Fair Value Measurements - Schedule of the Carrying Value and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Assets
Fixed maturity securities, available-for-sale	$ 1,300,217	$ 1,189,733
Equity securities	88,042	86,479
Bank loan participations	158,871	142,410
Cash and cash equivalents	220,041	362,345
Restricted cash equivalents	29,321	28,705	$ 27,963	$ 72,449
Short-term investments	111,216	97,074
Liabilities
Senior debt	225,800	200,800
Junior subordinated debt	104,055	104,055
Carrying Value
Assets
Fixed maturity securities, available-for-sale	1,300,217	1,189,733
Equity securities	88,042	86,479
Bank loan participations	158,871	142,410
Cash and cash equivalents	220,041	362,345
Restricted cash equivalents	29,321	28,705
Short-term investments	111,216	97,074
Other invested assets – notes receivable	33,076	13,902
Liabilities
Senior debt	225,800	200,800
Junior subordinated debt	104,055	104,055
Fair Value
Assets
Fixed maturity securities, available-for-sale	1,300,217	1,189,733
Equity securities	88,042	86,479
Bank loan participations	158,871	142,410
Cash and cash equivalents	220,041	362,345
Restricted cash equivalents	29,321	28,705
Short-term investments	111,216	97,074
Other invested assets – notes receivable	33,899	12,877
Liabilities
Senior debt	234,431	201,787
Junior subordinated debt	$ 121,250	$ 121,766