Secured Borrowings- Collateralized Loan Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Aug. 31, 2019
Summary of CLO
Principal Amount	$ 1,750,000	$ 1,950,000
Carrying value	$ 930,554	928,060
Spread (as a percent)	2.00%
Deferred financing costs, net of amortization	$ 5,589	$ 5,624
Collateral assets
Summary of CLO
Count	23	20
Amount issued	$ 1,002,445	$ 1,073,504
Carrying value	$ 1,099,439	$ 1,073,504
Financing
Summary of CLO
Count	1	1
Amount issued	$ 936,375	$ 936,375
Carrying value	930,554	928,060
Collateralized Loan Obligation
Summary of CLO
Amount issued			$ 1,100,000
Principal Amount			86,600
Carrying value			936,400
Liquidation preference			$ 77,000
Amortization of deferred financing costs	2,500	900
Deferred financing costs, net of amortization	9,200
Unamortized issuance costs	5,800	8,300
Additional Contribution to CLO	$ 134,700	$ 88,100
Collateralized Loan Obligation | Collateral assets
Summary of CLO
Fixed weighted average interest	7.07%	6.84%
Collateralized Loan Obligation | LIBOR | Collateral assets
Summary of CLO
Spread (as a percent)	3.93%	3.34%
Collateralized Loan Obligation | LIBOR | Financing
Summary of CLO
Spread (as a percent)	1.64%	1.65%