Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Interest income from loans	$ 430,908	$ 233,619
Interest income from investment securities	18,637	13,983
Servicing fees	7,256	9,992
Rental income	32,289	31,580
Other revenues	1,324	4,818
Total revenues	490,414	293,992
Costs and expenses:
Management fees	39,540	55,295
Interest expense	335,301	126,451
General and administrative	42,108	44,321
Acquisition and investment pursuit costs	269	422
Costs of rental operations	11,666	9,290
Depreciation and amortization	12,416	11,647
Credit loss provision (reversal), net	43,194	(3,658)
Other expense	848	55
Total costs and expenses	485,342	243,823
Other income (loss):
Change in net assets related to consolidated VIEs	41,138	26,749
Change in fair value of servicing rights	304	1,084
Change in fair value of investment securities, net	82	(355)
Change in fair value of mortgage loans, net	8,901	(125,783)
Earnings (loss) from unconsolidated entities	2,725	(910)
Gain on sale of investments and other assets, net	190	98,468
(Loss) gain on derivative financial instruments, net	(32,828)	127,268
Foreign currency (loss) gain, net	15,019	(27,281)
Loss on extinguishment of debt	(61)	(823)
Other (loss) income, net	(2,541)	(763)
Total other income	45,894	331,695
Income before income taxes	50,966	381,864
Income tax (provision) benefit	8,795	2,450
Net income	59,761	384,314
Net income attributable to non-controlling interests	(7,787)	(59,715)
Net income attributable to Starwood Property Trust, Inc.	51,974	324,599
Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	12,965	234,041
Subtotal
Revenues:
Interest income from loans	430,908	233,619
Interest income from investment securities	56,644	48,972
Servicing fees	9,993	14,207
Rental income	32,289	31,580
Other revenues	1,324	4,824
Total revenues	531,158	333,202
Costs and expenses:
Management fees	39,540	55,295
Interest expense	335,511	126,665
General and administrative	42,108	44,240
Acquisition and investment pursuit costs	269	422
Costs of rental operations	11,666	9,290
Depreciation and amortization	12,416	11,647
Credit loss provision (reversal), net	43,194	(3,658)
Other expense	848	55
Total costs and expenses	485,552	243,956
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	(50)	(217)
Change in fair value of investment securities, net	407	(11,396)
Change in fair value of mortgage loans, net	8,901	(125,783)
Earnings (loss) from unconsolidated entities	3,358	(844)
Gain on sale of investments and other assets, net	190	98,468
(Loss) gain on derivative financial instruments, net	(32,828)	127,268
Foreign currency (loss) gain, net	15,019	(27,281)
Loss on extinguishment of debt	(61)	(823)
Other (loss) income, net	(2,541)	(788)
Total other income	5,360	292,645
Income before income taxes	50,966	381,891
Income tax (provision) benefit	8,795	2,450
Net income	59,761	384,341
Net income attributable to non-controlling interests	(7,787)	(59,742)
Net income attributable to Starwood Property Trust, Inc.	51,974	324,599
Subtotal | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	12,965	234,041
Operating segment | Commercial and Residential Lending Segment
Revenues:
Interest income from loans	375,601	202,470
Interest income from investment securities	32,521	20,836
Servicing fees	159	136
Rental income	1,981	1,686
Other revenues	344	52
Total revenues	410,606	225,180
Costs and expenses:
Management fees	218	277
Interest expense	226,393	68,602
General and administrative	11,893	11,602
Acquisition and investment pursuit costs	207	499
Costs of rental operations	2,451	519
Depreciation and amortization	1,631	294
Credit loss provision (reversal), net	30,790	(3,299)
Other expense	832	0
Total costs and expenses	274,415	78,494
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	0	0
Change in fair value of investment securities, net	14,866	(2,105)
Change in fair value of mortgage loans, net	8,262	(116,228)
Earnings (loss) from unconsolidated entities	939	(1,340)
Gain on sale of investments and other assets, net	0	86,610
(Loss) gain on derivative financial instruments, net	(34,363)	118,395
Foreign currency (loss) gain, net	14,930	(27,254)
Loss on extinguishment of debt	(61)	(206)
Other (loss) income, net	(2,541)	(788)
Total other income	2,032	57,084
Income before income taxes	138,223	203,770
Income tax (provision) benefit	6,557	5,140
Net income	144,780	208,910
Net income attributable to non-controlling interests	(3)	(3)
Net income attributable to Starwood Property Trust, Inc.	144,777	208,907
Operating segment | Commercial and Residential Lending Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0
Operating segment | Infrastructure Lending Segment
Revenues:
Interest income from loans	54,760	26,983
Interest income from investment securities	1,338	747
Servicing fees	0	0
Rental income	0	0
Other revenues	216	68
Total revenues	56,314	27,798
Costs and expenses:
Management fees	0	0
Interest expense	32,818	11,930
General and administrative	3,964	3,511
Acquisition and investment pursuit costs	8	1
Costs of rental operations	0	0
Depreciation and amortization	30	105
Credit loss provision (reversal), net	12,404	(359)
Other expense	0	0
Total costs and expenses	49,224	15,188
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	0	0
Change in fair value of investment securities, net	0	0
Change in fair value of mortgage loans, net	0	0
Earnings (loss) from unconsolidated entities	1,740	345
Gain on sale of investments and other assets, net	0	0
(Loss) gain on derivative financial instruments, net	(51)	632
Foreign currency (loss) gain, net	75	(28)
Loss on extinguishment of debt	0	(469)
Other (loss) income, net	0	0
Total other income	1,764	480
Income before income taxes	8,854	13,090
Income tax (provision) benefit	46	4
Net income	8,900	13,094
Net income attributable to non-controlling interests	0	0
Net income attributable to Starwood Property Trust, Inc.	8,900	13,094
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
Interest income from investment securities	0	0
Servicing fees	0	0
Rental income	23,695	22,365
Other revenues	103	50
Total revenues	23,798	22,415
Costs and expenses:
Management fees	0	0
Interest expense	12,599	6,081
General and administrative	952	1,056
Acquisition and investment pursuit costs	0	5
Costs of rental operations	5,549	5,001
Depreciation and amortization	8,108	8,219
Credit loss provision (reversal), net	0	0
Other expense	0	55
Total costs and expenses	27,208	20,417
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	0	0
Change in fair value of investment securities, net	0	0
Change in fair value of mortgage loans, net	0	0
Earnings (loss) from unconsolidated entities	0	0
Gain on sale of investments and other assets, net	0	0
(Loss) gain on derivative financial instruments, net	(1,217)	17,546
Foreign currency (loss) gain, net	14	1
Loss on extinguishment of debt	0	0
Other (loss) income, net	0	0
Total other income	11,762	251,588
Income before income taxes	8,352	253,586
Income tax (provision) benefit	0	0
Net income	8,352	253,586
Net income attributable to non-controlling interests	(6,978)	(52,411)
Net income attributable to Starwood Property Trust, Inc.	1,374	201,175
Operating segment | Property Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	12,965	234,041
Operating segment | Investing and Servicing Segment
Revenues:
Interest income from loans	547	4,166
Interest income from investment securities	22,785	27,389
Servicing fees	9,834	14,071
Rental income	6,613	7,529
Other revenues	383	4,654
Total revenues	40,162	57,809
Costs and expenses:
Management fees	0	0
Interest expense	7,429	6,210
General and administrative	20,047	23,443
Acquisition and investment pursuit costs	54	(83)
Costs of rental operations	3,666	3,770
Depreciation and amortization	2,647	3,029
Credit loss provision (reversal), net	0	0
Other expense	16	0
Total costs and expenses	33,859	36,369
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	(50)	(217)
Change in fair value of investment securities, net	(14,459)	(9,291)
Change in fair value of mortgage loans, net	639	(9,555)
Earnings (loss) from unconsolidated entities	679	151
Gain on sale of investments and other assets, net	190	11,858
(Loss) gain on derivative financial instruments, net	(3,467)	27,863
Foreign currency (loss) gain, net	0	0
Loss on extinguishment of debt	0	(148)
Other (loss) income, net	0	0
Total other income	(16,468)	20,661
Income before income taxes	(10,165)	42,101
Income tax (provision) benefit	2,192	(2,694)
Net income	(7,973)	39,407
Net income attributable to non-controlling interests	(806)	(7,328)
Net income attributable to Starwood Property Trust, Inc.	(8,779)	32,079
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
Interest income from investment securities	0	0
Servicing fees	0	0
Rental income	0	0
Other revenues	278	0
Total revenues	278	0
Costs and expenses:
Management fees	39,322	55,018
Interest expense	56,272	33,842
General and administrative	5,252	4,628
Acquisition and investment pursuit costs	0	0
Costs of rental operations	0	0
Depreciation and amortization	0	0
Credit loss provision (reversal), net	0	0
Other expense	0	0
Total costs and expenses	100,846	93,488
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	0	0
Change in fair value of investment securities, net	0	0
Change in fair value of mortgage loans, net	0	0
Earnings (loss) from unconsolidated entities	0	0
Gain on sale of investments and other assets, net	0	0
(Loss) gain on derivative financial instruments, net	6,270	(37,168)
Foreign currency (loss) gain, net	0	0
Loss on extinguishment of debt	0	0
Other (loss) income, net	0	0
Total other income	6,270	(37,168)
Income before income taxes	(94,298)	(130,656)
Income tax (provision) benefit	0	0
Net income	(94,298)	(130,656)
Net income attributable to non-controlling interests	0	0
Net income attributable to Starwood Property Trust, Inc.	(94,298)	(130,656)
Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	0	0
Securitization VIEs
Revenues:
Interest income from loans	0	0
Interest income from investment securities	(38,007)	(34,989)
Servicing fees	(2,737)	(4,215)
Rental income	0	0
Other revenues	0	(6)
Total revenues	(40,744)	(39,210)
Costs and expenses:
Management fees	0	0
Interest expense	(210)	(214)
General and administrative	0	81
Acquisition and investment pursuit costs	0	0
Costs of rental operations	0	0
Depreciation and amortization	0	0
Credit loss provision (reversal), net	0	0
Other expense	0	0
Total costs and expenses	(210)	(133)
Other income (loss):
Change in net assets related to consolidated VIEs	41,138	26,749
Change in fair value of servicing rights	354	1,301
Change in fair value of investment securities, net	(325)	11,041
Change in fair value of mortgage loans, net	0	0
Earnings (loss) from unconsolidated entities	(633)	(66)
Gain on sale of investments and other assets, net	0	0
(Loss) gain on derivative financial instruments, net	0	0
Foreign currency (loss) gain, net	0	0
Loss on extinguishment of debt	0	0
Other (loss) income, net	0	25
Total other income	40,534	39,050
Income before income taxes	0	(27)
Income tax (provision) benefit	0	0
Net income	0	(27)
Net income attributable to non-controlling interests	0	27
Net income attributable to Starwood Property Trust, Inc.	0	0
Securitization VIEs | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	$ 0	$ 0