Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Increase (decrease) in equity
Balance at the beginning of the period	$ 16,873	$ 17,742	$ 15,862	$ 16,017
Net income	1,180	1,103	3,507	3,383
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	412	(490)	211	(14)
Defined benefit pension and postretirement plans adjustment	96	77	291	207
Debt and equity securities - unrealized gain (loss)	3	(2)	4	(5)
Cash flow hedging instruments - unrealized gain (loss)	(36)	54	(28)	37
Total other comprehensive income (loss), net of tax	475	(361)	478	225
Dividends paid	(408)	(388)	(1,228)	(1,171)
Stock-based compensation, net of tax impacts	44	42	231	258
Reacquired stock	(316)	(837)	(1,483)	(2,181)
Issuances pursuant to stock option and benefit plans	293	111	774	867
Business combination allocation to noncontrolling interest				56
Purchase and sale of subsidiary shares - net				(42)
Balance at the end of the period	18,141	17,412	18,141	17,412
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	3,963	3,692	3,776	3,477
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts	44	42	231	258
Purchase and sale of subsidiary shares - net				(1)
Balance at the end of the period	4,007	3,734	4,007	3,734
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	29,465	27,110	28,348	25,995
Net income	1,161	1,088	3,453	3,329
Other comprehensive income (loss), net of tax:
Dividends paid	(408)	(388)	(1,228)	(1,171)
Issuances pursuant to stock option and benefit plans	(68)	(26)	(423)	(369)
Balance at the end of the period	30,150	27,784	30,150	27,784
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(12,010)	(10,511)	(11,679)	(10,266)
Other comprehensive income (loss), net of tax:
Reacquired stock	(316)	(837)	(1,483)	(2,181)
Issuances pursuant to stock option and benefit plans	361	137	1,197	1,236
Balance at the end of the period	(11,965)	(11,211)	(11,965)	(11,211)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(5,012)	(2,961)	(5,025)	(3,543)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	401	(507)	210	(34)
Defined benefit pension and postretirement plans adjustment	96	77	291	206
Debt and equity securities - unrealized gain (loss)	3	(2)	4	(5)
Cash flow hedging instruments - unrealized gain (loss)	(36)	54	(28)	37
Balance at the end of the period	(4,548)	(3,339)	(4,548)	(3,339)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	467	412	442	354
Net income	19	15	54	54
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	11	17	1	20
Defined benefit pension and postretirement plans adjustment	0	0	0	1
Debt and equity securities - unrealized gain (loss)	0	0	0	0
Cash flow hedging instruments - unrealized gain (loss)	0	0	0	0
Business combination allocation to noncontrolling interest				56
Purchase and sale of subsidiary shares - net				(41)
Balance at the end of the period	$ 497	$ 444	$ 497	$ 444