Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net income	$ 211,885	$ 100,494	$ 25,424
Other comprehensive income
Unrealized (loss) gain on foreign currency remeasurement	(41,616)	(15,822)	798
Unrealized gain on derivative financial instruments	23,882
Other comprehensive (loss) income	(17,734)	(15,822)	798
Comprehensive income	194,151	84,672	26,222
Comprehensive income attributable to non-controlling interests	(15,056)	(10,449)	(10,392)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 179,095	$ 74,223	$ 15,830