Marketable Securities - Schedule of Fair Value and Amortized Cost of Company's Available-for-Sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 15,079	$ 57,650
Total, Amortized Cost	15,079	57,650
Due in one year or less, Fair Value	15,111	57,699
Total, Fair Value	$ 15,111	$ 57,699