Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Awards - Additional Information (Detail)

v2.4.0.6
Stock-Based Awards - Additional Information (Detail) (USD $)
9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
New awards authorized 8,000,000  
Available for grants 3,200,000  
Stock-based awards maximum term, years 10  
Tax withholdings related to stock-based awards $ 15,482,000 $ 7,291,000
Share-based liability 16,200,000  
Unrecognized compensation cost $ 19,700,000  
Weighted average period, years 1 year 9 months 18 days  
Performance-Based Equity Compensation Program [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period, years 3 years  
Stock Appreciation Rights (SARs) [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares granted 357,000  
Weighted average fair value $ 12.96  
Vesting period, years 3 years  
Weighted average exercise price $ 35.69  
Volatility factor 46.51%  
Risk-free interest rate 0.91%  
Expected term 5 years  
Expected dividend yield 1.40%  
Restricted Stock Units (RSUs) [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares granted 304,000  
Weighted average fair value $ 36.07  
Vesting period, years 3 years  
Employee Stock [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Shares granted 50,000  
Weighted average fair value $ 10.13  
Volatility factor 41.69%  
Risk-free interest rate 0.10%  
Expected term 6 months  
Expected dividend yield 1.30%