Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments:
Fixed maturities available-for-sale, cost	$ 1,389,038	$ 1,381,318
Private equity funds	82,460	66,846
Accounts Receivable, Allowance for Credit Loss	$ 408	$ 347
Common Stock Class A [Member]
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)	53,882,661	53,758,176
Common stock, shares outstanding (in shares)	53,882,661	53,758,176
Treasury Stock, Common, Shares	4,327,810	3,935,581
Common Stock Class B [Member]
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, Common, Shares	1,001,714	1,001,714