Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018
Allowance For Doubtful Accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 2,635	$ 3,585	$ 7,447
Charges to costs and expenses	589	0	744
Charged to other accounts	0	0	0
Deductions	444	950	4,606
Balance at end of period	2,780	2,635	3,585
Deferred Tax Asset Valuation Allowance [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	3,759	3,562	2,804
Charges to costs and expenses	83	197	758
Charged to other accounts	0	0	0
Deductions	624	0	0
Balance at end of period	$ 3,218	$ 3,759	$ 3,562