Note 11 - Common Stock and Earnings Per Share (Details) - Shares of Common Stock Outstanding	6 Months Ended
	Feb. 28, 2015		Feb. 28, 2014
Class of Stock [Line Items]
Balance at September 1	41,792,802		43,324,000
Common stock issued for employee stock plans	604,000		389,000
Stock issued for acquisition of a business	20,000		0
Repurchase of common stock	(769,854)
Balance at February 28, 2015 and 2014, respectively	41,630,258		42,362,000
Repurchase of Common Stock from Employees [Member]
Class of Stock [Line Items]
Repurchase of common stock	(17,000)	[1]	(21,000)	[1]
Share Repurchase Program [Member]
Class of Stock [Line Items]
Repurchase of common stock	(770,000)		(1,330,000)

[1] For the six months ended February 28, 2015 and 2014, the Company repurchased 17,165 and 21,289 shares, or $2.2 million and $2.3 million, of common stock, respectively, in settlement of employee tax withholding obligations due upon the vesting of restricted stock.