Revenue Recognition (Cumulative Effect on Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts and notes receivable, net	$ 528.5	$ 514.8	$ 506.5
Accounts Payable, Current	405.6	357.9	348.6
Accrued Liabilities, Current	226.0		270.3
Retained Earnings (Accumulated Deficit)	1,609.6	1,574.9	1,575.9
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts and notes receivable, net	521.8
Accounts Payable, Current	397.3
Retained Earnings (Accumulated Deficit)	1,611.2
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts and notes receivable, net	6.7	8.3
Accounts Payable, Current	8.3
Accrued Liabilities, Current		$ 9.3
Retained Earnings (Accumulated Deficit)	$ (1.6)		$ (1.0)