Revenue Recognition (Cumulative Effect on Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts and notes receivable, net	$ 741.3	$ 514.8	$ 506.5
Accounts Payable, Current	437.5	357.9	348.6
Accrued Liabilities, Current	253.6		270.3
Retained Earnings (Accumulated Deficit)	1,722.8	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	730.5
Accounts Payable, Current	424.2
Retained Earnings (Accumulated Deficit)	1,725.3
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	10.8	8.3
Accounts Payable, Current	13.3
Accrued Liabilities, Current		9.3
Retained Earnings (Accumulated Deficit)	$ (2.5)	$ (1.0)