Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Tax Credit Carryforward [Line Items]
Effective tax rate (percent)		26.60%	35.60%
Effective income tax rate reconciliation, stock option exercises, amount		$ 2.9	$ 6.7
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Research and Development, Amount		1.6
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount		$ 2.4
Change in deferred tax assets valuation allowance			$ 10.1
Period allowed for carryforward of operation loss		20 years
Income tax deductions generated from deferred payment obligation		$ 30.0
Deferred Tax Assets, Net [Abstract]
Deferred Tax Asset (Net of Liabilities)	$ 722.4	722.4
Valuation Allowance	(31.4)	(31.4)
Net Deferred Tax Asset	691.0	691.0
Taxable income required to realized DTA total amount		1,700.0
Taxable income required to realize DTA per year		95.0
United States - Federal
Deferred Tax Assets, Net [Abstract]
Deferred Tax Asset (Net of Liabilities)	615.7	615.7
Valuation Allowance	(17.7)	(17.7)
Net Deferred Tax Asset	598.0	598.0
United States - States
Deferred Tax Assets, Net [Abstract]
Deferred Tax Asset (Net of Liabilities)	54.6	54.6
Valuation Allowance	(11.2)	(11.2)
Net Deferred Tax Asset	43.4	43.4
Germany
Deferred Tax Assets, Net [Abstract]
Deferred Tax Asset (Net of Liabilities)	44.1	44.1
Valuation Allowance	0.0	0.0
Net Deferred Tax Asset	44.1	44.1
Other foreign
Deferred Tax Assets, Net [Abstract]
Deferred Tax Asset (Net of Liabilities)	8.0	8.0
Valuation Allowance	(2.5)	(2.5)
Net Deferred Tax Asset	5.5	5.5
ILLINOIS
Tax Credit Carryforward [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		2.0
TENNESSEE
Tax Credit Carryforward [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		1.1
Currency Translation Adjustments
Tax Credit Carryforward [Line Items]
Other comprehensive income (loss), tax out of period adjustment, portion attributable to parent	$ (14.2)	$ (16.9)