Segment Information - Summary of Financial Data by Segment (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Premiums earned:
Premiums earned	$ 185,714,110	$ 175,014,872	$ 367,478,690	$ 344,171,019
Net investment income	6,342,152	5,649,870	12,720,521	11,405,269
Realized investment gains	1,517,310	1,097,306	598,971	3,646,281
Equity in earnings of DFSC	787,856	386,615	1,419,970	619,565
Other	1,429,000	1,432,000	2,899,000	2,710,000
Total revenues	195,790,028	183,580,716	385,118,306	362,551,679
Underwriting income (loss):
SAP underwriting income (loss)	(12,731,000)	(14,067,000)	(50,208,000)	(19,225,000)
GAAP adjustments	2,406,000	2,904,000	4,775,000	5,779,000
GAAP underwriting loss	(10,325,000)	(11,163,000)	(45,433,000)	(13,446,000)
Net investment income	6,342,152	5,649,870	12,720,521	11,405,269
Realized investment gains	1,517,310	1,097,306	598,971	3,646,281
Equity in earnings of DFSC	787,856	386,615	1,419,970	619,565
Other	345,000	633,000	825,000	1,103,000
(Loss) income before income tax (benefit) expense	(1,333,046)	(3,396,469)	(29,868,217)	3,328,360
Commercial Lines [Member]
Premiums earned:
Premiums earned	84,552,000	79,094,000	166,778,000	155,713,000
Underwriting income (loss):
SAP underwriting income (loss)	150,000	3,340,000	(20,060,000)	3,672,000
Personal Lines [Member]
Premiums earned:
Premiums earned	101,162,000	95,921,000	200,701,000	188,458,000
Underwriting income (loss):
SAP underwriting income (loss)	$ (12,881,000)	$ (17,407,000)	$ (30,148,000)	$ (22,897,000)