Inventories (Schedule of Inventory) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012
Inventories [Abstract]
Finished goods	$ 560.7	$ 617.9
Work in process	39.0	36.7
Raw materials, supplies and other	241.6	220.0
Total FIFO value	841.3	874.6
Less: Excess of FIFO cost over LIFO cost	(94.8)	(88.0)
Inventories	$ 746.5	$ 786.6