Investments - Amortized Cost, Fair Value and Unrealized Gains and (Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Net Investment Income [Line Items]
Amortized Cost	$ 50,070	$ 188,143
Gross unrealized, gains	440	365
Gross unrealized, losses	(8)	(5,757)
Fair Value	50,502	182,751
Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	178,456
Gross unrealized, gains	2,073
Gross unrealized, losses	(2,673)
Fair Value	177,856
U.S. Treasuries
Net Investment Income [Line Items]
Amortized Cost	13,469	27,489
Gross unrealized, gains	95	34
Gross unrealized, losses	0	(421)
Fair Value	13,564	27,102
U.S. Treasuries | Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	9,855
Gross unrealized, gains	79
Gross unrealized, losses	(191)
Fair Value	9,743
Obligations of states, municipalities and political subdivisions
Net Investment Income [Line Items]
Amortized Cost	3,224	12,602
Gross unrealized, gains	49	26
Gross unrealized, losses	0	(756)
Fair Value	3,273	11,872
Obligations of states, municipalities and political subdivisions | Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	11,311
Gross unrealized, gains	99
Gross unrealized, losses	(406)
Fair Value	11,004
Corporate bonds
Net Investment Income [Line Items]
Amortized Cost	20,433	72,996
Gross unrealized, gains	183	192
Gross unrealized, losses	(6)	(2,292)
Fair Value	20,610	70,896
Corporate bonds | Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	70,123
Gross unrealized, gains	1,042
Gross unrealized, losses	(1,017)
Fair Value	70,148
Residential and commercial mortgage-backed securities
Net Investment Income [Line Items]
Amortized Cost	12,944	62,721
Gross unrealized, gains	113	85
Gross unrealized, losses	(2)	(2,032)
Fair Value	13,055	60,774
Residential and commercial mortgage-backed securities | Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	71,029
Gross unrealized, gains	707
Gross unrealized, losses	(904)
Fair Value	70,832
Other loan-backed and structured securities
Net Investment Income [Line Items]
Amortized Cost	0	12,335
Gross unrealized, gains	0	28
Gross unrealized, losses	0	(256)
Fair Value	0	$ 12,107
Other loan-backed and structured securities | Variable Interest Entity, Primary Beneficiary
Net Investment Income [Line Items]
Amortized Cost	16,138
Gross unrealized, gains	146
Gross unrealized, losses	(155)
Fair Value	$ 16,129