Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities:
Net Income	$ 2,415	$ 2,442	$ 2,123
Adjustments to reconcile net income to net cash from operating activities:
Provision for credit losses	547	572	428
Depreciation	408	405	356
Loss (gain) on early extinguishment of debt	392	(1)	172
Amortization of intangibles	142	150	105
Equity-based compensation expense	132	115	106
(Gain) loss on securities, net	1	(46)	3
Net change in operating assets and liabilities:
LHFS	618	(644)	422
Trading securities	115	432	(698)
Other assets, accounts payable and other liabilities	(15)	(18)	(14)
Cash paid to terminate FDIC loss share agreements	0	(230)	0
Other, net	(120)	(62)	128
Net cash from operating activities	4,635	3,115	3,131
Cash Flows From Investing Activities:
Proceeds from sales of AFS securities	4,934	4,612	6,302
Proceeds from maturities, calls and paydowns of AFS securities	4,800	5,888	5,064
Purchases of AFS securities	(7,397)	(10,033)	(12,698)
Proceeds from maturities, calls and paydowns of HTM securities	2,580	7,022	3,791
Purchases of HTM securities	(8,965)	(5,124)	(2,557)
Originations and purchases of loans and leases, net of principal collected	(1,230)	(2,986)	(3,196)
Net cash received (paid) for acquisitions and divestitures	0	(785)	1,055
Other, net	(31)	398	390
Net cash from investing activities	(5,309)	(1,008)	(1,849)
Cash Flows From Financing Activities:
Net change in deposits	(2,842)	4,507	2,506
Net change in short-term borrowings	3,532	(3,581)	(982)
Proceeds from issuance of long-term debt	8,883	3,878	2,272
Repayment of long-term debt	(7,453)	(5,849)	(2,433)
Repurchase of common stock	(1,613)	(520)	0
Net cash from common stock transactions in connection with equity awards	108	218	68
Net proceeds from preferred stock issued	0	450	0
Cash dividends paid on common stock	(1,005)	(925)	(789)
Cash dividends paid on preferred stock	(174)	(167)	(148)
Other, net	15	107	(390)
Net cash from financing activities	(549)	(1,882)	104
Net Change in Cash and Cash Equivalents	(1,223)	225	1,386
Cash and Cash Equivalents at Beginning of Period	3,936	3,711	2,325
Cash and Cash Equivalents at End of Period	2,713	3,936	3,711
Cash paid during the period for:
Interest	819	775	734
Income taxes	429	844	655
Noncash investing and financing activities:
Transfers of loans to foreclosed assets	260	258	320
Transfers of loans HFI to LHFS	1,050	263	153
Stock issued in acquisitions	0	1,063	2,188
Purchase of additional interest in AmRisc, LP	0	0	216
Transfer of HTM securities to AFS	$ 0	$ 0	$ 517