Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Increase (decrease) in equity
Balance at the beginning of the period	$ 18,319	$ 16,873	$ 18,040	$ 15,862
Net income	1,245	1,180	3,605	3,507
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	284	412	(393)	211
Defined benefit pension and postretirement plans adjustment	92	96	268	291
Debt and equity securities - unrealized gain (loss)	2	3	(2)	4
Cash flow hedging instruments - unrealized gain (loss)	(24)	(36)	8	(28)
Total other comprehensive income (loss), net of tax	354	475	(119)	478
Dividends paid	(431)	(408)	(1,307)	(1,228)
Stock-based compensation, net of tax impacts	66	44	258	231
Reacquired stock	(1,570)	(316)	(3,609)	(1,483)
Issuances pursuant to stock option and benefit plans	269	293	1,376	774
Sale of subsidiary shares			8
Balance at the end of the period	18,252	18,141	18,252	18,141
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,252	3,963	4,053	3,776
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts	66	44	258	231
Sale of subsidiary shares			7
Balance at the end of the period	4,318	4,007	4,318	4,007
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	31,716	29,465	30,679	28,348
Net income	1,230	1,161	3,556	3,453
Other comprehensive income (loss), net of tax:
Dividends paid	(431)	(408)	(1,307)	(1,228)
Issuances pursuant to stock option and benefit plans	(103)	(68)	(516)	(423)
Balance at the end of the period	32,412	30,150	32,412	30,150
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(12,926)	(12,010)	(12,407)	(11,679)
Other comprehensive income (loss), net of tax:
Reacquired stock	(1,570)	(316)	(3,609)	(1,483)
Issuances pursuant to stock option and benefit plans	372	361	1,892	1,197
Balance at the end of the period	(14,124)	(11,965)	(14,124)	(11,965)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(5,166)	(5,012)	(4,750)	(5,025)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	286	401	(334)	210
Defined benefit pension and postretirement plans adjustment	92	96	268	291
Debt and equity securities - unrealized gain (loss)	2	3	(2)	4
Cash flow hedging instruments - unrealized gain (loss)	(24)	(36)	8	(28)
Balance at the end of the period	(4,810)	(4,548)	(4,810)	(4,548)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	443	467	465	442
Net income	15	19	49	54
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(2)	11	(59)	1
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
Sale of subsidiary shares			1
Balance at the end of the period	$ 456	$ 497	$ 456	$ 497