Stock-Based Compensation - Weighted Average Assumptions Used to Estimate Fair Value of Stock Purchase Rights under ESPP (Details) - ESPP [Member]	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP
Volatility	66.00%	37.00%	47.00%	37.00%
Expected term (years)	6 months	6 months	6 months	6 months
Risk free interest rate	0.40%	2.40%	1.00%	2.50%

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Rate of weighted-average expected volatility for award under share-based payment arrangement.

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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