Segment and Geographic Data - Results of Operations (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Interest income from loans		$ 800,291	$ 751,943	$ 724,013
Interest income from investment securities		45,168	54,412	76,629
Servicing fees		38,739	29,634	54,296
Rental income		278,831	297,828	337,966
Other revenues		7,059	2,338	3,515
Total revenues		1,170,088	1,136,155	1,196,419
Costs and expenses:
Management fees		167,773	127,127	119,132
Interest expense		445,087	419,763	508,729
General and administrative		171,302	157,874	155,112
Acquisition and investment pursuit costs		1,184	3,572	1,056
Costs of rental operations		111,667	117,676	122,982
Depreciation and amortization		83,001	94,405	113,322
Credit loss provision, net		8,335	43,153	7,126
Other expense		708	838	2,365
Total costs and expenses		989,057	964,408	1,029,824
Other income (loss):
Change in net assets related to consolidated VIEs		162,333	78,258	236,309
Change in fair value of servicing rights		3,578	(3,715)	(3,640)
Change in fair value of investment securities, net		(387)	5,393	833
Change in fair value of mortgage loans, net		69,050	133,124	71,601
Earnings (loss) from unconsolidated entities		8,752	37,317	(101,354)
Gain on sale of investments and other assets, net		38,984	7,310	188,028
Gain (loss) on derivative financial instruments, net		82,363	(82,178)	(6,310)
Foreign currency (loss) gain, net		(36,292)	42,395	17,582
Loss on extinguishment of debt		(7,428)	(3,654)	(19,270)
Other (loss) income, net		(7,314)	281	(207)
Total other income		320,064	214,531	383,572
Income before income taxes		501,095	386,278	550,167
Income tax (provision) benefit		(8,669)	(20,197)	(13,232)
Net income		492,426	366,081	536,935
Net (income) loss attributable to non-controlling interests		(44,687)	(34,392)	(27,271)
Net income attributable to Starwood Property Trust, Inc.		447,739	331,689	509,664
Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	$ 6,425	6,425	0	0
Operating Segments and Corporate
Revenues:
Interest income from loans		800,291	751,943	724,013
Interest income from investment securities		166,550	174,950	205,236
Servicing fees		59,349	42,355	70,385
Rental income		278,831	297,828	337,966
Other revenues		7,063	2,343	3,541
Total revenues		1,312,084	1,269,419	1,341,141
Costs and expenses:
Management fees		167,749	127,069	118,971
Interest expense		445,939	420,149	509,377
General and administrative		170,975	157,538	154,769
Acquisition and investment pursuit costs		1,184	3,572	1,056
Costs of rental operations		111,667	117,676	122,982
Depreciation and amortization		83,001	94,405	113,322
Credit loss provision, net		8,335	43,153	7,126
Other expense		708	838	2,365
Total costs and expenses		989,558	964,400	1,029,968
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		4,319	11,415	(1,468)
Change in fair value of investment securities, net		19,944	(66,511)	88,122
Change in fair value of mortgage loans, net		69,050	133,124	71,601
Earnings (loss) from unconsolidated entities		8,959	38,857	(99,547)
Gain on sale of investments and other assets, net		38,984	7,310	188,028
Gain (loss) on derivative financial instruments, net		82,363	(82,178)	(6,310)
Foreign currency (loss) gain, net		(36,292)	42,395	17,582
Loss on extinguishment of debt		(7,428)	(3,654)	(19,270)
Other (loss) income, net		(7,314)	281	(207)
Total other income		179,010	81,039	238,531
Income before income taxes		501,536	386,058	549,704
Income tax (provision) benefit		(8,669)	(20,197)	(13,232)
Net income		492,867	365,861	536,472
Net (income) loss attributable to non-controlling interests		(45,128)	(34,172)	(26,808)
Net income attributable to Starwood Property Trust, Inc.		447,739	331,689	509,664
Operating Segments and Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		6,425
Operating segment | Commercial and Residential Lending Segment
Revenues:
Interest income from loans		705,499	665,503	610,316
Interest income from investment securities		67,589	78,490	81,255
Servicing fees		453	549	423
Rental income		5,486	4,706	0
Other revenues		294	412	1,038
Total revenues		779,321	749,660	693,032
Costs and expenses:
Management fees		948	796	1,495
Interest expense		206,353	176,230	222,118
General and administrative		42,000	41,972	29,481
Acquisition and investment pursuit costs		893	2,406	1,351
Costs of rental operations		1,769	3,186	2,691
Depreciation and amortization		1,243	1,708	1,091
Credit loss provision, net		(3,560)	47,256	2,616
Other expense		31	307	307
Total costs and expenses		249,677	273,861	261,150
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		0	0	0
Change in fair value of investment securities, net		(8,277)	(15,108)	(1,084)
Change in fair value of mortgage loans, net		13,836	76,897	10,462
Earnings (loss) from unconsolidated entities		6,984	8,779	10,649
Gain on sale of investments and other assets, net		16,584	(961)	4,619
Gain (loss) on derivative financial instruments, net		73,209	(58,664)	(20,325)
Foreign currency (loss) gain, net		(36,045)	42,205	17,342
Loss on extinguishment of debt		(289)	(22)	(857)
Other (loss) income, net		(7,407)	0	0
Total other income		58,595	53,126	20,806
Income before income taxes		588,239	528,925	452,688
Income tax (provision) benefit		(1,201)	(21,091)	(4,818)
Net income		587,038	507,834	447,870
Net (income) loss attributable to non-controlling interests		(14)	(14)	(392)
Net income attributable to Starwood Property Trust, Inc.		587,024	507,820	447,478
Operating segment | Commercial and Residential Lending Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		0
Operating segment | Infrastructure Lending Segment
Revenues:
Interest income from loans		85,057	77,851	99,580
Interest income from investment securities		2,190	2,637	6,318
Servicing fees		0	0	0
Rental income		0	0	0
Other revenues		293	499	751
Total revenues		87,540	80,987	106,649
Costs and expenses:
Management fees		0	0	0
Interest expense		37,671	40,913	62,836
General and administrative		14,557	15,673	18,260
Acquisition and investment pursuit costs		250	1,183	75
Costs of rental operations		0	0	0
Depreciation and amortization		402	342	83
Credit loss provision, net		11,895	(4,103)	4,510
Other expense		0	0	0
Total costs and expenses		64,775	54,008	85,764
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		0	0	0
Change in fair value of investment securities, net		0	0	0
Change in fair value of mortgage loans, net		0	0	0
Earnings (loss) from unconsolidated entities		1,160	(767)	0
Gain on sale of investments and other assets, net		189	306	3,041
Gain (loss) on derivative financial instruments, net		1,253	(1,499)	(3,349)
Foreign currency (loss) gain, net		(183)	207	205
Loss on extinguishment of debt		(1,264)	(959)	(11,357)
Other (loss) income, net		23	0	(50)
Total other income		1,178	(2,712)	(11,510)
Income before income taxes		23,943	24,267	9,375
Income tax (provision) benefit		306	(117)	89
Net income		24,249	24,150	9,464
Net (income) loss attributable to non-controlling interests		0	0	0
Net income attributable to Starwood Property Trust, Inc.		24,249	24,150	9,464
Operating segment | Infrastructure Lending Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		0
Operating segment | Property Segment
Revenues:
Interest income from loans		0	0	0
Interest income from investment securities		0	0	0
Servicing fees		0	0	0
Rental income		234,840	255,452	287,094
Other revenues		198	293	409
Total revenues		235,038	255,745	287,503
Costs and expenses:
Management fees		0	0	0
Interest expense		59,970	65,390	76,838
General and administrative		8,067	4,542	6,232
Acquisition and investment pursuit costs		(60)	12	217
Costs of rental operations		92,190	97,136	95,370
Depreciation and amortization		65,833	76,246	92,561
Credit loss provision, net		0	0	0
Other expense		583	531	1,693
Total costs and expenses		226,583	243,857	272,911
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		0	0	0
Change in fair value of investment securities, net		0	0	0
Change in fair value of mortgage loans, net		0	0	0
Earnings (loss) from unconsolidated entities		0	0	(114,362)
Gain on sale of investments and other assets, net		0	0	119,746
Gain (loss) on derivative financial instruments, net		10,155	(34,392)	(1,284)
Foreign currency (loss) gain, net		0	(14)	37
Loss on extinguishment of debt		(5,281)	(2,185)	(4,745)
Other (loss) income, net		0	(166)	(100)
Total other income		11,299	(36,757)	(708)
Income before income taxes		19,754	(24,869)	13,884
Income tax (provision) benefit		0	0	(393)
Net income		19,754	(24,869)	13,491
Net (income) loss attributable to non-controlling interests		(20,121)	(20,394)	(21,630)
Net income attributable to Starwood Property Trust, Inc.		(367)	(45,263)	(8,139)
Operating segment | Property Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		6,425
Operating segment | Investing and Servicing Segment
Revenues:
Interest income from loans		9,735	8,589	14,117
Interest income from investment securities		96,771	93,823	117,663
Servicing fees		58,896	41,806	69,962
Rental income		38,505	37,670	50,872
Other revenues		6,278	1,139	1,317
Total revenues		210,185	183,027	253,931
Costs and expenses:
Management fees		(793)	901	72
Interest expense		22,543	24,303	33,621
General and administrative		88,879	80,039	87,115
Acquisition and investment pursuit costs		101	(29)	(587)
Costs of rental operations		17,708	17,354	24,921
Depreciation and amortization		15,523	16,109	19,587
Credit loss provision, net		0	0	0
Other expense		94	0	365
Total costs and expenses		144,055	138,677	165,094
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		4,319	11,415	(1,468)
Change in fair value of investment securities, net		28,221	(51,403)	89,206
Change in fair value of mortgage loans, net		55,214	56,227	61,139
Earnings (loss) from unconsolidated entities		815	30,845	4,166
Gain on sale of investments and other assets, net		22,211	7,965	60,622
Gain (loss) on derivative financial instruments, net		8,288	(21,269)	(7,414)
Foreign currency (loss) gain, net		(64)	(3)	(2)
Loss on extinguishment of debt		(113)	0	(845)
Other (loss) income, net		70	447	16
Total other income		118,961	34,224	205,420
Income before income taxes		185,091	78,574	294,257
Income tax (provision) benefit		(7,775)	1,011	(8,110)
Net income		177,316	79,585	286,147
Net (income) loss attributable to non-controlling interests		(24,993)	(13,764)	(4,786)
Net income attributable to Starwood Property Trust, Inc.		152,323	65,821	281,361
Operating segment | Investing and Servicing Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		0
Corporate
Revenues:
Interest income from loans		0	0	0
Interest income from investment securities		0	0	0
Servicing fees		0	0	0
Rental income		0	0	0
Other revenues		0	0	26
Total revenues		0	0	26
Costs and expenses:
Management fees		167,594	125,372	117,404
Interest expense		119,402	113,313	113,964
General and administrative		17,472	15,312	13,681
Acquisition and investment pursuit costs		0	0	0
Costs of rental operations		0	0	0
Depreciation and amortization		0	0	0
Credit loss provision, net		0	0	0
Other expense		0	0	0
Total costs and expenses		304,468	253,997	245,049
Other income (loss):
Change in net assets related to consolidated VIEs		0	0	0
Change in fair value of servicing rights		0	0	0
Change in fair value of investment securities, net		0	0	0
Change in fair value of mortgage loans, net		0	0	0
Earnings (loss) from unconsolidated entities		0	0	0
Gain on sale of investments and other assets, net		0	0	0
Gain (loss) on derivative financial instruments, net		(10,542)	33,646	26,062
Foreign currency (loss) gain, net		0	0	0
Loss on extinguishment of debt		(481)	(488)	(1,466)
Other (loss) income, net		0	0	(73)
Total other income		(11,023)	33,158	24,523
Income before income taxes		(315,491)	(220,839)	(220,500)
Income tax (provision) benefit		1	0	0
Net income		(315,490)	(220,839)	(220,500)
Net (income) loss attributable to non-controlling interests		0	0	0
Net income attributable to Starwood Property Trust, Inc.		(315,490)	(220,839)	(220,500)
Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		0
Securitization VIEs
Revenues:
Interest income from loans		0	0	0
Interest income from investment securities		(121,382)	(120,538)	(128,607)
Servicing fees		(20,610)	(12,721)	(16,089)
Rental income		0	0	0
Other revenues		(4)	(5)	(26)
Total revenues		(141,996)	(133,264)	(144,722)
Costs and expenses:
Management fees		24	58	161
Interest expense		(852)	(386)	(648)
General and administrative		327	336	343
Acquisition and investment pursuit costs		0	0	0
Costs of rental operations		0	0	0
Depreciation and amortization		0	0	0
Credit loss provision, net		0	0	0
Other expense		0	0	0
Total costs and expenses		(501)	8	(144)
Other income (loss):
Change in net assets related to consolidated VIEs		162,333	78,258	236,309
Change in fair value of servicing rights		(741)	(15,130)	(2,172)
Change in fair value of investment securities, net		(20,331)	71,904	(87,289)
Change in fair value of mortgage loans, net		0	0	0
Earnings (loss) from unconsolidated entities		(207)	(1,540)	(1,807)
Gain on sale of investments and other assets, net		0	0	0
Gain (loss) on derivative financial instruments, net		0	0	0
Foreign currency (loss) gain, net		0	0	0
Loss on extinguishment of debt		0	0	0
Other (loss) income, net		0	0	0
Total other income		141,054	133,492	145,041
Income before income taxes		(441)	220	463
Income tax (provision) benefit		0	0	0
Net income		(441)	220	463
Net (income) loss attributable to non-controlling interests		441	(220)	(463)
Net income attributable to Starwood Property Trust, Inc.		0	$ 0	$ 0
Securitization VIEs | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments		$ 0