Supplemental Equity and Comprehensive Income Information - SE Rf (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Increase (decrease) in equity
Balance at the beginning of the period	$ 11,040	$ 11,495	$ 10,343	$ 11,468
Net income	1,585	1,293	2,911	2,571
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(67)	37	225	175
Defined benefit pension and postretirement plans adjustment	78	67	161	136
Cash flow hedging instruments - unrealized gain (loss)	(51)	(27)	(127)	(137)
Total other comprehensive income (loss), net of tax	(40)	77	259	174
Dividends declared	(701)	(672)	(1,403)	(1,344)
Stock-based compensation	55	47	183	172
Reacquired stock	(475)	(837)	(1,153)	(2,000)
Issuances pursuant to stock option and benefit plans	180	255	504	617
Balance at the end of the period	11,644	11,658	11,644	11,658
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	5,198	4,925	5,070	4,800
Other comprehensive income (loss), net of tax:
Stock-based compensation	55	47	183	172
Balance at the end of the period	5,253	4,972	5,253	4,972
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	38,094	36,506	37,907	36,296
Net income	1,583	1,291	2,906	2,566
Other comprehensive income (loss), net of tax:
Dividends declared	(701)	(672)	(1,403)	(1,344)
Issuances pursuant to stock option and benefit plans	(183)	(210)	(617)	(603)
Balance at the end of the period	38,793	36,915	38,793	36,915
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(25,354)	(23,716)	(25,434)	(23,308)
Other comprehensive income (loss), net of tax:
Reacquired stock	(475)	(837)	(1,153)	(2,000)
Issuances pursuant to stock option and benefit plans	363	465	1,121	1,220
Balance at the end of the period	(25,466)	(24,088)	(25,466)	(24,088)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(6,949)	(6,261)	(7,245)	(6,359)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(67)	37	222	176
Defined benefit pension and postretirement plans adjustment	78	67	161	136
Cash flow hedging instruments - unrealized gain (loss)	(51)	(27)	(127)	(137)
Balance at the end of the period	(6,989)	(6,184)	(6,989)	(6,184)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	51	41	45	39
Net income	2	2	5	5
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment			3	(1)
Balance at the end of the period	$ 53	$ 43	$ 53	$ 43