Supplemental Equity and Comprehensive Income Information - SE Rf (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (decrease) in equity
Balance at the beginning of the period	$ 11,747	$ 13,142
Net income	1,278	1,201
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	138	(193)
Defined benefit pension and postretirement plans adjustment	69	91
Cash flow hedging instruments - unrealized gain (loss)	(110)	70
Total other comprehensive income (loss), net of tax	97	(32)
Dividends declared	(672)	(3)
Stock-based compensation, net of tax impacts in 2015	125	228
Reacquired stock	(1,163)	(896)
Issuances pursuant to stock option and benefit plans	362	312
Balance at the end of the period	11,774	13,952
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,800	4,388
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts in 2015	125	228
Balance at the end of the period	4,925	4,616
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	36,575	34,317
Net income	1,275	1,199
Other comprehensive income (loss), net of tax:
Dividends declared	(672)	(3)
Issuances pursuant to stock option and benefit plans	(393)	(433)
Balance at the end of the period	36,785	35,080
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(23,308)	(19,307)
Other comprehensive income (loss), net of tax:
Reacquired stock	(1,163)	(896)
Issuances pursuant to stock option and benefit plans	755	745
Balance at the end of the period	(23,716)	(19,458)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(6,359)	(6,289)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	139	(193)
Defined benefit pension and postretirement plans adjustment	69	91
Cash flow hedging instruments - unrealized gain (loss)	(110)	70
Balance at the end of the period	(6,261)	(6,321)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	39	33
Net income	3	2
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(1)
Balance at the end of the period	$ 41	$ 35