Note 3 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
	Nov. 30, 2018 USD ($)	Aug. 31, 2019 USD ($)	Aug. 31, 2018 USD ($)	Aug. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
Unbilled Receivables, Current		$ 15,800	$ 6,400
Accounts Receivable, Allowance for Credit Loss, Ending Balance		10,500	3,500
Research and Development Expense, Total		214,700	217,100	$ 215,000
Interest Income and Fees, Bankers Acceptances, Certificates of Deposit and Commercial Paper		$ 1,500	1,300	1,600
Number of Reporting Units		3
Goodwill, Impairment Loss		$ 0
Impairment of Intangible Assets (Excluding Goodwill), Total		0
Accrued Bonuses		49,400	43,600
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance		(72,278)	(47,953)
Unrecognized Tax Benefits, Ending Balance		10,884	$ 9,223	$ 11,484	$ 8,782
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		$ 1,100
Accounting Standards Update 2014-09 [Member]
Cumulative Effect on Retained Earnings, before Tax	$ 2,500
Cumulative Effect on Retained Earnings, Net of Tax, Total	$ 2,000
Computer Equipment [Member]
Property, Plant and Equipment, Useful Life		3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life		7 years