Investments - Cost vs FV (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Gross Amortized Cost
Due in one year or less	$ 58,213	$ 63,073
Due after one through five years		2,094
Total	58,213	65,167
Fair Value
Due in one year or less	58,217	63,040
Due after one through five years		2,093
Total	$ 58,217	$ 65,133