Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Net income	$ 93,865	$ 132,468	$ 194,128	$ 213,008
Other comprehensive (loss) income
Unrealized (loss) gain on foreign currency translation	(130,207)	15,553	(175,429)	(19,404)
Realized and unrealized gain (loss) on derivative financial instruments	128,685	(16,094)	174,199	18,977
Other comprehensive loss	(1,522)	(541)	(1,230)	(427)
Comprehensive income	92,343	131,927	192,898	212,581
Comprehensive income attributable to non-controlling interests	(615)	(873)	(1,191)	(1,511)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 91,728	$ 131,054	$ 191,707	$ 211,070