Stock-based Compensation and Stock Plans (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended
Feb. 28, 2014
Feb. 28, 2013
Feb. 28, 2014
management_dividend_award
Feb. 28, 2013
May 31, 2013
Jul. 31, 2012
Stock Options [Member]
Jul. 30, 2012
Stock Options [Member]
Jul. 31, 2012
Restricted Stock Units [Member]
Jul. 30, 2012
Restricted Stock Units [Member]
Feb. 28, 2014
2012 Restricted Stock Unit Plan [Member]
Restricted Stock Units [Member]
Installment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Stock-based compensation expense recognized $ 5.5 $ 5.8 $ 14.7 $ 32.3            
Purchase of aggregate shares of common stock             29,821,500   3,665,000  
Stock based compensation, new options granted           29,821,500        
Stock based compensation, restricted stock units granted               10,795,000    
Exercise price for stock options decreased to current fair value   $ 7.88 $ 7.88              
Vesting schedule in excess of original vesting schedule     2 years              
Management dividend awards vested per each restricted stock unit     1              
Common stock, par value $ 0.01   $ 0.01   $ 0.01          
Maximum number of shares of common stock 14,000,000   14,000,000              
Number of installments                   3
Vesting period                   2 years
Options were exercise price was modified   3,193,167