Quarterly Summary of Information (Unaudited) - Summary of Unaudited Quarterly Statements of Income Data (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 |
|
| Selected Quarterly Financial Information [Abstract] | |||||||||||
| Total revenue | $ 63,787 | $ 69,030 | $ 64,121 | $ 52,500 | $ 50,851 | $ 54,422 | $ 54,567 | $ 42,989 | $ 249,438 | $ 202,829 | $ 159,005 |
| Gross profit | 30,756 | 33,170 | 31,567 | 25,744 | 24,688 | 25,128 | 26,215 | 21,279 | 121,237 | 97,310 | 76,258 |
| Income before provision (benefit) for income taxes | 5,794 | 8,817 | 9,166 | 5,879 | 5,834 | 5,449 | 8,042 | 3,400 | 29,656 | 22,725 | 14,727 |
| Provision (benefit) for income taxes | 6,400 | 1,479 | 828 | (53) | 574 | 203 | 550 | 879 | 8,654 | 2,206 | 3,142 |
| Net income | $ (606) | $ 7,338 | $ 8,338 | $ 5,932 | $ 5,260 | $ 5,246 | $ 7,492 | $ 2,521 | $ 21,002 | $ 20,519 | $ 11,585 |
| Net income (loss) per share attributable to common stockholders | |||||||||||
| Net income (loss) 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 (loss) 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: | |||||||||||
| Basic common shares | 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 |
| Diluted common shares | 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 |
| X | ||||||||||
- 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
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- Definition Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- 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
|