Revenue Recognition (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2021	May 31, 2020	Aug. 31, 2020
Disaggregation of Revenue [Line Items]
Accrued liabilities	$ 24,728,000		$ 24,728,000		$ 21,660,000
Reduction to revenue	136,405,000	$ 98,247,000	372,869,000	$ 296,852,000
Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Contract liabilities	2,200,000		2,200,000		1,400,000
Contract assets	0		0		0
Accounting Standards Update 2014-09 [Member] | Rebate [Member]
Disaggregation of Revenue [Line Items]
Accrued liabilities	8,500,000		8,500,000		7,500,000
Reduction to revenue	(7,500,000)	(5,200,000)	(20,200,000)	(14,600,000)
Accounting Standards Update 2014-09 [Member] | Cash Discounts [Member]
Disaggregation of Revenue [Line Items]
Reduction to revenue	(1,300,000)	$ (1,100,000)	(3,600,000)	$ (3,100,000)
Allowance for cash discount	$ 500,000		$ 500,000		$ 500,000