Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (314)	$ (338)
Other comprehensive income (loss) before reclassifications, net of tax	13	(29)
Less: Amounts reclassified from AOCI, net of tax	(2)	(3)
Other comprehensive income (loss), net of tax	15	(26)
Ending balance	(299)	(364)
Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	20	16
Other comprehensive income (loss) before reclassifications, net of tax	(8)	(1)
Less: Amounts reclassified from AOCI, net of tax	(2)	(2)
Other comprehensive income (loss), net of tax	(6)	1
Ending balance	14	17
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(221)	(302)
Other comprehensive income (loss) before reclassifications, net of tax	(3)	6
Less: Amounts reclassified from AOCI, net of tax	0	(1)
Other comprehensive income (loss), net of tax	(3)	7
Ending balance	(224)	(295)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(113)	(52)
Other comprehensive income (loss) before reclassifications, net of tax	24	(34)
Less: Amounts reclassified from AOCI, net of tax	0	0
Other comprehensive income (loss), net of tax	24	(34)
Ending balance	$ (89)	$ (86)