Investment Portfolio Financing - Schedule of Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Outstanding principal amount	$ 3,917,842	$ 3,722,199
Collateralized loan obligations
Debt Instrument [Line Items]
Outstanding principal amount	2,651,920	2,555,988
Secured credit agreements
Debt Instrument [Line Items]
Outstanding principal amount	1,089,655	1,166,211
Secured revolving credit facility
Debt Instrument [Line Items]
Outstanding principal amount	52,065	0
Asset-specific financing arrangements
Debt Instrument [Line Items]
Outstanding principal amount	$ 124,202	$ 0