Segment Data - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Interest income from loans	$ 233,619	$ 190,575
Interest income from investment securities	13,983	11,610
Servicing fees	9,992	8,402
Rental income	31,580	76,338
Other revenues	4,818	305
Total revenues	293,992	287,230
Costs and expenses:
Management fees	55,295	38,736
Interest expense	126,451	103,374
General and administrative	44,321	38,636
Acquisition and investment pursuit costs	422	185
Costs of rental operations	9,290	28,745
Depreciation and amortization	11,647	22,474
Credit loss (reversal) provision, net	(3,658)	44
Other expense	55	685
Total costs and expenses	243,823	232,879
Other income (loss):
Change in net assets related to consolidated VIEs	26,749	39,745
Change in fair value of servicing rights	1,084	(796)
Change in fair value of investment securities, net	(355)	(306)
Change in fair value of mortgage loans, net	(125,783)	(9,478)
(Loss) earnings from unconsolidated entities	(910)	1,734
Gain on sale of investments and other assets, net	98,468	17,693
Gain (loss) on derivative financial instruments, net	127,268	33,989
Foreign currency loss, net	(27,281)	(11,681)
Loss on extinguishment of debt	(823)	(516)
Other (loss) income, net	(763)	21
Total other income	331,695	70,405
Income before income taxes	381,864	124,756
Income tax (provision) benefit	2,450	(2,230)
Net income	384,314	122,526
Net income attributable to non-controlling interests	(59,715)	(11,148)
Net income attributable to Starwood Property Trust, Inc.	324,599	111,378
Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	234,041	0
Operating Segments and Corporate
Revenues:
Interest income from loans	233,619	190,575
Interest income from investment securities	48,972	39,889
Servicing fees	14,207	12,580
Rental income	31,580	76,338
Other revenues	4,824	305
Total revenues	333,202	319,687
Costs and expenses:
Management fees	55,295	38,725
Interest expense	126,665	103,565
General and administrative	44,240	38,549
Acquisition and investment pursuit costs	422	185
Costs of rental operations	9,290	28,745
Depreciation and amortization	11,647	22,474
Credit loss (reversal) provision, net	(3,658)	44
Other expense	55	685
Total costs and expenses	243,956	232,972
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	(217)	745
Change in fair value of investment securities, net	(11,396)	5,120
Change in fair value of mortgage loans, net	(125,783)	(9,478)
(Loss) earnings from unconsolidated entities	(844)	2,088
Gain on sale of investments and other assets, net	98,468	17,693
Gain (loss) on derivative financial instruments, net	127,268	33,989
Foreign currency loss, net	(27,281)	(11,681)
Loss on extinguishment of debt	(823)	(516)
Other (loss) income, net	(788)	21
Total other income	292,645	37,981
Income before income taxes	381,891	124,696
Income tax (provision) benefit	2,450	(2,230)
Net income	384,341	122,466
Net income attributable to non-controlling interests	(59,742)	(11,088)
Net income attributable to Starwood Property Trust, Inc.	324,599	111,378
Operating Segments and Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	234,041
Operating segment | Commercial and Residential Lending Segment
Revenues:
Interest income from loans	202,470	170,593
Interest income from investment securities	20,836	18,385
Servicing fees	136	124
Rental income	1,686	1,339
Other revenues	52	90
Total revenues	225,180	190,531
Costs and expenses:
Management fees	277	315
Interest expense	68,602	44,295
General and administrative	11,602	11,333
Acquisition and investment pursuit costs	499	185
Costs of rental operations	519	477
Depreciation and amortization	294	307
Credit loss (reversal) provision, net	(3,299)	(529)
Other expense	0	31
Total costs and expenses	78,494	56,414
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	(2,105)	(2,050)
Change in fair value of mortgage loans, net	(116,228)	(10,714)
(Loss) earnings from unconsolidated entities	(1,340)	1,753
Gain on sale of investments and other assets, net	86,610	17,693
Gain (loss) on derivative financial instruments, net	118,395	26,141
Foreign currency loss, net	(27,254)	(11,594)
Loss on extinguishment of debt	(206)	(68)
Other (loss) income, net	(788)	0
Total other income	57,084	21,161
Income before income taxes	203,770	155,278
Income tax (provision) benefit	5,140	(1,505)
Net income	208,910	153,773
Net income attributable to non-controlling interests	(3)	(3)
Net income attributable to Starwood Property Trust, Inc.	208,907	153,770
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	26,983	18,808
Interest income from investment securities	747	564
Servicing fees	0	0
Rental income	0	0
Other revenues	68	93
Total revenues	27,798	19,465
Costs and expenses:
Management fees	0	0
Interest expense	11,930	8,841
General and administrative	3,511	3,442
Acquisition and investment pursuit costs	1	0
Costs of rental operations	0	0
Depreciation and amortization	105	100
Credit loss (reversal) provision, net	(359)	573
Other expense	0	0
Total costs and expenses	15,188	12,956
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
(Loss) earnings from unconsolidated entities	345	(254)
Gain on sale of investments and other assets, net	0	0
Gain (loss) on derivative financial instruments, net	632	684
Foreign currency loss, net	(28)	(49)
Loss on extinguishment of debt	(469)	(307)
Other (loss) income, net	0	21
Total other income	480	95
Income before income taxes	13,090	6,604
Income tax (provision) benefit	4	(92)
Net income	13,094	6,512
Net income attributable to non-controlling interests	0	0
Net income attributable to Starwood Property Trust, Inc.	13,094	6,512
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
Interest income from investment securities	0	0
Servicing fees	0	0
Rental income	22,365	65,104
Other revenues	50	40
Total revenues	22,415	65,144
Costs and expenses:
Management fees	0	0
Interest expense	6,081	15,832
General and administrative	1,056	1,023
Acquisition and investment pursuit costs	5	0
Costs of rental operations	5,001	23,960
Depreciation and amortization	8,219	18,100
Credit loss (reversal) provision, net	0	0
Other expense	55	583
Total costs and expenses	20,417	59,498
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
(Loss) earnings from unconsolidated entities	0	0
Gain on sale of investments and other assets, net	0	0
Gain (loss) on derivative financial instruments, net	17,546	4,724
Foreign currency loss, net	1	25
Loss on extinguishment of debt	0	(141)
Other (loss) income, net	0	0
Total other income	251,588	4,608
Income before income taxes	253,586	10,254
Income tax (provision) benefit	0	0
Net income	253,586	10,254
Net income attributable to non-controlling interests	(52,411)	(5,077)
Net income attributable to Starwood Property Trust, Inc.	201,175	5,177
Operating segment | Property Segment | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	234,041
Operating segment | Investing and Servicing Segment
Revenues:
Interest income from loans	4,166	1,174
Interest income from investment securities	27,389	20,940
Servicing fees	14,071	12,456
Rental income	7,529	9,895
Other revenues	4,654	82
Total revenues	57,809	44,547
Costs and expenses:
Management fees	0	222
Interest expense	6,210	5,449
General and administrative	23,443	18,440
Acquisition and investment pursuit costs	(83)	0
Costs of rental operations	3,770	4,308
Depreciation and amortization	3,029	3,967
Credit loss (reversal) provision, net	0	0
Other expense	0	71
Total costs and expenses	36,369	32,457
Other income (loss):
Change in net assets related to consolidated VIEs	0	0
Change in fair value of servicing rights	(217)	745
Change in fair value of investment securities, net	(9,291)	7,170
Change in fair value of mortgage loans, net	(9,555)	1,236
(Loss) earnings from unconsolidated entities	151	589
Gain on sale of investments and other assets, net	11,858	0
Gain (loss) on derivative financial instruments, net	27,863	9,283
Foreign currency loss, net	0	(63)
Loss on extinguishment of debt	(148)	0
Other (loss) income, net	0	0
Total other income	20,661	18,960
Income before income taxes	42,101	31,050
Income tax (provision) benefit	(2,694)	(633)
Net income	39,407	30,417
Net income attributable to non-controlling interests	(7,328)	(6,008)
Net income attributable to Starwood Property Trust, Inc.	32,079	24,409
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
Interest income from investment securities	0	0
Servicing fees	0	0
Rental income	0	0
Other revenues	0	0
Total revenues	0	0
Costs and expenses:
Management fees	55,018	38,188
Interest expense	33,842	29,148
General and administrative	4,628	4,311
Acquisition and investment pursuit costs	0	0
Costs of rental operations	0	0
Depreciation and amortization	0	0
Credit loss (reversal) provision, net	0	0
Other expense	0	0
Total costs and expenses	93,488	71,647
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
(Loss) earnings from unconsolidated entities	0	0
Gain on sale of investments and other assets, net	0	0
Gain (loss) on derivative financial instruments, net	(37,168)	(6,843)
Foreign currency loss, net	0	0
Loss on extinguishment of debt	0	0
Other (loss) income, net	0	0
Total other income	(37,168)	(6,843)
Income before income taxes	(130,656)	(78,490)
Income tax (provision) benefit	0	0
Net income	(130,656)	(78,490)
Net income attributable to non-controlling interests	0	0
Net income attributable to Starwood Property Trust, Inc.	(130,656)	(78,490)
Corporate | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	0
Securitization VIEs
Revenues:
Interest income from loans	0	0
Interest income from investment securities	(34,989)	(28,279)
Servicing fees	(4,215)	(4,178)
Rental income	0	0
Other revenues	(6)	0
Total revenues	(39,210)	(32,457)
Costs and expenses:
Management fees	0	11
Interest expense	(214)	(191)
General and administrative	81	87
Acquisition and investment pursuit costs	0	0
Costs of rental operations	0	0
Depreciation and amortization	0	0
Credit loss (reversal) provision, net	0	0
Other expense	0	0
Total costs and expenses	(133)	(93)
Other income (loss):
Change in net assets related to consolidated VIEs	26,749	39,745
Change in fair value of servicing rights	1,301	(1,541)
Change in fair value of investment securities, net	11,041	(5,426)
Change in fair value of mortgage loans, net	0	0
(Loss) earnings from unconsolidated entities	(66)	(354)
Gain on sale of investments and other assets, net	0	0
Gain (loss) on derivative financial instruments, net	0	0
Foreign currency loss, net	0	0
Loss on extinguishment of debt	0	0
Other (loss) income, net	25	0
Total other income	39,050	32,424
Income before income taxes	(27)	60
Income tax (provision) benefit	0	0
Net income	(27)	60
Net income attributable to non-controlling interests	27	(60)
Net income attributable to Starwood Property Trust, Inc.	0	$ 0
Securitization VIEs | Primary beneficiary
Other income (loss):
Income from affordable housing fund investments	$ 0