Fair Value of Financial Instruments - Rollforward of Level 3 Assets Measured on Recurring Basis (Details) - Fair Value, Recurring Measurements [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Level 3 assets, beginning of period		$ 1,628	$ 1,634	$ 1,710	[1]	$ 3,596	[1]
Net unrealized gains (losses) included in other comprehensive income			(8)	(61)	[1]	99	[1]
Realized gains (losses) and accretion (amortization) recognized in earnings		(8)	(127)	(89)	[1]	(328)	[1]
Purchases			6,170	2,316	[1]	13,661	[1]
Settlements			15	(8)	[1]	(1,385)	[1]
Transfers into Level 3	[1]					1,399
Transfers out of Level 3	[1]			(2,248)		(9,358)
Level 3 assets, end of period	[1]	$ 1,620	$ 7,684	$ 1,620		$ 7,684

[1] Transfers of investments that enter and exit Level 3 in different quarters within the same fiscal year are not eliminated until the full year amounts are presented.