Fair Value Measurements - Summary of Placement in the Fair Value Hierarchy of Financial Assets that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets
Fair value of financial assets measured at fair value on a recurring basis	$ 85,358	$ 9,260
Quoted Prices in Active Markets (Level 1)
Assets
Fair value of financial assets measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2)
Assets
Fair value of financial assets measured at fair value on a recurring basis	85,358	9,260
Significant Unobservable Inputs (Level 3)
Assets
Fair value of financial assets measured at fair value on a recurring basis	0	0
U.S. government debt securities
Assets
Fair value of financial assets measured at fair value on a recurring basis	85,094	8,996
U.S. government debt securities | Quoted Prices in Active Markets (Level 1)
Assets
Fair value of financial assets measured at fair value on a recurring basis	0	0
U.S. government debt securities | Significant Other Observable Inputs (Level 2)
Assets
Fair value of financial assets measured at fair value on a recurring basis	85,094	8,996
U.S. government debt securities | Significant Unobservable Inputs (Level 3)
Assets
Fair value of financial assets measured at fair value on a recurring basis	0	0
Other
Assets
Fair value of financial assets measured at fair value on a recurring basis	264	264
Other | Quoted Prices in Active Markets (Level 1)
Assets
Fair value of financial assets measured at fair value on a recurring basis	0	0
Other | Significant Other Observable Inputs (Level 2)
Assets
Fair value of financial assets measured at fair value on a recurring basis	264	264
Other | Significant Unobservable Inputs (Level 3)
Assets
Fair value of financial assets measured at fair value on a recurring basis	$ 0	$ 0