Consolidated Statements of Changes in (Deficit) Equity (Unaudited) (USD $) In Thousands	Class A Common Stock	Restricted Class A Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total Blackstone Mortgage Trust, Inc. Stockholders' (Deficit) Equity	Noncontrolling Interests	Total
Balance, beginning at Dec. 31, 2011	$ 220	$ 2	$ 597,049	$ (40,584)	$ (667,111)	$ (110,424)	$ (18,515)	$ (128,939)
Net income (loss)					66,553	66,553	74,069	140,622
Other comprehensive income (loss)				3,830		3,830	10	3,840
Deconsolidation of CT Legacy Asset				1,293		1,293		1,293
Restricted class A common stock earned, net of shares deferred		1	125			126		126
Deferred directors' compensation			56			56		56
Balance, ending at Mar. 31, 2012	220	3	597,230	(35,461)	(600,558)	(38,566)	55,564	16,998
Balance, beginning at Dec. 31, 2012	293		609,002		(535,851)	73,444	80,009	153,453
Net income (loss)					(3,115)	(3,115)	1,518	(1,597)
Other comprehensive income (loss)
Distribution to noncontrolling interests							(1,412)	(1,412)
Consolidation of subsidiary					5,728	5,728	6,235	11,963
Deferred directors' compensation			38			38		38
Balance, ending at Mar. 31, 2013	$ 293		$ 609,040		$ (533,238)	$ 76,095	$ 86,350	$ 162,445