Supplemental Equity and Comprehensive Income Information (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	$ (5,001)	$ (4,785)	$ (4,750)	$ (5,025)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(308)	(298)	(702)	(167)
Amounts reclassifed out	198	162	449	320
Total other comprehensive income (loss), before tax	(110)	(136)	(253)	153
Tax effect	(55)	(91)	(163)	(140)
Total other comprehensive income (loss), net of tax	(165)	(227)	(416)	13
Balance at End of Period	(5,166)	(5,012)	(5,166)	(5,012)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(130)	269	230	114
Other comprehensive income (loss), before tax:
Amounts before reclassification	(260)	(324)	(584)	(169)
Amounts reclassifed out	0	0	0	0
Total other comprehensive income (loss), before tax	(260)	(324)	(584)	(169)
Tax effect	0	(22)	(36)	(22)
Total other comprehensive income (loss), net of tax	(260)	(346)	(620)	(191)
Balance at End of Period	(390)	(77)	(390)	(77)
Defined Benefit Pension and Postretirement Plans Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(4,870)	(5,058)	(4,955)	(5,155)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	0	0	0
Amounts reclassifed out	144	154	287	307
Total other comprehensive income (loss), before tax	144	154	287	307
Tax effect	(53)	(56)	(111)	(112)
Total other comprehensive income (loss), net of tax	91	98	176	195
Balance at End of Period	(4,779)	(4,960)	(4,779)	(4,960)
Debt and Equity Securities, Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(2)	(3)	(2)	(6)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(6)	(3)	(6)	1
Amounts reclassifed out	0	0	0	1
Total other comprehensive income (loss), before tax	(6)	(3)	(6)	2
Tax effect	2	1	2	(1)
Total other comprehensive income (loss), net of tax	(4)	(2)	(4)	1
Balance at End of Period	(6)	(5)	(6)	(5)
Cash Flow Hedging Instruments Unrealized Gain (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	1	7	(23)	22
Other comprehensive income (loss), before tax:
Amounts before reclassification	(42)	29	(112)	1
Amounts reclassifed out	54	8	162	12
Total other comprehensive income (loss), before tax	12	37	50	13
Tax effect	(4)	(14)	(18)	(5)
Total other comprehensive income (loss), net of tax	8	23	32	8
Balance at End of Period	$ 9	$ 30	$ 9	$ 30