Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income	$ 18,694	$ 13,266
Denominator:
Basic (shares)	39,112	39,109
Common stock options (shares)	1,423	1,970
Restricted stock units (shares)	311	467
Diluted (shares)	40,846	41,546
Basic (USD per share)	$ 0.48	$ 0.34
Diluted (USD per share)	$ 0.46	$ 0.32
Antidilutive Securities
Antidilutive securities (shares)	648	381
Stock Options
Antidilutive Securities
Antidilutive securities (shares)	582	343
Restricted Stock Units
Antidilutive Securities
Antidilutive securities (shares)	66	38

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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