Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income (loss)	$ 1,717	$ 1,866	$ 1,298
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for credit losses	445	246	229
Depreciation and amortization expense, net	241	382	407
Accretion of acquired loans	50	86	203
Increase in cash surrender value of corporate-owned life insurance	(121)	(117)	(119)
Stock-based compensation expense	96	99	100
FDIC reimbursement (payments), net of FDIC expense	0	(10)	(3)
Deferred income taxes (benefit)	53	98	303
Proceeds from sales of loans held for sale	11,980	14,019	11,963
Originations of loans held for sale, net of repayments	(11,704)	(13,948)	(11,846)
Net losses (gains) from sale of loans held for sale	(188)	(183)	(181)
Net losses (gains) and writedown on OREO	7	0	5
Net losses (gains) on leased equipment	(17)	41	3
Net losses (gains) on sales of fixed assets	(2)	9	24
Net securities losses (gains)	(20)	0	(1)
Net decrease (increase) in trading account assets	(191)	(13)	31
Gain on sale of KIBS	0	(83)	0
Other operating activities, net	560	14	(601)
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	2,906	2,506	1,815
INVESTING ACTIVITIES
Cash received (used) in acquisitions, net of cash acquired	(185)	0	(144)
Proceeds from sale of KIBS	0	124	0
Net decrease (increase) in short-term investments, excluding acquisitions	1,290	1,885	(1,672)
Purchases of securities available for sale	(5,714)	(4,594)	(3,002)
Proceeds from sales of securities available for sale	362	0	915
Proceeds from prepayments and maturities of securities available for sale	3,586	3,197	3,999
Proceeds from prepayments and maturities of held-to-maturity securities	1,477	1,558	1,797
Purchases of held-to-maturity securities	(22)	(1,242)	(3,398)
Purchases of other investments	(52)	(28)	(87)
Proceeds from sales of other investments	60	62	117
Proceeds from prepayments and maturities of other investments	56	40	4
Net decrease (increase) in loans, excluding acquisitions, sales, and transfers	(6,190)	(3,700)	(945)
Proceeds from sales of portfolio loans	399	204	183
Proceeds from corporate-owned life insurance	59	78	55
Purchases of premises, equipment, and software	(85)	(99)	(112)
Proceeds from sales of premises and equipment	18	2	0
Proceeds from sales of OREO	23	31	51
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(4,918)	(2,482)	(2,239)
FINANCING ACTIVITIES
Net increase (decrease) in deposits, excluding acquisitions	4,561	2,074	1,148
Net increase (decrease) in short-term borrowings	229
Net increase (decrease) in short-term borrowings		(148)	(1,299)
Net proceeds from issuance of long-term debt	2,129	2,306	2,852
Payments on long-term debt	(3,634)	(2,880)	(748)
Issuance of preferred shares	435	412	0
Repurchase of Common Shares	(835)	(1,098)	(664)
Employee equity compensation program Common Share repurchases	(33)	(47)	(66)
Redemption of Preferred Stock Series C	0	0	(350)
Net proceeds from reissuance of Common Shares	18	20	25
Cash dividends paid	(804)	(656)	(480)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	2,066	(17)	418
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	54	7	(6)
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	678	671	677
CASH AND DUE FROM BANKS AT END OF YEAR	732	678	671
Additional disclosures relative to cash flows:
Interest paid	1,251	892	598
Income taxes paid (refunded)	18	12	6
Noncash items:
Reduction of secured borrowing and related collateral	5	20	40
Loans transferred to portfolio from held for sale	157	24	105
Loans transferred to held for sale from portfolio	468	(33)	42
Loans transferred to other real estate owned	29	25	37
CMBS risk retentions	59	16	18
ABS risk retentions	$ 12	$ 0	$ 0