Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Increase (decrease) in equity
Balance at the beginning of the period	$ 18,040	$ 15,862
Net income	1,147	1,141
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(398)	134
Defined benefit pension and postretirement plans adjustment	85	97
Debt and equity securities - unrealized gain (loss)	0	3
Cash flow hedging instruments - unrealized gain (loss)	24	(15)
Total other comprehensive income (loss), net of tax	(289)	219
Dividends paid	(440)	(410)
Stock-based compensation, net of tax impacts	128	127
Reacquired stock	(807)	(534)
Issuances pursuant to stock option and benefit plans	741	214
Sale of subsidiary shares	8
Balance at the end of the period	18,528	16,619
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,053	3,776
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts	128	127
Sale of subsidiary shares	7
Balance at the end of the period	4,188	3,903
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	30,679	28,348
Net income	1,129	1,125
Other comprehensive income (loss), net of tax:
Dividends paid	(440)	(410)
Issuances pursuant to stock option and benefit plans	(295)	(205)
Balance at the end of the period	31,073	28,858
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(12,407)	(11,679)
Other comprehensive income (loss), net of tax:
Reacquired stock	(807)	(534)
Issuances pursuant to stock option and benefit plans	1,036	419
Balance at the end of the period	(12,178)	(11,794)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(4,750)	(5,025)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(360)	155
Defined benefit pension and postretirement plans adjustment	85	97
Debt and equity securities - unrealized gain (loss)	0	3
Cash flow hedging instruments - unrealized gain (loss)	24	(15)
Balance at the end of the period	(5,001)	(4,785)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	465	442
Net income	18	16
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(38)	(21)
Defined benefit pension and postretirement plans adjustment	0	0
Debt and equity securities - unrealized gain (loss)	0	0
Cash flow hedging instruments - unrealized gain (loss)	0	0
Sale of subsidiary shares	1
Balance at the end of the period	$ 446	$ 437