Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Increase (decrease) in equity
Balance at the beginning of the period	$ 18,528	$ 16,619	$ 18,040	$ 15,862
Net income	1,213	1,186	2,360	2,327
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(279)	(335)	(677)	(201)
Defined benefit pension and postretirement plans adjustment	91	98	176	195
Debt and equity securities - unrealized gain (loss)	(4)	(2)	(4)	1
Cash flow hedging instruments - unrealized gain (loss)	8	23	32	8
Total other comprehensive income (loss), net of tax	(184)	(216)	(473)	3
Dividends paid	(436)	(410)	(876)	(820)
Stock-based compensation, net of tax impacts	64	60	192	187
Reacquired stock	(1,232)	(633)	(2,039)	(1,167)
Issuances pursuant to stock option and benefit plans	366	267	1,107	481
Sale of subsidiary shares			8
Balance at the end of the period	18,319	16,873	18,319	16,873
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,188	3,903	4,053	3,776
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts	64	60	192	187
Sale of subsidiary shares			7
Balance at the end of the period	4,252	3,963	4,252	3,963
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	31,073	28,858	30,679	28,348
Net income	1,197	1,167	2,326	2,292
Other comprehensive income (loss), net of tax:
Dividends paid	(436)	(410)	(876)	(820)
Issuances pursuant to stock option and benefit plans	(118)	(150)	(413)	(355)
Balance at the end of the period	31,716	29,465	31,716	29,465
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(12,178)	(11,794)	(12,407)	(11,679)
Other comprehensive income (loss), net of tax:
Reacquired stock	(1,232)	(633)	(2,039)	(1,167)
Issuances pursuant to stock option and benefit plans	484	417	1,520	836
Balance at the end of the period	(12,926)	(12,010)	(12,926)	(12,010)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(5,001)	(4,785)	(4,750)	(5,025)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(260)	(346)	(620)	(191)
Defined benefit pension and postretirement plans adjustment	91	98	176	195
Debt and equity securities - unrealized gain (loss)	(4)	(2)	(4)	1
Cash flow hedging instruments - unrealized gain (loss)	8	23	32	8
Balance at the end of the period	(5,166)	(5,012)	(5,166)	(5,012)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	446	437	465	442
Net income	16	19	34	35
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(19)	11	(57)	(10)
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	$ 443	$ 467	$ 443	$ 467