The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

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

Treasury Stock - Additional Information (Detail)	Feb. 15, 2013	Feb. 15, 2013 Maximum	May 31, 2013 September 2011 authorization	Sep. 14, 2011 September 2011 authorization	May 31, 2013 September 2012 authorization
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be repurchased		364,476		1,000,000
Common stock available for repurchase			364,476		1,000,000
Stock repurchase program, expiration date	Feb. 15, 2014