Acquisitions (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Apr. 30, 2016 property	Mar. 31, 2016 USD ($) property item $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2015 USD ($) ft² property item
Liabilities assumed:
Revenues		$ 195,493	$ 178,849
Net income (loss)		27,046	120,779
Depreciation and amortization		16,759	3,692
(Loss) gain on derivative financial instruments, net		(24,718)	24,623
Goodwill		140,437		$ 140,437
Woodstar Portfolio, Ireland Portfolio and REIS Portfolio
Pro forma revenue and net income
Revenues		198,616	211,448
Net income attributable to STWD		$ 29,153	$ 115,025
Net income per share - Basic | $ / shares		$ 0.12	$ 0.51
Net income per share - Diluted | $ / shares		$ 0.12	$ 0.50
Management fee expense addition		$ 169	$ 2,065
Woodstar Portfolio And Ireland Portfolio
Acquisitions
Number of acquired properties closed | property		30		30
Woodstar Portfolio
Acquisitions
Number of properties in portfolio investment | item		32
Weighted average occupancy percentage		98.00%
Number of units | item		8,948
Assumed state sponsored debt		$ 147,500
Number of acquired properties closed | item		12
Number of units acquired | item		3,082
Number of properties under agreement not acquired | property		2
Assets acquired:
Cash and cash equivalents		$ 6,254
Properties		198,693		$ 339,040
Intangible assets		6,837		11,337
Other assets		15,595		652
Total assets acquired		227,379		351,029
Liabilities assumed:
Accounts payable, accrued expenses and other liabilities		18,070		18,030
Secured financing agreements		129,416		8,982
Total liabilities assumed		147,486		27,012
Net assets acquired		79,893		$ 324,017
Revenues		5,600
Net income (loss)		(800)
Depreciation and amortization		3,200
Acquisition related costs		600
Goodwill		0
Woodstar Portfolio | Subsequent event
Acquisitions
Number of units | property	628
Number of acquired properties closed | property	2
Ireland Portfolio
Acquisitions
Number of properties in portfolio investment | property				13
Area of property | ft²				600,000
Assumed state sponsored debt				$ 283,000
Assets acquired:
Restricted cash				10,829
Properties				445,369
Intangible assets				59,529
Other assets				2,508
Total assets acquired				518,235
Liabilities assumed:
Accounts payable, accrued expenses and other liabilities				17,552
Secured financing agreements				283,010
Total liabilities assumed				300,562
Net assets acquired				217,673
Goodwill				0
Ireland Portfolio | Lender 6 Mortgage Facility
Acquisitions
Debt incurred to partially fund acquisition				328,600
REO Portfolio
Assets acquired:
Properties		20,707		128,218
Intangible assets		5,558		19,381
Other assets		103		4,973
Total assets acquired		26,368		152,572
Liabilities assumed:
Accounts payable, accrued expenses and other liabilities		1,715		6,998
Total liabilities assumed		1,715		6,998
Non-controlling interests		3,084		6,904
Net assets acquired		$ 21,569		$ 138,670
Net Leased Office Property | Ireland Portfolio
Acquisitions
Number of acquired properties closed | property				12
Multifamily Property | Ireland Portfolio
Acquisitions
Number of acquired properties closed | property				1
Investment and Servicing Segment | REO Portfolio
Acquisitions
Number of acquired properties closed | item		2
Number of properties under agreement not acquired | item				14
Purchase price		$ 21,600		$ 138,700
Purchase price of properties - non-performing loans		8,200
Liabilities assumed:
Goodwill		$ 0