Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Investments:
Fixed maturities available-for-sale, cost	$ 1,385,121	$ 1,381,318
Limited partnership	76,999	66,846
Due premiums, allowance for doubtful accounts	$ 328	$ 347
Liabilities and Stockholders' Equity
Treasury stock	5,262,000	4,937,000
Common Stock Class A [Member]
Liabilities and Stockholders' Equity
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	53,864,545	53,758,176
Common stock, shares outstanding (in shares)	53,864,545	53,758,176
Treasury stock	4,261,005	3,935,581
Common Stock Class B [Member]
Liabilities and Stockholders' Equity
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	2,000,000	2,000,000
Common stock, shares issued (in shares)	1,001,714	1,001,714
Common stock, shares outstanding (in shares)	1,001,714	1,001,714
Treasury stock	1,001,714	1,001,714