Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Interest income from loans	$ 328,354	$ 203,252	$ 823,123	$ 583,099
Interest income from investment securities	19,019	10,697	48,308	32,955
Servicing fees	8,427	10,473	30,972	29,739
Rental income	32,932	77,512	96,036	230,969
Other revenues	1,809	352	11,680	3,621
Total revenues	390,541	302,286	1,010,119	880,383
Costs and expenses:
Management fees	27,356	23,727	114,275	91,713
Interest expense	222,423	115,531	501,492	328,558
General and administrative	45,495	38,864	134,821	122,765
Acquisition and investment pursuit costs	1,213	214	2,152	806
Costs of rental operations	12,206	31,516	32,094	90,992
Depreciation and amortization	12,611	22,041	36,498	66,992
Credit loss provision (reversal), net	15,343	(563)	20,123	(12,363)
Other expense	0	23	1,313	708
Total costs and expenses	336,647	231,353	842,768	690,171
Other income (loss):
Change in net assets related to consolidated VIEs	37,146	28,049	72,268	80,303
Change in fair value of servicing rights	515	2,237	1,234	2,740
Change in fair value of investment securities, net	(83)	(299)	(1,683)	903
Change in fair value of mortgage loans, net	(87,474)	31,727	(326,737)	68,116
(Loss) earnings from unconsolidated entities	(2,044)	2,042	911	6,002
Gain (loss) on sale of investments and other assets, net	13,453	(47)	112,059	26,377
Gain (loss) on derivative financial instruments, net	206,070	41,812	461,921	65,792
Foreign currency (loss) gain, net	(107,318)	(27,003)	(213,201)	(36,057)
Loss on extinguishment of debt	(212)	(499)	(1,035)	(2,197)
Contingency expense	(56,391)	(964)	(90,963)	(6,416)
Total other income	121,189	77,055	673,507	205,563
Income before income taxes	175,083	147,988	840,858	395,775
Income tax (provision) benefit	48,755	(7,501)	48,999	(6,378)
Net income	223,838	140,487	889,857	389,397
Net income attributable to non-controlling interests	(29,276)	(11,885)	(158,409)	(33,107)
Net income attributable to Starwood Property Trust, Inc.	194,562	128,602	731,448	356,290
Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	117,527	0	658,733	0
Operating Segments and Corporate
Revenues:
Interest income from loans	328,354	203,252	823,123	583,099
Interest income from investment securities	57,349	41,723	151,075	125,025
Servicing fees	11,972	15,546	41,937	44,601
Rental income	32,932	77,512	96,036	230,969
Other revenues	1,812	352	11,692	3,621
Total revenues	432,419	338,385	1,123,863	987,315
Costs and expenses:
Management fees	27,356	23,727	114,275	91,692
Interest expense	222,640	115,752	502,139	329,190
General and administrative	45,409	38,792	134,556	122,521
Acquisition and investment pursuit costs	1,213	214	2,152	806
Costs of rental operations	12,206	31,516	32,094	90,992
Depreciation and amortization	12,611	22,041	36,498	66,992
Credit loss provision (reversal), net	15,343	(563)	20,123	(12,363)
Other expense		23	1,313	708
Total costs and expenses	336,778	231,502	843,150	690,538
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	357	(410)	683	795
Change in fair value of investment securities, net	(5,014)	(5,812)	(43,872)	(22,679)
Change in fair value of mortgage loans, net	(87,474)	31,727	(326,737)	68,116
(Loss) earnings from unconsolidated entities	(1,550)	2,218	2,534	5,725
Gain (loss) on sale of investments and other assets, net	13,453	(47)	112,059	26,377
Gain (loss) on derivative financial instruments, net	206,070	41,812	461,921	65,792
Foreign currency (loss) gain, net	(107,318)	(27,003)	(213,201)	(36,057)
Loss on extinguishment of debt	(212)	(499)	(1,035)	(2,197)
Contingency expense	(56,391)	(964)	(90,988)	(6,416)
Total other income	79,448	41,022	560,097	99,456
Income before income taxes	175,089	147,905	840,810	396,233
Income tax (provision) benefit	48,755	(7,501)	48,999	(6,378)
Net income	223,844	140,404	889,809	389,855
Net income attributable to non-controlling interests	(29,282)	(11,802)	(158,361)	(33,565)
Net income attributable to Starwood Property Trust, Inc.	194,562	128,602	731,448	356,290
Operating Segments and Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	117,527		658,733
Operating segment | Loan Transfers Accounted for as Sales
Revenues:
Interest income from loans	284,197	179,486	714,222	515,776
Interest income from investment securities	28,560	16,043	71,987	51,618
Servicing fees	142	99	420	333
Rental income	1,944	1,358	4,674	4,116
Other revenues	138	59	251	223
Total revenues	314,981	197,045	791,554	572,066
Costs and expenses:
Management fees	227	286	758	901
Interest expense	145,107	52,066	301,935	144,717
General and administrative	16,458	9,178	39,905	30,922
Acquisition and investment pursuit costs	1,164	158	2,401	522
Costs of rental operations	2,633	438	4,978	1,348
Depreciation and amortization	1,629	312	3,106	930
Credit loss provision (reversal), net	8,401	19	13,027	(12,957)
Other expense		0	1,251	31
Total costs and expenses	175,619	62,457	367,361	166,414
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	16,398	(8,682)	(5,019)	(20,134)
Change in fair value of mortgage loans, net	(90,159)	22,464	(327,743)	24,079
(Loss) earnings from unconsolidated entities	(4,044)	1,666	(2,598)	5,415
Gain (loss) on sale of investments and other assets, net	(288)	(47)	86,460	16,627
Gain (loss) on derivative financial instruments, net	220,296	38,016	465,831	59,212
Foreign currency (loss) gain, net	(107,087)	(26,820)	(212,672)	(35,699)
Loss on extinguishment of debt	0	0	(206)	(289)
Contingency expense	(56,391)	(964)	(90,988)	(6,468)
Total other income	(21,275)	25,633	(86,935)	42,743
Income before income taxes	118,087	160,221	337,258	448,395
Income tax (provision) benefit	53,099	(5,652)	57,682	886
Net income	171,186	154,569	394,940	449,281
Net income attributable to non-controlling interests	(3)	(3)	(10)	(10)
Net income attributable to Starwood Property Trust, Inc.	171,183	154,566	394,930	449,271
Operating segment | Loan Transfers Accounted for as Sales | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	0		0
Operating segment | Infrastructure Lending Segment
Revenues:
Interest income from loans	43,018	21,566	100,097	61,545
Interest income from investment securities	1,204	540	3,124	1,659
Servicing fees	0	0	0	0
Rental income	0	0	0	0
Other revenues	129	66	287	228
Total revenues	44,351	22,172	103,508	63,432
Costs and expenses:
Management fees	0	0	0	0
Interest expense	22,500	9,381	49,431	27,916
General and administrative	3,588	3,307	10,730	10,281
Acquisition and investment pursuit costs	2	0	3	249
Costs of rental operations	0	0	0	0
Depreciation and amortization	101	101	310	301
Credit loss provision (reversal), net	6,942	(582)	7,096	594
Other expense		0	0	0
Total costs and expenses	33,133	12,207	67,570	39,341
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
(Loss) earnings from unconsolidated entities	1,892	399	2,631	75
Gain (loss) on sale of investments and other assets, net	0	0	0	27
Gain (loss) on derivative financial instruments, net	331	87	1,228	883
Foreign currency (loss) gain, net	(253)	(168)	(570)	(279)
Loss on extinguishment of debt	0	(18)	(469)	(1,264)
Contingency expense	0	0	0	23
Total other income	1,970	300	2,820	(535)
Income before income taxes	13,188	10,265	38,758	23,556
Income tax (provision) benefit	2	488	7	338
Net income	13,190	10,753	38,765	23,894
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to Starwood Property Trust, Inc.	13,190	10,753	38,765	23,894
Operating segment | Infrastructure Lending Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	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	22,886	66,673	67,879	197,187
Other revenues	54	54	152	138
Total revenues	22,940	66,727	68,031	197,325
Costs and expenses:
Management fees	0	0	0	0
Interest expense	9,266	17,002	22,421	49,697
General and administrative	933	913	2,964	2,964
Acquisition and investment pursuit costs	0	0	7	0
Costs of rental operations	5,793	26,634	16,010	76,516
Depreciation and amortization	8,161	17,882	24,559	53,883
Credit loss provision (reversal), net	0	0	0	0
Other expense		0	55	583
Total costs and expenses	24,153	62,431	66,016	183,643
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
(Loss) earnings from unconsolidated entities	0	0	0	0
Gain (loss) on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	10,262	(318)	33,162	4,034
Foreign currency (loss) gain, net	22	(16)	41	(16)
Loss on extinguishment of debt	0	0	0	(141)
Contingency expense	0	0	0	0
Total other income	127,811	(334)	691,936	3,877
Income before income taxes	126,598	3,962	693,951	17,559
Income tax (provision) benefit	0	0	0	0
Net income	126,598	3,962	693,951	17,559
Net income attributable to non-controlling interests	(28,486)	(4,691)	(148,379)	(14,682)
Net income attributable to Starwood Property Trust, Inc.	98,112	(729)	545,572	2,877
Operating segment | Property Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	117,527		658,733
Operating segment | Investing and Servicing Segment
Revenues:
Interest income from loans	1,139	2,200	8,804	5,778
Interest income from investment securities	27,585	25,140	75,964	71,748
Servicing fees	11,830	15,447	41,517	44,268
Rental income	8,102	9,481	23,483	29,666
Other revenues	1,491	173	10,999	3,032
Total revenues	50,147	52,441	160,767	154,492
Costs and expenses:
Management fees	0	(1,239)	0	(793)
Interest expense	6,601	5,652	19,202	16,890
General and administrative	20,046	21,022	66,603	65,182
Acquisition and investment pursuit costs	47	56	(259)	35
Costs of rental operations	3,780	4,444	11,106	13,128
Depreciation and amortization	2,720	3,746	8,523	11,878
Credit loss provision (reversal), net	0	0	0	0
Other expense		23	7	94
Total costs and expenses	33,194	33,704	105,182	106,414
Other income (loss):
Change in net assets related to consolidated VIEs	0	0	0	0
Change in fair value of servicing rights	357	(410)	683	795
Change in fair value of investment securities, net	(21,412)	2,870	(38,853)	(2,545)
Change in fair value of mortgage loans, net	2,685	9,263	1,006	44,037
(Loss) earnings from unconsolidated entities	602	153	2,501	235
Gain (loss) on sale of investments and other assets, net	13,741	0	25,599	9,723
Gain (loss) on derivative financial instruments, net	6,849	3,992	43,719	7,544
Foreign currency (loss) gain, net	0	1	0	(63)
Loss on extinguishment of debt	(212)	0	(360)	(22)
Contingency expense	0	0	0	29
Total other income	2,610	15,869	34,295	59,733
Income before income taxes	19,563	34,606	89,880	107,811
Income tax (provision) benefit	(4,346)	(2,337)	(8,690)	(7,602)
Net income	15,217	32,269	81,190	100,209
Net income attributable to non-controlling interests	(793)	(7,108)	(9,972)	(18,873)
Net income attributable to Starwood Property Trust, Inc.	14,424	25,161	71,218	81,336
Operating segment | Investing and Servicing Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	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	0	0	3	0
Total revenues	0	0	3	0
Costs and expenses:
Management fees	27,129	24,680	113,517	91,584
Interest expense	39,166	31,651	109,150	89,970
General and administrative	4,384	4,372	14,354	13,172
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 (reversal), net	0	0	0	0
Other expense		0	0	0
Total costs and expenses	70,679	60,703	237,021	194,726
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
(Loss) earnings from unconsolidated entities	0	0	0	0
Gain (loss) on sale of investments and other assets, net	0	0	0	0
Gain (loss) on derivative financial instruments, net	(31,668)	35	(82,019)	(5,881)
Foreign currency (loss) gain, net	0	0	0	0
Loss on extinguishment of debt	0	(481)	0	(481)
Contingency expense	0	0	0	0
Total other income	(31,668)	(446)	(82,019)	(6,362)
Income before income taxes	(102,347)	(61,149)	(319,037)	(201,088)
Income tax (provision) benefit	0	0	0	0
Net income	(102,347)	(61,149)	(319,037)	(201,088)
Net income attributable to non-controlling interests	0	0	0	0
Net income attributable to Starwood Property Trust, Inc.	(102,347)	(61,149)	(319,037)	(201,088)
Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	0		0
Securitization VIEs
Revenues:
Interest income from loans	0	0	0	0
Interest income from investment securities	(38,330)	(31,026)	(102,767)	(92,070)
Servicing fees	(3,545)	(5,073)	(10,965)	(14,862)
Rental income	0	0	0	0
Other revenues	(3)	0	(12)	0
Total revenues	(41,878)	(36,099)	(113,744)	(106,932)
Costs and expenses:
Management fees	0	0	0	21
Interest expense	(217)	(221)	(647)	(632)
General and administrative	86	72	265	244
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 (reversal), net	0	0	0	0
Other expense		0	0	0
Total costs and expenses	(131)	(149)	(382)	(367)
Other income (loss):
Change in net assets related to consolidated VIEs	37,146	28,049	72,268	80,303
Change in fair value of servicing rights	158	2,647	551	1,945
Change in fair value of investment securities, net	4,931	5,513	42,189	23,582
Change in fair value of mortgage loans, net	0	0	0	0
(Loss) earnings from unconsolidated entities	(494)	(176)	(1,623)	277
Gain (loss) 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
Contingency expense	0	0	25	0
Total other income	41,741	36,033	113,410	106,107
Income before income taxes	(6)	83	48	(458)
Income tax (provision) benefit	0	0	0	0
Net income	(6)	83	48	(458)
Net income attributable to non-controlling interests	6	(83)	(48)	458
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