Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Increase (decrease) in equity
Balance at the beginning of the period	$ 17,948	$ 18,040
Net income	1,225	1,147
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	20	(398)
Defined benefit pension and postretirement plans adjustment	61	85
Debt and equity securities - unrealized gain (loss)	1	0
Cash flow hedging instruments - unrealized gain (loss)	2	24
Total other comprehensive income (loss), net of tax	84	(289)
Dividends declared	1	(440)
Sale of subsidiary shares		8
Stock-based compensation, net of tax impacts	170	128
Reacquired stock	(1,773)	(807)
Issuances pursuant to stock option and benefit plans	269	741
Balance at the end of the period	17,924	18,528
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,384	4,053
Other comprehensive income (loss), net of tax:
Sale of subsidiary shares		7
Stock-based compensation, net of tax impacts	170	128
Balance at the end of the period	4,554	4,188
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	32,416	30,679
Net income	1,207	1,129
Other comprehensive income (loss), net of tax:
Dividends declared	1	(440)
Issuances pursuant to stock option and benefit plans	(312)	(295)
Balance at the end of the period	33,312	31,073
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(15,385)	(12,407)
Other comprehensive income (loss), net of tax:
Reacquired stock	(1,773)	(807)
Issuances pursuant to stock option and benefit plans	581	1,036
Balance at the end of the period	(16,577)	(12,178)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(3,913)	(4,750)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	8	(360)
Defined benefit pension and postretirement plans adjustment	61	85
Debt and equity securities - unrealized gain (loss)	1	0
Cash flow hedging instruments - unrealized gain (loss)	2	24
Balance at the end of the period	(3,841)	(5,001)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	446	465
Net income	18	18
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	12	(38)
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	$ 476	$ 446