Mexican Fuel Excise Tax Credit (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Mexican Fuel Excise Tax Credit [Line Items]
Benefit recognized by the Company relating to a Mexican fuel excise tax credit	$ 11.1	$ 15.6	$ 35.6	$ 49.6
Mexican Tax Authority [Member]
Mexican Fuel Excise Tax Credit [Line Items]
Benefit recognized by the Company relating to a Mexican fuel excise tax credit	$ 11.1	$ 15.6	$ 35.6	$ 49.6