Financial Instruments (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	[1]	$ 3,325	$ 3,626
Foreign currency forward contracts	[2]	6	(14)
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	[1]	3,526	3,754
Foreign currency forward contracts	[2]	$ 6	$ (14)

[1] The Company measures the fair value of its Senior Notes using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market.

[2] The Company measures the fair values of foreign currency forward contracts based on forward exchange rates. See Note 14 for additional disclosures regarding the notional amounts and fair values of foreign currency forward contracts.