Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income from loans and other investments
Interest and related income	$ 854,690	$ 779,648	$ 882,679
Less: Interest and related expenses	340,223	347,471	458,503
Income from loans and other investments, net	514,467	432,177	424,176
Other expenses
Management and incentive fees	88,467	77,916	78,435
General and administrative expenses	43,168	45,871	38,854
Total other expenses	131,635	123,787	117,289
Decrease (increase) in current expected credit loss reserve	39,864	(167,653)	0
Income before income taxes	422,696	140,737	306,887
Income tax provision (benefit)	423	323	(506)
Net income	422,273	140,414	307,393
Net income attributable to non-controlling interests	(3,080)	(2,744)	(1,826)
Net income attributable to Blackstone Mortgage Trust, Inc.	$ 419,193	$ 137,670	$ 305,567
Net income per share of common stock basic (in USD per share)	$ 2.77	$ 0.97	$ 2.35
Net income per share of common stock diluted (in USD per share)	$ 2.77	$ 0.97	$ 2.35
Weighted-average shares of common stock outstanding, basic (in shares)	151,521,941	141,795,977	130,085,398
Weighted-average shares of common stock outstanding, diluted (in shares)	151,521,941	141,795,977	130,085,398