Debt and Credit Arrangements - Summary of Outstanding Borrowings (Details) € in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 EUR (€)	Jan. 01, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Jun. 14, 2019 USD ($)	Nov. 06, 2017 USD ($)
Debt Instrument
Total debt, net of unamortized discount and debt issuance costs	$ 706,100,000		$ 706,100,000				$ 442,500,000
Less: current maturities	255,500,000		255,500,000				220,900,000
Long-term debt	450,600,000		450,600,000				221,600,000
Foreign currency transaction gain	(1,700,000)	$ (1,200,000)	(1,500,000)	$ (1,500,000)
Convertible Notes, due 2024 | Convertible Debt
Debt Instrument
Unamortized debt issuance costs	(3,300,000)		(3,300,000)			$ (3,900,000)	(3,100,000)
Principal amount	258,800,000	$ 258,800,000	258,800,000	$ 258,800,000			258,800,000			$ 258,800,000
Unamortized discount	0		0				(34,800,000)
Convertible Debt	255,500,000		255,500,000				220,900,000
Debt instrument stated interest rate (percent)										1.00%
Revolving Credit Facility | Credit Facilities 2019
Debt Instrument
Unamortized debt issuance costs	(4,300,000)		(4,300,000)				(5,000,000.0)
Senior secured revolving credit facility and term loan, net of debt issuance costs	450,600,000		450,600,000				221,600,000
Revolving Credit Facility | Term loan
Debt Instrument
Long term debt	$ 103,100,000		$ 103,100,000				$ 103,100,000
Principal amount									$ 450,000,000.0
Debt instrument stated interest rate (percent)	2.00%		2.00%		2.00%		2.50%	2.50%
Revolving Credit Facility | Senior secured revolving credit facility
Debt Instrument
Long term debt	$ 351,800,000		$ 351,800,000				$ 123,500,000
Unamortized debt issuance costs	$ (6,700,000)		$ (6,700,000)
Maximum borrowing capacity									$ 550,000,000.0
Weighted average interest rate (percent)	1.90%		1.90%		1.90%		2.10%	2.10%
Letters of credit outstanding	$ 45,200,000		$ 45,200,000
Line of credit remaining borrowing amount	153,000,000.0		153,000,000.0
Revolving Credit Facility | Euro senior secured revolving credit facility
Debt Instrument
Long term debt	102,800,000		102,800,000		€ 86.5		$ 91,400,000	€ 74.5
Foreign currency transaction gain	8,900,000		5,000,000.0
Revolving Credit Facility Sub-limit - Letters of Credit | Senior secured revolving credit facility
Debt Instrument
Maximum borrowing capacity	100,000,000.0		100,000,000.0
Revolving Credit Facility Sub-limit - Discretionary Letters of Credit | Senior secured revolving credit facility
Debt Instrument
Maximum borrowing capacity	250,000,000.0		250,000,000.0
Revolving Credit Facility Sub-limit - Swingline | Senior secured revolving credit facility
Debt Instrument
Maximum borrowing capacity	$ 50,000,000.0		$ 50,000,000.0