Environmental (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Environmental remediation costs	$ 6.6	$ 14.7	$ 28.5
Accrued environmental liability	96.4	98.1
Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Accrued environmental liability	$ 82.9	$ 83.5