Statements of Cash Flows - Cash Flow Supplemental Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Supplemental Cash Flow Information [Abstract]
Interest	$ 8,544	$ 8,528
Federal income tax	0	0
Operating cash flows from operating leases	1,777	2,235
Operating cash flows from financing leases	22	11
Financing cash flows from finance leases	731	615
Corporate actions related to fixed income securities, available-for-sale ("AFS")	2,298	4,629
Assets acquired under finance lease arrangements	3	0
Assets acquired under operating lease arrangements	674	4,237
Non-cash purchase of property and equipment	$ 8	$ 23

Amount of interest paid on finance lease liability.

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Amount of cash outflow for principal payment on finance lease.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

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Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

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