Income Taxes (Textuals) (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Income tax expense	$ 59,000,000.0	$ 41,400,000	$ 80,900,000
Other Income Tax Expense (Benefit), Continuing Operations	(300,000)
Discrete tax charge, Tax Cuts and Jobs Act of 2017		(2,500,000)	48,800,000
Accrued liabilities for interest and penalties	200,000
Total gross unrecognized tax benefits	5,000,000.0	3,900,000	3,200,000
Estimated reduction in the liability for unrecognized tax benefits	500,000
Discrete tax charge, Tax Cuts and Jobs Act of 2017		(2,500,000)	48,800,000
Income tax expense (benefit)	59,000,000.0	41,400,000	80,900,000
Provisional Transition Tax, Tax Cuts and Jobs Act of 2017			27,900,000
Provisional tax charge, Tax Cuts and Jobs Act of 2017			11,400,000
Reduction in Transition Tax, Tax Cuts and Jobs Act of 2017		7,500,000
Measurement period adjustment, Tax Cuts and Jobs Act of 2017		4,000,000.0
Transitional Tax, Tax Cuts and Jobs Act of 2017		$ 20,400,000
Net impact to the 2018 effective tax rate, Tax Cuts and Jobs Act of 2017		0.0145
Undistributed earnings of foreign subsidiaries	214,200,000
Accounting Standards Update 2016-09 [Member]
Income tax expense	(10,300,000)	$ (14,300,000)	(33,100,000)
Income tax expense (benefit)	$ (10,300,000)	$ (14,300,000)	$ (33,100,000)