Federal Income Tax - Net Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Deferred tax liabilities
Equity securities	$ 5,414,000	$ 19,701,000
Deferred policy acquisition costs	26,572,000	21,887,000
Investments in partnerships	1,713,000	1,303,000
Over funded pension benefit	4,256,000	232,000
Prepaid pension cost	7,090,000	5,653,000
Net bond discount accretion	213,000	238,000
Depreciation	3,637,000	3,996,000
Revaluation of investment basis	0	119,000
Identifiable intangible assets	944,000	1,093,000
Capitalized Software	2,310,000	3,607,000
Other	2,432,000	1,550,000
Gross deferred tax liability	54,581,000	59,379,000
Deferred tax assets
Financial statement reserves in excess of income tax reserves	20,414,000	22,522,000
Unearned premium adjustment	20,618,000	18,513,000
Employee profit sharing	1,623,000	1,624,000
Other-than-temporary impairment of investments	451,000	1,109,000
Compensation expense related to stock options	1,760,000	1,822,000
Nonqualified deferred compensation	2,493,000	2,399,000
Net Unrealized Appreciation - all other securities	17,753,000	23,382,000
Revaluation of investment basis	23,000	0
Other	3,067,000	3,539,000
Gross deferred tax asset	68,202,000	74,910,000
Valuation allowance	0	0
Deferred tax asset	68,202,000	74,910,000
Net deferred tax liability (asset)	$ (13,621,000)	$ (15,531,000)