XML 16 R29.htm IDEA: XBRL DOCUMENT v2.4.0.6
Stock Incentive Plans And Stock Purchase Plans (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 3 Months Ended 9 Months Ended 9 Months Ended 1 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
May 10, 2012
Sep. 30, 2012
Stock Options [Member]
Y
Sep. 30, 2012
Restricted Stock [Member]
Sep. 30, 2012
Deferred Stock Awards [Member]
Sep. 30, 2012
1996 Non-Qualified Employee Stock Purchase Plan [Member]
May 10, 2012
Extended Maturity [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Vesting period expiration year                   10 years
Shares available for future grants and awards under Stock Incentive Plans 4,200,000   4,200,000   5,029,717          
Vesting period of options, maximum years           10        
Number of years over which options become exercisable on a pro rata basis           3        
Vesting period of options, years             3 years 5 years    
Restricted stock granted to employees     450,059              
Restricted stock granted to non-employee directors     14,625              
Percentage of market value of common stock at which employees are permitted to purchase                 85.00%  
Shares issued                 101,425  
Shares reserved for issuance                 454,000  
Stock-based compensation expense related to its Stock Incentive Plans and Non-Qualified Plan $ 7.3 $ 6.8 $ 20.4 $ 20.0            
Net excess tax benefit recognized in additional paid-in capital related to the exercise of stock options and the vesting of restricted stock     $ 4.0