Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings (Loss) Per Share [Line Items]
Net income (loss) attributable to stockholders	$ 1,846	$ 2,992		$ 3,161	$ 6,358
Lower share price boundary for two class method				$ 33.00
US Pension Plans [Member]
Earnings (Loss) Per Share [Line Items]
Stock issued during period, shares, employee benefit					61
Series A Preferred Stock [Member]
Earnings (Loss) Per Share [Line Items]
Earned but Undistributed Dividends				26	26
Series B Preferred Stock [Member]
Earnings (Loss) Per Share [Line Items]
Earned but Undistributed Dividends				20	20
Earnings Per Share, Basic [Member]
Earnings (Loss) Per Share [Line Items]
Net income (loss) attributable to stockholders	1,846	2,992		3,161	6,358
Less: cumulative dividends on and undistributed earnings allocated to Series B Preferred Stock participating security	(359)	(468)		(670)	(971)
Net income (loss) attributable to common stockholders	1,487	2,524		2,491	5,387
Basic earnings per common share	$ 0.95	$ 1.68		$ 1.59	$ 3.58
Weighted-average common shares outstanding - basic	1,569	1,505		1,571	1,505
Earnings Per Share, Basic [Member] | Series B Preferred Stock [Member]
Earnings (Loss) Per Share [Line Items]
Dividends Allocated to Series B Preferred Stock	214	214		429	429
Earnings Allocated to Series B Preferred Stock	145	254		241	542
Earnings Per Share, Diluted [Member]
Earnings (Loss) Per Share [Line Items]
Net income (loss) attributable to stockholders	1,846	2,992		3,161	6,358
Less: cumulative dividends on and undistributed earnings allocated to Series B Preferred Stock participating security	(350)	(447)		(655)	(924)
Net income (loss) attibutable to common stockholders	1,496	2,545		2,506	5,434
Weighted-average common shares outstanding - basic	1,569	1,505		1,571	1,505
Dilutive effect of warrants	98	147	147	106	154
Divlutive effect of restricted stock units	4	2		4	2
Weighted-average common shares outstanding - diluted	1,671	1,654		1,681	1,661
Diluted earnings per common share	$ 0.90	$ 1.54		$ 1.49	$ 3.27
Preferred Stock Assumed Converted				152	152
Warrants Outstanding	313	317		313	317
Warrants Excluded from EPS				46	46
Unvested RSUs outstanding	17	14		17	14
Earnings Per Share, Diluted [Member] | MLC [Member]
Earnings (Loss) Per Share [Line Items]
Warrants Outstanding	272			272
Earnings Per Share, Diluted [Member] | Series B Preferred Stock [Member]
Earnings (Loss) Per Share [Line Items]
Dividends Allocated to Series B Preferred Stock	214	214		429	429
Earnings Allocated to Series B Preferred Stock	$ 136	$ 233		$ 226	$ 495