Equity - Additional Information - 2004 Equity Incentive Plan (Detail) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Maximum number of shares of common stock reserved for issuance |
1,329,364
|
|
|
| Restricted stock units |
329,325
|
145,979
|
34,292
|
| Stock Options [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Maximum number of shares eligible under share based compensation plan by individual within a year |
15,000
|
|
|
| Restricted Stock [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Maximum number of shares eligible under share based compensation plan by individual within a year |
20,000
|
|
|
| Stock Appreciation Rights [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Maximum number of shares eligible under share based compensation plan by individual within a year |
20,000
|
|
|
| Performance Shares [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Maximum number of shares eligible under share based compensation plan by individual within a year |
10,000
|
|
|
| Restricted Stock Units [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Restricted stock units |
329,325
|
145,979
|
34,292
|
| Compensation expense related to restricted stock units |
$ 1,129
|
$ 1,270
|
$ 875
|
| Compensation expense related to restricted stock units for year 2017 |
916
|
|
|
| Compensation expense related to restricted stock units for year 2018 |
565
|
|
|
| Compensation expense related to restricted stock units for year 2019 |
$ 215
|
|
|