Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.28,29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

Name:	us-gaap_TreasuryStockShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Capital Stock and Share Repurchase Share Repurchase (Details) - shares	May 31, 2016	Aug. 31, 2015	Mar. 16, 2015	Oct. 01, 2014	Mar. 19, 2014	Sep. 28, 2011
Equity [Abstract]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			7,000,000	7,000,000	7,000,000	7,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	7,673,521
Treasury Stock, Shares	20,326,479	19,726,479