Note 17 - Income Taxes - Components of the Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Current
U.S. federal	$ 58,835	$ 58,057	$ 97,703
U.S. state and local	5,159	5,659	4,917
Non-U.S.	22,669	17,458	15,030
Total current taxes	86,663	81,174	117,650
Deferred
U.S. federal	2,079	4,320	3,915
U.S. state and local	(295)	(77)	136
Non-U.S.	(3,694)	636	477
Total deferred taxes	(1,910)	4,879	4,528
Total provision for income taxes	$ 84,753	$ 86,053	$ 122,178