Fair Value of Financial Instruments - Summary of Fair Value of Level 3 Investments and Ranges of Significant Unobservable Inputs Used to Value Level 3 Investments (Details) $ in Thousands	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 56,363	$ 13,760
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	1,450,794	1,167,987
Level 3 | Senior Secured First Lien
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	426,019	277,786
Level 3 | Senior Secured First Lien | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 355,842	$ 201,043
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	8.9	9.4
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	18.2	19.4
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	11.6	10.9
Level 3 | Senior Secured First Lien | Enterprise Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 21,782	$ 13,593
Level 3 | Senior Secured First Lien | Enterprise Value | Comparable EBITDA Multiple | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	0.3	8.3
Level 3 | Senior Secured First Lien | Enterprise Value | Comparable EBITDA Multiple | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	14.8	14.8
Level 3 | Senior Secured First Lien | Enterprise Value | Comparable EBITDA Multiple | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	5.0	9.1
Level 3 | Senior Secured First Lien | Broker Quoted
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 38,755	$ 63,150
Level 3 | Senior Secured First Lien | Collateral Analysis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 326
Level 3 | Senior Secured First Lien | Collateral Analysis | Recovery Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	2.4
Level 3 | Senior Secured First Lien | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 9,314
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Royalty Payment Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	6.0
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Royalty Payment Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	16.5
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Royalty Payment Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	15.5
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Revenue Growth Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	(2.0)
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Revenue Growth Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	5.0
Level 3 | Senior Secured First Lien | Discounted Cash Flows | Revenue Growth Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	3.0
Level 3 | Unitranche First Lien
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 906,111	771,348
Level 3 | Unitranche First Lien | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 827,532	$ 620,221
Level 3 | Unitranche First Lien | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	7.6	6.8
Level 3 | Unitranche First Lien | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	19.7	15.7
Level 3 | Unitranche First Lien | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	11.6	10.8
Level 3 | Unitranche First Lien | Enterprise Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 14,481	$ 15,576
Level 3 | Unitranche First Lien | Enterprise Value | Comparable EBITDA Multiple | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	4.5	13.1
Level 3 | Unitranche First Lien | Enterprise Value | Comparable EBITDA Multiple | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	13.7	6.8
Level 3 | Unitranche First Lien | Enterprise Value | Comparable EBITDA Multiple | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	12	11.5
Level 3 | Unitranche First Lien | Broker Quoted
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 64,098	$ 135,551
Level 3 | Unitranche First Lien Last Out
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	13,946	13,827
Level 3 | Unitranche First Lien Last Out | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 11,737	$ 11,642
Level 3 | Unitranche First Lien Last Out | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	9.2	8.4
Level 3 | Unitranche First Lien Last Out | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	16.9	16.5
Level 3 | Unitranche First Lien Last Out | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	11.8	10.9
Level 3 | Unitranche First Lien Last Out | Collateral Analysis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 2,209	$ 2,185
Level 3 | Unitranche First Lien Last Out | Collateral Analysis | Recovery Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	43.4	42.9
Level 3 | Senior Secured Second Lien
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 51,913	$ 56,586
Level 3 | Senior Secured Second Lien | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 30,259	$ 29,749
Level 3 | Senior Secured Second Lien | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	13.0	11.5
Level 3 | Senior Secured Second Lien | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	20.6	26.0
Level 3 | Senior Secured Second Lien | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	15.5	15.6
Level 3 | Senior Secured Second Lien | Enterprise Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 8,277	$ 7,397
Level 3 | Senior Secured Second Lien | Enterprise Value | Comparable EBITDA Multiple | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	4.6	8.3
Level 3 | Senior Secured Second Lien | Enterprise Value | Comparable EBITDA Multiple | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	14.8	14.8
Level 3 | Senior Secured Second Lien | Enterprise Value | Comparable EBITDA Multiple | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	8.6	10.8
Level 3 | Senior Secured Second Lien | Broker Quoted
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 13,377	$ 19,440
Level 3 | Unsecured Debt | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 4,926	$ 4,533
Level 3 | Unsecured Debt | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	15.4	15.2
Level 3 | Unsecured Debt | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	17.7	17.3
Level 3 | Unsecured Debt | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	16.2	16.1
Level 3 | Equity & Other
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 47,879	$ 43,907
Level 3 | Equity & Other | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	314	$ 200
Level 3 | Equity & Other | Discounted Cash Flows | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range		22.1
Level 3 | Equity & Other | Discounted Cash Flows | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range		22.1
Level 3 | Equity & Other | Discounted Cash Flows | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range		22.1
Level 3 | Equity & Other | Enterprise Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 47,151	$ 43,311
Level 3 | Equity & Other | Enterprise Value | Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	20.6
Level 3 | Equity & Other | Enterprise Value | Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	20.6
Level 3 | Equity & Other | Enterprise Value | Discount Rate | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	20.6
Level 3 | Equity & Other | Enterprise Value | Comparable EBITDA Multiple | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	1.1	10.9
Level 3 | Equity & Other | Enterprise Value | Comparable EBITDA Multiple | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	28.4	27.8
Level 3 | Equity & Other | Enterprise Value | Comparable EBITDA Multiple | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range	15.5	15.7
Level 3 | Equity & Other | Broker Quoted
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 414	$ 396