Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Revenues:
Interest income from loans		$ 117,532	$ 118,429
Interest income from investment securities		19,403	27,744
Servicing fees		24,691	28,257
Rental income		32,677	2,672
Other revenues		1,190	1,747
Total revenues		195,493	178,849
Costs and expenses:
Management fees		24,963	27,968
Interest expense		56,520	50,534
General and administrative		32,798	35,264
Acquisition and investment pursuit costs		1,285	1,186
Costs of rental operations		12,655	1,698
Depreciation and amortization		18,760	4,085
Loan loss allowance, net		(761)	317
Other expense		100	375
Total costs and expenses		146,320	121,427
Income before other income (loss), income taxes and non-controlling interests		49,173	57,422
Other income (loss):
Change in net assets related to consolidated VIEs		(4,167)	47,861
Change in fair value of servicing rights		(6,739)	(1,542)
Change in fair value of investment securities, net		753	(499)
Change in fair value of mortgage loans held-for-sale, net		6,891	21,131
Earnings from unconsolidated entities		4,065	6,090
Gain on sale of investments and other assets, net		245	17,198
Gain (loss) on derivative financial instruments, net		(24,718)	24,623
Foreign currency (loss), gain net		(378)	(30,307)
Loss on extinguishment of debt			(5,292)
Other income, net		2,015	45
Total other income (loss)		(22,033)	79,308
Income before income taxes		27,140	136,730
Income tax benefit (provision)		(94)	(15,951)
Net income		27,046	120,779
Net income attributable to non-controlling interests		(389)	(416)
Net income attributable to Starwood Property Trust, Inc.		26,657	120,363
Investment and Servicing Segment
Other income (loss):
Gain on sale of investments and other assets, net	$ 17,100
Operating Segments and Corporate
Revenues:
Interest income from loans		117,532	118,429
Interest income from investment securities		57,254	46,992
Servicing fees		36,377	51,032
Rental income		32,677	2,672
Other revenues		1,371	2,009
Total revenues		245,211	221,134
Costs and expenses:
Management fees		24,921	27,918
Interest expense		56,520	50,534
General and administrative		32,621	35,078
Acquisition and investment pursuit costs		1,285	1,186
Costs of rental operations		12,655	1,698
Depreciation and amortization		18,760	4,085
Loan loss allowance, net		(761)	317
Other expense		100	375
Total costs and expenses		146,101	121,191
Income before other income (loss), income taxes and non-controlling interests		99,110	99,943
Other income (loss):
Change in fair value of servicing rights		(8,670)	(4,875)
Change in fair value of investment securities, net		(51,742)	7,974
Change in fair value of mortgage loans held-for-sale, net		6,891	21,131
Earnings from unconsolidated entities		4,274	6,220
Gain on sale of investments and other assets, net		245	17,198
Gain (loss) on derivative financial instruments, net		(24,718)	24,623
Foreign currency (loss), gain net		(378)	(30,307)
Loss on extinguishment of debt			(5,292)
Other income, net		2,015	45
Total other income (loss)		(72,083)	36,717
Income before income taxes		27,027	136,660
Income tax benefit (provision)		(94)	(15,951)
Net income		26,933	120,709
Net income attributable to non-controlling interests		(276)	(346)
Net income attributable to Starwood Property Trust, Inc.		26,657	120,363
Operating segment | Lending Segment
Revenues:
Interest income from loans		114,658	113,472
Interest income from investment securities		9,628	22,296
Servicing fees		159	84
Other revenues		23	79
Total revenues		124,468	135,931
Costs and expenses:
Management fees		375	388
Interest expense		22,335	21,523
General and administrative		3,922	4,858
Acquisition and investment pursuit costs		338	773
Loan loss allowance, net		(761)	317
Total costs and expenses		26,209	27,859
Income before other income (loss), income taxes and non-controlling interests		98,259	108,072
Other income (loss):
Change in fair value of investment securities, net		(214)	(339)
Earnings from unconsolidated entities		468	855
Gain on sale of investments and other assets, net		245	98
Gain (loss) on derivative financial instruments, net		(3,026)	32,863
Foreign currency (loss), gain net		(1,822)	(29,336)
Total other income (loss)		(4,349)	4,141
Income before income taxes		93,910	112,213
Income tax benefit (provision)		(75)	30
Net income		93,835	112,243
Net income attributable to non-controlling interests		(350)	(346)
Net income attributable to Starwood Property Trust, Inc.		93,485	111,897
Operating segment | Investment and Servicing Segment
Revenues:
Interest income from loans		2,874	4,957
Interest income from investment securities		47,626	24,696
Servicing fees		36,218	50,948
Rental income		6,475	2,672
Other revenues		1,342	1,930
Total revenues		94,535	85,203
Costs and expenses:
Management fees		18	18
Interest expense		3,238	2,119
General and administrative		25,294	29,189
Acquisition and investment pursuit costs		355	213
Costs of rental operations		3,062	1,698
Depreciation and amortization		3,051	4,085
Other expense		100	375
Total costs and expenses		35,118	37,697
Income before other income (loss), income taxes and non-controlling interests		59,417	47,506
Other income (loss):
Change in fair value of servicing rights		(8,670)	(4,875)
Change in fair value of investment securities, net		(51,528)	8,313
Change in fair value of mortgage loans held-for-sale, net		6,891	21,131
Earnings from unconsolidated entities		1,377	2,724
Gain on sale of investments and other assets, net			17,100
Gain (loss) on derivative financial instruments, net		(11,245)	(8,007)
Foreign currency (loss), gain net		1,460	(1,171)
Other income, net		43	31
Total other income (loss)		(61,672)	35,246
Income before income taxes		(2,255)	82,752
Income tax benefit (provision)		(19)	(15,981)
Net income		(2,274)	66,771
Net income attributable to non-controlling interests		74
Net income attributable to Starwood Property Trust, Inc.		(2,200)	66,771
Operating segment | Property Segment
Revenues:
Rental income		26,202
Other revenues		6
Total revenues		26,208
Costs and expenses:
Interest expense		4,949
General and administrative		555	2
Acquisition and investment pursuit costs		592
Costs of rental operations		9,593
Depreciation and amortization		15,709
Total costs and expenses		31,398	2
Income before other income (loss), income taxes and non-controlling interests		(5,190)	(2)
Other income (loss):
Earnings from unconsolidated entities		2,429	2,641
Gain (loss) on derivative financial instruments, net		(10,447)	(233)
Foreign currency (loss), gain net		(16)	200
Other income, net		422
Total other income (loss)		(7,612)	2,608
Income before income taxes		(12,802)	2,606
Net income		(12,802)	2,606
Net income attributable to Starwood Property Trust, Inc.		(12,802)	2,606
Corporate
Costs and expenses:
Management fees		24,528	27,512
Interest expense		25,998	26,892
General and administrative		2,850	1,029
Acquisition and investment pursuit costs			200
Total costs and expenses		53,376	55,633
Income before other income (loss), income taxes and non-controlling interests		(53,376)	(55,633)
Other income (loss):
Loss on extinguishment of debt			(5,292)
Other income, net		1,550	14
Total other income (loss)		1,550	(5,278)
Income before income taxes		(51,826)	(60,911)
Net income		(51,826)	(60,911)
Net income attributable to Starwood Property Trust, Inc.		(51,826)	(60,911)
Investment and Servicing VIEs
Revenues:
Interest income from investment securities		(37,851)	(19,248)
Servicing fees		(11,686)	(22,775)
Other revenues		(181)	(262)
Total revenues		(49,718)	(42,285)
Costs and expenses:
Management fees		42	50
General and administrative		177	186
Total costs and expenses		219	236
Income before other income (loss), income taxes and non-controlling interests		(49,937)	(42,521)
Other income (loss):
Change in net assets related to consolidated VIEs		(4,167)	47,861
Change in fair value of servicing rights		1,931	3,333
Change in fair value of investment securities, net		52,495	(8,473)
Earnings from unconsolidated entities		(209)	(130)
Total other income (loss)		50,050	42,591
Income before income taxes		113	70
Net income		113	70
Net income attributable to non-controlling interests		$ (113)	$ (70)