Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Net income (loss)	$ 13,116	$ (1,597)
Other comprehensive income:
Unrealized gain on foreign currency remeasurement	36
Other comprehensive income	36
Comprehensive income (loss)	13,152	(1,597)
Comprehensive income attributable to non-controlling interests	(51)	(1,518)
Comprehensive income (loss) attributable to Blackstone Mortgage Trust, Inc.	$ 13,101	$ (3,115)