Earnings per Share (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Continuing Operations:
Income from continuing operations attributable to STWD common stockholders	$ 117,868,000	$ 66,512,000	$ 240,020,000	$ 131,043,000
Less: Income attributable to unvested shares	(1,367,000)	(369,000)	(3,100,000)	(823,000)
Basic - Income from continuing operations	116,501,000	66,143,000	236,920,000	130,220,000
Discontinued Operations:
Loss from discontinued operations		(6,058,000)	(1,551,000)	(8,346,000)
Basic - Net income attributable to STWD common stockholders after allocation to participating securities	116,501,000	60,085,000	235,369,000	121,874,000
Continuing Operations:
Basic - Income from continuing operations attributable to STWD common stockholders	117,868,000	66,512,000	240,020,000	131,043,000
Less: Income attributable to unvested shares	(1,367,000)	(369,000)	(3,100,000)	(823,000)
Add: Undistributed earnings to unvested shares	128,000		480,000
Less: Undistributed earnings reallocated to unvested shares	(126,000)		(471,000)
Diluted - Income from continuing operations	116,503,000	66,143,000	236,929,000	130,220,000
Discontinued Operations:
Basic - Loss from discontinued operations		(6,058,000)	(1,551,000)	(8,346,000)
Diluted - Net income attributable to STWD common stockholders after allocation to participating securities	116,503,000	60,085,000	235,378,000	121,874,000
Number of Shares:
Basic - Average shares outstanding	218,751,000	162,448,000	207,203,000	149,037,000
Effect of dilutive securities - Convertible Notes	4,056,000		3,906,000
Effect of dilutive securities - Contingently Issuable Shares	85,000		85,000
Diluted (in shares)	222,892,000	162,448,000	211,194,000	149,037,000
Earnings Per Share Attributable to STWD Common Stockholders - Basic:
Income from continuing operations (in dollars per share)	$ 0.53	$ 0.41	$ 1.14	$ 0.87
Loss from discontinued operations (in dollars per share)		$ (0.04)	$ (0.01)	$ (0.05)
Net income (in dollars per share)	$ 0.53	$ 0.37	$ 1.13	$ 0.82
Earnings Per Share Attributable to STWD Common Stockholders - Diluted:
Income from continuing operations (in dollars per share)	$ 0.52	$ 0.41	$ 1.12	$ 0.87
Loss from discontinued operations (in dollars per share)		$ (0.04)	$ (0.01)	$ (0.05)
Net income (in dollars per share)	$ 0.52	$ 0.37	$ 1.11	$ 0.82
Restricted stock
Anti-dilutive shares
Number of anti-dilutive common shares excluded from the calculation of diluted income per share			2,600,000	900,000
Convertible Senior Notes
Anti-dilutive shares
Number of anti-dilutive common shares excluded from the calculation of diluted income per share	44,600,000		44,800,000
Potential shares of common stock contingently issuable upon conversion of the Convertible Notes			48,700,000
2018 Notes
Anti-dilutive shares
Amount by which if-converted value of the Notes exceed principal amount			36,700,000
2019 Notes
Anti-dilutive shares
Amount by which if-converted value of the Notes exceed principal amount			$ 59,900,000