Borrowings - Revolving Credit Facility (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Dec. 31, 2022
Borrowings
Fair value of investments of the Company held as collateral	$ 1,543,910	$ 1,468,996
Outstanding borrowings	699,683	751,486
Financing costs incurred	$ 11,703	11,914
Credit Facility
Borrowings
Maximum borrowing capacity, Percentage of the principal balance of Company's portfolio company investments	72.00%
Maximum percentage of advance rate on the portfolio	67.00%
Outstanding borrowings	$ 251,413	$ 354,904
Weighted average interest rate	7.40%	6.90%
Financing costs incurred	$ 11	$ 447
During the reinvestment period \| Minimum \| Credit Facility
Borrowings
Interest rate, basis spread	2.75%
During the reinvestment period \| Maximum \| Credit Facility
Borrowings
Interest rate, basis spread	3.00%
After the reinvestment period \| Credit Facility
Borrowings
Interest rate, basis spread	3.25%
When the outstanding borrowings are less than or equal to 60% of the facility \| Credit Facility
Borrowings
Commitment fee (in percent)	0.50%
Outstanding borrowings as a percentage of facility amount considered for payment of commitment fee	60.00%
When the outstanding borrowings are greater than 60% of the facility \| Credit Facility
Borrowings
Commitment fee (in percent)	0.35%
Outstanding borrowings as a percentage of facility amount considered for payment of commitment fee	60.00%
LIBOR \| Credit Facility
Borrowings
Interest rate, floor	0.50%
Asset pledged as collateral \| Credit Facility
Borrowings
Fair value of investments of the Company held as collateral	$ 671,146	$ 691,225

Floor rate for a debt instrument.

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Percentage of line of credit facility, maximum advance rate on the portfolio.

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Percentage line of credit facility, maximum borrowing capacity, percentage on principal balance of company's portfolio company investments.

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Percentage of line of credit facility, unused capacity, commitment fee percentage, outstanding borrowings as a percentage of facility amount considered.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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