Investments - Schedule of Changes in Assets Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Realized gains (losses)	Realized gains (losses)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Percent of total fixed maturities	100.00%		100.00%
Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Beginning Balance	$ 474,114	$ 496,879
Included in realized gains / losses	(1)	0
Included in other comprehensive income	(1,924)	(8,031)
Acquisitions	21,580	7,800
Sales	0	0
Amortization	1,133	1,137
Other	(3,468)	(20,490)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending Balance	$ 491,434	$ 477,295
Percent of total fixed maturities	3.00%	3.00%	3.00%
Significant Unobservable Inputs (Level 3) | Asset- backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Beginning Balance	$ 11,183	$ 0
Included in realized gains / losses	0	0
Included in other comprehensive income	30	0
Acquisitions	12,380	0
Sales	0	0
Amortization	0	0
Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending Balance	$ 23,593	$ 0
Percent of total fixed maturities	0.00%	0.00%
Significant Unobservable Inputs (Level 3) | Collateralized debt obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Beginning Balance	$ 42,866	$ 42,146
Included in realized gains / losses	0	0
Included in other comprehensive income	5,046	(2,035)
Acquisitions	0	0
Sales	0	0
Amortization	1,136	1,141
Other	(7,393)	(1,521)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending Balance	$ 41,655	$ 39,731
Percent of total fixed maturities	0.00%	0.00%
Significant Unobservable Inputs (Level 3) | Corporates
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Beginning Balance	$ 420,065	$ 454,733
Included in realized gains / losses	(1)	0
Included in other comprehensive income	(7,000)	(5,996)
Acquisitions	9,200	7,800
Sales	0	0
Amortization	(3)	(4)
Other	3,925	(18,969)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending Balance	$ 426,186	$ 437,564
Percent of total fixed maturities	3.00%	3.00%