Revenue Recognition (Summary of Impacts of ASU on Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	May 31, 2019	Sep. 01, 2018	Aug. 31, 2018	May 31, 2018
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Inventories, net	$ 91,091		$ 79,233	$ 82,635
Other current assets	17,903		11,087	12,341
Other current liabilities	49,102		46,935	53,911
Deferred income tax liabilities	918		1,083	1,117
Retained earnings	476,580		484,886	$ 483,243
ASC Topic 606 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Inventories, net		$ 78,291
Other current assets		12,738
Other current liabilities		46,949
Deferred income tax liabilities		1,246
Retained earnings		$ 485,418
ASC Topic 606 Adjustments [Member] | ASC Topic 606 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Inventories, net	3,652		(942)
Other current assets	(1,114)		1,651
Other current liabilities	5,039		14
Deferred income tax liabilities			163
Retained earnings	(2,500)		$ 532
Balance Without Adoption of ASC Topic 606 [Member] | ASC Topic 606 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Inventories, net	94,743
Other current assets	16,789
Other current liabilities	54,141
Retained earnings	$ 474,080