Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Interest income from loans	$ 111,883	$ 117,532
Interest income from investment securities	15,224	19,403
Servicing fees	14,102	24,691
Rental income	57,042	32,677
Other revenues	469	1,190
Total revenues	198,720	195,493
Costs and expenses:
Management fees	24,384	24,963
Interest expense	65,860	56,520
General and administrative	30,429	32,798
Acquisition and investment pursuit costs	671	1,285
Costs of rental operations	20,878	12,655
Depreciation and amortization	22,228	18,760
Loan loss allowance, net	(305)	(761)
Other expense	758	100
Total costs and expenses	164,903	146,320
Income before other income (loss), income taxes and non-controlling interests	33,817	49,173
Other income (loss):
Change in net assets related to consolidated VIEs	69,170	(4,167)
Change in fair value of servicing rights	(8,433)	(6,739)
Change in fair value of investment securities, net	(1,171)	753
Change in fair value of mortgage loans held-for-sale, net	10,593	6,891
Earnings from unconsolidated entities	2,987	4,065
(Loss) gain on sale of investments and other assets, net	(56)	245
Loss on derivative financial instruments, net	(4,349)	(24,718)
Foreign currency (loss), gain net	4,864	(378)
Loss on extinguishment of debt	(5,916)
Other income, net	365	2,015
Total other income (loss)	68,054	(22,033)
Income before income taxes	101,871	27,140
Income tax benefit (provision)	983	(94)
Net income	102,854	27,046
Net income attributable to non-controlling interests	(496)	(389)
Net income attributable to Starwood Property Trust, Inc.	102,358	26,657
Operating Segments and Corporate
Revenues:
Interest income from loans	111,883	117,532
Interest income from investment securities	47,555	57,254
Servicing fees	30,291	36,377
Rental income	57,042	32,677
Other revenues	588	1,371
Total revenues	247,359	245,211
Costs and expenses:
Management fees	24,334	24,921
Interest expense	66,129	56,520
General and administrative	30,342	32,621
Acquisition and investment pursuit costs	671	1,285
Costs of rental operations	20,878	12,655
Depreciation and amortization	22,228	18,760
Loan loss allowance, net	(305)	(761)
Other expense	758	100
Total costs and expenses	165,035	146,101
Income before other income (loss), income taxes and non-controlling interests	82,324	99,110
Other income (loss):
Change in fair value of servicing rights	(9,637)	(8,670)
Change in fair value of investment securities, net	19,217	(51,742)
Change in fair value of mortgage loans held-for-sale, net	10,593	6,891
Earnings from unconsolidated entities	3,948	4,274
(Loss) gain on sale of investments and other assets, net	(56)	245
Loss on derivative financial instruments, net	(4,349)	(24,718)
Foreign currency (loss), gain net	4,864	(378)
Loss on extinguishment of debt	(5,916)
Other income, net	365	2,015
Total other income (loss)	19,029	(72,083)
Income before income taxes	101,353	27,027
Income tax benefit (provision)	983	(94)
Net income	102,336	26,933
Net income attributable to non-controlling interests	22	(276)
Net income attributable to Starwood Property Trust, Inc.	102,358	26,657
Operating segment | Lending Segment
Revenues:
Interest income from loans	109,046	114,658
Interest income from investment securities	12,719	9,628
Servicing fees	210	159
Other revenues	79	23
Total revenues	122,054	124,468
Costs and expenses:
Management fees	454	375
Interest expense	19,957	22,335
General and administrative	4,211	3,922
Acquisition and investment pursuit costs	515	338
Depreciation and amortization	17
Loan loss allowance, net	(305)	(761)
Total costs and expenses	24,849	26,209
Income before other income (loss), income taxes and non-controlling interests	97,205	98,259
Other income (loss):
Change in fair value of investment securities, net	172	(214)
Earnings from unconsolidated entities	470	468
(Loss) gain on sale of investments and other assets, net	(56)	245
Loss on derivative financial instruments, net	(4,535)	(3,026)
Foreign currency (loss), gain net	4,863	(1,822)
Total other income (loss)	914	(4,349)
Income before income taxes	98,119	93,910
Income tax benefit (provision)	(215)	(75)
Net income	97,904	93,835
Net income attributable to non-controlling interests	(354)	(350)
Net income attributable to Starwood Property Trust, Inc.	97,550	93,485
Operating segment | Investment and Servicing Segment
Revenues:
Interest income from loans	2,837	2,874
Interest income from investment securities	34,836	47,626
Servicing fees	30,081	36,218
Rental income	12,189	6,475
Other revenues	464	1,342
Total revenues	80,407	94,535
Costs and expenses:
Management fees	18	18
Interest expense	4,358	3,238
General and administrative	22,580	25,294
Acquisition and investment pursuit costs	(16)	355
Costs of rental operations	5,487	3,062
Depreciation and amortization	5,054	3,051
Other expense	758	100
Total costs and expenses	38,239	35,118
Income before other income (loss), income taxes and non-controlling interests	42,168	59,417
Other income (loss):
Change in fair value of servicing rights	(9,637)	(8,670)
Change in fair value of investment securities, net	19,045	(51,528)
Change in fair value of mortgage loans held-for-sale, net	10,593	6,891
Earnings from unconsolidated entities	1,017	1,377
Loss on derivative financial instruments, net	697	(11,245)
Foreign currency (loss), gain net	1	1,460
Other income, net	365	43
Total other income (loss)	22,081	(61,672)
Income before income taxes	64,249	(2,255)
Income tax benefit (provision)	1,198	(19)
Net income	65,447	(2,274)
Net income attributable to non-controlling interests	376	74
Net income attributable to Starwood Property Trust, Inc.	65,823	(2,200)
Operating segment | Property Segment
Revenues:
Rental income	44,853	26,202
Other revenues	45	6
Total revenues	44,898	26,208
Costs and expenses:
Interest expense	10,207	4,949
General and administrative	1,381	555
Acquisition and investment pursuit costs	172	592
Costs of rental operations	15,391	9,593
Depreciation and amortization	17,157	15,709
Total costs and expenses	44,308	31,398
Income before other income (loss), income taxes and non-controlling interests	590	(5,190)
Other income (loss):
Earnings from unconsolidated entities	2,461	2,429
Loss on derivative financial instruments, net	(511)	(10,447)
Foreign currency (loss), gain net		(16)
Other income, net		422
Total other income (loss)	1,950	(7,612)
Income before income taxes	2,540	(12,802)
Net income	2,540	(12,802)
Net income attributable to Starwood Property Trust, Inc.	2,540	(12,802)
Corporate
Costs and expenses:
Management fees	23,862	24,528
Interest expense	31,607	25,998
General and administrative	2,170	2,850
Total costs and expenses	57,639	53,376
Income before other income (loss), income taxes and non-controlling interests	(57,639)	(53,376)
Other income (loss):
Loss on extinguishment of debt	(5,916)
Other income, net		1,550
Total other income (loss)	(5,916)	1,550
Income before income taxes	(63,555)	(51,826)
Net income	(63,555)	(51,826)
Net income attributable to Starwood Property Trust, Inc.	(63,555)	(51,826)
Investment and Servicing VIEs
Revenues:
Interest income from investment securities	(32,331)	(37,851)
Servicing fees	(16,189)	(11,686)
Other revenues	(119)	(181)
Total revenues	(48,639)	(49,718)
Costs and expenses:
Management fees	50	42
Interest expense	(269)
General and administrative	87	177
Total costs and expenses	(132)	219
Income before other income (loss), income taxes and non-controlling interests	(48,507)	(49,937)
Other income (loss):
Change in net assets related to consolidated VIEs	69,170	(4,167)
Change in fair value of servicing rights	1,204	1,931
Change in fair value of investment securities, net	(20,388)	52,495
Earnings from unconsolidated entities	(961)	(209)
Total other income (loss)	49,025	50,050
Income before income taxes	518	113
Net income	518	113
Net income attributable to non-controlling interests	$ (518)	$ (113)