Investment Securities (Investment Securities Available-for-Sale) (Details) (USD $) In Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010
Amortized Cost	$ 7,415		$ 7,538
Gross Unrealized Gains	171		98
Gross Unrealized Losses	49		76
Total investment securities available-for-sale, Fair Value	7,537		7,560		7,188
U.S. Treasury and Other U.S. Government Agency Securities [Member]
Amortized Cost	20		131
Total investment securities available-for-sale, Fair Value	20		131
Residential Mortgage-Backed Securities [Member]
Amortized Cost	6,741	[1]	6,653	[1]
Gross Unrealized Gains	169	[1]	95	[1]
Gross Unrealized Losses	11	[1]	39	[1]
Total investment securities available-for-sale, Fair Value	6,899	[2]	6,709	[2]
State And Municipal Securities [Member]
Amortized Cost	32	[3]	46	[3]
Gross Unrealized Losses	6	[3]	7	[3]
Total investment securities available-for-sale, Fair Value	26		39
Auction-Rate Debt Securities [Member]
Amortized Cost	1		1
Total investment securities available-for-sale, Fair Value	1		1
Other Corporate Debt Securities [Member]
Amortized Cost	49		26
Total investment securities available-for-sale, Fair Value	49		26
Auction-Rate Preferred Securities [Member]
Amortized Cost	467		597
Gross Unrealized Gains	2		3
Gross Unrealized Losses	32		30
Total investment securities available-for-sale, Fair Value	437		570
Money Market and Other Mutual Funds [Member]
Amortized Cost	105		84
Total investment securities available-for-sale, Fair Value	$ 105		$ 84

[1] Residential mortgage-backed securities issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.

[2] Residential mortgage-backed securities issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.

[3] Primarily auction-rate securities.