Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Additional Information (Detail)

v2.4.0.8
Share-Based Compensation - Additional Information (Detail) (USD $)
12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2013
Plans
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
Independent Director Stock Units [Member]
Feb. 28, 2009
Chairman and Chief Executive Officer [Member]
Mar. 31, 2008
Chairman and Chief Executive Officer [Member]
Dec. 31, 2013
Performance conditions [Member]
June 2014 [Member]
Dec. 31, 2013
Performance conditions [Member]
June 2015 [Member]
Dec. 31, 2013
Performance conditions [Member]
June 2016 [Member]
Dec. 31, 2013
Management Plan [Member]
Dec. 31, 2013
2004 Stock Incentive Plan [Member]
Dec. 31, 2013
Incentive Plan Stock Units [Member]
Dec. 31, 2013
SARs [Member]
Dec. 31, 2013
SARs [Member]
Incentive Plan Stock Units Other [Member]
Dec. 31, 2013
Stock Options [Member]
Dec. 31, 2013
Stock Units [Member]
Independent Director Stock Units [Member]
Mar. 31, 2008
Stock Units [Member]
Chairman and Chief Executive Officer [Member]
Mar. 31, 2008
Market Condition 1 [Member]
Mar. 31, 2008
Market Condition Target 2 [Member]
Dec. 31, 2013
Service condition awards [Member]
Dec. 31, 2012
Service condition awards [Member]
Dec. 31, 2011
Service condition awards [Member]
Dec. 31, 2013
Market and performance condition awards [Member]
Dec. 31, 2012
Market and performance condition awards [Member]
Dec. 31, 2011
Market and performance condition awards [Member]
Dec. 31, 2013
Performance condition awards [Member]
Dec. 31, 2012
Performance condition awards [Member]
Dec. 31, 2011
Performance condition awards [Member]
Dec. 31, 2013
Market condition awards [Member]
Dec. 31, 2012
Market condition awards [Member]
Dec. 31, 2011
Market condition awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                                              
Number of share-based compensation plan 5                                                            
Additional awards       0           0 0                                        
Common shares authorized under 2005 Stock Incentive Plan 14,400,000                                                            
Common shares remain for future issuance under share-based compensation plans 1,900,000                                                            
Contractual term                       3 years 10 years   10 years                                
Vesting period beginning from the grant date                       3 years 5 years 3 years 5 years   4 years                            
Stock units vesting rate                               25.00%                              
Stock units vesting rate during first three years                                 30.00%                            
Stock units vesting rate during fourth year                                 10.00%                            
Granted stock unit awards to Chairman and Chief Executive Officer vesting         The Company granted stock units and SARs to certain employees subject to continued service, one-third of which vest on the third anniversary of the date of grant, one-third of which vest on the fourth anniversary of the date of grant, and the remaining one-third of which vest on the fifth anniversary of the date of grant. Over a four-year period at a rate of 30% during each of the first three years and 10% during the fourth year                                                  
Stock price appreciation rate                                   10.00% 15.00%                        
Awards vest, percentage             20.00% 20.00% 60.00%                                            
Share-based compensation expense                                       $ 24,600,000 $ 22,700,000 $ 19,200,000 $ 4,500,000 $ 4,600,000 $ 1,400,000 $ 300,000     $ 0 $ 700,000 $ 2,900,000
Realized income tax benefit for all awards 10,400,000 9,500,000 7,500,000                                                        
Unrecognized compensation cost on non-vested stock awards                                       41,600,000     4,500,000     12,700,000          
Unrecognized compensation cost on non-vested stock awards, weighted-average period of recognition                                       1 year 4 months 24 days     1 year     1 year 8 months 12 days          
Excess tax benefit 15,566,000 29,684,000 26,241,000                                                        
Awards granted 0 0 0                                       0 0 0   0 0      
Total intrinsic value of awards exercised for options and SARs                                       16,100,000 98,600,000 133,800,000 0 0 0 0 0 0 0 0 0
Weighted-average grant date fair value of SARs granted                                       $ 30.57 $ 15.36 $ 21.23     $ 17.37 $ 33.04          
Total vesting date fair value of stock units $ 7,300,000 $ 24,300,000 $ 19,800,000                                                        
Percent of fair market value for which eligible employees can purchase common shares under employee stock purchase plan 85.00%                                                            
Reserved for issuance under employee stock purchase plan 2,000,000                                                            
Future Issuance of employee stock purchase plan 1,800,000