Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share, Basic, Two Class Method [Abstract]
Net income	$ 24,442	$ 21,745	$ 17,886
Less: Preferred stock dividends	1,515	1,125	805
Net income applicable to common equity	22,927	20,620	17,081
Less: Dividends and undistributed earnings allocated to participating securities	521	543	524
Net income applicable to common stockholders	$ 22,406	$ 20,077	$ 16,557
Weighted-average basic shares (in shares)	3,700.4	3,763.5	3,782.4
Basic earnings per share (in dollars per share)	$ 6.05	$ 5.33	$ 4.38
Earnings Per Share, Diluted, Two Class Method [Abstract]
Net income applicable to common stockholders	$ 22,406	$ 20,077	$ 16,557
Weighted-average basic shares (in shares)	3,700.4	3,763.5	3,782.4
Add: Employee stock options, SARs and warrants (in shares)	32.4	34.0	32.5
Total weighted-average diluted shares (in shares)	3,732.8	3,797.5	3,814.9
Diluted earnings per share (in dollars per share)	$ 6.00	$ 5.29	$ 4.34
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)		1.0	6.0