Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (55,844)	$ 30,560	$ (239,216)	$ 251,613
Other comprehensive income (loss)
Unrealized gain (loss) on foreign currency translation	91,072	(71,782)	49,009	(21,455)
Realized and unrealized (loss) gain on derivative financial instruments	(90,309)	71,648	(47,372)	22,039
Other comprehensive income (loss)	763	(134)	1,637	584
Comprehensive (loss) income	(55,081)	30,426	(237,579)	252,197
Comprehensive income attributable to non-controlling interests	(540)	(1,036)	(2,063)	(2,681)
Comprehensive (loss) income attributable to Blackstone Mortgage Trust, Inc.	$ (55,621)	$ 29,390	$ (239,642)	$ 249,516