Fair Value of Financial Instruments - Level 3 Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement Of Income, Extensible List, Not Disclosed Flag	Realized gains (loss) (1)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Change in net unrealized appreciation on investments
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 6,476	$ 1,670
Realized gains (loss)	0	(595)
Unrealized gains (losses)	(715)	(124)
Purchases	0	0
Disposals	0	(150)
Amortization	0
Transfers in	4,823	5,675
Transfers out	0	0
Ending Balance	10,584	6,476
Recurring | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,675	150
Realized gains (loss)	0	0
Unrealized gains (losses)	(783)	0
Purchases	0	0
Disposals	0	(150)
Amortization	0
Transfers in	0	5,675
Transfers out	0	0
Ending Balance	4,892	5,675
Recurring | Asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	801	925
Realized gains (loss)	0	0
Unrealized gains (losses)	68	(124)
Purchases	0	0
Disposals	0	0
Amortization	0
Transfers in	4,823	0
Transfers out	0	0
Ending Balance	5,692	801
Recurring | Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	595
Realized gains (loss)	0	(595)
Unrealized gains (losses)	0	0
Purchases	0	0
Disposals	0	0
Amortization	0
Transfers in	0	0
Transfers out	0	0
Ending Balance	$ 0	$ 0