Benefit Plans (Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Current liabilities	$ (2.2)	$ (5.6)
Noncurrent liabilities	(75.6)	(62.0)
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Current liabilities	(1.5)	(5.0)
Noncurrent liabilities	(68.3)	(52.4)
Total liabilities	(69.8)	(57.4)
Other Retirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Current liabilities	(0.7)	(0.6)
Noncurrent liabilities	(7.3)	(9.6)
Total liabilities	$ (8.0)	$ (10.2)