Segment Information - Revenues and Segment Earnings (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Total revenues	$ 1,434	$ 1,493	$ 4,330	$ 4,490
Other revenues from managed and franchised hotels	686	686	2,057	2,052
Corporate selling, general, administrative and other – unallocated	(102)	(96)	(292)	(293)
Loss on asset dispositions and impairments, net	(46)	(22)	(32)	(55)
Restructuring and other special (charges) credits	(9)	0	(63)	3
Adjustments to equity earnings	(10)	(12)	(22)	(31)
Interest expense	(30)	(27)	(90)	(75)
Loss on early extinguishment of debt, net		(1)		(1)
Depreciation and amortization	(69)	(72)	(211)	(210)
Discontinued operations				1
Income tax expense	(42)	(54)	(138)	(135)
Net income attributable to Starwood	88	109	323	399
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	720	783	2,192	2,366
Total segment earnings	299	312	911	954
Operating Segments [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Total revenues	345	372	1,098	1,159
Total segment earnings	160	156	509	512
Operating Segments [Member] | EAME [Member]
Segment Reporting Information [Line Items]
Total revenues	135	162	366	453
Total segment earnings	50	65	130	158
Operating Segments [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Total revenues	71	92	203	257
Total segment earnings	46	54	136	159
Operating Segments [Member] | Vacation ownership and residential [Member]
Segment Reporting Information [Line Items]
Total revenues	169	157	525	497
Total segment earnings	43	37	136	125
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other revenues from managed and franchised hotels	686	686	2,057	2,052
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	28	24	81	72
Other corporate unallocated	29	25	84	73
Corporate selling, general, administrative and other – unallocated	$ (34)	$ (40)	$ (116)	$ (125)