Investments - Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized Cost
Due in one year or less	$ 1,413	$ 1,807
Due after one year through five years	17,236	16,121
Due after five years through ten years	630	630
Total investments	19,279	18,558
Fair Value
Due in one year or less	1,413	1,810
Due after one year through five years	18,138	16,542
Due after five years through ten years	634	627
Total investments	$ 20,185	$ 18,979