Segment Information - Revenues, Adjusted Ebitda, Ebitda from Unconsolidated Ventures, Capital Expenditures, Total Assets, and Investments (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenues	$ 1,433	$ 1,434	$ 1,481	$ 1,415	$ 1,493	$ 1,493	$ 1,539	$ 1,458	$ 5,763	$ 5,983	$ 6,115
Other revenues from managed and franchised hotels									2,736	2,711	2,614
Corporate selling, general, administrative and other expenses — unallocated									(388)	(402)	(384)
Loss on asset dispositions and impairments, net									(1)	(33)	(23)
Restructuring and other special (charges) credits									(100)	4	(1)
Adjustments to equity earnings									(31)	(46)	(42)
Interest expense									(116)	(97)	(103)
Loss on early extinguishment of debt, net										(1)	4
Depreciation and amortization									(280)	(283)	(267)
Discontinued operations										(10)	71
Income tax expense									(180)	(139)	(263)
Net income attributable to Starwood	166	$ 88	$ 136	$ 99	234	$ 109	$ 153	$ 137	489	633	635
Capital expenditures, net									403	376	388
Assets, net	8,268				8,659				8,268	8,659
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues									2,915	3,173	3,417
Total segment earnings									1,237	1,314	1,334
Total earnings from unconsolidated ventures									72	73	68
Capital expenditures, net									305	230	305
Assets, net	4,259				4,871				4,259	4,871
Total investments in unconsolidated ventures	183				214				183	214
Operating Segments [Member] | Americas Segment [Member]
Segment Reporting Information [Line Items]
Total revenues									1,472	1,559	1,548
Total segment earnings									691	697	617
Total earnings from unconsolidated ventures									41	38	32
Capital expenditures, net									165	151	256
Assets, net	1,564				1,845				1,564	1,845
Total investments in unconsolidated ventures	26				50				26	50
Operating Segments [Member] | EAME [Member]
Segment Reporting Information [Line Items]
Total revenues									475	597	615
Total segment earnings									175	220	220
Total earnings from unconsolidated ventures									1
Capital expenditures, net									27	53	45
Assets, net	634				840				634	840
Total investments in unconsolidated ventures	22				24				22	24
Operating Segments [Member] | Asia Pacific Segment [Member]
Segment Reporting Information [Line Items]
Total revenues									287	354	349
Total segment earnings									203	228	221
Total earnings from unconsolidated ventures									29	34	34
Capital expenditures, net									20	12	17
Assets, net	685				901				685	901
Total investments in unconsolidated ventures	122				125				122	125
Operating Segments [Member] | Vacation ownership and residential [Member]
Segment Reporting Information [Line Items]
Total revenues									681	663	905
Total segment earnings									168	169	276
Total earnings from unconsolidated ventures									1	1	2
Capital expenditures, net									93	14	(13)
Assets, net	1,376				1,285				1,376	1,285
Total investments in unconsolidated ventures	13				15				13	15
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other revenues from managed and franchised hotels									2,736	2,711	2,614
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total revenues									112	99	84
Other corporate income — unallocated									116	100	86
Corporate selling, general, administrative and other expenses — unallocated									(156)	(176)	(157)
Capital expenditures, net									98	146	$ 83
Assets, net	$ 4,009				$ 3,788				$ 4,009	$ 3,788