Stock-Based Compensation - Additional Information (Detail) - shares |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
|
| Time-based Restricted Units [Member] | ||||
| Stock Based Compensation [Line Items] | ||||
| Restricted units awarded to managers | 14,288 | 1,118 | 14,288 | 20,048 |
| Performance-based Restricted Units [Member] | ||||
| Stock Based Compensation [Line Items] | ||||
| Restricted units awarded to managers | 5,102 | 151,566 | 308,163 | 151,566 |