Investments - Summary of Marketable Debt Securities Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	$ 124,368	$ 169,962
Unrealized Gains	92	4
Unrealized Losses	(1)	(99)
Fair Value	124,459	169,867
Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	36,926	14,131
Fair Value	36,926	14,131
Cash Equivalents \| Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	29,377	14,131
Fair Value	29,377	14,131
Cash Equivalents \| U.S. and Foreign Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	4,999
Fair Value	4,999
Cash Equivalents \| US Government Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	2,550
Fair Value	2,550
Short-Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	84,417	155,831
Unrealized Gains	92	4
Unrealized Losses	(1)	(99)
Fair Value	84,508	155,736
Short-Term Marketable Securities \| U.S. and Foreign Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	11,965	10,638
Unrealized Gains	7
Unrealized Losses		(3)
Fair Value	11,972	10,635
Short-Term Marketable Securities \| US Government Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	48,647	81,755
Unrealized Gains	71	1
Unrealized Losses		(57)
Fair Value	48,718	81,699
Short-Term Marketable Securities \| U.S. and Foreign Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	8,748	26,552
Unrealized Gains	8	2
Unrealized Losses	(1)	(21)
Fair Value	8,755	26,533
Short-Term Marketable Securities \| U.S. Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	15,057	34,136
Unrealized Gains	6	1
Unrealized Losses		(16)
Fair Value	15,063	34,121
Short-Term Marketable Securities \| Asset-backed Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis		2,750
Unrealized Losses		(2)
Fair Value		$ 2,748
Long Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	3,025
Fair Value	3,025
Long Term Marketable Securities \| U.S. Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	3,025
Fair Value	$ 3,025

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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