Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net income	$ 61,116	$ 51,405
Other comprehensive income
Unrealized gain on foreign currency remeasurement	10,738	7,770
Realized and unrealized loss on derivative financial instruments	(2,935)	(3,925)
Other comprehensive income (loss)	7,803	3,845
Comprehensive income	68,919	55,250
Comprehensive income attributable to non-controlling interests	(158)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 68,761	$ 55,250

Other comprehensive income realized and unrealized gain (loss) on derivatives arising during period before tax.

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

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

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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 after tax and reclassification adjustments of other comprehensive income (loss).

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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