{"cik":717954,"taxonomy":"us-gaap","tag":"EarningsPerShareBasic","label":"Earnings Per Share, Basic","description":"The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.","entityName":"UNIFIRST CORPORATION","units":{"USD/shares":[{"start":"2008-08-31","end":"2009-08-29","val":4.14,"accn":"0001284084-11-000042","fy":2011,"fp":"FY","form":"10-K/A","filed":"2011-11-01","frame":"CY2009"},{"start":"2009-08-30","end":"2010-08-28","val":4.11,"accn":"0001284084-11-000042","fy":2011,"fp":"FY","form":"10-K/A","filed":"2011-11-01","frame":"CY2010"},{"start":"2010-08-29","end":"2011-08-27","val":4.05,"accn":"0001284084-11-000042","fy":2011,"fp":"FY","form":"10-K/A","filed":"2011-11-01","frame":"CY2011"}]}}