Inventories (Schedule of Inventory) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Inventories [Abstract]
Finished goods	$ 548.7	$ 617.9
Work in process	36.2	36.7
Raw materials, supplies and other	238.0	220.0
Total FIFO value	822.9	874.6
Less: Excess of FIFO cost over LIFO cost	(94.8)	(88.0)
Inventories	$ 728.1	$ 786.6