Summary of Significant Accounting Policies - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Numerator—basic and diluted: | |||||||||||
| Net income | $ (606) | $ 7,338 | $ 8,338 | $ 5,932 | $ 5,260 | $ 5,246 | $ 7,492 | $ 2,521 | $ 21,002 | $ 20,519 | $ 11,585 |
| Denominator: | |||||||||||
| Weighted-average common shares - basic common stock | 20,869,589 | 20,753,789 | 20,622,320 | 20,489,532 | 20,310,857 | 20,157,688 | 19,972,395 | 19,827,669 | 20,683,807 | 20,067,152 | 19,398,991 |
| Weighted-average common shares - diluted common stock | 22,167,358 | 21,998,660 | 21,848,359 | 21,579,721 | 21,362,513 | 21,182,587 | 20,997,429 | 20,840,367 | 21,897,988 | 21,095,867 | 20,708,170 |
| Net income per share - basic common stock | $ (0.03) | $ 0.35 | $ 0.40 | $ 0.29 | $ 0.26 | $ 0.26 | $ 0.38 | $ 0.13 | $ 1.02 | $ 1.02 | $ 0.60 |
| Net income per share - diluted common stock | $ (0.03) | $ 0.33 | $ 0.38 | $ 0.27 | $ 0.25 | $ 0.25 | $ 0.36 | $ 0.12 | $ 0.96 | $ 0.97 | $ 0.56 |
| Weighted-average number of shares used in calculating net income per share attributable to common stockholders: | |||||||||||
| Weighted-average common shares - basic common stock | 20,869,589 | 20,753,789 | 20,622,320 | 20,489,532 | 20,310,857 | 20,157,688 | 19,972,395 | 19,827,669 | 20,683,807 | 20,067,152 | 19,398,991 |
| Warrants | 10,579 | ||||||||||
| Stock options and other dilutive awards | 1,214,181 | 1,028,715 | 1,298,600 | ||||||||
| Weighted-average common shares - diluted common stock | 22,167,358 | 21,998,660 | 21,848,359 | 21,579,721 | 21,362,513 | 21,182,587 | 20,997,429 | 20,840,367 | 21,897,988 | 21,095,867 | 20,708,170 |
| Shares excluded from diluted weighted-average shares: | |||||||||||
| Shares excluded from diluted weighted-average shares | 63,313 | 841,760 | 744,301 | ||||||||
| Stock options | |||||||||||
| Shares excluded from diluted weighted-average shares: | |||||||||||
| Shares excluded from diluted weighted-average shares | 37,249 | 841,760 | 744,301 | ||||||||
| Restricted stock units and restricted stock awards | |||||||||||
| Shares excluded from diluted weighted-average shares: | |||||||||||
| Shares excluded from diluted weighted-average shares | 26,064 | ||||||||||
| X | ||||||||||
- Definition Denominators for basic and diluted earnings per share. No definition available.
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| X | ||||||||||
- Definition Net income loss available to common stockholders basic and diluted. No definition available.
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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