Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net income	$ 57,199	$ 46,093
Other comprehensive loss
Unrealized gain (loss) on foreign currency remeasurement	5,979	(20,069)
Unrealized (loss) gain on derivative financial instruments	(6,666)	3,337
Other comprehensive loss	(687)	(16,732)
Comprehensive income	56,512	29,361
Comprehensive income attributable to non-controlling interests	(152)	(10,700)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 56,360	$ 18,661

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount before tax, after reclassification adjustments of other comprehensive income (loss).

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Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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