CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Amortized cost of investments	$ 132,417	$ 117,902
Allowance for premiums, fees and Commission receivable	$ 459	$ 279
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	41,200,000	41,160,000
Common stock, shares outstanding	41,200,000	41,160,000
Accumulated Other Comprehensive Income, tax	$ (321)	$ (1,110)