Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (840)
Ending balance		(860)	$ (840)
Currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]	(549)	(545)	$ (513)
Other comprehensive income (loss) before reclassifications	[1]	33	(5)	(70)
Amounts reclassified from accumulated other comprehensive loss	[1]	5	1	0
Other comprehensive income (loss)	[1]	38	(4)	(70)
Ending balance	[1]	(511)	(549)	(545)
Pension liability adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[2]	(269)	(260)	(229)
Other comprehensive income (loss) before reclassifications	[2]	(30)	(17)	(18)
Amounts reclassified from accumulated other comprehensive loss	[2]	10	8	9
Other comprehensive income (loss)	[2]	(20)	(9)	(9)
Ending balance	[2]	(289)	(269)	(260)
Cash flow hedge adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[3]	(22)	23	1
Other comprehensive income (loss) before reclassifications	[3]	(46)	(35)	17
Amounts reclassified from accumulated other comprehensive loss	[3]	8	(10)	5
Other comprehensive income (loss)	[3]	(38)	(45)	22
Ending balance	[3]	(60)	(22)	23
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(840)	(782)	(741)
Other comprehensive income (loss) before reclassifications		(43)	(57)	(71)
Amounts reclassified from accumulated other comprehensive loss		23	(1)	14
Other comprehensive income (loss)		(20)	(58)	(57)
Ending balance		$ (860)	$ (840)	(782)
Accounting standards update 2018-02 | Currency translation adjustment | Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)	[1]			38
Accounting standards update 2018-02 | Pension liability adjustment | Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)	[2]			(22)
Accounting standards update 2018-02 | Cash flow hedge adjustment | Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)	[3]			0
Accounting standards update 2018-02 | Accumulated other comprehensive loss | Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)				$ 16

[1] Includes net investment hedges and intra-entity foreign currency transactions that are of a long-term investment nature. Amounts reclassified related to the liquidation of investments in foreign entities and were recognized in loss on foreign currency transactions in our consolidated statements of operations.

[2] Amounts reclassified related to the amortization of prior service costs and amortization of net loss and were recognized in other non-operating income (loss), net in our consolidated statements of operations.

[3] Amounts reclassified related to interest rate swaps, including interest rate swaps that were dedesignated and subsequently settled, and forward contracts that hedge our foreign currency denominated fees and were recognized in interest expense and franchise and licensing fees, base and other management fees and other revenues from managed and franchised properties, respectively, in our consolidated statements of operations.