Inventories - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Inventory Disclosure [Abstract]
Inventory valued under the LIFO method	5.00%	5.00%
Inventory, LIFO reserve	$ 55	$ 52
Decrease in cost of goods sold	1	1	0
Effect of LIFO inventory liquidation on income	1	1	0
Liquidation of LIFO inventory, resulted per diluted common share	$ 0.01	$ 0.01	$ 0.00
Obsolete inventory reserve	$ 15	$ 15