Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Status of Options Related to Stock Plans (Detail)

v3.3.1.900
Employee Benefit Plans - Status of Options Related to Stock Plans (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Options Outstanding Beginning Balance 1,064,000    
Options Outstanding Exercised (325,000)    
Options Outstanding Forfeited (25,000)    
Options Outstanding Ending Balance 714,000 1,064,000  
Options Outstanding Exercisable 714,000    
Weighted Average Exercise Price Per Share, Beginning Balance $ 17.62    
Weighted Average Exercise Price Per Share, Exercised 17.18    
Weighted Average Exercise Price Per Share, Forfeited 24.83    
Weighted Average Exercise Price Per Share, Ending Balance 17.56 $ 17.62  
Weighted Average Exercise Price Per Share, Exercisable $ 17.56    
Weighted Average Remaining Contractual Term 1 year 7 months 6 days 2 years 2 months 12 days  
Weighted Average Remaining Contractual Term, Exercisable 1 year 7 months 6 days    
Aggregate Intrinsic Value, Beginning Balance $ 10,444    
Aggregate Intrinsic Value, Ending Balance 5,605 $ 10,444  
Aggregate Intrinsic Value, Exercisable 5,605    
Intrinsic value of options exercised $ 2,511 $ 1,187 $ 1,657
Minimum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Exercise Price Per Share, Beginning Balance $ 1.81    
Exercise Price Per Share, Exercised 1.81    
Exercise Price Per Share, Forfeited 19.23    
Exercise Price Per Share, Ending Balance 1.81 $ 1.81  
Exercise Price Per Share, Exercisable 1.81    
Maximum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Exercise Price Per Share, Beginning Balance 25.05    
Exercise Price Per Share, Exercised 23.94    
Exercise Price Per Share, Forfeited 30.07    
Exercise Price Per Share, Ending Balance 30.07 $ 25.05  
Exercise Price Per Share, Exercisable $ 30.07