Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES
Net income	$ 444	$ 424
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	25	37
Provision (benefit) for deferred income taxes	7	(6)
Depreciation and amortization	92	92
Net periodic defined benefit cost	29	65
Share-based compensation expense	31	27
Net amortization of securities	9	21
Accretion of loan purchase discount	(25)	(26)
Net securities losses	0	1
Net gains on sales of foreclosed property	(3)	(4)
Gain on debt redemption	(32)	(1)
Excess tax benefits from share-based compensation arrangements	(6)	(3)
Net change in trading securities	1	15
Net change in accrued income receivable	(2)	9
Net change in accrued expenses payable	(44)	(13)
Other, net	39	(228)
Net cash provided by operating activities	565	410
INVESTING ACTIVITIES
Maturities and redemptions of investment securities available-for-sale	1,328	2,418
Purchases of investment securities available-for-sale	(1,413)	(1,899)
Net change in loans	(2,254)	1,864
Proceeds from sales of foreclosed property	13	40
Net increase in premises and equipment	(38)	(70)
Sales of Federal Home Loan Bank stock	41	41
Other, net	(4)	10
Net cash (used in) provided by investing activities	(2,327)	2,404
FINANCING ACTIVITIES
Net change in deposits	4,205	999
Net change in short-term borrowings	(51)	116
Maturities and redemptions of medium- and long-term debt	(1,406)	(1,080)
Issuances of medium- and long-term debt	596	0
Repurchases of common stock	(200)	(218)
Cash dividends paid on common stock	(101)	(92)
Issuances of common stock under employee stock plans	45	22
Excess tax benefits from share-based compensation arrangements	6	3
Other, net	4	(10)
Net cash used in financing activities	3,098	(260)
Net increase in cash and cash equivalents	1,336	2,554
Cash and cash equivalents at beginning of period	6,451	4,534
Cash and cash equivalents at end of period	7,787	7,088
Interest paid	74	88
Income taxes and tax-related interest paid	154	104
Noncash investing and financing activities:
Loans transferred to other real estate	$ 13	$ 10