Segment Information - Summary of Financial Data by Segment (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Premiums earned
Net premiums earned	$ 175,014,872	$ 161,942,637	$ 344,171,019	$ 320,417,916
Net investment income	5,649,870	5,343,883	11,405,269	10,890,392
Realized investment gains	1,097,306	715,177	3,646,281	1,186,118
Equity in earnings of DFSC	386,615	305,475	619,565	340,702
Other	1,432,000	1,540,000	2,710,000	3,081,000
Total revenues	183,580,716	169,846,867	362,551,679	335,915,643
Underwriting (loss) income:
SAP underwriting (loss) income	(14,067,000)	1,810,000	(19,225,000)	9,325,000
GAAP adjustments	2,904,000	3,051,000	5,779,000	5,007,000
GAAP underwriting (loss) income	(11,163,000)	4,861,000	(13,446,000)	14,332,000
Net investment income	5,649,870	5,343,883	11,405,269	10,890,392
Realized investment gains	1,097,306	715,177	3,646,281	1,186,118
Equity in earnings of DFSC	386,615	305,475	619,565	340,702
Other	633,000	821,000	1,103,000	1,315,000
(Loss) income before income tax (benefit) expense	(3,396,469)	12,045,692	3,328,360	28,064,231
Commercial Lines [Member]
Premiums earned
Net premiums earned	79,094,000	72,962,000	155,713,000	142,834,000
Underwriting (loss) income:
SAP underwriting (loss) income	3,340,000	5,577,000	3,672,000	10,417,000
Personal Lines [Member]
Premiums earned
Net premiums earned	95,921,000	88,981,000	188,458,000	177,584,000
Underwriting (loss) income:
SAP underwriting (loss) income	$ (17,407,000)	$ (3,767,000)	$ (22,897,000)	$ (1,092,000)