Inventories - Narrative (Details) (USD $) In Millions, unless otherwise specified	Aug. 31, 2012	Aug. 31, 2011
Inventory Disclosure [Abstract]
Percentage of LIFO inventory	11.00%	12.00%
LIFO inventory, difference amount had FIFO inventory valuation method been used	$ 566.6	$ 551.0

The percentage of LIFO (last in first out) inventory to total inventory as of the balance sheet date if other than 100 percent.

No definition available.

Name:	us-gaap_PercentageOfLIFOInventory
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant