Parent Company Financial Statements (Parent Company Condensed Statements of Cash Flows) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows From Operating Activities:
Net income	$ 1,729	$ 2,028	$ 1,332
Net change in other assets	(273)	(800)	(240)
Net change in accounts payable and accrued liabilities	(812)	346	572
Other, net	(5)	(161)	(103)
Net cash from operating activities	5,339	3,714	4,276
Cash Flows From Investing Activities:
Purchases of AFS securities	(6,463)	(7,026)	(13,926)
Proceeds from maturities, calls and paydowns of HTM securities	2,863	5,536	1,828
Net cash from business combinations	(6)	675	(86)
Net cash from divestitures	522
Net cash from investing activities	(4,240)	(7,047)	(18,007)
Cash Flows From Financing Activities:
Net change in long-term debt	4,164	2,327	2,010
Net change in short-term borrowings	1,274	(702)	(2,107)
Net cash from preferred stock transactions	487	2,116
Other, net	248	55	154
Net cash from financing activities	(1,973)	2,796	15,220
Net Change in Cash and Cash Equivalents	(874)	(537)	1,489
Cash and Cash Equivalents at Beginning of Period	3,039	3,576	2,087
Cash and Cash Equivalents at End of Period	2,165	3,039	3,576
Parent Company [Member]
Cash Flows From Operating Activities:
Net income	1,729	2,028	1,332
Equity in undistributed earnings of subsidiaries in excess of dividends from subsidiaries	(616)	(418)	(661)
Net change in other assets	95	265	63
Net change in accounts payable and accrued liabilities	42	(71)	(3)
Other, net	(79)	(228)	20
Net cash from operating activities	1,171	1,576	751
Cash Flows From Investing Activities:
Proceeds from sales, calls and maturities of AFS securities	24	26	49
Purchases of AFS securities	(24)	(26)	(48)
Proceeds from maturities, calls and paydowns of HTM securities	2	4	24
Investment in subsidiaries	(4)	(30)	(12)
Advances to subsidiaries	(5,815)	(10,785)	(20,306)
Proceeds from repayment of advances to subsidiaries	5,898	11,325	22,637
Net cash from business combinations	0	51	0
Net cash from divestitures	9
Net cash from investing activities	90	565	2,344
Cash Flows From Financing Activities:
Net change in long-term debt	499	(2,764)	1,121
Net change in short-term borrowings	(13)	(259)	(509)
Net change in advances from subsidiaries	50	(72)	69
Net proceeds from common stock issued	108	15	22
Net cash from preferred stock transactions	487	2,116
Cash dividends paid on common and preferred stock	(912)	(564)	(446)
Other, net	8	62
Net cash from financing activities	227	(1,466)	257
Net Change in Cash and Cash Equivalents	1,488	675	3,352
Cash and Cash Equivalents at Beginning of Period	4,239	3,564	212
Cash and Cash Equivalents at End of Period	$ 5,727	$ 4,239	$ 3,564