Stockholders' Equity, Stock-based Valuation Information (Details)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Stock Options [Member]
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	0.60%	1.50%	2.30%
Dividend yield	0.00%	0.00%	0.00%
Volatility	54.00%	58.60%	60.30%
Expected life	4 years 10 months 24 days	4 years 8 months 12 days	4 years 9 months 18 days
Board of Director Stock Options [Member]
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	1.20%	0.50%	1.90%
Dividend yield	0.00%	0.00%	0.00%
Volatility	55.90%	57.60%	60.70%
Expected life	7 years 3 months 18 days	6 years 8 months 12 days	6 years 7 months 6 days
ESPP [Member]
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	0.10%	0.80%	2.40%
Dividend yield	0.00%	0.00%	0.00%
Volatility	42.40%	47.90%	45.60%
Expected life	6 months	6 months	6 months

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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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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