Share-Based Compensation - Summary of RSUs (Detail)
|
12 Months Ended |
|
Dec. 31, 2016
$ / shares
shares
|
|---|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
| Nonvested as of January 1, 2016 |
102,475
|
| Granted |
89,142
|
| Vested |
(4,799)
|
| Forfeited |
(40,676)
|
| Nonvested as of December 31, 2016 |
146,142
|
| Nonvested as of January 1, 2016, Weighted-Average Grant-Date Fair Value | $ / shares |
$ 53.88
|
| Weighted-Average Grant-Date Fair Value, Granted | $ / shares |
33.73
|
| Weighted-Average Grant-Date Fair Value, Vested | $ / shares |
63.95
|
| Weighted-Average Grant-Date Fair Value, Forfeited | $ / shares |
63.95
|
| Nonvested as of December 31, 2016, Weighted-Average Grant- Date Fair Value | $ / shares |
$ 38.46
|
| Performance Required [Member] |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
| Nonvested as of January 1, 2016 |
91,603
|
| Granted |
79,241
|
| Vested |
0
|
| Forfeited |
(40,676)
|
| Nonvested as of December 31, 2016 |
130,168
|
| Service Required [Member] |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
| Nonvested as of January 1, 2016 |
10,872
|
| Granted |
9,901
|
| Vested |
(4,799)
|
| Forfeited |
0
|
| Nonvested as of December 31, 2016 |
15,974
|