Long-Term Debt - Additional Information (Detail)

v3.20.4

Long-Term Debt - Additional Information (Detail)						1 Months Ended				3 Months Ended	12 Months Ended
	Mar. 19, 2020 USD ($)	Dec. 12, 2019 USD ($)	Aug. 15, 2019 USD ($)	Aug. 16, 2018 USD ($)	Feb. 15, 2017 USD ($)	May 31, 2020 USD ($)	Aug. 31, 2018 USD ($)	Mar. 31, 2018 USD ($) $ / shares	Feb. 28, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($)	Dec. 31, 2020 USD ($) Day $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 04, 2020 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2018 USD ($)
Debt Instrument [Line Items]
Outstanding principal amount											$ 2,537,200,000
Credit facility, amount repaid											5,000,000.0		$ 1,231,900,000
Loss on extinguishment of debt													48,500,000
Borrowings under the senior secured credit facility											976,500,000	$ 965,300,000
Interest expense											133,000,000.0	153,000,000.0	181,000,000.0
Amortization of deferred financing costs											4,600,000	5,300,000	7,300,000
Paid-in-capital in excess of par value											342,300,000	366,600,000
Long-term debt											2,428,400,000	1,803,000,000.0
Convertible notes paid												675,000,000.0	582,500,000
Letters of credit issued but undrawn											41,900,000
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]
Forward share repurchase transactions amount									685,800,000	$ 685,800,000
Convertible Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Outstanding principal amount									1,150,000,000
Deferred financing costs										26,600,000
Aggregate principal amount of convertible senior notes issued									1,000,000,000
Interest expense												27,000,000.0	48,500,000
Non-cash interest expense												17,000,000.0	29,800,000
Amortization of deferred financing costs												1,700,000	2,900,000
Additional principal amount of convertible notes									$ 150,000,000
Convertible notes, interest rate									2.00%
Convertible notes maturity									Aug. 15, 2019
Principal amount of convertible notes									$ 1,000
Convertible notes conversion rate									23.1816
Convertible notes conversion price | $ / shares									$ 43.14
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			$ 675,000,000.0					$ 583,500,000
Accrued interest			$ 6,700,000					1,000,000.0
Convertible Senior Notes Due 2019 [Member] | Repurchase of 2019 Convertible Notes [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt								13,100,000					13,100,000
Repurchase of convertible notes								475,000,000.0					475,000,000.0
Fair value of liability to convertible notes								459,400,000
Fair value of equity component to convertible notes								123,000,000.0
Reduction to long-term debt representing liability component of convertible notes								446,400,000
Reduction to additional paid-in capital representing equity component								123,000,000.0
Convertible Senior Notes Due 2019 [Member] | Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs										$ 21,500,000
2.625% Convertible Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Outstanding principal amount											550,000,000.0	550,000,000.0
Deferred financing costs								12,900,000
Aggregate principal amount of convertible senior notes issued								$ 550,000,000
Interest expense											37,700,000	35,800,000	26,600,000
Non-cash interest expense											21,800,000	20,000,000.0	14,500,000
Amortization of deferred financing costs											$ 1,500,000	1,400,000	1,000,000.0
Convertible notes, interest rate								2.625%			2.625%
Convertible notes maturity								Mar. 15, 2024			Mar. 15, 2024
Principal amount of convertible notes								$ 1,000			$ 1,000
Convertible notes conversion rate								16.0056			16.0352
Convertible notes conversion price | $ / shares								$ 62.48			$ 62.36
Paid-in-capital in excess of par value								$ 139,900,000
Long-term debt								$ 410,100,000
Effective interest rate on convertible notes								8.40%
Fair value of liability to convertible notes											$ 541,800,000	508,600,000
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) | 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%
Minimum percentage of the product of common share price and conversion rate for convertible notes								98.00%
Deferred financing costs recorded as additional paid-in-capital in excess of par value								$ 3,300,000
Unamortized debt discount and debt issuance costs											$ 89,400,000	112,600,000
Convertible senior notes, carrying value of liability component											460,600,000	437,400,000
2.625% Convertible Senior Notes Due 2024 [Member] | Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs								$ 9,600,000
7.875% Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Outstanding principal amount											600,000,000.0
Deferred financing costs											7,100,000				$ 7,900,000
Aggregate principal amount of convertible senior notes issued						$ 600,000,000
Interest expense											28,500,000
Amortization of deferred financing costs											$ 700,000
Convertible notes, interest rate						7.875%					7.875%
Convertible notes maturity						Sep. 01, 2025					Sep. 01, 2025
Long-term debt											$ 592,900,000
Senior notes, redemption price, percentage						100.00%
Senior notes, redemption price percentage with equity offerings						107.875%
Carrying amount											592,900,000
Fair value of notes											656,300,000
7.875% Senior Notes Due 2025 [Member] | Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs															$ 7,900,000
7.875% Senior Notes Due 2025 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of aggregate principal amount of senior notes being redeemed						40.00%
7.250% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Outstanding principal amount											400,000,000.0	400,000,000.0
Deferred financing costs											4,100,000	4,700,000				$ 5,400,000
Aggregate principal amount of convertible senior notes issued							$ 400,000,000
Interest expense											29,600,000	29,500,000	11,100,000
Amortization of deferred financing costs											$ 600,000	500,000	200,000
Convertible notes, interest rate							7.25%				7.25%
Convertible notes maturity							Aug. 15, 2026				Aug. 15, 2026
Senior notes, redemption price, percentage							100.00%
Senior notes, redemption price percentage with equity offerings							107.25%
Carrying amount											$ 395,900,000	395,300,000
Fair value of notes											$ 425,000,000.0	$ 424,100,000
7.250% Senior Notes Due 2026 [Member] | Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Deferred financing costs																$ 5,400,000
7.250% Senior Notes Due 2026 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of aggregate principal amount of senior notes being redeemed							40.00%
Eurodollar [Member]
Debt Instrument [Line Items]
Base rate interest rate floor											0.00%
2018 Revolving Credit Facility [Member] | Eurodollar [Member] | Second Amendment [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate											3.00%
2017 Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount					$ 1,450,000,000.0
Credit Facility amended, effective date											Mar. 16, 2018
Deferred financing costs					$ 22,600,000
Credit facility, amount repaid				$ 1,178,100,000							$ 1,226,900,000
Interest expense													83,600,000
Non-cash interest expense													2,900,000
2017 Credit Facility [Member] | Other Expense (Income), Net [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt													35,400,000
2017 Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Base rate interest rate floor					1.75%
2017 Credit Facility [Member] | 2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount					$ 150,000,000.0
Credit facility, maturity date											Feb. 15, 2022
Repayment of prior senior secured credit facility				1,178,100,000
Credit facility LIBOR minimum floor rate interest					0.75%
2017 Credit Facility [Member] | 2017 Revolving Credit Facility [Member] | Base Rate [Member] | Scenario Leverage Ratio One [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					3.50%
2017 Credit Facility [Member] | 2017 Revolving Credit Facility [Member] | Base Rate [Member] | Scenario Leverage Ratio Two [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					3.75%
2017 Credit Facility [Member] | 2017 Revolving Credit Facility [Member] | Eurodollar [Member] | Scenario Leverage Ratio One [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					4.50%
2017 Credit Facility [Member] | 2017 Revolving Credit Facility [Member] | Eurodollar [Member] | Scenario Leverage Ratio Two [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					4.75%
2017 Credit Facility [Member] | 2017 Term Loan B [Member]
Debt Instrument [Line Items]
Outstanding principal amount					$ 1,300,000,000.0
Credit facility, maturity date											Feb. 15, 2023
Senior secured credit facility, discount percentage					2.00%
Senior secured credit facility, discount amount					$ 26,000,000.0
2017 Credit Facility [Member] | 2017 Term Loan B [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					4.50%
2017 Credit Facility [Member] | 2017 Term Loan B [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					5.50%
2017 Credit Facility [Member] | 2017 Term Loan B [Member] | 2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility termination date											Aug. 16, 2018
2018 Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount				1,250,000,000
Deferred financing costs		$ 1,200,000		11,700,000
Credit facility, amount repaid											$ 30,400,000
Credit facility amendment date											Dec. 12, 2019
Line of credit facility, frequency of interest payments											quarterly
Long-term debt, weighted average interest rate											3.39%	5.52%
Borrowings under the senior secured credit facility											$ 984,700,000	$ 975,000,000.0
Interest expense											37,200,000	58,900,000
Non-cash interest expense											300,000	200,000
Amortization of deferred financing costs											1,800,000	1,700,000	$ 3,200,000
2018 Credit Facility [Member] | 2024 Convertible Notes Exceeds 350 Million [Member] | Minimum [Member]
Debt Instrument [Line Items]
Outstanding principal amount				350,000,000.0							350,000,000.0
2018 Credit Facility [Member] | Second Amendment [Member]
Debt Instrument [Line Items]
Deferred financing costs	$ 1,600,000										$ 1,600,000
Credit facility amendment date											Mar. 19, 2020
Extended maturity date											Mar. 19, 2025
Amortization	1,100,000
Recognized in interest expense, net											$ 500,000
2018 Credit Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					1.00%						1.00%
2018 Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Base rate interest rate floor											1.00%
2018 Credit Facility [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate					0.50%						0.50%
2018 Credit Facility [Member] | 2018 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount	250,000,000.0			250,000,000.0
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage											0.35%
Borrowings under the senior secured credit facility											$ 0	0
2018 Credit Facility [Member] | 2018 Revolving Credit Facility [Member] | Second Amendment [Member] | Maximum [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount	$ 282,500,000
2018 Credit Facility [Member] | 2018 Revolving Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate											1.50%
2018 Credit Facility [Member] | 2018 Revolving Credit Facility [Member] | Base Rate [Member] | Second Amendment [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate	1.50%										2.00%
2018 Credit Facility [Member] | 2018 Revolving Credit Facility [Member] | Eurodollar [Member] | Second Amendment [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate											2.50%
2018 Credit Facility [Member] | 2018 Term Loan A [Member]
Debt Instrument [Line Items]
Outstanding principal amount				$ 250,000,000.0
Credit facility, maturity date				Aug. 16, 2023
Borrowings under the senior secured credit facility											$ 251,600,000	234,400,000
2018 Credit Facility [Member] | 2018 Term Loan A [Member] | Level 2 [Member]
Debt Instrument [Line Items]
Outstanding principal amount											250,500,000	233,200,000
Debt instrument, fair value											$ 251,900,000	235,700,000
2018 Credit Facility [Member] | 2018 Term Loan A [Member] | 2024 Convertible Notes Exceeds 350 Million [Member]
Debt Instrument [Line Items]
Credit facility, maturity date											Sep. 15, 2023
2018 Credit Facility [Member] | 2018 Term Loan A [Member] | Second Amendment [Member] | Minimum [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount														$ 234,400,000
2018 Credit Facility [Member] | 2018 Term Loan A [Member] | Second Amendment [Member] | Maximum [Member]
Debt Instrument [Line Items]
Credit facility, maximum amount											$ 264,800,000
2018 Credit Facility [Member] | 2018 Term Loan A [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate											2.50%
2018 Credit Facility [Member] | 2018 Term Loan B [Member]
Debt Instrument [Line Items]
Outstanding principal amount				$ 750,000,000.0
Credit facility, maturity date				Aug. 18, 2025
Senior secured credit facility, discount percentage				0.25%
Senior secured credit facility, discount amount				$ 1,900,000
Borrowings under the senior secured credit facility											$ 733,100,000	740,600,000
2018 Credit Facility [Member] | 2018 Term Loan B [Member] | Level 2 [Member]
Debt Instrument [Line Items]
Outstanding principal amount											726,000,000.0	732,100,000
Debt instrument, fair value											$ 734,000,000.0	$ 744,800,000
2018 Credit Facility [Member] | 2018 Term Loan B [Member] | 2024 Convertible Notes Exceeds 350 Million [Member]
Debt Instrument [Line Items]
Credit facility, maturity date				Dec. 15, 2023
2018 Credit Facility [Member] | 2018 Term Loan B [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		1.75%		2.25%							1.75%
2018 Credit Facility [Member] | 2018 Term Loan B [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate spread on variable rate		2.75%		3.25%							2.75%
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of convertible senior notes issued				$ 400,000,000