Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
OPERATING ACTIVITIES
Net income	$ 139	$ 134
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	9	16
Provision (benefit) for deferred income taxes	(5)	29
Depreciation and amortization	29	30
Net periodic defined benefit cost	9	21
Share-based compensation expense	14	10
Net amortization of securities	2	10
Accretion of loan purchase discount	(12)	(11)
Net securities gains	(1)	0
Net gain on foreclosed property sold	(1)	(1)
Excess tax benefits from share-based compensation arrangements	(5)	(1)
Net change in trading securities	5	10
Net change in accrued income receivable	0	(10)
Net change in accrued expenses payable	(61)	(72)
Other, net	92	94
Net cash provided by operating activities	214	259
INVESTING ACTIVITIES
Maturities and redemptions of investment securities available-for-sale	411	938
Purchases of investment securities available-for-sale	(499)	(955)
Net change in loans	(1,026)	971
Proceeds from sales of foreclosed property	3	18
Net increase in premises and equipment	(16)	(19)
Other, net	(1)	5
Net cash (used in) provided by investing activities	(1,128)	958
FINANCING ACTIVITIES
Net change in deposits	255	0
Net change in short-term borrowings	(93)	(52)
Repurchases of common stock	(80)	(74)
Cash dividends paid on common stock	(31)	(29)
Issuances of common stock under employee stock plans	26	5
Excess tax benefits from share-based compensation arrangements	5	1
Other, net	1	(5)
Net cash provided by (used in) financing activities	83	(154)
Net (decrease) increase in cash and cash equivalents	(831)	1,063
Cash and cash equivalents at beginning of period	6,451	4,534
Cash and cash equivalents at end of period	5,620	5,597
Interest paid	25	29
Income taxes and tax-related interest paid	0	1
Noncash investing and financing activities:
Loans transferred to other real estate	$ 7	$ 5