Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Environmental remediation liabilities - discounted	$ 24.7	$ 22.8
Accrual for environmental loss contingencies - weighted-average discount rate	3.60%
Environmental remediation liabilities - undiscounted	$ 64.6	61.1
Potential revision on future environmental remediation costs before tax	17.0
Tax indemnification liability	$ 43.4	$ 38.2