Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income
Interest and fees on loans and leases	$ 6,230	$ 5,985	$ 5,347
Interest and dividends on securities	1,092	1,029	941
Interest on other earning assets	52	52	39
Total interest income	7,374	7,066	6,327
Interest Expense
Interest on deposits	344	251	233
Interest on short-term borrowings	41	9	4
Interest on long-term debt	454	485	498
Total interest expense	839	745	735
Net Interest Income	6,535	6,321	5,592
Provision for credit losses	547	572	428
Net Interest Income After Provision for Credit Losses	5,988	5,749	5,164
Noninterest Income
Insurance income	1,754	1,713	1,596
Service charges on deposits	706	664	631
Mortgage banking income	415	463	455
Investment banking and brokerage fees and commissions	410	408	398
Trust and investment advisory revenues	278	266	240
Bankcard fees and merchant discounts	271	237	218
Checkcard fees	214	195	174
Operating lease income	146	137	124
Income from bank-owned life insurance	122	123	113
FDIC loss share income, net	0	(142)	(253)
Other income	467	362	326
Securities gains (losses), net
Gross realized gains	17	46	41
Gross realized losses	(18)	0	(40)
OTTI charges	0	0	(2)
Non-credit portion recognized in OCI	0	0	(2)
Total securities gains (losses), net	(1)	46	(3)
Total noninterest income	4,782	4,472	4,019
Noninterest Expense
Personnel expense	4,121	3,964	3,469
Occupancy and equipment expense	784	786	708
Software expense	242	224	192
Outside IT services	160	186	135
Regulatory charges	153	145	101
Amortization of intangibles	142	150	105
Loan-related expense	130	95	150
Professional services	123	102	130
Merger-related and restructuring charges, net	115	171	165
Loss (gain) on early extinguishment of debt	392	(1)	172
Other expense	1,082	899	939
Total noninterest expense	7,444	6,721	6,266
Earnings
Income (loss) before income taxes	3,326	3,500	2,917
Provision for income taxes	911	1,058	794
Net income	2,415	2,442	2,123
Noncontrolling interests	21	16	39
Dividends on preferred stock	174	167	148
Net income available to common shareholders	$ 2,220	$ 2,259	$ 1,936
Basic EPS (in usd per share)	$ 2.78	$ 2.81	$ 2.59
Diluted EPS (in usd per share)	2.74	2.77	2.56
Cash dividends declared per share (in usd per share)	$ 1.26	$ 1.15	$ 1.05
Basic weighted average shares outstanding	799,217	804,680	748,010
Diluted weighted average shares outstanding	810,977	814,916	757,765