Investments, Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Held To Maturity [Abstract]
Due in one year or less, amortized cost	$ 42,228,000
Due after one year through five years, amortized cost	130,205,000
Due after five years through ten years, amortized cost	237,241,000
Due after ten years, amortized cost	261,861,000
Mortgage-backed securities, amortized cost	13,193,000
Held to maturity, amortized cost	684,728,000	$ 680,823,000
Available For Sale [Abstract]
Due in one year or less, amortized cost	62,925,000
Due after one year through five years, amortized cost	170,058,000
Due after five years through ten years, amortized cost	86,138,000
Due after ten years, amortized cost	23,221,000
Mortgage-backed securities, amortized cost	300,874,000
Total available for sale, amortized cost	643,216,000	629,727,000
Held To Maturity [Abstract]
Due in one year or less, estimated fair value	41,549,000
Due after one year through five years, estimated fair value	121,873,000
Due after five years through ten years, estimated fair value	216,118,000
Due after ten years, estimated fair value	217,519,000
Mortgage-backed securities, estimated fair value	12,755,000
Total held to maturity, estimated fair value	609,814,000	611,526,000
Available For Sale [Abstract]
Due in one year or less, estimated fair value	61,761,000
Due after one year through five years, estimated fair value	160,071,000
Due after five years through ten years, estimated fair value	77,937,000
Due after ten years, estimated fair value	20,195,000
Mortgage-backed securities, estimated fair value	280,797,000
Total available for sale, estimated fair value	$ 600,761,425	$ 589,348,243