Supplemental Equity and Comprehensive Income Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Increase (decrease) in equity
Balance at the beginning of the period	$ 13,142	$ 17,948
Net income	1,201	1,225
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(193)	20
Defined benefit pension and postretirement plans adjustment	91	61
Debt and equity securities - unrealized gain (loss)	0	1
Cash flow hedging instruments - unrealized gain (loss)	70	2
Total other comprehensive income (loss), net of tax	(32)	84
Dividends declared	(3)	1
Stock-based compensation, net of tax impacts	228	170
Reacquired stock	(896)	(1,773)
Issuances pursuant to stock option and benefit plans	312	269
Balance at the end of the period	13,952	17,924
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	4,388	4,384
Other comprehensive income (loss), net of tax:
Stock-based compensation, net of tax impacts	228	170
Balance at the end of the period	4,616	4,554
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	34,317	32,416
Net income	1,199	1,207
Other comprehensive income (loss), net of tax:
Dividends declared	(3)	1
Issuances pursuant to stock option and benefit plans	(433)	(312)
Balance at the end of the period	35,080	33,312
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(19,307)	(15,385)
Other comprehensive income (loss), net of tax:
Reacquired stock	(896)	(1,773)
Issuances pursuant to stock option and benefit plans	745	581
Balance at the end of the period	(19,458)	(16,577)
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(6,289)	(3,913)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(193)	8
Defined benefit pension and postretirement plans adjustment	91	61
Debt and equity securities - unrealized gain (loss)	0	1
Cash flow hedging instruments - unrealized gain (loss)	70	2
Balance at the end of the period	(6,321)	(3,841)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	33	446
Net income	2	18
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	0	12
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
Balance at the end of the period	$ 35	$ 476