Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Computation of basic and diluted net loss per share [Abstract]
Net income (loss)	$ 12,379	$ (178)	$ (18,104)	$ 6,245
Denominator for basic earnings per share - weighted average shares (in shares)	107,157,561	105,935,736	106,929,643	104,403,622
Effect of dilutive securities: Stock options and restricted stock outstanding (in shares)	2,432,447	998,964	1,635,797	4,773,955
Denominator for diluted earnings per share - weighted average shares adjusted for dilutive securities (in shares)	109,590,008	105,935,736	106,929,643	109,177,577
Income per common share - basic (in dollars per share)	$ 0.12	$ 0.00	$ (0.17)	$ 0.06
Income per common share - diluted (in dollars per share)	$ 0.11	$ 0.00	$ (0.17)	$ 0.06
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,432,447	998,964	1,635,797	4,773,955
Outstanding Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	848,507	936,844	903,344	4,168,720
Restricted Stock Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,583,940	62,120	732,453	605,235

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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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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