Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Line Items]
Net Realized Investment Gains (Losses)	$ 1,274	$ (15,892)	$ 47,383
Claims and Claim Adjustment Expenses Incurred Related to: Current Year	701,664	624,411	701,064
Claims and Claim Adjustment Expenses Incurred Related to: Prior Years	(67,750)	(12,890)	48,909
Consolidated Property and Casualty Insurance Entity
SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Line Items]
Deferred Policy Acquisition Costs	126,532	104,225	91,446
Reserves for Unpaid Claims and Claim Adjustment Expenses	1,638,755	1,497,274	1,514,265
Unearned Premiums	549,384	474,388	439,733
Earned Premiums	1,034,587	951,541	962,823
Net Realized Investment Gains (Losses)	1,274	(15,892)	47,383
Net Investment Income	59,606	44,932	55,778
Claims and Claim Adjustment Expenses Incurred Related to: Current Year	701,664	624,411	691,933
Claims and Claim Adjustment Expenses Incurred Related to: Prior Years	67,750	12,890	(39,778)
Amortization of Deferred Policy Acquisition Costs	244,991	213,075	203,432
Paid Claims and Claim Adjustment Expenses	672,699	688,268	697,078
Premiums Written	$ 1,066,901	$ 984,223	$ 941,348