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STOCKHOLDERS' EQUITY - Narrative (Detail) $ / shares in Units, $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 USD ($) vote $ / shares shares | Dec. 31, 2016 USD ($) vote $ / shares shares | Dec. 31, 2015 USD ($) $ / shares
Limited Partners' Capital Account [Line Items] |  |  |
Preferred stock authorized to issue (up to) (in shares) | shares | 944,000 |  |
Shares issued (in shares) | shares | 0 | 0 |
Options granted (in dollars per share) | $ / shares | $ 0.00 | $ 0.00 | $ 5.35
Expected dividend yield | 0.00% | 0.00% | 0.00%
Expected life | 1 day | 1 day | 7 years 2 months 27 days
Risk-free interest rate | 0.00% | 0.00% | 2.02%
Expected volatility | 0.00% | 0.00% | 81.31%
Total fair value of other stock awards vested | $ 5,706 | $ 3,238 | $ 2,340
Tax benefits from additional paid-in-capital adjustments | 0 | 0 | 185
Stock Options |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Stock-based compensation expense | 644 | 605 | 671
Aggregate intrinsic value of stock options exercised | 4,664 | $ 22 | 52
Total unrecognized stock-based compensation expense related to all outstanding stock options (in shares) | 474 |  |
Market-based Performance Stock Options |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Expected dividend yield |  | 0.00% |
Weighted average fair value of market-based performance (in dollars per share) | $ / shares |  | $ 6.70 |
Expected life |  | 7 years 4 months 24 days |
Risk-free interest rate |  | 2.15% |
Expected volatility |  | 43.10% |
Restricted Stock, Restricted Stock Units and Performance Stock Units |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Stock-based compensation expense | $ 5,652 | $ 2,673 | 2,314
Granted (in dollars per share) | $ / shares | $ 12.32 |  |
Restricted Stock and Restricted Stock Unit |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Incremental compensation expense |  |  | $ 270
Unrecognized stock-based compensation expense | $ 2,945 |  |
Restricted Stock, Restricted Stock Units and Performance Stock Units |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options | $ 117 |  |
Granted (in dollars per share) | $ / shares | $ 12.32 | $ 8.97 | $ 4.40
Income taxes associated with stock-based compensation expense |  | $ 0 | $ 19
Market-based Performance Stock Units |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Expected dividend yield | 0.00% |  |
Weighted average fair value of market-based performance (in dollars per share) | $ / shares | $ 12.51 |  |
Risk-free interest rate | 1.45% |  |
Expected volatility | 32.80% |  |
Amended and Restated 1997 Employee Stock Purchase Plan |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Stock-based compensation expense | $ 136 | $ 115 | $ 94
Non-Employee Director | Restricted Stock Awards |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Options vesting period | 3 years |  |
Maximum | Performance Stock Units |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Unrecognized stock-based compensation expense | $ 5,268 |  |
Weighted Average | Stock Options |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Unrecognized stock-based compensation expense, weighted average period | 8 months |  |
Weighted Average | Restricted Stock and Restricted Stock Unit |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Unrecognized stock-based compensation expense, weighted average period | 1 year 1 month 6 days |  |
Weighted Average | Performance Stock Units |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Unrecognized stock-based compensation expense, weighted average period | 1 year 6 months |  |
2016 Incentive Plan |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Options granted period | 10 years |  |
2016 Incentive Plan | Minimum |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Options vesting period | 1 year |  |
2016 Incentive Plan | Maximum |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Options vesting period | 4 years |  |
Class A Common Stock |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Vote for each share held (in votes per share) | vote | 1 |  |
Number of shares available for future grant (in shares) | shares | 143,000 |  |
Class A Common Stock | 2016 Incentive Plan |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Common stock, authorized shares (in shares) | shares |  | 2,250,000 |
Number of shares available for future grant (in shares) | shares | 1,930,000 |  |
Class B Common Stock |  |  |
Limited Partners' Capital Account [Line Items] |  |  |
Vote for each share held (in votes per share) | vote | 10 | 10 |

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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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