Parent Company Financial Statements (Parent Company Statement Of Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Total revenue	$ 9,649	$ 9,594	$ 8,953
Other Expense	591	459	374
Total expenses	6,886	7,058	6,842
Income tax benefit	705	616	530
Net income	2,061	1,920	1,556
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash dividends from consolidated banking subsidiary	1,785	0	1,400
Cash dividends from consolidated non-banking subsidiaries and unconsolidated entities	68	60	100
Other, net	38	34	9
Total revenue	1,891	94	1,509
Interest expense	163	203	162
Other Expense	85	60	421
Total expenses	248	263	583
Income tax benefit	(63)	(125)	(93)
Income (Loss) before equity in undistributed income of consolidated subsidiaries and unconsolidated entities	1,706	(44)	1,019
Consolidated banking subsidiary	173	1,773	484
Consolidated non-banking subsidiaries and unconsolidated entities	182	191	53
Net income	$ 2,061	$ 1,920	$ 1,556