Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v2.4.0.8
Long-Term Debt - Additional Information (Detail) (USD $)
3 Months Ended 6 Months Ended 1 Months Ended 3 Months Ended 6 Months Ended 1 Months Ended 3 Months Ended 1 Months Ended 3 Months Ended 6 Months Ended 6 Months Ended 1 Months Ended 1 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Dec. 31, 2013
Feb. 28, 2014
Convertible Senior Notes [Member]
Jun. 30, 2014
Convertible Senior Notes [Member]
Mar. 31, 2014
Convertible Senior Notes [Member]
Jun. 30, 2014
Convertible Senior Notes [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Feb. 28, 2014
Prepaid forward share repurchase transactions [Member]
Mar. 31, 2014
Prepaid forward share repurchase transactions [Member]
Feb. 28, 2014
Capped call transactions [Member]
Mar. 31, 2014
Debt Issuance Costs [Member]
Convertible Senior Notes [Member]
Mar. 31, 2011
Senior Secured Credit Facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Mar. 31, 2014
Senior Secured Credit Facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Dec. 31, 2013
Senior Secured Credit Facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Senior secured revolving credit facility [Member]
Dec. 31, 2013
Senior Secured Credit Facility [Member]
Senior secured revolving credit facility [Member]
Mar. 09, 2011
Senior Secured Credit Facility [Member]
Senior secured revolving credit facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Senior secured revolving credit facility [Member]
Maximum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Senior secured revolving credit facility [Member]
Minimum [Member]
Jul. 31, 2012
Senior Secured Credit Facility [Member]
Term Loan [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Term Loan [Member]
Dec. 31, 2013
Senior Secured Credit Facility [Member]
Term Loan [Member]
Jul. 26, 2012
Senior Secured Credit Facility [Member]
Term Loan [Member]
Feb. 28, 2014
Senior Secured Credit Facility [Member]
Convertible Notes [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Convertible Notes [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Senior secured revolving credit facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Senior secured revolving credit facility [Member]
Maximum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Senior secured revolving credit facility [Member]
Minimum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Term Loan [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Term Loan [Member]
Maximum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option one [Member]
Term Loan [Member]
Minimum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Senior secured revolving credit facility [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Senior secured revolving credit facility [Member]
Maximum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Senior secured revolving credit facility [Member]
Minimum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Term Loan [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Term Loan [Member]
Maximum [Member]
Jun. 30, 2014
Senior Secured Credit Facility [Member]
Interest rate option two [Member]
Term Loan [Member]
Minimum [Member]
Debt Instrument [Line Items]                                                                                    
Credit facility, maximum amount                                           $ 700,000,000           $ 500,000,000                            
Credit facility, maturity period                                   5 years                                                
Credit facility, expiration date                                   Mar. 09, 2016                                                
Interest rate spread on variable rate                                                               2.50% 1.50%   2.50% 1.50%   1.50% 0.50%   1.50% 0.50%
Variable rate basis                                                             LIBOR     LIBOR     The base rate under the Credit Facility represents the highest of the Federal Funds Rate plus 0.50%, one-month LIBOR plus 1.00%, and the prime rate offered by Bank of America.     Base rate    
Base rate in excess of Federal Funds Rate                                                                         0.50%          
Base rate in excess of one-month LIBOR                                                                         1.00%          
Credit facility, unused capacity, commitment fee percentage                                             0.50% 0.25%                                    
Credit facility borrowings used to repay outstanding borrowings                             196,000,000                   500,000,000                                  
Deferred financing costs               21,500,000             5,700,000                   4,500,000       2,300,000                          
Applicable margin payable, percentage                                                         0.50%                          
Consolidated leverage ratio                                                           2.50 to 1.00                        
Long-term debt, weighted average interest rate                               3.01%   3.01% 2.17%                                              
Credit facility, amount repaid                               18,800,000 18,800,000                                                  
Credit facility, amount outstanding 893,800,000   893,800,000   931,300,000                     893,800,000   893,800,000 931,300,000 500,000,000 500,000,000         393,800,000 431,300,000                              
Foreign currency borrowings, outstanding                               0   0 0                                              
Aggregate principal amount of convertible senior notes issued           1,000,000,000                                                                        
Additional principal amount of convertible notes           150,000,000                                                                        
Convertible notes, interest rate           2.00%                                                                        
Convertible notes maturity           Aug. 15, 2019                                                                        
Total principal amount of convertible notes           1,150,000,000 1,150,000,000   1,150,000,000                                                                  
Convertible notes, conversion feature                 Holders of the Convertible Notes may convert their notes at their option under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending March 31, 2014, if the last reported sale price of the Company’s common shares for at least 20 trading days (whether or not consecutive) in a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds 130% of the conversion price for the Convertible Notes on each applicable trading day; (ii) during the five business-day period immediately after any five consecutive trading day period, which we refer to as the measurement period, in which the trading price per $1,000 principal amount of Convertible Notes for each trading day of that measurement period was less than 98% of the product of the last reported sale price of the Company’s common shares and the conversion rate for the Convertible Notes for each such day; or (iii) upon the occurrence of specified corporate events. On and after May 15, 2019, holders may convert their Convertible Notes at any time, regardless of the foregoing circumstances.                                                                  
Convertible notes, number of trading days of threshold limit (whether or not consecutive)                 20 days                                                                  
Convertible notes, number of trading days of threshold limit in consecutive days                 30 days                                                                  
Maximum percentage of conversion price for convertible notes           130.00%                                                                        
Principal amount of convertible notes           1,000                                                                        
Minimum percentage of conversion price for convertible notes           98.00%                                                                        
Convertible notes initial conversion rate           11.5908                                                                        
Convertible notes initial conversion price $ 86.28   $ 86.28     $ 86.28                                                                        
Issuance costs               26,600,000                                                                    
Additional paid-in capital 398,436,000   398,436,000   323,860,000 219,100,000           31,900,000   5,100,000                                                        
Proceeds received from the issuance of the Convertible notes     1,150,000,000     1,150,000,000                                                                        
Long-term debt           930,900,000                                                                        
Effective interest rate on convertible notes           6.20%                                                                        
Unamortized debt discount             205,800,000   205,800,000                                                                  
Convertible senior notes, carrying value of liability component             944,200,000   944,200,000                                                                  
Fair value of liability to convertible notes             911,300,000   911,300,000                                                                  
Forward share repurchase transactions amount                     685,800,000 685,800,000                                                            
Capped call transactions with financial institutions                         123,800,000                                                          
Interest expense 24,200,000 7,500,000 41,900,000 14,300,000     15,200,000   24,000,000                                                                  
Non-cash interest expense             8,500,000   13,300,000                                                                  
Amortization of deferred financing costs             900,000   1,400,000                                                                  
Aggregate annual maturities of credit facility, remainder of 2014                   43,800,000                                                                
Aggregate annual maturities of credit facility, 2015                   100,000,000                                                                
Aggregate annual maturities of credit facility, 2016                   $ 750,000,000                                                                
Convertible senior notes due                 2019