Stockholders' Equity and Non-Controlling Interests - Narrative (Details) $ / shares in Units, $ in Thousands			1 Months Ended		2 Months Ended	12 Months Ended
	Nov. 06, 2021 USD ($)	Nov. 05, 2021 USD ($)	Apr. 30, 2022 USD ($) shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares	Dec. 31, 2023 USD ($) extension $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2018 shares	May 31, 2022 USD ($)	May 31, 2014 shares
Equity Incentive Plans
Preferred stock, shares authorized (in shares) | shares						100,000,000	100,000,000
Preferred stock, par value (in dollars per share) | $ / shares						$ 0.01	$ 0.01
Common stock, shares authorized (in shares) | shares						500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares						$ 0.01	$ 0.01
Commission costs under ATM agreement						$ 0	$ 1,074	$ 720
Shares authorized under DRIP plan (in shares) | shares											11,000,000
Granted (in shares) | shares						914,694
Granted (in dollars per share) | $ / shares						$ 18.93	$ 21.95	$ 22.14
Unrecognized compensation expense						$ 37,400
Compensation recognition period						1 year 8 months 12 days
Fair value of shares vested in period						$ 30,300	$ 30,000	$ 32,400
Contributions from non-controlling interests						2,724	21,925	219,757
Net income					$ 700	58,410	153,820	748
Net income attributable to non-controlling interests						$ 78,944	$ 187,586	44,687
CMBS JV
Equity Incentive Plans
Participation / Ownership %						51.00%
Class A Units
Equity Incentive Plans
Value of shares issued to settle redemption						$ 100		900
Number of shares redeemed (in shares) | shares							0
Cash amount settled						$ 1,300
Number of units outstanding (in shares) | shares						9,700,000
Woodstar II Portfolio | Class A Units
Equity Incentive Plans
Net income attributable to non-controlling interests						$ 18,700	$ 18,800	19,400
Subsidiaries | Woodstar II Portfolio | Class A Units
Equity Incentive Plans
Shares issued (in shares) | shares									10,200,000
Right to receive additional shares (in shares) | shares						1,900,000			1,900,000
Subsidiaries | Woodstar II Portfolio | Class A Units | Non- Controlling Interests
Equity Incentive Plans
Redemption of units						$ 207,100	208,500
Woodstar Fund
Equity Incentive Plans
Percentage of interest sold		20.60%
Contributions from non-controlling interests	$ 214,200	$ 216,000
Initial term						8 years
Number of extension options | extension						2
Extension term						1 year
CMBS JV
Equity Incentive Plans
Non-controlling interest						$ 129,200	144,300
CMBS JV | Joint Venture Partner
Equity Incentive Plans
Ownership percentage						49.00%
CMBS JV | Woodstar II Portfolio | Class A Units
Equity Incentive Plans
Net income attributable to non-controlling interests						$ (1,500)	$ 6,200	$ 22,700
Starwood Property Trust, Inc. Equity Plan and Manager Equity Plan
Equity Incentive Plans
Number of shares of authorized for issuance (in shares) | shares			18,700,000
Number of shares available for future grants (in shares) | shares						16,510,282
Vesting Period						3 years
Employee Stock
Equity Incentive Plans
Purchase price of fair market value			85.00%
Maximum purchase value during calendar year, per employee			$ 25
Number of shares of authorized for issuance (in shares) | shares			2,000,000
Number of shares issued for future grants (in shares) | shares						123,327	67,965
Purchase price (in dollars per share) | $ / shares						$ 15.46	$ 17.36
Common stock available for future issuance (in shares) | shares						1,800,000
Restricted stock | Starwood Property Trust, Inc. Equity Plan and Manager Equity Plan
Equity Incentive Plans
Granted (in shares) | shares						914,694	829,805	1,708,935
ATM Agreement
Equity Incentive Plans
Authorized value of stock under ATM agreement										$ 500,000
Number of shares issued (in shares) | shares						0	2,168,710	0
Proceeds from ATM Agreement							$ 49,300
Sale of stock average price (in dollars per share) | $ / shares							$ 22.72
Commission costs under ATM agreement							$ 1,000
Public Offering
Equity Incentive Plans
Number of shares issued (in shares) | shares				16,000,000
Proceeds from ATM Agreement				$ 393,100
Sale of stock average price (in dollars per share) | $ / shares				$ 24.57	$ 24.57			$ 24.57