Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	$ 148,263	$ 162,942
Fair Value, Measurements, Recurring
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	148,263	162,942
Fair Value, Measurements, Recurring | US Government
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		66,094
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		68,084
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		7,658
Fair Value, Measurements, Recurring | Money Market Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		16,998
Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		4,108
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	82,318	83,092
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | US Government
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		66,094
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		16,998
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	65,945	79,850
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate Bonds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		68,084
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		7,658
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Certificates of Deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:		$ 4,108
Fair Value, Measurements, Recurring | US Government
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	68,414
Fair Value, Measurements, Recurring | US Government | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	68,414
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	55,671
Fair Value, Measurements, Recurring | Corporate Bonds | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	55,671
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	8,486
Fair Value, Measurements, Recurring | Commercial Paper | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	8,486
Fair Value, Measurements, Recurring | Money Market Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	13,904
Fair Value, Measurements, Recurring | Money Market Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	13,904
Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	1,788
Fair Value, Measurements, Recurring | Certificates of Deposit | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Marketable securities:	$ 1,788