Investments - Amortized Cost and Estimated Fair Values of Fixed Maturities (Details) - USD ($)
|
Jun. 30, 2026 |
Mar. 31, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
| Investments [Abstract] |
|
|
|
|
|
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| Held to maturity, carrying value |
$ 803,294,965
|
$ 783,952,000
|
$ 776,447,347
|
$ 737,356,000
|
$ 706,098,000
|
$ 705,714,000
|
| Held to maturity, allowance for credit losses |
1,306,225
|
$ 1,274,000
|
1,312,903
|
$ 1,374,000
|
$ 1,351,000
|
$ 1,388,000
|
| Held to maturity, amortized cost |
804,601,000
|
|
777,760,000
|
|
|
|
| Held to maturity, gross unrealized gains |
5,011,000
|
|
5,582,000
|
|
|
|
| Held to maturity, gross unrealized losses |
54,847,000
|
|
51,683,000
|
|
|
|
| Held to maturity, estimated fair value |
754,765,403
|
|
731,659,323
|
|
|
|
| Total available for sale, amortized cost |
676,989,000
|
|
689,082,000
|
|
|
|
| Available for sale, gross unrealized gains |
2,350,000
|
|
4,403,000
|
|
|
|
| Available for sale, gross unrealized losses |
16,289,000
|
|
14,050,000
|
|
|
|
| Available for sale, estimated fair value |
663,050,000
|
|
679,435,000
|
|
|
|
| U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member] |
|
|
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| Investments [Abstract] |
|
|
|
|
|
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| Held to maturity, carrying value |
73,827,000
|
|
79,243,000
|
|
|
|
| Held to maturity, allowance for credit losses |
44,000
|
|
47,000
|
|
|
|
| Held to maturity, amortized cost |
73,871,000
|
|
79,290,000
|
|
|
|
| Held to maturity, gross unrealized gains |
26,000
|
|
84,000
|
|
|
|
| Held to maturity, gross unrealized losses |
5,394,000
|
|
4,864,000
|
|
|
|
| Held to maturity, estimated fair value |
68,503,000
|
|
74,510,000
|
|
|
|
| Total available for sale, amortized cost |
21,354,000
|
|
25,057,000
|
|
|
|
| Available for sale, gross unrealized gains |
4,000
|
|
107,000
|
|
|
|
| Available for sale, gross unrealized losses |
960,000
|
|
835,000
|
|
|
|
| Available for sale, estimated fair value |
20,398,000
|
|
24,329,000
|
|
|
|
| Obligations of States and Political Subdivisions [Member] |
|
|
|
|
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| Investments [Abstract] |
|
|
|
|
|
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| Held to maturity, carrying value |
462,293,000
|
|
436,802,000
|
|
|
|
| Held to maturity, allowance for credit losses |
372,000
|
|
357,000
|
|
|
|
| Held to maturity, amortized cost |
462,665,000
|
|
437,159,000
|
|
|
|
| Held to maturity, gross unrealized gains |
3,864,000
|
|
3,221,000
|
|
|
|
| Held to maturity, gross unrealized losses |
40,279,000
|
|
39,248,000
|
|
|
|
| Held to maturity, estimated fair value |
426,250,000
|
|
401,132,000
|
|
|
|
| Total available for sale, amortized cost |
51,450,000
|
|
49,982,000
|
|
|
|
| Available for sale, gross unrealized gains |
633,000
|
|
505,000
|
|
|
|
| Available for sale, gross unrealized losses |
1,824,000
|
|
1,936,000
|
|
|
|
| Available for sale, estimated fair value |
50,259,000
|
|
48,551,000
|
|
|
|
| Corporate Securities [Member] |
|
|
|
|
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| Investments [Abstract] |
|
|
|
|
|
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| Held to maturity, carrying value |
260,114,000
|
|
252,098,000
|
|
|
|
| Held to maturity, allowance for credit losses |
886,000
|
|
904,000
|
|
|
|
| Held to maturity, amortized cost |
261,000,000
|
|
253,002,000
|
|
|
|
| Held to maturity, gross unrealized gains |
1,066,000
|
|
2,211,000
|
|
|
|
| Held to maturity, gross unrealized losses |
9,025,000
|
|
7,423,000
|
|
|
|
| Held to maturity, estimated fair value |
253,041,000
|
|
247,790,000
|
|
|
|
| Total available for sale, amortized cost |
129,527,000
|
|
132,203,000
|
|
|
|
| Available for sale, gross unrealized gains |
409,000
|
|
700,000
|
|
|
|
| Available for sale, gross unrealized losses |
1,942,000
|
|
1,978,000
|
|
|
|
| Available for sale, estimated fair value |
127,994,000
|
|
130,925,000
|
|
|
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| Mortgage-Backed Securities [Member] |
|
|
|
|
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| Investments [Abstract] |
|
|
|
|
|
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| Held to maturity, carrying value |
7,061,000
|
|
8,304,000
|
|
|
|
| Held to maturity, allowance for credit losses |
4,000
|
|
5,000
|
|
|
|
| Held to maturity, amortized cost |
7,065,000
|
|
8,309,000
|
|
|
|
| Held to maturity, gross unrealized gains |
55,000
|
|
66,000
|
|
|
|
| Held to maturity, gross unrealized losses |
149,000
|
|
148,000
|
|
|
|
| Held to maturity, estimated fair value |
6,971,000
|
|
8,227,000
|
|
|
|
| Total available for sale, amortized cost |
448,128,000
|
|
443,128,000
|
|
|
|
| Available for sale, gross unrealized gains |
1,304,000
|
|
3,091,000
|
|
|
|
| Available for sale, gross unrealized losses |
11,563,000
|
|
9,301,000
|
|
|
|
| Available for sale, estimated fair value |
437,869,000
|
|
436,918,000
|
|
|
|
| Short-Term Investments [Member] |
|
|
|
|
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| Investments [Abstract] |
|
|
|
|
|
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| Total available for sale, amortized cost |
26,530,000
|
|
38,712,000
|
|
|
|
| Available for sale, gross unrealized gains |
0
|
|
0
|
|
|
|
| Available for sale, gross unrealized losses |
0
|
|
0
|
|
|
|
| Available for sale, estimated fair value |
$ 26,530,000
|
|
$ 38,712,000
|
|
|
|