Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Basic earnings per share
Income (Loss) from Operations before Extraordinary Items	$ 18,976	$ 17,370	$ 11,652
Extraordinary Item, Gain (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	0	76
Net income	18,976	17,370	11,728
Less: Preferred stock dividends	629	642	1,327
Preferred Stock Redemption Premium	0	0	1,112
Net income applicable to common equity	18,347	16,728	9,289
Less: Dividends and undistributed earnings allocated to participating securities	779	964	515
Net income applicable to common stockholders	17,568	15,764	8,774
Total weighted-average basic shares outstanding	3,900.4	3,956.3	3,862.8
Income (Loss) from Operations before Extraordinary Items, Per Basic Share	$ 4.50	$ 3.98	$ 2.25
Income (Loss) from Extraordinary Items, Net of Tax, Per Basic Share	$ 0.00	$ 0.00	$ 0.02
Net income per share	$ 4.50	$ 3.98	$ 2.27
Diluted earnings per share
Net income applicable to common stockholders	17,568	15,764	8,774
Total weighted-average basic shares outstanding	3,900.4	3,956.3	3,862.8
Add: Employee stock options, SARs and warrants	19.9	20.6	16.9
Total weighted-average diluted shares outstanding	3,920.3	3,976.9	3,879.7
Income (Loss) from Operations before Extraordinary Items, Per Diluted Share	$ 4.48	$ 3.96	$ 2.24
Income (Loss) from Extraordinary Items, Net of Tax, Per Diluted Share	$ 0.00	$ 0.00	$ 0.02
Net income per share	$ 4.48	$ 3.96	$ 2.26
Earnings per share (Numeric) [Abstract]
Antidilutive options and warrants excluded from the computation of diluted EPS	133	233	266
Preferred Stock Redemption Premium	$ 0	$ 0	$ 1,112
Preferred Stock Redemption Premium Per Share			$ 0.27