Fair Value of Financial Instruments - Carrying Values and Fair Values of Non-Current Financial Assets and Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	$ 218	$ 215
Other noncurrent liabilities	(1,041)	(1,010)
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	218	215
Marketable securities	40	37
Total noncurrent financial assets	258	252
Senior notes	(2,768)	(2,766)
Commercial paper	(991)	(938)
Other long-term debt	(97)	(99)
Other noncurrent liabilities	(65)	(63)
Total noncurrent financial liabilities	(3,921)	(3,866)
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	211	209
Marketable securities	40	37
Total noncurrent financial assets	251	246
Senior notes	(2,875)	(2,826)
Commercial paper	(991)	(938)
Other long-term debt	(105)	(108)
Other noncurrent liabilities	(65)	(63)
Total noncurrent financial liabilities	$ (4,036)	$ (3,935)