Stockholders' Equity - Equity Attributable to Starwood's Stockholders (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	$ 1,347		$ 1,299
Net income	(263)	$ 136	(173)	$ 235
Equity compensation activity and other	20		18
Dividends	(63)		(126)
Distribution of Vistana	(1,041)		(1,041)
Other comprehensive income	177	$ 20	200	$ (90)
Ending Balance	177		177
Common Shares [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	2		2
Ending Balance	2		2
Additional Paid-in Capital [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	115		115
Equity compensation activity and other	20		20
Ending Balance	135		135
Accumulated Other Comprehensive Loss [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	(645)		(668)
Other comprehensive income	177		200
Ending Balance	(468)		(468)
Retained Earnings [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	1,872		1,847
Net income	(263)		(173)
Equity compensation activity and other			(2)
Dividends	(63)		(126)
Distribution of Vistana	(1,041)		(1,041)
Ending Balance	505		505
Equity Attributable to Noncontrolling Interests [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance	3		3
Ending Balance	$ 3		$ 3