Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Allowance For Doubtful Accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 3,585	$ 7,447	$ 8,312
Charges to costs and expenses		744	483
Deductions	950	4,606	1,348
Balance at end of period	2,635	3,585	7,447
Deferred Tax Asset Valuation Allowance [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	3,562	2,804	2,825
Charges to costs and expenses	197	758
Deductions			21
Balance at end of period	$ 3,759	$ 3,562	$ 2,804