CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Amortized cost of investments	$ 132,727	$ 119,119
Allowance for premiums and fees receivable	$ 459	$ 392
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	41,041,000	41,016,000
Common stock, shares outstanding	41,041,000	41,016,000
Accumulated Other Comprehensive Income, tax	$ 331	$ 923