Supplemental Equity and Comprehensive Income Information (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	$ (5,166)	$ (5,012)	$ (4,750)	$ (5,025)
Other comprehensive income (loss), before tax:
Amounts before reclassification	263	405	(439)	238
Amounts reclassified out	86	75	535	395
Total other comprehensive income (loss), before tax	349	480	96	633
Tax effect	7	(16)	(156)	(156)
Total other comprehensive income (loss), net of tax	356	464	(60)	477
Balance at End of Period	(4,810)	(4,548)	(4,810)	(4,548)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(390)	(77)	230	114
Other comprehensive income (loss), before tax:
Amounts before reclassification	240	380	(344)	211
Amounts reclassified out	0	0	0	0
Total other comprehensive income (loss), before tax	240	380	(344)	211
Tax effect	46	21	10	(1)
Total other comprehensive income (loss), net of tax	286	401	(334)	210
Balance at End of Period	(104)	324	(104)	324
Defined Benefit Pension and Postretirement Plans Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(4,779)	(4,960)	(4,955)	(5,155)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	0	0	0
Amounts reclassified out	144	153	431	460
Total other comprehensive income (loss), before tax	144	153	431	460
Tax effect	(52)	(57)	(163)	(169)
Total other comprehensive income (loss), net of tax	92	96	268	291
Balance at End of Period	(4,687)	(4,864)	(4,687)	(4,864)
Debt and Equity Securities, Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(6)	(5)	(2)	(6)
Other comprehensive income (loss), before tax:
Amounts before reclassification	3	4	(3)	5
Amounts reclassified out	0	0	0	1
Total other comprehensive income (loss), before tax	3	4	(3)	6
Tax effect	(1)	(1)	1	(2)
Total other comprehensive income (loss), net of tax	2	3	(2)	4
Balance at End of Period	(4)	(2)	(4)	(2)
Cash Flow Hedging Instruments Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	9	30	(23)	22
Other comprehensive income (loss), before tax:
Amounts before reclassification	20	21	(92)	22
Amounts reclassified out	(58)	(78)	104	(66)
Total other comprehensive income (loss), before tax	(38)	(57)	12	(44)
Tax effect	14	21	(4)	16
Total other comprehensive income (loss), net of tax	(24)	(36)	8	(28)
Balance at End of Period	$ (15)	$ (6)	$ (15)	$ (6)