Selected Quarterly Financial Information (Unaudited) (Out-of-period Adjustment) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended													12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Increase of provision (increase of benefit) for credit losses	$ (1,890)	[1]	$ 2,079	[1]	$ (3,041)	[1]	$ 2,000	[1]	$ 5,476		$ 4,151	$ 6,537	$ 10,554	$ (852)	$ 26,718	$ 24,896
Net income (loss)	7,570		1,813		5,119		2,718		(2,407)	[2]	(5,085)	(2,892)	(6,471)	17,220	(16,855)	(14,018)
Available-for-sale securities	748		789		1,035		727		(248)	[2]	1,160	1,152	1,213	3,299	3,277	5,290
Other-than-temporary impairments	(18)		(17)		(196)		(80)		(297)	[2]	(232)	(28)	(57)	(311)	(614)	(694)
Out-of-Period Adjustment [Member]
Increase of provision (increase of benefit) for credit losses	172		850		503		548							2,100
Net income (loss)									(933)
Available-for-sale securities									(1,200)						727
Other-than-temporary impairments									$ 264

[1] Includes out-of-period adjustments of $548 million, $503 million, $850 million, and $172 million which increased our provision for credit losses for the three months ended March 31, 2012, June 30, 2012, September 30, 2012, and December 31, 2012, respectively.

[2] Includes an out-of-period adjustment of $933 million comprised of $1.2 billion to reduce “Interest Income: Available-for-sale securities” offset by a $264 million reduction to “Other-than-temporary impairments” in our consolidated statement of operations and comprehensive loss for the three months ended December 31, 2011.