Contracts with Customers	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Contracts with Customers	CONTRACTS WITH CUSTOMERS Our current and noncurrent Loyalty Program liability increased by $132 million, to $6,403 million at March 31, 2021, from $6,271 million at December 31, 2020, primarily reflecting an increase in points earned by members. This includes amounts reclassified from deferred revenue to the liability for guest loyalty program as a result of points that were earned during the period by members using our U.S.-issued co-brand credit cards, which were prepaid by the financial institutions in 2020. The increase was partially offset by $292 million of revenue recognized in the 2021 first quarter, that was deferred as of December 31, 2020. The current portion of our Loyalty Program liability increased compared to December 31, 2020 due to higher estimated redemptions in the short-term.Our allowance for credit losses increased to $223 million at March 31, 2021 from $207 million at December 31, 2020