Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v3.8.0.1
Long-Term Debt - Additional Information (Detail)
1 Months Ended 3 Months Ended
Jun. 30, 2017
USD ($)
Feb. 15, 2017
USD ($)
Sep. 30, 2015
USD ($)
May 04, 2015
USD ($)
Mar. 31, 2018
USD ($)
$ / shares
Feb. 28, 2014
USD ($)
$ / shares
Mar. 31, 2018
USD ($)
Day
d
$ / shares
Mar. 31, 2017
USD ($)
$ / shares
Mar. 31, 2014
USD ($)
Dec. 31, 2017
USD ($)
Jul. 26, 2012
USD ($)
Mar. 09, 2011
USD ($)
Debt Instrument [Line Items]                        
Deferred financing costs       $ 6,200,000                
Outstanding principal amount         $ 2,435,200,000   $ 2,435,200,000          
Interest expense             44,600,000 $ 32,500,000        
Paid-in-capital in excess of par value         425,400,000   425,400,000     $ 407,300,000    
Long-term debt         2,211,400,000   2,211,400,000     2,268,100,000    
Convertible notes paid             582,500,000          
Letters of credit issued but undrawn         41,700,000   41,700,000          
Prepaid forward share repurchase transactions [Member]                        
Debt Instrument [Line Items]                        
Forward share repurchase transactions amount           $ 685,800,000     $ 685,800,000      
Capped call transactions [Member]                        
Debt Instrument [Line Items]                        
Capped call transactions with financial institutions           123,800,000            
Convertible Senior Notes Due 2019 [Member]                        
Debt Instrument [Line Items]                        
Deferred financing costs                 26,600,000      
Outstanding principal amount         $ 675,000,000 1,150,000,000 675,000,000     1,150,000,000    
Interest expense             18,700,000 16,800,000        
Non-cash interest expense             10,400,000 10,000,000        
Amortization of deferred financing costs             $ 1,000,000 $ 1,000,000        
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% 2.00% 2.00%          
Convertible notes maturity           Aug. 15, 2019 Aug. 15, 2019          
Convertible notes, conversion feature             Holders of the 2019 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 2019 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 2019 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 2019 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 2019 Convertible Notes at any time, regardless of the foregoing circumstances.          
Convertible notes, number of trading days of threshold limit (whether or not consecutive) | Day             20          
Convertible notes, number of trading days of threshold limit in consecutive days | Day             30          
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            
Convertible notes initial conversion price | $ / shares         $ 86.28   $ 86.28 $ 86.28        
Paid-in-capital in excess of par value           $ 219,100,000     5,100,000      
Long-term debt           $ 930,900,000            
Effective interest rate on convertible notes           6.20%            
Convertible notes paid         $ 583,500,000              
Accrued interest         1,000,000   $ 1,000,000          
Fair value of liability to convertible notes         652,900,000   652,900,000     1,066,000,000    
Unamortized debt discount and debt issuance costs         40,000,000   40,000,000     80,000,000    
Convertible senior notes, carrying value of liability component         635,000,000   635,000,000     1,070,000,000    
Convertible Senior Notes Due 2019 [Member] | Repurchase of 2019 Convertible Notes [Member]                        
Debt Instrument [Line Items]                        
Repurchase of convertible notes         475,000,000   475,000,000          
Fair value of liability to convertible notes         459,400,000   459,400,000          
Fair value of equity component to convertible notes         123,000,000   123,000,000          
Reduction to long-term debt representing liability component of convertible notes         446,400,000              
Reduction to additional paid-in capital representing equity component         123,000,000              
Loss on extinguishment of debt         13,100,000   13,100,000          
Convertible Senior Notes Due 2019 [Member] | Debt Issuance Costs [Member]                        
Debt Instrument [Line Items]                        
Deferred financing costs                 $ 21,500,000      
Convertible Senior Notes Due 2019 [Member] | Capped call transactions [Member]                        
Debt Instrument [Line Items]                        
Convertible notes initial conversion price | $ / shares           $ 86.28            
Convertible Senior Notes Due 2024 [Member]                        
Debt Instrument [Line Items]                        
Deferred financing costs         12,900,000   12,900,000          
Outstanding principal amount         550,000,000   550,000,000          
Interest expense             800,000          
Non-cash interest expense             500,000          
Aggregate principal amount of convertible senior notes issued         $ 550,000,000   $ 550,000,000          
Convertible notes, interest rate         2.625%   2.625%          
Convertible notes maturity         Mar. 15, 2024   Mar. 15, 2024          
Convertible notes, conversion feature             Holders of the 2024 Convertible Notes may convert their notes at their option under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending June 30, 2018, 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 2024 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 2024 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 2024 Convertible Notes for each such day; (iii) if the Company calls the 2024 Convertible Notes for redemption; or (iv) upon the occurrence of specified corporate events. On and after December 15, 2023, holders may convert their 2024 Convertible Notes at any time, regardless of the foregoing circumstances.          
Convertible notes, number of trading days of threshold limit (whether or not consecutive) | d             20          
Convertible notes, number of trading days of threshold limit in consecutive days | d             30          
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         8.0028              
Convertible notes initial conversion price | $ / shares         $ 124.96   $ 124.96 $ 124.96        
Paid-in-capital in excess of par value         $ 139,900,000   $ 139,900,000          
Long-term debt         $ 410,100,000   $ 410,100,000          
Effective interest rate on convertible notes         8.40%   8.40%          
Fair value of liability to convertible notes         $ 410,100,000   $ 410,100,000          
Unamortized debt discount and debt issuance costs         149,000,000   149,000,000          
Convertible senior notes, carrying value of liability component         401,000,000   401,000,000          
Deferred financing costs recorded as additional paid-in-capital in excess of par value         3,300,000   3,300,000          
Convertible Senior Notes Due 2024 [Member] | Debt Issuance Costs [Member]                        
Debt Instrument [Line Items]                        
Deferred financing costs         $ 9,600,000   $ 9,600,000          
Convertible Senior Notes Due 2024 [Member] | Capped call transactions [Member]                        
Debt Instrument [Line Items]                        
Convertible notes initial conversion price | $ / shares         $ 124.96   $ 124.96          
Senior secured prior revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Repayment of prior senior secured credit facility   $ 410,000,000                    
Credit facility, amount repaid               $ 410,000,000        
Prior Senior Secured Credit Facility [Member]                        
Debt Instrument [Line Items]                        
Credit facility amendment date             May 04, 2015          
Credit facility interest rate description             After March 9, 2016, the applicable interest rates on the Company’s borrowings under the Prior Credit Facility increased by 2.00% such that borrowings under the Prior Credit Facility began bearing 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 revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Borrowings under the senior secured credit facility         $ 0   $ 0     0    
Term Loan [Member]                        
Debt Instrument [Line Items]                        
Quarterly periodic payment, Principal $ 24,400,000                      
Interest expense             23,700,000 11,200,000        
Non-cash interest expense             1,100,000 600,000        
Amortization of deferred financing costs             800,000 $ 400,000        
Term Loan [Member] | Level 2 [Member]                        
Debt Instrument [Line Items]                        
Outstanding principal amount         1,167,700,000   1,167,700,000     1,190,200,000    
Debt instrument, fair value         $ 1,212,300,000   $ 1,212,300,000     $ 1,226,100,000    
Base Rate [Member] | Senior secured prior revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Variable rate basis             Facility increased by 2.00% such that borrowings under the Prior Credit Facility began bearing 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%          
Base rate interest rate floor   1.75%                    
Senior Secured Credit Facility [Member]                        
Debt Instrument [Line Items]                        
Credit facility, maximum amount   $ 1,450,000,000                    
Deferred financing costs   $ 22,600,000                    
Credit Facility amended, effective date             Mar. 16, 2018          
Senior secured credit facility, discount percentage   2.00%                    
Senior secured credit facility, discount amount   $ 26,000,000                    
Line of credit facility, frequency of interest payments   quarterly                    
Amount required to maintain on consolidated cash and cash equivalents             $ 200,000,000          
Long-term debt, weighted average interest rate         7.15%   7.15%     6.79%    
Credit facility, amount repaid             $ 24,400,000          
Borrowings under the senior secured credit facility         $ 1,167,700,000   $ 1,167,700,000     $ 1,190,200,000    
Senior Secured Credit Facility [Member] | Senior secured prior revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Line of credit facility extended maturity period             1 year          
Credit facility prepayments       50,900,000                
Credit facility, maximum amount         425,000,000   $ 425,000,000         $ 700,000,000
Amended maturity date of credit facility             Mar. 09, 2017          
Decreased amount in credit facility borrowing capacity     $ (39,100,000) (235,900,000)                
Foreign currency borrowings, outstanding         0   $ 0     0    
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Credit facility, maximum amount   $ 150,000,000                    
Credit facility, maturity date             Feb. 15, 2022          
Credit facility LIBOR minimum floor rate interest   0.75%                    
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage   0.50%                    
Senior Secured Credit Facility [Member] | Senior secured revolving credit facility [Member] | 2019 Convertible Notes Exceeds 250 Million [Member]                        
Debt Instrument [Line Items]                        
Credit facility, maturity date             Feb. 14, 2019          
Senior Secured Credit Facility [Member] | Minimum [Member] | 2019 Convertible Notes Exceeds 250 Million [Member]                        
Debt Instrument [Line Items]                        
Outstanding principal amount   $ 250,000,000                    
Senior Secured Credit Facility [Member] | Prior Term Loan [Member]                        
Debt Instrument [Line Items]                        
Credit facility prepayments       $ 20,300,000                
Credit facility, maximum amount                     $ 500,000,000  
Senior Secured Credit Facility [Member] | Term Loan [Member]                        
Debt Instrument [Line Items]                        
Outstanding principal amount   $ 1,300,000,000                    
Credit facility, maturity date             Feb. 15, 2023          
Borrowings under the senior secured credit facility         $ 1,202,500,000   $ 1,202,500,000     $ 1,226,900,000    
Senior Secured Credit Facility [Member] | Term Loan [Member] | 2019 Convertible Notes Exceeds 250 Million [Member]                        
Debt Instrument [Line Items]                        
Credit facility, maturity date             May 16, 2019          
Senior Secured Credit Facility [Member] | LIBOR [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   1.00%                    
Senior Secured Credit Facility [Member] | LIBOR [Member] | Senior secured prior revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Credit facility LIBOR minimum floor rate interest       0.25%                
Senior Secured Credit Facility [Member] | Base Rate [Member] | Term Loan [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   4.50%                    
Senior Secured Credit Facility [Member] | Eurodollar [Member] | Term Loan [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   5.50%                    
Senior Secured Credit Facility [Member] | Federal Funds Rate [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   0.50%                    
Until March 9, 2016 [Member] | Senior Secured Credit Facility [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate increase by percentage       0.50%                
After March 9, 2016 [Member] | Senior Secured Credit Facility [Member]                        
Debt Instrument [Line Items]                        
Interest rate increased by percentage       2.00%                
After March 9, 2016 [Member] | Senior Secured Credit Facility [Member] | LIBOR [Member] | Minimum [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate       4.00%                
After March 9, 2016 [Member] | Senior Secured Credit Facility [Member] | LIBOR [Member] | Maximum [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate       5.00%                
After March 9, 2016 [Member] | Senior Secured Credit Facility [Member] | Base Rate [Member] | Minimum [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate       3.00%                
After March 9, 2016 [Member] | Senior Secured Credit Facility [Member] | Base Rate [Member] | Maximum [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate       4.00%                
Until August 15, 2017 [Member] | Senior Secured Credit Facility [Member] | Base Rate [Member] | Senior secured revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   3.75%                    
Until August 15, 2017 [Member] | Senior Secured Credit Facility [Member] | Eurodollar [Member] | Senior secured revolving credit facility [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   4.75%                    
Scenario Leverage Ratio One [Member] | Senior Secured Credit Facility [Member] | Base Rate [Member] | Senior secured revolving credit facility [Member] | After August 15, 2017 [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   3.50%                    
Scenario Leverage Ratio One [Member] | Senior Secured Credit Facility [Member] | Eurodollar [Member] | Senior secured revolving credit facility [Member] | After August 15, 2017 [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   4.50%                    
Scenario Leverage Ratio Two [Member] | Senior Secured Credit Facility [Member] | Base Rate [Member] | Senior secured revolving credit facility [Member] | After August 15, 2017 [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   3.75%                    
Scenario Leverage Ratio Two [Member] | Senior Secured Credit Facility [Member] | Eurodollar [Member] | Senior secured revolving credit facility [Member] | After August 15, 2017 [Member]                        
Debt Instrument [Line Items]                        
Interest rate spread on variable rate   4.75%