Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Interest income from loans	$ 457,299	$ 328,354	$ 1,344,056	$ 823,123
Interest income from investment securities	20,133	19,019	57,689	48,308
Servicing fees	8,630	8,427	22,228	30,972
Rental income	33,091	32,932	97,687	96,036
Other revenues	2,394	1,809	5,970	11,680
Total revenues	521,547	390,541	1,527,630	1,010,119
Costs and expenses:
Management fees	27,143	27,356	97,661	114,275
Interest expense	368,357	222,423	1,066,990	501,492
General and administrative	46,691	45,495	131,955	134,821
Acquisition and investment pursuit costs	211	1,213	625	2,152
Costs of rental operations	11,777	12,206	34,910	32,094
Depreciation and amortization	12,271	12,611	37,010	36,498
Credit loss provision, net	52,634	15,343	217,753	20,123
Other expense	516	0	1,490	1,313
Total costs and expenses	519,600	336,647	1,588,394	842,768
Other income (loss):
Change in net assets related to consolidated VIEs	43,763	37,146	139,024	72,268
Change in fair value of servicing rights	(68)	515	398	1,234
Change in fair value of investment securities, net	283	(83)	353	(1,683)
Change in fair value of mortgage loans, net	(66,806)	(87,474)	(111,247)	(326,737)
Earnings (loss) from unconsolidated entities	(1,309)	(2,044)	11,378	911
(Loss) gain on sale of investments and other assets, net	10,616	13,453	15,486	112,059
Gain (loss) on derivative financial instruments, net	94,883	206,070	118,431	461,921
Foreign currency (loss) gain, net	(56,646)	(107,318)	(18,293)	(213,201)
Loss on extinguishment of debt	(1,072)	(212)	(2,256)	(1,035)
Other (loss) income, net	(2,521)	(56,391)	(31,686)	(90,963)
Total other income	38,031	121,189	375,284	673,507
Income before income taxes	39,978	175,083	314,520	840,858
Income tax benefit	11,399	48,755	18,997	48,999
Net income	51,377	223,838	333,517	889,857
Net income attributable to non-controlling interests	(3,942)	(29,276)	(65,265)	(158,409)
Net income attributable to Starwood Property Trust, Inc.	47,435	194,562	268,252	731,448
Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	16,908	117,527	253,696	658,733
Subtotal
Revenues:
Interest income from loans	457,299	328,354	1,344,056	823,123
Interest income from investment securities	61,466	57,349	173,641	151,075
Servicing fees	11,375	11,972	30,913	41,937
Rental income	33,091	32,932	97,687	96,036
Other revenues	2,394	1,812	5,970	11,692
Total revenues	565,625	432,419	1,652,267	1,123,863
Costs and expenses:
Management fees	27,143	27,356	97,661	114,275
Interest expense	368,569	222,640	1,067,623	502,139
General and administrative	46,691	45,409	131,955	134,556
Acquisition and investment pursuit costs	211	1,213	625	2,152
Costs of rental operations	11,777	12,206	34,910	32,094
Depreciation and amortization	12,271	12,611	37,010	36,498
Credit loss provision, net	52,634	15,343	217,753	20,123
Other expense	516		1,490	1,313
Total costs and expenses	519,812	336,778	1,589,027	843,150
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	(983)	357	(2,684)	683
Change in fair value of investment securities, net	703	(5,014)	16,553	(43,872)
Change in fair value of mortgage loans, net	(66,806)	(87,474)	(111,247)	(326,737)
Earnings (loss) from unconsolidated entities	(917)	(1,550)	13,280	2,534
(Loss) gain on sale of investments and other assets, net	10,616	13,453	15,486	112,059
Gain (loss) on derivative financial instruments, net	94,883	206,070	118,431	461,921
Foreign currency (loss) gain, net	(56,646)	(107,318)	(18,293)	(213,201)
Loss on extinguishment of debt	(1,072)	(212)	(2,256)	(1,035)
Other (loss) income, net	(2,521)	(56,391)	(31,686)	(90,988)
Total other income	(5,835)	79,448	251,280	560,097
Income before income taxes	39,978	175,089	314,520	840,810
Income tax benefit	11,399	48,755	18,997	48,999
Net income	51,377	223,844	333,517	889,809
Net income attributable to non-controlling interests	(3,942)	(29,282)	(65,265)	(158,361)
Net income attributable to Starwood Property Trust, Inc.	47,435	194,562	268,252	731,448
Subtotal | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	16,908	117,527	253,696	658,733
Operating segment | Commercial and Residential Lending Segment
Revenues:
Interest income from loans	397,045	284,197	1,166,758	714,222
Interest income from investment securities	36,178	28,560	102,462	71,987
Servicing fees	147	142	441	420
Rental income	2,470	1,944	6,410	4,674
Other revenues	822	138	2,007	251
Total revenues	436,662	314,981	1,278,078	791,554
Costs and expenses:
Management fees	199	227	629	758
Interest expense	247,727	145,107	724,452	301,935
General and administrative	15,659	16,458	42,117	39,905
Acquisition and investment pursuit costs	207	1,164	665	2,401
Costs of rental operations	2,475	2,633	7,505	4,978
Depreciation and amortization	1,912	1,629	5,262	3,106
Credit loss provision, net	51,487	8,401	200,439	13,027
Other expense	516		1,451	1,251
Total costs and expenses	320,182	175,619	982,520	367,361
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	0	0	0	0
Change in fair value of investment securities, net	21,456	16,398	62,766	(5,019)
Change in fair value of mortgage loans, net	(68,450)	(90,159)	(125,390)	(327,743)
Earnings (loss) from unconsolidated entities	1,142	(4,044)	3,563	(2,598)
(Loss) gain on sale of investments and other assets, net	(52)	(288)	(140)	86,460
Gain (loss) on derivative financial instruments, net	99,735	220,296	132,686	465,831
Foreign currency (loss) gain, net	(56,309)	(107,087)	(18,118)	(212,672)
Loss on extinguishment of debt	(757)	0	(1,822)	(206)
Other (loss) income, net	(2,527)	(56,391)	(31,693)	(90,988)
Total other income	(5,762)	(21,275)	21,852	(86,935)
Income before income taxes	110,718	118,087	317,410	337,258
Income tax benefit	9,823	53,099	15,981	57,682
Net income	120,541	171,186	333,391	394,940
Net income attributable to non-controlling interests	(3)	(3)	(10)	(10)
Net income attributable to Starwood Property Trust, Inc.	120,538	171,183	333,381	394,930
Operating segment | Commercial and Residential Lending Segment | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0	0	0
Operating segment | Infrastructure Lending Segment
Revenues:
Interest income from loans	58,628	43,018	172,969	100,097
Interest income from investment securities	155	1,204	1,658	3,124
Servicing fees	0	0	0	0
Rental income	0	0	0	0
Other revenues	469	129	995	287
Total revenues	59,252	44,351	175,622	103,508
Costs and expenses:
Management fees	0	0	0	0
Interest expense	34,887	22,500	103,188	49,431
General and administrative	3,822	3,588	11,520	10,730
Acquisition and investment pursuit costs	4	2	17	3
Costs of rental operations	0	0	0	0
Depreciation and amortization	27	101	84	310
Credit loss provision, net	1,147	6,942	17,314	7,096
Other expense	0		0	0
Total costs and expenses	39,887	33,133	132,123	67,570
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	0	0	0	0
Change in fair value of investment securities, net	0	0	0	0
Change in fair value of mortgage loans, net	0	0	0	0
Earnings (loss) from unconsolidated entities	(2,459)	1,892	1,324	2,631
(Loss) gain on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	98	331	244	1,228
Foreign currency (loss) gain, net	(382)	(253)	(225)	(570)
Loss on extinguishment of debt	0	0	0	(469)
Other (loss) income, net	(6)	0	0	0
Total other income	(2,749)	1,970	1,343	2,820
Income before income taxes	16,616	13,188	44,842	38,758
Income tax benefit	243	2	581	7
Net income	16,859	13,190	45,423	38,765
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to Starwood Property Trust, Inc.	16,859	13,190	45,423	38,765
Operating segment | Infrastructure Lending Segment | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0	0	0
Operating segment | Property Segment
Revenues:
Interest income from loans	0	0	0	0
Interest income from investment securities	0	0	0	0
Servicing fees	0	0	0	0
Rental income	23,567	22,886	70,587	67,879
Other revenues	193	54	494	152
Total revenues	23,760	22,940	71,081	68,031
Costs and expenses:
Management fees	0	0	0	0
Interest expense	14,161	9,266	40,229	22,421
General and administrative	1,021	933	2,966	2,964
Acquisition and investment pursuit costs	0	0	0	7
Costs of rental operations	6,039	5,793	17,034	16,010
Depreciation and amortization	7,930	8,161	24,061	24,559
Credit loss provision, net	0	0	0	0
Other expense	0		23	55
Total costs and expenses	29,151	24,153	84,313	66,016
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	0	0	0	0
Change in fair value of investment securities, net	0	0	0	0
Change in fair value of mortgage loans, net	0	0	0	0
Earnings (loss) from unconsolidated entities	0	0	0	0
(Loss) gain on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	557	10,262	4,448	33,162
Foreign currency (loss) gain, net	45	22	50	41
Loss on extinguishment of debt	0	0	0	0
Other (loss) income, net	0	0	(5)	0
Total other income	17,510	127,811	258,189	691,936
Income before income taxes	12,119	126,598	244,957	693,951
Income tax benefit	0	0	0	0
Net income	12,119	126,598	244,957	693,951
Net income attributable to non-controlling interests	(7,812)	(28,486)	(65,149)	(148,379)
Net income attributable to Starwood Property Trust, Inc.	4,307	98,112	179,808	545,572
Operating segment | Property Segment | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	16,908	117,527	253,696	658,733
Operating segment | Investing and Servicing Segment
Revenues:
Interest income from loans	1,626	1,139	4,329	8,804
Interest income from investment securities	25,133	27,585	69,521	75,964
Servicing fees	11,228	11,830	30,472	41,517
Rental income	7,054	8,102	20,690	23,483
Other revenues	407	1,491	1,302	10,999
Total revenues	45,448	50,147	126,314	160,767
Costs and expenses:
Management fees	0	0	0	0
Interest expense	8,448	6,601	24,752	19,202
General and administrative	21,365	20,046	62,052	66,603
Acquisition and investment pursuit costs	0	47	(57)	(259)
Costs of rental operations	3,263	3,780	10,371	11,106
Depreciation and amortization	2,402	2,720	7,603	8,523
Credit loss provision, net	0	0	0	0
Other expense	0		16	7
Total costs and expenses	35,478	33,194	104,737	105,182
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	(983)	357	(2,684)	683
Change in fair value of investment securities, net	(20,753)	(21,412)	(46,213)	(38,853)
Change in fair value of mortgage loans, net	1,644	2,685	14,143	1,006
Earnings (loss) from unconsolidated entities	400	602	8,393	2,501
(Loss) gain on sale of investments and other assets, net	10,668	13,741	15,626	25,599
Gain (loss) on derivative financial instruments, net	4,116	6,849	4,469	43,719
Foreign currency (loss) gain, net	0	0	0	0
Loss on extinguishment of debt	(315)	(212)	(434)	(360)
Other (loss) income, net	12	0	12	0
Total other income	(5,211)	2,610	(6,688)	34,295
Income before income taxes	4,759	19,563	14,889	89,880
Income tax benefit	1,333	(4,346)	2,435	(8,690)
Net income	6,092	15,217	17,324	81,190
Net income attributable to non-controlling interests	3,873	(793)	(106)	(9,972)
Net income attributable to Starwood Property Trust, Inc.	9,965	14,424	17,218	71,218
Operating segment | Investing and Servicing Segment | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0	0	0
Corporate
Revenues:
Interest income from loans	0	0	0	0
Interest income from investment securities	0	0	0	0
Servicing fees	0	0	0	0
Rental income	0	0	0	0
Other revenues	503	0	1,172	3
Total revenues	503	0	1,172	3
Costs and expenses:
Management fees	26,944	27,129	97,032	113,517
Interest expense	63,346	39,166	175,002	109,150
General and administrative	4,824	4,384	13,300	14,354
Acquisition and investment pursuit costs	0	0	0	0
Costs of rental operations	0	0	0	0
Depreciation and amortization	0	0	0	0
Credit loss provision, net	0	0	0	0
Other expense	0		0	0
Total costs and expenses	95,114	70,679	285,334	237,021
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	0	0	0	0
Change in fair value of investment securities, net	0	0	0	0
Change in fair value of mortgage loans, net	0	0	0	0
Earnings (loss) from unconsolidated entities	0	0	0	0
(Loss) gain on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	(9,623)	(31,668)	(23,416)	(82,019)
Foreign currency (loss) gain, net	0	0	0	0
Loss on extinguishment of debt	0	0	0	0
Other (loss) income, net	0	0	0	0
Total other income	(9,623)	(31,668)	(23,416)	(82,019)
Income before income taxes	(104,234)	(102,347)	(307,578)	(319,037)
Income tax benefit	0	0	0	0
Net income	(104,234)	(102,347)	(307,578)	(319,037)
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to Starwood Property Trust, Inc.	(104,234)	(102,347)	(307,578)	(319,037)
Corporate | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0	0	0
Securitization VIEs
Revenues:
Interest income from loans	0	0	0	0
Interest income from investment securities	(41,333)	(38,330)	(115,952)	(102,767)
Servicing fees	(2,745)	(3,545)	(8,685)	(10,965)
Rental income	0	0	0	0
Other revenues	0	(3)	0	(12)
Total revenues	(44,078)	(41,878)	(124,637)	(113,744)
Costs and expenses:
Management fees	0	0	0	0
Interest expense	(212)	(217)	(633)	(647)
General and administrative	0	86	0	265
Acquisition and investment pursuit costs	0	0	0	0
Costs of rental operations	0	0	0	0
Depreciation and amortization	0	0	0	0
Credit loss provision, net	0	0	0	0
Other expense	0		0	0
Total costs and expenses	(212)	(131)	(633)	(382)
Other income (loss):
Change in net assets related to consolidated VIEs	43,763	37,146	139,024	72,268
Change in fair value of servicing rights	915	158	3,082	551
Change in fair value of investment securities, net	(420)	4,931	(16,200)	42,189
Change in fair value of mortgage loans, net	0	0	0	0
Earnings (loss) from unconsolidated entities	(392)	(494)	(1,902)	(1,623)
(Loss) gain on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	0	0	0	0
Foreign currency (loss) gain, net	0	0	0	0
Loss on extinguishment of debt	0	0	0	0
Other (loss) income, net	0	0	0	25
Total other income	43,866	41,741	124,004	113,410
Income before income taxes	0	(6)	0	48
Income tax benefit	0	0	0	0
Net income	0	(6)	0	48
Net income attributable to non-controlling interests	0	6	0	(48)
Net income attributable to Starwood Property Trust, Inc.	0	0	0	0
Securitization VIEs | Primary Beneficiary
Other income (loss):
Income from affordable housing fund investments	$ 0	$ 0	$ 0	$ 0