Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES
Net income	$ 339	$ 281
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(13)	12
(Benefit) provision for deferred income taxes	(4)	7
Depreciation and amortization	29	31
Net periodic defined benefit credit	(7)	(5)
Share-based compensation expense	24	24
Net amortization of securities	0	1
Net securities (losses) gains	8	(1)
Net change in accrued income receivable	(20)	(26)
Net change in accrued expenses payable	(27)	(22)
Other, net	(289)	56
Net cash provided by operating activities	40	358
INVESTING ACTIVITIES
Maturities and redemptions of investment securities available-for-sale	487	444
Sales of investment securities available-for-sale	987	5
Purchases of investment securities available-for-sale	(1,532)	(441)
Net change in loans	(151)	(98)
Proceeds from sales of foreclosed property	0	1
Net increase in premises and equipment	(16)	(20)
Purchases of Federal Home Loan Bank stock	(16)	(41)
Proceeds from bank-owned life insurance settlements	2	3
Net cash used in investing activities	(239)	(147)
FINANCING ACTIVITIES
Net change in deposits	(1,586)	(77)
Net change in short-term borrowings	891	38
Issuances and advances of medium- and long-term debt	350	1,000
Repurchases of common stock	(443)	(168)
Cash dividends paid on common stock	(99)	(53)
Issuances of common stock under employee stock plans	6	40
Net cash (used in) provided by financing activities	(881)	780
Net (decrease) increase in cash and cash equivalents	(1,080)	991
Cash and cash equivalents at beginning of period	4,561	5,845
Cash and cash equivalents at end of period	3,481	6,836
Interest paid	98	40
Income tax paid	12	2
Noncash investing and financing activities:
Loans transferred to other real estate	0	1
Securities transferred from held-to-maturity to available-for-sale	0	1,266
Securities transferred from available-for-sale to equity securities	$ 0	$ 81