Inventories (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories at FIFO, net of reserves	$ 474.6		$ 474.6		$ 533.1
Less: LIFO reserve	(124.5)		(124.5)		(115.3)
Total inventories at LIFO, net of reserves	350.1		350.1		$ 417.8
LIFO expense	$ 3.3	$ 6.5	$ 9.2	$ 13.6