Consolidated Statements of Comprehensive Income (Unaudited) Parenthetical - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2017	May 31, 2016
Postretirement benefit plan activity, tax expense (benefit)	$ 2,257	$ 2,122	$ 6,580	$ 5,911
Unrealized net gain (loss) on available for sale investments, tax expense (benefit)	(72)	744	1,010	303
Cash flow hedges, tax expense (benefit)	233	1,595	1,238	(2,456)
Foreign currency translation adjustment, tax expense (benefit)	$ (334)	$ 0	$ (329)	$ 0