Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitment to contribute capital	$ 55,900		$ 55,500
Reserve for Unfunded Loan Commitments	$ 74,571	$ 90,571	$ 85,571	$ 80,571	$ 53,571	$ 39,571	$ 35,861