Stock Options and Other Equity-Based Incentive Instruments - Summary of Options Outstanding (Detail)
$ / shares in Units, $ in Thousands |
12 Months Ended |
|
Dec. 31, 2015
USD ($)
$ / shares
shares
|
|---|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
| Number of options | shares |
948,350
|
| Weighted average exercise price | $ / shares |
$ 17.94
|
| Intrinsic value (in thousands) | $ |
$ 9,010
|
| Weighted average remaining contractual term (yrs.) |
4 years 9 months 18 days
|
| Currently Exercisable [Member] |
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
| Number of options | shares |
710,650
|
| Weighted average exercise price | $ / shares |
$ 18.10
|
| Intrinsic value (in thousands) | $ |
$ 6,641
|
| Weighted average remaining contractual term (yrs.) |
4 years 1 month 6 days
|
| Currently Not Exercisable [Member] |
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
| Number of options | shares |
237,700
|
| Weighted average exercise price | $ / shares |
$ 17.48
|
| Intrinsic value (in thousands) | $ |
$ 2,369
|
| Weighted average remaining contractual term (yrs.) |
6 years 7 months 6 days
|