Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v3.2.0.727
Long-Term Debt - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Sep. 30, 2015
May. 04, 2015
Feb. 28, 2014
Jul. 31, 2012
Mar. 31, 2011
Jun. 30, 2015
Mar. 31, 2015
Jun. 30, 2014
Mar. 31, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Jul. 26, 2012
Mar. 09, 2011
Debt Instrument [Line Items]                            
Issuance costs   $ 6,200,000                        
Allowable annual dividend payment or repurchase of common stock under credit facility                   $ 233,000,000        
Credit facility terms description                   The Credit Facility restricts the Company’s ability to pay dividends or repurchase its common shares to a maximum of $233.0 million until maturity and for every one dollar of share repurchase or dividend paid, the revolving credit facility’s borrowing capacity is permanently decreased by two dollars.        
Credit facility, amount outstanding           $ 689,700,000       $ 689,700,000   $ 850,000,000    
Paid-in-capital in excess of par value           426,300,000       426,300,000   409,100,000    
Proceeds received from the issuance of the Convertible notes                     $ 1,150,000,000      
Long-term debt           1,683,000,000       1,683,000,000   1,811,700,000    
Convertible senior notes, carrying value of liability component           979,500,000       979,500,000   $ 961,700,000    
Interest expense           24,800,000   $ 24,200,000   48,200,000 $ 41,900,000      
Write off of unamortized deferred financing cost                   600,000        
Letters of credit issued but undrawn           $ 33,100,000       $ 33,100,000        
Capped call transactions [Member]                            
Debt Instrument [Line Items]                            
Capped call transactions with financial institutions     $ 123,800,000                      
Prepaid forward share repurchase transactions [Member]                            
Debt Instrument [Line Items]                            
Paid-in-capital in excess of par value                 $ (31,900,000)          
Forward share repurchase transactions amount     $ 685,800,000           685,800,000          
Convertible Notes [Member]                            
Debt Instrument [Line Items]                            
Convertible notes initial conversion price           $ 86.28   $ 86.28   $ 86.28 $ 86.28      
Convertible Notes [Member] | Capped call transactions [Member]                            
Debt Instrument [Line Items]                            
Convertible notes initial conversion price     $ 86.28                      
Convertible Senior Notes [Member]                            
Debt Instrument [Line Items]                            
Deferred financing costs                 21,500,000          
Total principal amount of convertible notes     $ 1,150,000,000     $ 1,150,000,000       $ 1,150,000,000        
Debt maturity date     Aug. 15, 2019                      
Issuance costs                 26,600,000          
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, 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, or 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        
Minimum percentage of common share price over conversion price for conversion     130.00%                      
Principal amount of convertible notes     $ 1,000                      
Minimum percentage of the product of common share price and conversion rate for convertible notes     98.00%                      
Convertible notes initial conversion rate     11.5908                      
Paid-in-capital in excess of par value     $ 219,100,000                      
Proceeds received from the issuance of the Convertible notes     1,150,000,000                      
Long-term debt     $ 930,900,000                      
Effective interest rate on convertible notes     6.20%                      
Unamortized debt discount           170,500,000       $ 170,500,000        
Convertible senior notes, carrying value of liability component           979,500,000       979,500,000        
Fair value of liability to convertible notes           850,800,000       850,800,000        
Interest expense           15,600,000   $ 15,200,000   30,800,000 $ 24,000,000      
Non-cash interest expense           8,900,000   8,500,000   17,700,000 13,300,000      
Amortization of deferred financing costs           $ 1,000,000   $ 900,000   1,900,000 $ 1,400,000      
Convertible Senior Notes [Member] | Debt Issuance Costs [Member]                            
Debt Instrument [Line Items]                            
Paid-in-capital in excess of par value                 $ 5,100,000          
Convertible Senior Notes [Member] | Convertible Notes [Member]                            
Debt Instrument [Line Items]                            
Convertible notes initial conversion price     $ 86.28                      
Senior secured revolving credit facility [Member]                            
Debt Instrument [Line Items]                            
Amount required to maintain on consolidated cash and cash equivalents                   $ 200,000,000        
Senior Secured Credit Facility [Member]                            
Debt Instrument [Line Items]                            
Credit facility borrowings used to repay outstanding borrowings         $ 196,000,000                  
Deferred financing costs         $ 5,700,000                  
Credit facility amendment date                   May 04, 2015        
Variable rate basis                   Credit Facility now bear interest at either LIBOR plus the applicable margin between 2.00% and 3.00% or the base rate plus the applicable margin between 1.00% and 2.00%.        
Credit facility interest rate description                   Until March 9, 2016, the interest rates on the Company’s borrowings under the Credit Facility, as amended, will effectively remain unchanged except that the minimum applicable margin will be increased by 0.50% and LIBOR will have a minimum floor of 0.25%. After March 9, 2016, the applicable interest rates on the Company’s borrowings under the Credit Facility, as amended, will increase by 2.00% such that borrowings under the Credit Facility will bear interest at either LIBOR plus the applicable margin between 4.00% and 5.00% or the base rate plus the applicable margin between 3.00% and 4.00%.        
Long-term debt, weighted average interest rate           2.74%       2.74%   3.04%    
Credit facility, amount repaid           $ 135,300,000 $ 25,000,000              
Credit facility, amount outstanding           689,700,000       $ 689,700,000   $ 850,000,000    
Foreign currency borrowings, outstanding           0       0   0    
Aggregate annual maturities of credit facility, remainder of 2015           50,000,000       50,000,000        
Aggregate annual maturities of credit facility, 2016           229,700,000       229,700,000        
Aggregate annual maturities of credit facility, 2017           410,000,000       410,000,000        
Aggregate annual maturities of credit facility, 2019           1,150,000,000       $ 1,150,000,000        
Senior Secured Credit Facility [Member] | Base Rate [Member]                            
Debt Instrument [Line Items]                            
Variable rate basis                   Facility will bear interest at either LIBOR plus the applicable margin between 4.00% and 5.00% or the base rate plus the applicable margin between 3.00% and 4.00%        
Senior Secured Credit Facility [Member] | Until March 9, 2016 [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate increase by percentage   0.50%                        
Senior Secured Credit Facility [Member] | After March 9, 2016 [Member]                            
Debt Instrument [Line Items]                            
Interest rate increased by percentage   2.00%                        
Senior Secured Credit Facility [Member] | After March 9, 2016 [Member] | LIBOR [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   4.00%                        
Senior Secured Credit Facility [Member] | After March 9, 2016 [Member] | LIBOR [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   5.00%                        
Senior Secured Credit Facility [Member] | After March 9, 2016 [Member] | Base Rate [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   3.00%                        
Senior Secured Credit Facility [Member] | After March 9, 2016 [Member] | Base Rate [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   4.00%                        
Senior Secured Credit Facility [Member] | Convertible Notes [Member]                            
Debt Instrument [Line Items]                            
Deferred financing costs     $ 2,300,000                      
Applicable margin payable, percentage     0.50%                      
Consolidated leverage ratio                   2.50 to 1.00        
Senior Secured Credit Facility [Member] | Term Loan [Member]                            
Debt Instrument [Line Items]                            
Credit facility, maximum amount                         $ 500,000,000  
Credit facility borrowings used to repay outstanding borrowings       $ 500,000,000                    
Deferred financing costs       $ 4,500,000                    
Debt maturity date   Mar. 09, 2016                        
Credit facility prepayments   $ 20,300,000                        
Credit facility, amount outstanding           279,700,000       $ 279,700,000   350,000,000    
Senior Secured Credit Facility [Member] | Convertible Senior Notes [Member]                            
Debt Instrument [Line Items]                            
Total principal amount of convertible notes     $ 1,150,000,000                      
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member]                            
Debt Instrument [Line Items]                            
Credit facility, maximum amount                           $ 700,000,000
Line of credit facility extended maturity period                   1 year        
Credit facility prepayments   $ 50,900,000                        
Amended maturity date of credit facility   Mar. 09, 2017                        
Decreased amount in credit facility borrowing capacity   $ 235,900,000                        
Credit facility, amount outstanding           $ 410,000,000       $ 410,000,000   $ 500,000,000    
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage                   0.40%        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage                   0.50%        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | LIBOR [Member]                            
Debt Instrument [Line Items]                            
Credit facility LIBOR minimum floor rate interest   0.25%                        
Variable rate basis                   LIBOR        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | LIBOR [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   2.00%                        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | LIBOR [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   3.00%                        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Base Rate [Member]                            
Debt Instrument [Line Items]                            
Variable rate basis                   The base rate under the Credit Facility represents the highest of the Federal Funds Rate plus 0.50%, the one-month LIBOR plus 1.00%, and the prime rate offered by Bank of America.        
Base rate in excess of Federal Funds Rate                   0.50%        
Base rate in excess of one-month LIBOR                   1.00%        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Base Rate [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   1.00%                        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Base Rate [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Interest rate spread on variable rate   2.00%                        
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | Scenario Forecast [Member]                            
Debt Instrument [Line Items]                            
Credit facility, maximum amount $ 425,000,000                          
Decreased amount in credit facility borrowing capacity $ 39,100,000