Supplemental Equity and Comprehensive Income Information (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	$ (4,750)	$ (5,025)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(394)	131
Amounts reclassifed out	251	158
Total other comprehensive income (loss), before tax	(143)	289
Tax effect	(108)	(49)
Total other comprehensive income (loss), net of tax	(251)	240
Balance at End of Period	(5,001)	(4,785)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	230	114
Other comprehensive income (loss), before tax:
Amounts before reclassification	(324)	155
Amounts reclassifed out	0	0
Total other comprehensive income (loss), before tax	(324)	155
Tax effect	(36)	0
Total other comprehensive income (loss), net of tax	(360)	155
Balance at End of Period	(130)	269
Defined Benefit Pension and Postretirement Plans Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(4,955)	(5,155)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	0
Amounts reclassifed out	143	153
Total other comprehensive income (loss), before tax	143	153
Tax effect	(58)	(56)
Total other comprehensive income (loss), net of tax	85	97
Balance at End of Period	(4,870)	(5,058)
Debt and Equity Securities, Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(2)	(6)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	4
Amounts reclassifed out	0	1
Total other comprehensive income (loss), before tax	0	5
Tax effect	0	(2)
Total other comprehensive income (loss), net of tax	0	3
Balance at End of Period	(2)	(3)
Cash Flow Hedging Instruments Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(23)	22
Other comprehensive income (loss), before tax:
Amounts before reclassification	(70)	(28)
Amounts reclassifed out	108	4
Total other comprehensive income (loss), before tax	38	(24)
Tax effect	(14)	9
Total other comprehensive income (loss), net of tax	24	(15)
Balance at End of Period	$ 1	$ 7