Consolidated Variable Interest Entities and Investments in Affiliates - Schedule of Assets and Liabilities Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Property and equipment, net	$ 8,311	[1]	$ 8,541	$ 8,676
Cash and cash equivalents	364		337
Restricted cash	15		13
Accounts receivable, net	125		130
Prepaid expenses	48		58
Other assets	83		26
Debt	2,961		3,012
Accounts payable and accrued expenses	215		167
Deferred income tax liabilities	65		2,437
Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Property and equipment, net	215		208
Cash and cash equivalents	14		14
Restricted cash	7		13
Accounts receivable, net	2		2
Prepaid expenses	2		2
Other assets	5
Debt	207		207
Accounts payable and accrued expenses	$ 15		6
Deferred income tax liabilities			$ 49

[1] Excludes $31 million of property and equipment, net classified as held for sale as of December 31, 2017.