Earnings per Share - Schedule of Reconciliation of Net Income and Number of Shares used in Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Basic Earnings
Income attributable to STWD common stockholders	$ 154,332	$ 51,974
Less: Income attributable to participating shares not already deducted as non-controlling interests	(2,576)	(1,811)
Basic earnings	151,756	50,163
Diluted Earnings
Income attributable to STWD common stockholders	154,332	51,974
Less: Income attributable to participating shares not already deducted as non-controlling interests	(2,576)	(1,811)
Add: Undistributed earnings to participating shares	68	0
Less: Undistributed earnings reallocated to participating shares	(65)	0
Diluted earnings	$ 158,764	$ 50,163
Number of Shares:
Basic - Average shares outstanding (in shares)	311,827	308,408
Effect of dilutive securities - Contingently issuable shares (in shares)	469	357
Effect of dilutive securities - Unvested non-participating shares (in shares)	200	231
Diluted - Average shares outstanding (in shares)	330,840	308,996
Earnings Per Share Attributable to STWD Common Stockholders:
Basic (in dollars per share)	$ 0.49	$ 0.16
Diluted (in dollars per share)	$ 0.48	$ 0.16
Unamortized discount—Convertible Notes
Diluted Earnings
Add: Interest expense on Convertible Notes	$ 7,005
Number of Shares:
Effect of dilutive securities - Convertible Notes (in shares)	18,344