Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2010
Schedule Of Significant Accounting Policies [Line Items]
Maximum maturity period of highly liquid investments		3 months
Allowances for doubtful accounts		$ 446,000		$ 530,000
Accruals for premium deficiency		0		0
Unsecured amounts due from reinsurers exceeding a fixed percentage of stockholders equity		3.00%
Deferred policy acquisition costs		15,899,000	12,996,000	17,282,000	9,445,000
Deferred policy acquisition costs, net, difference percentage			13.00%
Deferred policy acquisition costs, pre-tax charge against earnings	1,600,000
Maximum amortization period for capitalized cost		12 months
Minimum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Useful life of property and equipment		3 years
Number of installments to pay policy premiums		2
Maximum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Useful life of property and equipment		27 years 6 months
Number of installments to pay policy premiums		4
Acquisition-Related Costs [Member] | Minimum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Deferred policy acquisition costs			11,400,000
Acquisition-Related Costs [Member] | Maximum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Deferred policy acquisition costs			$ 13,000,000