Investments (Details 1) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Amortized Cost
One year or less	$ 2,416
More than one to five years	19,759
More than five to ten years	11,780
More than ten years	11,297
Total	45,252	$ 26,793
Estimated Fair Value
One year or less	2,415
More than one to five years	19,757
More than five to ten years	11,804
More than ten years	11,231
Total	$ 45,207	$ 26,559