Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Basic Earnings
Income attributable to STWD common stockholders	$ 51,974	$ 324,599
Less: Income attributable to participating shares not already deducted as non-controlling interests	(1,811)	(8,869)
Basic earnings	50,163	315,730
Diluted Earnings
Income attributable to STWD common stockholders	51,974	324,599
Less: Income attributable to participating shares not already deducted as non-controlling interests	(1,811)	(8,869)
Add: Undistributed earnings to participating shares	0	7,342
Less: Undistributed earnings reallocated to participating shares	0	(7,109)
Diluted earnings	$ 50,163	$ 318,867
Number of Shares:
Basic - Average shares outstanding (in shares)	308,408	302,944
Effect of dilutive securities - Contingently issuable shares (in shares)	357	605
Effect of dilutive securities - Unvested non-participating shares (in shares)	231	131
Diluted - Average shares outstanding (in shares)	308,996	313,329
Earnings Per Share Attributable to STWD Common Stockholders:
Basic (in dollars per share)	$ 0.16	$ 1.04
Diluted (in dollars per share)	$ 0.16	$ 1.02
Unamortized discount—Convertible Notes
Diluted Earnings
Add: Interest expense on Convertible Notes	$ 0	$ 2,904
Number of Shares:
Effect of dilutive securities - Convertible Notes (in shares)	0	9,649