Amount of assets pledged to secure a debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Borrowing Arrangements - Term Loan Credit Facility (Details) - Secured debt - USD ($)	Jan. 01, 2019	Jun. 30, 2021	Dec. 31, 2016
Term loan credit facility
Amount of senior secured draw term loan credit facility			$ 100,000,000
Fixed interest rate of credit facility (as a percent)	4.35%
Repayment period of credit facility	28 years
Fair value of investments pledged as collateral on the credit facility		$ 122,600,000