Investments - Additional Information (Detail) (USD $)	0 Months Ended	6 Months Ended						3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended
	Nov. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Obligations of States and Political Subdivisions [Member]	Dec. 31, 2013 Obligations of States and Political Subdivisions [Member] General Obligation Bonds [Member]	Jun. 30, 2014 Special Revenue Bonds [Member]	Dec. 31, 2013 Special Revenue Bonds [Member]	Jun. 30, 2014 Education Bonds [Member]	Dec. 31, 2013 Education Bonds [Member]	Jun. 30, 2014 Water and Sewer Utility Bonds [Member]	Dec. 31, 2013 Water and Sewer Utility Bonds [Member]	Jun. 30, 2014 Equity Securities [Member] Securities	Jun. 30, 2014 Fixed Maturities [Member] Securities	Jun. 30, 2014 Accumulated Net Unrealized Investment Losses [Member]	Dec. 31, 2013 Accumulated Net Unrealized Investment Losses [Member]
Schedule of Investments [Line Items]
Aggregate fair value of bond held				$ 277,600,000	$ 294,100,000	$ 94,300,000	$ 91,900,000
Amortized cost of bond held				259,400,000	284,900,000	86,800,000	89,300,000
Percentage of which the company held security of any issuer		10.00%	10.00%
Percentage of investments in special revenue bonds								60.00%	56.00%	24.00%	23.00%
Net unrealized losses arising prior to reclassification date and classified in accumulated other comprehensive income	15,100,000
Amortization of unrealized losses recorded in accumulated other comprehensive income		617,325
Net unrealized losses reclassified in accumulated other comprehensive income														$ 14,400,000	$ 15,000,000
Depreciation of original cost value		20.00%
Time period for which individual security should be in unrealized position of twenty percentage or more to assume it as other than temporary decline		More than six months
Number of fixed maturity securities classified as available for sale												6	30
Percentage of ownership interest		48.20%