Parent Company Financial Statements (Parent Company Statement Of Cash Flows) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (1,974)	$ 1,927	$ 3,374
Net decrease (increase) in interest-bearing deposits with consolidated banking subsidiary	(13,494)	8,123	(36,652)
Proceeds from sales and maturities of available-for-sale securities	37,529	44,375	44,810
Business acquisitions	0	(511)	(214)
Net cash used in investing activities	(14,085)	(4,591)	(53,895)
Net decrease in short-term borrowings	(1,155)	(1,587)	(8,555)
Proceeds from issuance of long-term debt, net of issuance costs	2,485	998	1,986
Payments for long-term debt	(134)	(1,781)	(2,486)
Proceeds from issuance of preferred stock, net of issuance costs	0	488	500
Proceeds from exercises of common stock options	121	53	49
Purchases of common stock	(2,040)	(1,440)	(675)
Repurchases of common stock for employee tax withholding	(189)	(101)	(63)
Payments for cash dividends	(486)	(463)	(295)
Net cash provided by financing activities	16,689	3,061	49,403
Net increase (decrease)	630	397	(1,118)
Cash and due from banks at beginning of period	2,590	2,193	3,311
Cash and due from banks at end of period	3,220	2,590	2,193
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	2,296	2,706	(571)
Net decrease (increase) in interest-bearing deposits with consolidated banking subsidiary	(620)	1,115	144
Investments in consolidated banking and non-banking subsidiaries	(1,100)	(68)	(648)
Sale or repayment of investment in consolidated banking and non-banking subsidiaries	32	28	39
Business acquisitions	0	(2)	(51)
Net cash used in investing activities	(1,688)	1,073	(516)
Net decrease in short-term borrowings	0	(500)	0
Net decrease in commercial paper	(499)	(66)	(415)
Proceeds from issuance of long-term debt, net of issuance costs	2,485	0	1,986
Payments for long-term debt	0	(1,750)	0
Proceeds from issuance of preferred stock, net of issuance costs	0	488	500
Proceeds from exercises of common stock options	121	53	49
Purchases of common stock	(2,040)	(1,440)	(675)
Repurchases of common stock for employee tax withholding	(189)	(101)	(63)
Payments for cash dividends	(486)	(463)	(295)
Net cash provided by financing activities	(608)	(3,779)	1,087
Net increase (decrease)	0	0	0
Cash and due from banks at beginning of period	0	0	0
Cash and due from banks at end of period	$ 0	$ 0	$ 0