Supplemental Equity and Comprehensive Income Information (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	$ (6,321)	$ (3,841)	$ (6,289)	$ (3,913)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(28)	108	88	125
Amounts reclassified out	107	97	204	182
Total other comprehensive income (loss), before tax	79	205	292	307
Tax effect	9	(30)	(236)	(60)
Total other comprehensive income (loss), net of tax	88	175	56	247
Balance at End of Period	(6,233)	(3,666)	(6,233)	(3,666)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(1,288)	(180)	(1,095)	(188)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(12)	128	(56)	134
Amounts reclassified out	0	0	0	0
Total other comprehensive income (loss), before tax	(12)	128	(56)	134
Tax effect	36	(5)	(113)	(3)
Total other comprehensive income (loss), net of tax	24	123	(169)	131
Balance at End of Period	(1,264)	(57)	(1,264)	(57)
Gains (losses) associated with defined benefit pension and postretirement plans amortization
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	(5,202)	(3,654)	(5,293)	(3,715)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	0	24	0
Amounts reclassified out	141	92	265	183
Total other comprehensive income (loss), before tax	141	92	289	183
Tax effect	(45)	(32)	(102)	(62)
Total other comprehensive income (loss), net of tax	96	60	187	121
Balance at End of Period	(5,106)	(3,594)	(5,106)	(3,594)
Debt and equity security gains (losses)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	0	(1)	0	(2)
Other comprehensive income (loss), before tax:
Amounts before reclassification	0	1	0	3
Amounts reclassified out	0	0	0	0
Total other comprehensive income (loss), before tax	0	1	0	3
Tax effect	0	0	0	(1)
Total other comprehensive income (loss), net of tax	0	1	0	2
Balance at End of Period	0	0	0	0
Cash flow hedging instruments gains (losses)
Accumulated Other Comprehensive Income (Loss)
Balance at Beginning of Period	169	(6)	99	(8)
Other comprehensive income (loss), before tax:
Amounts before reclassification	(16)	(21)	120	(12)
Amounts reclassified out	(34)	5	(61)	(1)
Total other comprehensive income (loss), before tax	(50)	(16)	59	(13)
Tax effect	18	7	(21)	6
Total other comprehensive income (loss), net of tax	(32)	(9)	38	(7)
Balance at End of Period	$ 137	$ (15)	$ 137	$ (15)