Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Increase (decrease) in equity
Balance at the beginning of the period	$ 17,846	$ 18,319	$ 17,948	$ 18,040
Net income	1,311	1,245	3,819	3,605
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(603)	284	(456)	(393)
Defined benefit pension and postretirement plans adjustment	59	92	180	268
Debt and equity securities - unrealized gain (loss)	(1)	2	1	(2)
Cash flow hedging instruments - unrealized gain (loss)	68	(24)	61	8
Total other comprehensive income (loss), net of tax	(477)	354	(214)	(119)
Dividends declared	(550)	(431)	(1,105)	(1,307)
Purchase of subsidiary shares	(865)		(870)
Sale of subsidiary shares				8
Stock-based compensation, net of tax impacts	69	66	336	258
Reacquired stock	(1,283)	(1,570)	(4,438)	(3,609)
Issuances pursuant to stock option and benefit plans	155	269	730	1,376
Balance at the end of the period	16,206	18,252	16,206	18,252
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,650	4,252	4,384	4,053
Other comprehensive income (loss), net of tax:
Purchase of subsidiary shares	(433)		(434)
Sale of subsidiary shares				7
Stock-based compensation, net of tax impacts	69	66	336	258
Balance at the end of the period	4,286	4,318	4,286	4,318
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	33,836	31,716	32,416	30,679
Net income	1,303	1,230	3,777	3,556
Other comprehensive income (loss), net of tax:
Dividends declared	(550)	(431)	(1,105)	(1,307)
Issuances pursuant to stock option and benefit plans	(105)	(103)	(604)	(516)
Balance at the end of the period	34,484	32,412	34,484	32,412
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(17,466)	(12,926)	(15,385)	(12,407)
Other comprehensive income (loss), net of tax:
Reacquired stock	(1,283)	(1,570)	(4,438)	(3,609)
Issuances pursuant to stock option and benefit plans	260	372	1,334	1,892
Balance at the end of the period	(18,489)	(14,124)	(18,489)	(14,124)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(3,666)	(5,166)	(3,913)	(4,750)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(593)	286	(462)	(334)
Defined benefit pension and postretirement plans adjustment	59	92	180	268
Debt and equity securities - unrealized gain (loss)	(1)	2	1	(2)
Cash flow hedging instruments - unrealized gain (loss)	68	(24)	61	8
Purchase of subsidiary shares	25		25
Balance at the end of the period	(4,108)	(4,810)	(4,108)	(4,810)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	492	443	446	465
Net income	8	15	42	49
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(10)	(2)	6	(59)
Defined benefit pension and postretirement plans adjustment	0	0	0	0
Debt and equity securities - unrealized gain (loss)	0	0	0	0
Cash flow hedging instruments - unrealized gain (loss)	0	0	0	0
Purchase of subsidiary shares	(457)		(461)
Sale of subsidiary shares				1
Balance at the end of the period	$ 33	$ 456	$ 33	$ 456