Annual report pursuant to Section 13 and 15(d)

Capital Stock - Additional Information (Detail)

v3.3.1.900
Capital Stock - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Stockholders Equity Note [Line Items]      
Intrinsic value of options exercised   $ 296 $ 168
Tax benefit recognized on stock option exercised   $ 124 $ 71
Restricted Stock      
Stockholders Equity Note [Line Items]      
Shares of Restricted Stock, Granted 226,212 269,774 271,532
Weighted average grant date fair value per share $ 42.79 $ 28.93 $ 30.09
Minimum forfeiture rate for restricted stock awards 0.00%    
Maximum forfeiture rate for restricted stock awards 10.00%    
Unrecognized compensation expense $ 11,944    
Remaining Compensation Expense recognition period (in years) 2 years    
Restricted Stock | Director      
Stockholders Equity Note [Line Items]      
Award vesting period for restricted stock granted 1 year    
Restricted Stock | Minimum      
Stockholders Equity Note [Line Items]      
Weighted average grant date fair value per share $ 40.75    
Restricted Stock | Minimum | Employees      
Stockholders Equity Note [Line Items]      
Award vesting period for restricted stock granted 1 year    
Restricted Stock | Maximum      
Stockholders Equity Note [Line Items]      
Weighted average grant date fair value per share $ 43.28    
Restricted Stock | Maximum | Employees      
Stockholders Equity Note [Line Items]      
Award vesting period for restricted stock granted 4 years    
Restricted Stock Units (RSUs)      
Stockholders Equity Note [Line Items]      
Weighted average grant date fair value per share $ 43.19 $ 28.54 $ 29.44
Remaining Compensation Expense recognition period (in years) 2 years    
Number of hypothetical shares of common stock 142,917 197,515 115,107
Percentage of IRR, which is the threshold 8.50%    
Percentage of IRR, which is the target 10.50%    
Percentage of IRR, which is the maximum 12.50%    
Percentage of IRR expected 11.00%    
Stock price at the date of modification $ 33.02    
Incremental compensation expense $ 2,460    
Number of hypothetical shares of common stock 544,076    
Actual cumulative forfeitures (in units) 22,985    
Unrecognized Compensation expense related to outstanding restricted stock $ 6,600    
Restricted Stock Units (RSUs) | 2012 Grants      
Stockholders Equity Note [Line Items]      
Actual IRR calculated for grant 11.10%    
Restricted Stock Units (RSUs) | Minimum      
Stockholders Equity Note [Line Items]      
Expected forfeiture rate 0.00%    
Restricted Stock Units (RSUs) | Maximum      
Stockholders Equity Note [Line Items]      
Expected forfeiture rate 5.00%