Investments (Details 2) $ in Thousands	Sep. 30, 2016 USD ($)
Amortized cost
Due in one year or less	$ 51,666
Due after one year through five years	314,652
Due after five years through ten years	195,967
Due after ten years	118,838
Amortized cost, fixed maturities	681,123
Estimated fair value
Due in one year or less	51,821
Due after one year through five years	319,198
Due after five years through ten years	203,310
Due after ten years	121,026
Estimated fair value, fixed maturities	$ 695,355