Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Change in contract with customer liability		$ (230)
Contract with customer liability	$ 1,637	1,637	$ 1,867
Deferred revenue recognized		154
Accounts and notes receivable, net, allowance for credit losses	224	224	207
Provision for credit losses	4	23
Loyalty Program
Disaggregation of Revenue [Line Items]
Change in contract with customer liability		204
Contract with customer liability	$ 6,475	6,475	$ 6,271
Reclassification of deferred revenue to liability for guest loyalty program		114
Deferred revenue recognized		$ 760