Consolidated Statements of Comprehensive Income Parenthetical (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Net Change in Net Actuarial Gains (Losses) [Member]
Net change in tax on pension and other postretirement benefit plans	$ (55)	$ (4,204)	$ 4,178
Net Change in Prior Service (Costs) Credit [Member]
Net change in tax on pension and other postretirement benefit plans	$ 0	$ 0	$ 0