Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Net income	$ 30,560	$ 103,919	$ 251,613	$ 298,047
Other comprehensive (loss) income
Unrealized loss on foreign currency translation	(71,782)	(158,097)	(21,455)	(333,526)
Realized and unrealized gain on derivative financial instruments	71,648	154,849	22,039	329,048
Other comprehensive (loss) income	(134)	(3,248)	584	(4,478)
Comprehensive income	30,426	100,671	252,197	293,569
Comprehensive income attributable to non-controlling interests	(1,036)	(673)	(2,681)	(1,864)
Comprehensive income attributable to Blackstone Mortgage Trust, Inc.	$ 29,390	$ 99,998	$ 249,516	$ 291,705