Annual report pursuant to Section 13 and 15(d)

Share-based Compensation - Summary of Stock Options Outstanding under Plans (Detail)

v3.3.1.900
Share-based Compensation - Summary of Stock Options Outstanding under Plans (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Options Outstanding, Number of Shares 510,148 603,872 546,595 342,950
Options Outstanding, Intrinsic Value $ 3,219      
Options Outstanding, Weighted-Average Exercise Price Per Share (in usd per share) $ 24.38 $ 23.78 $ 28.09 $ 37.44
Options Outstanding, Weighted-Average Remaining Contractual Life 7 years 3 months 18 days      
Options Exercisable, Number of Shares 333,460 224,766 154,970  
Options Exercisable, Intrinsic Value $ 2,398      
Options Exercisable, Weighted-Average Exercise Price Per Share (in usd per share) $ 27.16 $ 33.35 $ 59.77  
Options Exercisable, Weighted-Average Remaining Contractual Life 6 years 9 months 61 days      
Intrinsic value of stock options outstanding (in usd per share) $ 23.72      
$10.80 to $49.99 [Member]        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Exercise Price Range, Lower Limit (in usd per share) 10.88      
Exercise Price Range, Upper Limit (in usd per share) $ 49.99      
Options Outstanding, Number of Shares 482,898      
Options Outstanding, Intrinsic Value $ 3,219      
Options Outstanding, Weighted-Average Exercise Price Per Share (in usd per share) $ 17.06      
Options Outstanding, Weighted-Average Remaining Contractual Life 7 years 8 months 12 days      
Options Exercisable, Number of Shares 306,210      
Options Exercisable, Intrinsic Value $ 2,398      
Options Exercisable, Weighted-Average Exercise Price Per Share (in usd per share) $ 15.87      
Options Exercisable, Weighted-Average Remaining Contractual Life 7 years 4 months 24 days      
$50.00 to $99.99 [Member]        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Exercise Price Range, Lower Limit (in usd per share) $ 50.00      
Exercise Price Range, Upper Limit (in usd per share) $ 99.99      
Options Outstanding, Number of Shares 0      
Options Outstanding, Intrinsic Value $ 0      
Options Outstanding, Weighted-Average Exercise Price Per Share (in usd per share) $ 0.00      
Options Outstanding, Weighted-Average Remaining Contractual Life 0 years      
Options Exercisable, Number of Shares 0      
Options Exercisable, Intrinsic Value $ 0      
Options Exercisable, Weighted-Average Exercise Price Per Share (in usd per share) $ 0.00      
Options Exercisable, Weighted-Average Remaining Contractual Life 0 years      
$100.00 to $149.99 [Member]        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Exercise Price Range, Lower Limit (in usd per share) $ 100.00      
Exercise Price Range, Upper Limit (in usd per share) $ 149.99      
Options Outstanding, Number of Shares 16,000      
Options Outstanding, Intrinsic Value $ 0      
Options Outstanding, Weighted-Average Exercise Price Per Share (in usd per share) $ 143.63      
Options Outstanding, Weighted-Average Remaining Contractual Life 3 months 18 days      
Options Exercisable, Number of Shares 16,000      
Options Exercisable, Intrinsic Value $ 0      
Options Exercisable, Weighted-Average Exercise Price Per Share (in usd per share) $ 143.63      
Options Exercisable, Weighted-Average Remaining Contractual Life 3 months 18 days      
$150.00 to $173.04 [Member]        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Exercise Price Range, Lower Limit (in usd per share) $ 150.00      
Exercise Price Range, Upper Limit (in usd per share) $ 173.04      
Options Outstanding, Number of Shares 11,250      
Options Outstanding, Intrinsic Value $ 0      
Options Outstanding, Weighted-Average Exercise Price Per Share (in usd per share) $ 168.86      
Options Outstanding, Weighted-Average Remaining Contractual Life 9 months 18 days      
Options Exercisable, Number of Shares 11,250      
Options Exercisable, Intrinsic Value $ 0      
Options Exercisable, Weighted-Average Exercise Price Per Share (in usd per share) $ 168.86      
Options Exercisable, Weighted-Average Remaining Contractual Life 9 months 18 days