Environmental (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 01, 2017
Loss Contingencies [Line Items]
Environmental remediation costs	$ 13.1	$ 6.6	$ 14.7
Accrued environmental liability	$ 103.7	96.4
Length of Time for Environmental Remediation	30 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other				$ 2.9
Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Accrued environmental liability	$ 89.6	$ 82.9