Fair Value Measurements and Derivatives - Fair Value of Financial Instruments (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value $ 1,805 $ 1,804
Fair Value 1,840 1,889
Term Facility [Member]    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value 275 275
Other indebtedness [Member]    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value 30 29
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Market Approach Valuation Technique [Member] | Senior Notes Total [Member]    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value 1,500 1,500
Fair Value 1,542 1,592
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Market Approach Valuation Technique [Member] | Term Facility [Member]    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value 275 275
Fair Value 275 275
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Income Approach Valuation Technique [Member] | Other indebtedness [Member]    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Carrying Value 30 [1] 29
Fair Value $ 23 $ 22
[1] *The carrying value includes the unamortized portion of a fair value adjustment related to a terminated interest rate swap at both dates. The carrying value and fair value also include a financial liability associated with certain build-to-suit lease arrangements at both dates.