Reconciliation of Statutory Filings to Amounts Reported in the Consolidated Financial Statements - Reconciliations of Statutory Net (loss) Income and Capital and Surplus (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Text Block [Abstract]
Statutory net (loss) income of insurance subsidiaries									$ (33,246,417)	$ 1,677,549	$ 26,926,349
Increases (decreases):
Deferred policy acquisition costs									325,267	3,980,664	4,200,808
Deferred federal income taxes									4,179,807	1,334,410	(2,030,865)
Salvage and subrogation recoverable									2,061,600	1,199,200	1,502,600
Consolidating eliminations and adjustments									(16,013,971)	(13,534,428)	(12,327,517)
Parent-only net income									9,933,374	12,458,705	12,529,762
Net (loss) income	$ (14,998,763)	$ 1,206,356	$ (789,855)	$ (18,178,078)	$ (2,778,644)	$ 7,108,574	$ (2,318,648)	$ 5,104,818	(32,760,340)	7,116,100	30,801,137
Statutory capital and surplus of insurance subsidiaries	364,518,536				407,125,532				364,518,536	407,125,532	421,752,063
Increases (decreases):
Deferred policy acquisition costs	60,615,127				60,289,860				60,615,127	60,289,860	56,309,196	$ 52,108,388
Deferred federal income taxes	(20,094,374)				(14,422,511)				(20,094,374)	(14,422,511)	(20,843,506)
Salvage and subrogation recoverable	20,038,200				17,976,600				20,038,200	17,976,600	16,777,400
Non-admitted assets and other adjustments, net	1,904,083				1,960,089				1,904,083	1,960,089	1,689,814
Fixed maturities	(16,528,367)				(8,748,140)				(16,528,367)	(8,748,140)	(7,271,932)
Parent-only equity and other adjustments	(11,583,304)				(15,485,326)				(11,583,304)	(15,485,326)	(29,797,715)
Total stockholders' equity	$ 398,869,901				$ 448,696,104				$ 398,869,901	$ 448,696,104	$ 438,615,320	$ 408,388,568