Balance Sheets - Parent Company Only (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Assets [Abstract]
Cash and Due from Banks	$ 7,134		$ 3,696
Interest-bearing Deposits in Banks and Other Financial Institutions	22		21
Cash and cash equivalents	8,257		4,509		5,378	6,997
Trading assets	6,049		6,279
Available-for-sale Securities	21,953		28,117
Goodwill	6,369		6,344		6,323
Other assets	5,335		6,159
Total assets	173,442		176,859
Liabilities and Shareholders' Equity
Long-term debt	9,357	[1]	10,908	[1]
Other liabilities	4,129		4,691
Total liabilities	152,457		156,793
Preferred Stock, Value, Outstanding	725		275
Common stock	550		550
Additional paid in capital	9,174		9,306
Retained earnings	10,817		8,978
Treasury stock, at cost, and other	(590)	[2]	(792)	[2]
Accumulated other comprehensive income	309		1,749		1,616	1,070
Total liabilities and shareholders' equity	173,442		176,859
Parent Company [Member]
Assets [Abstract]
Cash and Due from Banks	137		220
Interest-bearing Deposits in Banks and Other Financial Institutions	20		19
Cash and cash equivalents	761		1,641		2,877	2,795
Trading assets	103		93
Available-for-sale Securities	279		324
Loans to subsidiaries	2,733		3,666
Goodwill	99		99
Other assets	561		397
Total assets	28,425		29,281
Liabilities and Shareholders' Equity
Long-term debt	3,249		6,294
Other liabilities	1,108		766
Total liabilities	7,554		9,322
Preferred Stock, Value, Outstanding	725		275
Common stock	550		550
Additional paid in capital	9,174		9,306
Retained earnings	10,817		8,978
Treasury stock, at cost, and other	(704)	[3]	(899)	[3]
Accumulated other comprehensive income	309		1,749
Total shareholders' equity	20,871		19,959
Total liabilities and shareholders' equity	28,425		29,281
Parent Company [Member] | Bank Subsidiaries [Member]
Assets [Abstract]
Interest-bearing Deposits in Banks and Other Financial Institutions	604		1,402
Investments in capital stock of subsidiaries stated on the basis of the Company's equity in subsidiaries' capital accounts	22,521		21,783
Parent Company [Member] | Nonbank Subsidiaries [Member]
Assets [Abstract]
Investments in capital stock of subsidiaries stated on the basis of the Company's equity in subsidiaries' capital accounts	1,368		1,278
Parent Company [Member] | Subsidiaries [Member]
Liabilities and Shareholders' Equity
Short-term borrowings from	1,525		392
Long-term debt	160		160
Parent Company [Member] | Other Entity [Member]
Liabilities and Shareholders' Equity
Short-term borrowings from	1,512		1,710
Long-term debt	3,249		6,294
Treasury Stock and Other
Liabilities and Shareholders' Equity
Treasury stock, at cost, and other	(656)		(851)		(974)
Deferred Compensation Equity	48		48		43
Treasury Stock and Other | Parent Company [Member]
Liabilities and Shareholders' Equity
Treasury stock, at cost, and other	(656)		(851)
Deferred Compensation Equity	$ 48		$ 48

[1] 3 Includes debt of consolidated VIEs ($286 and $289 at fair value as of December 31, 2012 and December 31, 2011, respectively)666 722

[2] 4 Includes noncontrolling interest held114 107

[3] 1 At December 31, 2012, includes ($656) million for treasury stock and ($48) million for compensation element of restricted stock. At December 31, 2011, includes ($851) million for treasury stock and ($48) million for compensation element of restricted stock.