CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income
Interest and fees on loans and leases	$ 1,722	$ 1,394	$ 1,286
Interest and fees on loans held for sale	30	31	45
Interest on securities available for sale	104	120	130
Interest on trading securities	35	47	59
Interest on other earning assets	7	32	26
Total interest income	1,898	1,624	1,546
Interest expense:
Interest on deposits	152	307	217
Interest on trading liabilities	6	13	19
Interest on short-term borrowings	14	41	37
Interest on term borrowings	64	53	53
Total interest expense	236	414	326
Net interest income	1,662	1,210	1,220
Provision for credit losses	503	45	8
Net interest income after provision for credit losses	1,159	1,165	1,212
Noninterest income
Fixed income	423	279	168
Deposit transactions and cash management	148	132	133
Mortgage banking and title income	129	10	11
Brokerage, management fees and commissions	66	55	55
Trust services and investment management	39	30	30
Bankcard income	37	28	29
Securities gains (losses), net	(6)	0	213
Purchase accounting gain	533	0	0
Other income	123	120	84
Total noninterest income	1,492	654	723
Noninterest expense
Personnel expense	1,033	695	658
Net occupancy expense	116	80	85
Computer software	85	61	61
Legal and professional fees	84	72	57
Operations services	56	46	56
Contributions	41	11	1
Equipment expense	42	34	39
Amortization of intangible assets	40	25	26
Communications and delivery	31	25	30
Advertising and public relations	18	34	25
Other expense	172	150	183
Total noninterest expense	1,718	1,233	1,221
Income before income taxes	933	586	714
Income tax expense	76	134	157
Net income	857	452	557
Net income attributable to noncontrolling interest	12	11	12
Net income attributable to controlling interest	845	441	545
Preferred stock dividends	23	6	6
Net income available to common shareholders	$ 822	$ 435	$ 539
Basic earnings per share (in dollars per share)	$ 1.90	$ 1.39	$ 1.66
Diluted earnings per share (in dollars per share)	$ 1.89	$ 1.38	$ 1.65
Weighted average common shares (in shares)	432,125	313,637	324,375
Diluted average common shares (in shares)	433,954	315,657	327,445