Consolidated Variable Interest Entities ("VIEs") and Investments in Affiliates - Schedule of Assets and Liabilities Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Jun. 30, 2021		Dec. 31, 2020
Variable Interest Entity [Line Items]
Property and equipment, net	$ 8,820	[1]	$ 9,193
Cash and cash equivalents	909		951
Restricted cash	35		30
Accounts receivable, net	63		26
Prepaid expenses	35		39
Other assets	50		60
Debt	5,100		5,121
Accounts payable and accrued expenses	178		147
Other liabilities	107		134
Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Property and equipment, net	212		216
Cash and cash equivalents	13		8
Restricted cash	5		2
Accounts receivable, net	3		1
Prepaid expenses	1		1
Other assets	1		1
Debt	208		207
Accounts payable and accrued expenses	7		5
Other liabilities	$ 2		$ 1

[1] Excludes $77 million of property and equipment, net classified as held for sale as of June 30, 2021.