Merger-Related Costs and Charges Merger-Related Costs and Charges- Types of Merger-related Costs and Charges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Merger-related costs and charges
Transaction and integration costs	$ 51	$ 8
Interest expense	70	47
Starwood Hotels & Resorts Worldwide, Inc.
Merger-related costs and charges
Transaction costs	7	7
Transaction and integration costs	51	8
Interest expense	0	2
Transaction, integration, and interest costs	51	10
Employee termination costs | Starwood Hotels & Resorts Worldwide, Inc.
Merger-related costs and charges
Integration costs	21	0
Integration costs | Starwood Hotels & Resorts Worldwide, Inc.
Merger-related costs and charges
Integration costs	$ 23	$ 1