Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Fixed maturities, held-to-maturity securities, fair value	$ 150	$ 150
Fixed maturities, available-for-sale securities, amortized cost	1,577,448	1,516,610
Fixed maturities, trading securities, amortized cost	13,229	14,582
Equity securities, amortized cost	65,481	63,275
Allowance for doubtful accounts	1,082	1,255
Property and equipment accumulated depreciation	$ 52,693	$ 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)	24,912,748	24,916,806
Common stock, shares outstanding (in shares)	24,912,748	24,916,806