Note 15 - Stock Option and Retirement Plans - Changes to the Current Estimate of the Vesting Percentage and Related Expense (Details) - Performance Shares [Member] $ in Thousands	12 Months Ended
	Aug. 31, 2018 USD ($)
Share-based Compensation Award, Tranche One [Member] | Vermilion Holdings Limited [Member]
Cumulative Catch-up Adjustment		[1]
Remaining Expense to be Recognized
Share-based Compensation Award, Tranche One [Member] | BI-SAM Technologies [Member]
Cumulative Catch-up Adjustment		[1]
Remaining Expense to be Recognized
Share-based Compensation Award, Tranche Two [Member] | Vermilion Holdings Limited [Member]
Cumulative Catch-up Adjustment	613	[1]
Remaining Expense to be Recognized	1,272
Share-based Compensation Award, Tranche Two [Member] | BI-SAM Technologies [Member]
Cumulative Catch-up Adjustment	1,658	[1]
Remaining Expense to be Recognized	5,449
Share-based Compensation Award, Tranche Three [Member] | BI-SAM Technologies [Member]
Cumulative Catch-up Adjustment	1,866	[1]
Remaining Expense to be Recognized	6,130
Share-based Compensation Award, Tranche Four [Member] | BI-SAM Technologies [Member]
Cumulative Catch-up Adjustment	2,073	[1]
Remaining Expense to be Recognized	$ 6,811

[1] Amounts represent the cumulative catch-up adjustment to be recorded if there was a change in the vesting percentage as of August 31, 2018.