and commercial letters of credit	$ 136	$ 110
As a percentage of total outstanding standby and commercial letters of credit	3.60%	2.70%

Variable Interest Entities (V61

Variable Interest Entities (VIEs) (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Variable Interest Entity
Unfunded commitments to fund tax credit entities	$ 150
Amount of financial or other support not contractually required provided by the Corporation to VIEs	0	$ 0
Low Income Housing Tax Credit Entities
Variable Interest Entity
Exposure to loss as a result of involvement with VIEs	406
Other Tax Credit Entities
Variable Interest Entity
Exposure to loss as a result of involvement with VIEs	$ 8

Variable Interest Entities (V62

Variable Interest Entities (VIEs) (Impact Of VIEs On The Consolidated Statements Of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Variable Interest Entity
Other noninterest income	$ 29	$ 25	$ 75	$ 79
Provision (benefit) for income taxes	64	63	131	188
Variable Interest Entity
Variable Interest Entity
Other noninterest income	(1)	0	(1)	1
Provision for income taxes, amortization of LIHTC investments	17	15	49	45
Provision (benefit) for income taxes	(6)	(5)	(17)	(15)
Low income housing tax credits | Variable Interest Entity
Variable Interest Entity
Provision for income taxes, affordable housing tax credits and other tax benefits	(16)	(15)	(47)	(45)
Other tax benefits related to tax credit entities | Variable Interest Entity
Variable Interest Entity
Provision for income taxes, affordable housing tax credits and other tax benefits	$ (7)	$ (5)	$ (19)	$ (15)

Medium- And Long-Term Debt (Nar

Medium- And Long-Term Debt (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Unamortized debt issuance cost	$ 7	$ 8
Subsidiaries
Debt Instrument [Line Items]
Blanket lien on real estate-related loans securing FHLB advances	15,300
Potential FHLB borrowing capacity	3,800
Floating-rate FHLB advances | Subsidiaries
Debt Instrument [Line Items]
Floating-rate FHLB advances	$ 2,800	$ 0
Number of notes	8
Weighted-average interest rate	0.4045%
Minimum | Floating-rate FHLB advances | Subsidiaries
Debt Instrument [Line Items]
Maturity date	Mar. 4, 2026
Maximum | Floating-rate FHLB advances | Subsidiaries
Debt Instrument [Line Items]
Maturity date	May 20, 2026

Medium- And Long-Term Debt (Sch

Medium- And Long-Term Debt (Schedule Of Medium- And Long-Term Debt) (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total medium- and long-term debt		$ 5,890	$ 3,058
Parent Company
Debt Instrument [Line Items]
Total medium- and long-term debt		626	608
Subsidiaries
Debt Instrument [Line Items]
Subordinated notes		1,767	1,763
Total medium- and long-term debt		5,264	2,450
3.80% subordinated notes due 2026 | Parent Company
Debt Instrument [Line Items]
Subordinated notes	[1]	$ 274	$ 259
Stated interest rate		3.80%	3.80%
Maturity date		Jul. 22, 2026	Jul. 22, 2026
2.125% notes due 2019 | Parent Company
Debt Instrument [Line Items]
Medium-term notes	[1]	$ 352	$ 349
Stated interest rate		2.125%	2.125%
Maturity date		May 23, 2019	May 23, 2019
5.75% subordinated notes due 2016 | Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	[1],[2]	$ 651	$ 659
Par value swapped to variable rate		250
Total par value outstanding		$ 650
Stated interest rate		5.75%	5.75%
Maturity date		Nov. 21, 2016	Nov. 21, 2016
5.20% subordinated notes due 2017 | Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	[1]	$ 516	$ 530
Stated interest rate		5.20%	5.20%
Maturity date		Aug. 22, 2017	Aug. 22, 2017
4.00% subordinated notes due 2025 | Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	[1]	$ 370	$ 351
Stated interest rate		4.00%	4.00%
Maturity date		Jul. 27, 2025	Jul. 27, 2025
7.875% subordinated notes due 2026 | Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	[1]	$ 230	$ 223
Stated interest rate		7.875%	7.875%
Maturity date		Sep. 15, 2026	Sep. 15, 2026
2.50% notes due 2020 | Subsidiaries
Debt Instrument [Line Items]
Medium-term notes	[1]	$ 681	$ 671
Stated interest rate		2.50%	2.50%
Maturity date		Jun. 2, 2020	Jun. 2, 2020
Floating-rate based on FHLB auction rate due 2026 | Subsidiaries
Debt Instrument [Line Items]
Federal Home Loan Bank advances		$ 2,800	$ 0
Weighted-average interest rate		0.4045%
Floating-rate based on FHLB auction rate due 2026 | Subsidiaries | Minimum
Debt Instrument [Line Items]
Maturity date		Mar. 4, 2026
Floating-rate based on FHLB auction rate due 2026 | Subsidiaries | Maximum
Debt Instrument [Line Items]
Maturity date		May 20, 2026
6.0% - 6.4% fixed-rate notes due 2020 | Subsidiaries
Debt Instrument [Line Items]
Other notes		$ 16	$ 16
Maturity date		Jun. 30, 2020	Jun. 30, 2020
6.0% - 6.4% fixed-rate notes due 2020 | Subsidiaries | Minimum
Debt Instrument [Line Items]
Stated interest rate		6.00%	6.00%
6.0% - 6.4% fixed-rate notes due 2020 | Subsidiaries | Maximum
Debt Instrument [Line Items]
Stated interest rate		6.40%	6.40%
[1]	The fixed interest rates on these notes have been swapped to a variable rate and designated in a hedging relationship. Accordingly, carrying value has been adjusted to reflect the change in the fair value of the debt as a result of changes in the benchmark rate.
[2]	The fixed interest rate on $250 million of $650 million total par value of these notes have been swapped to a variable rate. The remaining amount is not swapped.

Accumulated Other Comprehensi65

Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Investment securities, Balance at beginning of period, net of tax	$ 9	$ 37
Investment securities, Net unrealized holding gains arising during the period	140	44
Investment securities, Less: Provision for income taxes	51	16
Investment securities, Net unrealized holding gains arising during the period, net of tax	89	28
Investment securities, Net realized losses included in net securities losses	0	(2)
Investment securities, Less: Benefit for income taxes	0	(1)
Investment securities, Reclassification adjustment for net securities losses included in net income, net of tax	0	(1)
Investment securities, Net losses realized as a yield adjustment in interest on investment securities	(2)	(6)
Investment securities, Less: Benefit for income taxes	(1)	(2)
Investment securities, Reclassification adjustment for net losses realized as a yield adjustment included in net income, net of tax	(1)	(4)
Investment securities, Change in net unrealized gains on investment securities, net of tax	90	33
Investment securities, Balance at end of period, net of tax	99	70
Benefit plans, Balance at beginning of period, net of tax	(438)	(449)
Benefit plans, Actuarial loss arising during the period	(191)	0
Benefit plans, Prior service credit arising during the period	235	0
Benefit plans, Net defined pension and other postretirement adjustment arising during the period	44	0
Benefit plans, Less: provision for income taxes	16	0
Benefit plans, Net defined benefit pension and other postretirement adjustment arising during the period, net of tax	28	0
Benefit plans, Amortization of actuarial net loss recognized in salaries and benefits expense	29	53
Benefit plans, Less: Provision for income taxes	10	19
Benefit plans, Adjustment for amounts recognized as components of net periodic benefit cost during the period, net of tax	19	34
Benefit plans, Change in defined benefit pension and other postretirement plans adjustment, net of tax	47	34
Benefit plans, Balance at end of period, net of tax	(391)	(415)
Total accumulated other comprehensive loss at end of period, net of tax	$ (292)	$ (345)	$ (429)

Net Income Per Common Share (Ba

Net Income Per Common Share (Basic And Diluted Net Income Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income	$ 149	$ 136	$ 313	$ 405
Income allocated to participating securities	1	2	3	5
Net income attributable to common shares	$ 148	$ 134	$ 310	$ 400
Basic average common shares	171	176	173	176
Basic net income per common share	$ 0.87	$ 0.76	$ 1.80	$ 2.27
Basic average common shares	171	176	173	176
Net effect of the assumed exercise of stock options	2	2	1	2
Net effect of the assumed exercise of warrants	3	3	2	4
Diluted average common shares	176	181	176	182
Diluted net income per common share	$ 0.84	$ 0.74	$ 1.76	$ 2.20

Net Income Per Common Share (Sc

Net Income Per Common Share (Schedule of Average Shares Excluded From Diluted Net Income Per Common Share Computation) (Details) - Stock Options - $ / shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Average outstanding options	2.6	4.6	4	5.4
Minimum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Range of exercise prices	$ 46.68	$ 46.68	$ 37.26	$ 46.68
Maximum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Range of exercise prices	$ 59.86	$ 60.82	$ 59.86	$ 60.82

Employee Benefit Plans Employee

Employee Benefit Plans Employee Benefit Plans (Net Periodic Defined Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Net periodic defined benefit cost			$ 11	$ 34
Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 9	24	27
Interest cost	23	22	69	66
Expected return on plan assets	(39)	(40)	(120)	(120)
Amortization of prior service cost (credit)	1	1	3	3
Amortization of net loss	7	15	23	44
Net periodic defined benefit cost	0	7	(1)	20
Non-Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	2	3
Interest cost	3	2	8	7
Amortization of prior service cost (credit)	(1)	(1)	(3)	(3)
Amortization of net loss	2	3	5	8
Net periodic defined benefit cost	4	5	12	15
Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0	1	2	2
Expected return on plan assets	(1)	(1)	(3)	(3)
Amortization of net loss	1	0	1	1
Net periodic defined benefit cost	$ 0	$ 0	$ 0	$ 0

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Benefit plans, Net defined pension and other postretirement adjustment arising during the period	$ 44	$ 0
Benefit plans, Prior service credit arising during the period	235	0
Benefit plans, Actuarial loss arising during the period	$ (191)	$ 0
Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions, Discount rate, Percent	3.64%
Fair value of plan assets at September 30, 2016	$ 2,600
Benefit plans, Net defined pension and other postretirement adjustment arising during the period	41
Benefit plans, Prior service credit arising during the period	201
Benefit plans, Actuarial loss arising during the period	$ 160
Non-Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions, Discount rate, Percent	3.64%
Benefit plans, Net defined pension and other postretirement adjustment arising during the period	$ 3
Benefit plans, Prior service credit arising during the period	34
Benefit plans, Actuarial loss arising during the period	$ 31

Income Taxes And Tax-Related 70

Income Taxes And Tax-Related Items Income Taxes And Tax-Related Items (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Unrecognized tax benefits	$ 15	$ 22
Decrease in unrecognized tax benefits due to recognition of federal settlements	7
Reasonably possible decrease in unrecognized tax benefits in next 12 months	1
Tax-related interest and penalties payable	8	3
Net deferred tax assets	187	199
Decrease in net deferred tax assets	12
State net operating loss carryforwards	5	5
Valuation allowance for deferred tax assets	$ 3	$ 3
Minimum
Years state net operating loss carryforwards expire	Dec. 31, 2016
Maximum
Years state net operating loss carryforwards expire	Dec. 31, 2026

Contingent Liabilities (Narrati

Contingent Liabilities (Narrative) (Details) - USD ($) $ in Millions	Jan. 17, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Loss Contingencies [Line Items]
Legal fees		$ 4	$ 5	$ 14	$ 15
Pending Litigation | Minimum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss		0		0
Pending Litigation | Maximum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss		$ 32		$ 32
Butte Local Development v. Masters Group v. Comerica Bank
Loss Contingencies [Line Items]
Amount of damages awarded by the jury	$ 52

Restructuring Charges (Narrativ

Restructuring Charges (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)
Restructuring Cost and Reserve [Line Items]
Number of banking centers to be consolidated under restructuring plan	38
Restructuring charges	$ 20	$ 0	$ 73	$ 0
Business Bank
Restructuring Cost and Reserve [Line Items]
Restructuring charges	10		36
Retail Bank
Restructuring Cost and Reserve [Line Items]
Restructuring charges	8		27
Wealth Management
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2		$ 10

Restructuring Charges (Schedule

Restructuring Charges (Schedule of Changes in Restructuring Reserves) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period		$ 50		$ 0
Restructuring charges		20	$ 0	73	$ 0
Payments		(21)		(24)
Adjustments for non-cash charges	[1]	(2)		(2)
Balance at end of period		47		47
Total restructuring charges incurred to date		73		$ 73
Expected completion date of restructuring activities				Dec. 31, 2018
Employee costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period		46		$ 0
Restructuring charges		4		50
Payments		(12)		(12)
Adjustments for non-cash charges	[1]	2		2
Balance at end of period		40		40
Total restructuring charges incurred to date		50		50
Facilities costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period		0		0
Restructuring charges		5		5
Payments		(1)		(1)
Adjustments for non-cash charges	[1]	(4)		(4)
Balance at end of period		0		0
Total restructuring charges incurred to date		5		5
Technology costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period		0		0
Restructuring charges		0		0
Payments		0		0
Adjustments for non-cash charges	[1]	0		0
Balance at end of period		0		0
Total restructuring charges incurred to date		0		0
Other costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period		4		0
Restructuring charges		11		18
Payments		(8)		(11)
Adjustments for non-cash charges	[1]	0		0
Balance at end of period		7		7
Total restructuring charges incurred to date		18		18
Minimum
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	140		140
Minimum | Employee costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	65		65
Minimum | Facilities costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	35		35
Minimum | Technology costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	10		10
Minimum | Other costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	30		30
Maximum
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	160		160
Maximum | Employee costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	70		70
Maximum | Facilities costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	40		40
Maximum | Technology costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	15		15
Maximum | Other costs
Restructuring Cost and Reserve [Line Items]
Total expected restructuring charges	[2]	$ 35		$ 35
[1]	Adjustments for non-cash charges include the benefit from forfeitures of nonvested stock compensation in Employee Costs and accelerated depreciation expense in Facilities Costs.
[2]	Restructuring activities are expected to be substantially completed by 12/31/2018.

Business Segment Information (N

Business Segment Information (Narrative) (Details)	9 Months Ended
	Sep. 30, 2016segmentsmarkets
Segment Reporting [Abstract]
Number of Major Business Segments | segments	3
Number of Primary Market Segments | markets	3

Business Segment Information (B

Business Segment Information (Business Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net interest income (expense)		$ 450	$ 422	$ 1,342	$ 1,256
Provision for credit losses		16	26	213	87
Noninterest income		272	260	784	769
Noninterest expenses		493	457	1,469	1,345
Provision (benefit) for income taxes		64	63	131	188
Net income (loss)		149	136	313	405
Net credit-related charge-offs (recoveries)		16	23	121	50
Assets, average		72,909	71,333	70,942	69,688
Loans, average		49,206	48,972	49,023	48,655
Deposits, average		$ 58,065	$ 59,140	$ 57,102	$ 57,851
Return on average assets	[1],[2]	0.82%	0.76%	0.59%	0.78%
Efficiency ratio	[3],[4]	68.15%	66.87%	68.88%	66.25%
Business Bank
Net interest income (expense)		$ 361	$ 378	$ 1,077	$ 1,117
Provision for credit losses		2	30	200	116
Noninterest income		145	144	426	426
Noninterest expenses		215	198	644	572
Provision (benefit) for income taxes		97	99	217	289
Net income (loss)		192	195	442	566
Net credit-related charge-offs (recoveries)		14	23	113	55
Assets, average		39,618	39,768	39,589	39,567
Loans, average		38,243	38,113	38,126	37,950
Deposits, average		$ 30,019	$ 31,405	$ 29,195	$ 30,607
Return on average assets	[2]	1.94%	1.96%	1.49%	1.91%
Efficiency ratio	[4]	42.38%	37.98%	42.70%	37.00%
Retail Bank
Net interest income (expense)		$ 156	$ 158	$ 466	$ 466
Provision for credit losses		10	2	13	(14)
Noninterest income		50	49	141	136
Noninterest expenses		195	185	579	542
Provision (benefit) for income taxes		0	7	5	26
Net income (loss)		1	13	10	48
Net credit-related charge-offs (recoveries)		3	1	6	3
Assets, average		6,544	6,518	6,548	6,449
Loans, average		5,871	5,835	5,872	5,767
Deposits, average		$ 23,654	$ 23,079	$ 23,438	$ 22,746
Return on average assets	[2]	0.01%	0.23%	0.06%	0.28%
Efficiency ratio	[4]	94.57%	89.33%	94.87%	89.91%
Wealth Management
Net interest income (expense)		$ 41	$ 45	$ 128	$ 133
Provision for credit losses		(1)	(3)	(3)	(13)
Noninterest income		61	59	181	177
Noninterest expenses		75	75	229	225
Provision (benefit) for income taxes		10	11	30	35
Net income (loss)		18	21	53	63
Net credit-related charge-offs (recoveries)		(1)	(1)	2	(8)
Assets, average		5,283	5,228	5,220	5,137
Loans, average		5,092	5,024	5,025	4,938
Deposits, average		$ 4,030	$ 4,188	$ 4,137	$ 4,082
Return on average assets	[2]	1.39%	1.62%	1.37%	1.64%
Efficiency ratio	[4]	73.07%	71.12%	74.09%	71.98%
Finance
Net interest income (expense)		$ (114)	$ (163)	$ (346)	$ (471)
Provision for credit losses		0	0	0	0
Noninterest income		13	12	33	32
Noninterest expenses		(1)	0	(3)	(2)
Provision (benefit) for income taxes		(39)	(57)	(119)	(163)
Net income (loss)		(61)	(94)	(191)	(274)
Net credit-related charge-offs (recoveries)		0	0	0	0
Assets, average		14,144	11,761	13,955	11,593
Loans, average		0	0	0	0
Deposits, average		98	203	81	146
Other
Net interest income (expense)		6	4	17	11
Provision for credit losses		5	(3)	3	(2)
Noninterest income		3	(4)	3	(2)
Noninterest expenses		9	(1)	20	8
Provision (benefit) for income taxes		(4)	3	(2)	1
Net income (loss)		(1)	1	(1)	2
Net credit-related charge-offs (recoveries)		0	0	0	0
Assets, average		7,320	8,058	5,630	6,942
Loans, average		0	0	0	0
Deposits, average		$ 264	$ 265	$ 251	$ 270
[1]	Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.
[2]	Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.
[3]	Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains.
[4]	Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains.

Business Segment Information (M

Business Segment Information (Market Segment Financial Results) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net interest income (expense)		$ 450	$ 422	$ 1,342	$ 1,256
Provision for credit losses		16	26	213	87
Noninterest income		272	260	784	769
Noninterest expenses		493	457	1,469	1,345
Provision (benefit) for income taxes		64	63	131	188
Net income (loss)		149	136	313	405
Net credit-related charge-offs (recoveries)		16	23	121	50
Assets, average		72,909	71,333	70,942	69,688
Loans, average		49,206	48,972	49,023	48,655
Deposits, average		$ 58,065	$ 59,140	$ 57,102	$ 57,851
Return on average assets	[1],[2]	0.82%	0.76%	0.59%	0.78%
Efficiency ratio	[3],[4]	68.15%	66.87%	68.88%	66.25%
Michigan
Net interest income (expense)		$ 169	$ 179	$ 509	$ 533
Provision for credit losses		13	6	10	(15)
Noninterest income		82	84	240	249
Noninterest expenses		161	152	471	433
Provision (benefit) for income taxes		26	35	90	122
Net income (loss)		51	70	178	242
Net credit-related charge-offs (recoveries)		1	9	6	10
Assets, average		13,174	13,856	13,291	13,815
Loans, average		12,488	13,223	12,640	13,245
Deposits, average		$ 21,944	$ 21,946	$ 21,731	$ 21,788
Return on average assets	[1]	0.90%	1.23%	1.06%	1.42%
Efficiency ratio	[3]	64.10%	57.42%	62.60%	55.18%
California
Net interest income (expense)		$ 181	$ 186	$ 537	$ 542
Provision for credit losses		(4)	24	8	24
Noninterest income		44	38	120	109
Noninterest expenses		110	101	333	298
Provision (benefit) for income taxes		44	37	118	123
Net income (loss)		75	62	198	206
Net credit-related charge-offs (recoveries)		0	10	25	16
Assets, average		17,933	17,060	17,824	16,741
Loans, average		17,637	16,789	17,544	16,473
Deposits, average		$ 17,674	$ 18,371	$ 17,089	$ 17,500
Return on average assets	[1]	1.61%	1.27%	1.46%	1.47%
Efficiency ratio	[3]	48.56%	45.19%	50.63%	45.74%
Texas
Net interest income (expense)		$ 118	$ 129	$ 360	$ 390
Provision for credit losses		(3)	10	199	74
Noninterest income		33	34	95	99
Noninterest expenses		102	97	316	286
Provision (benefit) for income taxes		19	20	(20)	48
Net income (loss)		33	36	(40)	81
Net credit-related charge-offs (recoveries)		10	4	88	13
Assets, average		11,014	11,578	11,198	11,880
Loans, average		10,566	10,997	10,722	11,260
Deposits, average		$ 9,860	$ 10,753	$ 10,095	$ 10,907
Return on average assets	[1]	1.18%	1.16%	(0.45%)	0.87%
Efficiency ratio	[3]	67.29%	59.48%	69.16%	58.32%
Other Markets
Net interest income (expense)		$ 90	$ 87	$ 265	$ 251
Provision for credit losses		5	(11)	(7)	6
Noninterest income		97	96	293	282
Noninterest expenses		112	108	332	322
Provision (benefit) for income taxes		18	25	64	57
Net income (loss)		52	61	169	148
Net credit-related charge-offs (recoveries)		5	0	2	11
Assets, average		9,324	9,020	9,044	8,717
Loans, average		8,515	7,963	8,117	7,677
Deposits, average		$ 8,225	$ 7,602	$ 7,855	$ 7,240
Return on average assets	[1]	2.23%	2.70%	2.48%	2.26%
Efficiency ratio	[3]	59.87%	59.00%	59.36%	60.23%
Finance & Other
Net interest income (expense)		$ (108)	$ (159)	$ (329)	$ (460)
Provision for credit losses		5	(3)	3	(2)
Noninterest income		16	8	36	30
Noninterest expenses		8	(1)	17	6
Provision (benefit) for income taxes		(43)	(54)	(121)	(162)
Net income (loss)		(62)	(93)	(192)	(272)
Net credit-related charge-offs (recoveries)		0	0	0	0
Assets, average		21,464	19,819	19,585	18,535
Loans, average		0	0	0	0
Deposits, average		$ 362	$ 468	$ 332	$ 416
[1]	Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.
[2]	Return on average assets is calculated based on the greater of average assets or average liabilities and attributed equity.
[3]	Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains.
[4]	Noninterest expenses as a percentage of the sum of net interest income (fully taxable equivalent basis) and noninterest income excluding net securities gains.