Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Property, Plant and Equipment [Line Items]
Payment, Tax Withholding, Share-based Payment Arrangement	$ 15,400,000	$ 5,400,000	$ 11,400,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(19,900,000)	(67,400,000)	47,100,000
Cumulative Effect of New Accounting Principle in Period of Adoption		(4,000,000.0)
Unbilled Receivables, Current	545,100,000	546,600,000
Other Assets, Noncurrent	18,000,000.0	37,000,000.0		$ 21,700,000
Long-term Debt, Excluding Current Maturities	1,648,100,000	1,638,600,000
Short-term Investments	25,800,000	21,800,000
Foreign Currency Transaction Gain (Loss), before Tax	6,100,000	3,600,000	3,700,000
Income Tax Expense (Benefit)	97,700,000	$ 102,600,000	57,600,000
Finance Lease, Right-of-Use Asset	5,000,000.0
Finance Lease, Liability	$ 3,400,000
Maximum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years	20 years
Minimum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Software and Software Development Costs [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Software and Software Development Costs [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		20 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		3 years
Accumulated Other Comprehensive Income (Loss)
Property, Plant and Equipment [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax		$ (60,500,000)	$ 44,700,000