Statements of Income/(Loss) - Parent Company Only (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income
Trading account gains/(losses) and commissions	$ 211		$ 248		$ 173
Expenses
Interest on long-term debt	299		449		580
Income/(loss) before income taxes and equity in undistributed income/(loss) of subsidiaries	2,757		739		21
Income Tax Expense (Benefit)	773		79		(185)
Net income	1,958		647		189
Series A preferred dividends	(12)		(7)		(7)
U.S. Treasury preferred dividends and accretion of discount	0		(66)		(267)
Undistributed Earnings Allocated to Participating Securities	(15)		(5)		(2)
Net income/(loss) available to common shareholders	1,931		495		(87)
Parent Company [Member]
Income
Dividends	27	[1]	29	[1]	28	[1]
Interest on loans	36		11		2
Trading account gains/(losses) and commissions	18		53		44
Other income	23		132		165
Total interest income	104		225		239
Expenses
Interest on short-term borrowings	13		9		9
Interest on long-term debt	177		226		228
Employee compensation and benefits	111	[2]	(7)	[2]	(13)	[2]
Service fees to subsidiaries	3		11		2
Other Expenses	43		133		21
Total expense	347		372		247
Income/(loss) before income taxes and equity in undistributed income/(loss) of subsidiaries	(243)		(147)		(8)
Income Tax Expense (Benefit)	(91)		(49)		(12)
Income/(loss) before equity in undistributed income/(loss) of subsidiaries	(152)		(98)		4
Equity in undistributed income/(loss) of subsidiaries	2,110		745		185
Net income	1,958		647		189
Net income/(loss) available to common shareholders	1,931		495		(87)
Series C and Series D Preferred Stock [Member]
Expenses
Stock Redeemed or Called During Period, Value			(4,850)
Retained Earnings [Member]
Expenses
Net income	1,958		647		189
Series A preferred dividends	(12)		(7)		(7)
Retained Earnings [Member] | Series C and Series D Preferred Stock [Member]
Expenses
Stock Redeemed or Called During Period, Value	$ 0		$ (74)		$ 0

[1] Substantially all dividend income received from subsidiaries.

[2] Includes incentive compensation allocations between Parent Company and subsidiaries.