Investment Securities (Impairments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Pre-tax, Other-Than-Temporary Impairments on Investment Securities
Total pre tax, OTTI recognized	$ 5		$ 62		$ 52		$ 503
Less other-than-temporary impairment recognized in accumulated other comprehensive income	0		(6)		(4)		(36)
Net other-than-temporary impairment on investment securities recognized in earnings	5		56		48		467
Other Than Temporary Impairment Related To Equity Securities	0				3		14
Other Than Temporary Impairment Related To Equity Securities Insignificant Amount			13
Changes in Cumulative Credit Loss Impairments Recognized on Debt Securities
Cumulative credit loss impairments recognized, beginning of period	1,003		777		1,025		420
Credit loss impairments recognized on securities not previously impaired	2		0		3		385
Incremental credit loss impairments recognized on securities previously impaired	3		42		34		61
Less: credit loss impairments previously recognized on securities sold during the period	6		52		60		99
Cumulative credit loss impairments recognized, end of period	$ 1,002	[1],[2],[3]	$ 767	[1],[2],[3]	$ 1,002	[1],[2],[3]	$ 767	[1],[2],[3]

[1] Excluding net other-than-temporary impairment on investment securities.

[2]

[3] (a) Excluding net other-than-temporary impairment on investment securities.