Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Fixed maturities, Held-to-maturity, at fair value	$ 0	$ 150
Fixed maturities, Available-for-sale securities, amortized cost	1,761,289	1,516,610
Fixed maturities, Trading securities, at amortized cost	11,277	14,582
Equity securities, cost	64,819	63,275
Allowance for doubtful accounts	785	1,255
Property and equipment, accumulated depreciation	$ 39,894	$ 51,603
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	25,097,408	24,916,806
Common stock, shares outstanding (in shares)	25,097,408	24,916,806