CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ (7,400)	$ 19,890
Unrealized gain/(loss) on available-for-sale securities	(67,607)	145
Comprehensive income attributable to Benefit Street Partners Realty Trust, Inc.	$ (75,007)	$ 20,035