Stockholders' Equity (Dividends) (Details 5) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Quarter One [Member]
Dividends Payable [Line Items]
Dividend Declaration Date	Oct. 14, 2015	Oct. 16, 2014
Dividend per Share	$ 0.08	$ 0.08
Total of Cash Dividends Declared	$ 15,906	$ 15,973
Date of Record for Dividend Payment	Nov. 16, 2015	Nov. 14, 2014
Dividend Cash Payment Date	Dec. 01, 2015	Dec. 01, 2014
Quarter Two [Member]
Dividends Payable [Line Items]
Dividend Declaration Date	Jan. 21, 2016	Jan. 21, 2015
Dividend per Share	$ 0.08	$ 0.08
Total of Cash Dividends Declared	$ 15,947	$ 16,020
Date of Record for Dividend Payment	Feb. 16, 2016	Feb. 13, 2015
Dividend Cash Payment Date	Mar. 01, 2016	Mar. 02, 2015
Quarter Three [Member]
Dividends Payable [Line Items]
Dividend Declaration Date	Apr. 21, 2016	Apr. 15, 2015
Dividend per Share	$ 0.08	$ 0.08
Total of Cash Dividends Declared	$ 15,940	$ 15,988
Date of Record for Dividend Payment	May 16, 2016	May 15, 2015
Dividend Cash Payment Date	Jun. 01, 2016	Jun. 01, 2015
Quarter Four [Member]
Dividends Payable [Line Items]
Dividend Declaration Date	Jul. 21, 2016	Jul. 16, 2015
Dividend per Share	$ 0.08	$ 0.08
Total of Cash Dividends Declared	$ 15,575	$ 15,980
Date of Record for Dividend Payment	Aug. 15, 2016	Aug. 14, 2015
Dividend Cash Payment Date	Sep. 01, 2016	Sep. 01, 2015