Employee Benefit Plans - Schedule of Stock Appreciation Rights Activity (Detail) - Stock appreciation rights (SARs) [Member] - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | |
---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Number of SARs Outstanding Beginning Balance | 418,801 | |
Number of SARs Granted | 176,200 | |
Number of SARs Exercised | (33,262) | |
Number of SARs Canceled | (31,038) | |
Number of SARs Outstanding Ending Balance | 530,701 | |
Weighted Average Grant Price Outstanding Beginning Balance | $ 43.55 | |
Weighted Average Grant Price Granted | 64.93 | |
Weighted Average Grant Price Exercised | 39.61 | |
Weighted Average Grant Price Canceled | 51.00 | |
Weighted Average Grant Price Outstanding Ending Balance | $ 50.46 | |
Aggregate Intrinsic Value | $ 9,659 | $ 6,417 |