Merger-Related Costs and Charges Merger-Related Costs and Charges- Types of Merger-related Costs and Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Merger-related costs and charges
Transaction and integration costs	$ 21	$ 14	$ 72	$ 22
Interest expense	73	57	143	104
Starwood Hotels & Resorts Worldwide, Inc.
Merger-related costs and charges
Transaction costs	3	6	10	13
Employee termination costs	(9)	0	12	0
Integration costs	27	8	50	9
Transaction and integration costs	21	14	72	22
Interest expense	0	11	0	13
Transaction, integration, and interest costs	$ 21	$ 25	$ 72	$ 35