XML 64 R49.htm IDEA: XBRL DOCUMENT v3.3.0.814
Shares Repurchased - Additional Information (Detail) - Three-Year Share Repurchase Program [Member] - USD ($)
 3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Oct. 29, 2014
Equity, Class of Treasury Stock [Line Items]          
Common stock purchase authorized amount         $ 100,000,000
Repurchased common stock, shares 330   1,165    
Repurchased common stock, value $ 8,424,000   $ 23,689,000    
Repurchased shares, remaining for future purchases $ 76,311,000   $ 76,311,000    
Tax Withholding Obligations [Member]          
Equity, Class of Treasury Stock [Line Items]          
Repurchased common stock, shares   80 278 392  
Repurchased common stock, value   $ 834,000 $ 4,842,000 $ 6,259,000  
Employee Equity Grants [Member]          
Equity, Class of Treasury Stock [Line Items]          
Repurchased common stock, shares     887,000    
Repurchased common stock, value     $ 18,847,000