Performance Awards - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items] | ||||
Unearned compensation | $ 2,100 | $ 2,100 | ||
Performance Awards | ||||
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items] | ||||
Compensation expense | (300) | $ 200 | 400 | $ 400 |
Unearned compensation | $ 1,362 | $ 1,200 | $ 1,362 | $ 1,200 |
2014 Equity Incentive Plan | Performance Awards | ||||
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items] | ||||
Performance period | 3 years |