Fair Value of Financial Instruments - Carrying Values and Fair Values of Non-Current Financial Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	$ 240	$ 215
Other noncurrent liabilities	(1,580)	(993)
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	240	215
Marketable securities	30	37
Total noncurrent financial assets	270	252
Senior notes	(5,650)	(2,766)
Commercial paper/ Credit Facility	(2,588)	(938)
Other long-term debt	(100)	(99)
Other noncurrent liabilities	(63)	(63)
Total noncurrent financial liabilities	(8,401)	(3,866)
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	226	209
Marketable securities	30	37
Total noncurrent financial assets	256	246
Senior notes	(5,828)	(2,826)
Commercial paper/ Credit Facility	(2,588)	(938)
Other long-term debt	(111)	(108)
Other noncurrent liabilities	(63)	(63)
Total noncurrent financial liabilities	$ (8,590)	$ (3,935)