Consolidated Balance Sheets (Parentheticals) (USD $)
Nov. 30, 2012
Aug. 31, 2012
Cash and cash equivalents related to variable interest entities (VIEs) (in Dollars) $ 74,569,000 $ 92,176,000
Short-term investments related to VIEs (in Dollars) 3,000,000 3,000,000
Accounts receivable, including retainage, net related to VIEs (in Dollars) 45,894,000 22,664,000
Accumulated depreciation (in Dollars) $ 390,300,000 $ 376,300,000
Preferred stock, shares authorized 20,000,000 20,000,000
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Preferred stock, par value (in Dollars per share) $ 0 $ 0
Common stock, shares authorized 200,000,000 200,000,000
Common stock, shares issued 93,227,119 93,016,409
Common stock, shares outstanding 66,635,878 66,425,168
Common stock, par value (in Dollars per share) $ 0 $ 0
Treasury stock shares 26,591,241 26,591,241