Fair Value Measurements (Schedule Of Financial Assets And Liabilities Measured At Fair Value) (Details) - USD ($) $ in Thousands	May 31, 2018	Aug. 31, 2017	May 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 111,779	$ 121,620	$ 113,212
Derivative assets	2,241	9	71
Derivative liabilities	(60)	(1,747)	(2,112)
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	111,779	121,620	113,212
Derivative assets
Derivative liabilities
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents
Derivative assets	2,241	9	71
Derivative liabilities	(60)	(1,747)	(2,112)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents
Derivative assets
Derivative liabilities