Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Basic Earnings
Income attributable to STWD common stockholders	$ 324,599	$ 111,378
Less: Income attributable to participating shares not already deducted as non-controlling interests	(8,869)	(1,925)
Basic earnings	315,730	109,453
Diluted Earnings
Income attributable to STWD common stockholders	324,599	111,378
Less: Income attributable to participating shares not already deducted as non-controlling interests	(8,869)	(1,925)
Add: Undistributed earnings to participating shares	7,342	0
Less: Undistributed earnings reallocated to participating shares	(7,109)	0
Diluted earnings	$ 318,867	$ 112,369
Number of Shares:
Basic - Average shares outstanding (in shares)	302,944	283,319
Effect of dilutive securities - Contingently issuable shares (in shares)	605	263
Effect of dilutive securities - Unvested non-participating shares (in shares)	131	0
Diluted - Average shares outstanding (in shares)	313,329	293,231
Earnings per share data attributable to Starwood Property Trust, Inc.:
Basic (in dollars per share)	$ 1.04	$ 0.39
Diluted (in dollars per share)	$ 1.02	$ 0.38
Convertible Senior Notes
Diluted Earnings
Add: Interest expense on Convertible Notes	$ 2,904	$ 2,916
Number of Shares:
Effect of dilutive securities - Convertible Notes (in shares)	9,649	9,649