Long-Term Debt - Summary of Carrying Value of Debt (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 0	$ 4
Long-term debt, less current maturities	3,012	3,156
Carry Value of Debt
Debt Instrument [Line Items]
Senior Notes	1,050	1,050
Term loan	2,035	2,200
Less debt issuance costs	(26)	(30)
Less unamortized discounts	(47)	(60)
Total outstanding debt	3,012	3,160
Current maturities of long-term debt	0	16
Less: current portion of unamortized discounts	0	(9)
Less: current portion of debt issuance costs	0	(3)
Total short-term debt	0	4
Long-term debt, less current maturities	$ 3,012	$ 3,156