Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
OPERATING ACTIVITIES
Net (loss) income	$ (65)	$ 339
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Provision for credit losses	411	(13)
Benefit for deferred income taxes	(73)	(4)
Depreciation and amortization	26	29
Net periodic defined benefit credit	(5)	(7)
Share-based compensation expense	8	24
Net amortization of securities	1	0
Net securities losses	1	8
Net change in accrued income receivable	8	(20)
Net change in accrued expenses payable	(12)	(27)
Other, net	399	(289)
Net cash provided by operating activities	699	40
INVESTING ACTIVITIES
Maturities and redemptions of investment securities available-for-sale	598	487
Sales of investment securities available-for-sale	0	987
Purchases of investment securities available-for-sale	(920)	(1,532)
Net change in loans	(3,174)	(151)
Net increase in premises and equipment	(15)	(16)
Purchases of Federal Home Loan Bank stock	(31)	(16)
Proceeds from bank-owned life insurance settlements	8	2
Net cash used in investing activities	(3,534)	(239)
FINANCING ACTIVITIES
Net change in deposits	(29)	(1,586)
Net change in short-term borrowings	2,192	891
Issuances and advances of medium- and long-term debt	0	350
Repurchases of common stock	(199)	(443)
Cash dividends paid on common stock	(95)	(99)
Issuances of common stock under employee stock plans	3	6
Net cash provided by (used in) financing activities	1,872	(881)
Net decrease in cash and cash equivalents	(963)	(1,080)
Cash and cash equivalents at beginning of period	5,818	4,561
Cash and cash equivalents at end of period	4,855	3,481
Interest paid	102	98
Income tax paid	$ 3	$ 12