Investments - Summary of Amortized Cost and Estimated Fair Values of Fixed Maturities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	$ 476,093,782	$ 402,798,518
Held to Maturity, Gross Unrealized Gains	24,926,519	8,872,223
Held to Maturity, Gross Unrealized Losses	705,957	6,632,445
Total held to maturity, Estimated Fair Value	500,314,344	405,038,296
Available for Sale, Amortized Cost	556,839,278	535,112,451
Available for Sale, Gross Unrealized Gains	9,056,799	2,139,728
Available for Sale, Gross Unrealized Losses	944,274	10,693,875
Available for Sale, Estimated Fair Value	564,951,803	526,558,304
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	82,916,052	76,222,306
Held to Maturity, Gross Unrealized Gains	1,803,230	174,904
Held to Maturity, Gross Unrealized Losses	68,560	1,086,613
Total held to maturity, Estimated Fair Value	84,650,722	75,310,597
Available for Sale, Amortized Cost	19,302,056	45,188,053
Available for Sale, Gross Unrealized Gains	81,773	25,241
Available for Sale, Gross Unrealized Losses	19,370	1,003,365
Available for Sale, Estimated Fair Value	19,364,459	44,209,929
Obligations of States and Political Subdivisions [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	204,634,486	159,292,158
Held to Maturity, Gross Unrealized Gains	14,236,736	8,236,804
Held to Maturity, Gross Unrealized Losses	288,174	704,104
Total held to maturity, Estimated Fair Value	218,583,048	166,824,858
Available for Sale, Amortized Cost	55,162,046	73,760,836
Available for Sale, Gross Unrealized Gains	1,641,171	1,762,127
Available for Sale, Gross Unrealized Losses	6,929	306,994
Available for Sale, Estimated Fair Value	56,796,288	75,215,969
Corporate Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	156,398,001	127,010,071
Held to Maturity, Gross Unrealized Gains	8,274,912	396,197
Held to Maturity, Gross Unrealized Losses	333,166	4,391,451
Total held to maturity, Estimated Fair Value	164,339,747	123,014,817
Available for Sale, Amortized Cost	154,946,586	140,688,937
Available for Sale, Gross Unrealized Gains	4,477,035	203,393
Available for Sale, Gross Unrealized Losses	180,312	3,059,185
Available for Sale, Estimated Fair Value	159,243,309	137,833,145
Mortgage-Backed Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	32,145,243	40,273,983
Held to Maturity, Gross Unrealized Gains	611,641	64,318
Held to Maturity, Gross Unrealized Losses	16,057	450,277
Total held to maturity, Estimated Fair Value	32,740,827	39,888,024
Available for Sale, Amortized Cost	327,428,590	275,474,625
Available for Sale, Gross Unrealized Gains	2,856,820	148,967
Available for Sale, Gross Unrealized Losses	737,663	6,324,331
Available for Sale, Estimated Fair Value	$ 329,547,747	$ 269,299,261

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount of investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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