Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	$ 44,351	$ 78,066
Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	27,509	15,478
Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	16,842	62,588
U.S. Government and Agency Obligations
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	30,015	43,368
U.S. Government and Agency Obligations | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	27,509	15,478
U.S. Government and Agency Obligations | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	2,506	27,890
Certificates of Deposit
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	5,800	5,982
Certificates of Deposit | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	5,800	5,982
Commercial Paper
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	2,998	17,645
Commercial Paper | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	2,998	17,645
Corporate Debt Securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	5,538	11,071
Corporate Debt Securities | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	$ 5,538	$ 11,071