Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	$ (1,447)	$ (1,260)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(367)
Other Comprehensive Income (Loss), Before Reclassifications, Tax	153
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	27
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(187)
Unrealized foreign currency translation adjustments, tax benefit	15
Pension and other postretirement benefit adjustments, tax cost	20
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(272)	(38)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(367)
Other Comprehensive Income (Loss), Before Reclassifications, Tax	133
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(234)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(1,116)	(1,157)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	5
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	36
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	41
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(59)	(65)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	15
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(9)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 6