Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Fixed maturities, Held-to-maturity, at fair value	$ 199	$ 675
Fixed maturities, Available-for-sale securities, at amortized cost	2,887,505	2,793,069
Fixed maturities, Trading securities, at amortized cost	13,054	11,475
Equity securities, Available-for-sale securities, at amortized cost	68,504	68,514
Equity securities, Trading securities, at amortized cost	5,434	4,443
Allowance for doubtful accounts	1,255	867
Property and equipment, accumulated depreciation	$ 50,925	$ 46,590
Common stock, par value per share (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	25,429,769	25,151,428
Common stock, shares outstanding (in shares)	25,429,769	25,151,428