Investments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015 Securities	Dec. 31, 2014 Securities
Investments, Debt and Equity Securities [Abstract]
Number of securities in unrealized loss position	39	38
Proceeds from sale of investment in fixed maturity securities	$ 100,000
Investment security maturity date, start	Jan. 01, 2015
Investment security maturity date, End	Mar. 31, 2015
Gross realized gains and losses of securities	0
Investments on deposit with the state insurance department	$ 4,100,000