Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Basic EPS Calculation
Earnings available to common stockholders - Basic	$ 21,423		$ 26,179	[1]	$ 26,895	[1]
Weighted-average number of common shares outstanding	1,916		1,950		1,986
Add: Deferred awards held as stock units	1		0		0
Total weighted-average number of common shares outstanding	1,917		1,950		1,986
Earnings per share of common stock - Basic	$ 11.18		$ 13.42		$ 13.54
Diluted EPS Calculation
Earnings available to common stockholders - Diluted	$ 21,423	[1]	$ 26,179	[1]	$ 26,895	[1]
Weighted-average number of common shares outstanding	1,916		1,950		1,986
Add: Deferred awards held as stock units	1		0		0
Add: Dilutive effect of employee stock-based awards	15		15		15
Total weighted-average number of common shares outstanding	1,932		1,965		2,001
Earnings per share of common stock - Diluted	$ 11.09		$ 13.32		$ 13.44

[1] There was no effect of dividend equivalents paid on stock units or dilutive impact of employee stock-based awards on earnings.