Short-Term Investments - Summary of Investments Included in Cash Equivalents and Short Term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	$ 234,698	$ 261,955
Cash equivalents and short-term investments, Unrealized Gains	45	183
Cash equivalents and short-term investments, Unrealized Losses	(64)
Cash equivalents and short-term investments, Fair Value	234,679	262,138
Money Market Mutual Funds
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	143,122	39,524
Cash equivalents and short-term investments, Fair Value	143,122	39,524
Repurchase Agreements
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost		14,000
Cash equivalents and short-term investments, Fair Value		14,000
Asset-backed Securities
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	4,500	14,866
Cash equivalents and short-term investments, Unrealized Gains		10
Cash equivalents and short-term investments, Fair Value	4,500	14,876
Commercial Paper
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	25,913	41,259
Cash equivalents and short-term investments, Fair Value	25,913	41,259
Corporate Debt Securities
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	45,172	92,380
Cash equivalents and short-term investments, Unrealized Gains		128
Cash equivalents and short-term investments, Unrealized Losses	(64)
Cash equivalents and short-term investments, Fair Value	45,108	92,508
U.S Treasury Securities
Schedule Of Cash Cash Equivalents And Available For Sale Securities [Line Items]
Cash equivalents and short-term investments, Amortized Cost	15,991	59,926
Cash equivalents and short-term investments, Unrealized Gains	45	45
Cash equivalents and short-term investments, Fair Value	$ 16,036	$ 59,971