Note 13 - Employee Stock Option and Retirement Plans (Details) - Change in the Actual Financial Performance Level (November 2012 Annual Employee Performance-Based Option Grant Review [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2013
Financial Performance Level One [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Change in the Actual Financial Performance Level [Line Items]
Vesting percentage	0.00%
One-time adjustment	$ (1,550)	[1]
Financial Performance Level Two [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Change in the Actual Financial Performance Level [Line Items]
Vesting percentage	20.00%
Total unamortized stock-based compensation expense	3,198
One-time adjustment		[1]
Average remaining quarterly expense to be recognized	204
Financial Performance Level Three [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Change in the Actual Financial Performance Level [Line Items]
Vesting percentage	60.00%
Total unamortized stock-based compensation expense	9,594
One-time adjustment	3,100	[1]
Average remaining quarterly expense to be recognized	612
Financial Performance Level Four [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Change in the Actual Financial Performance Level [Line Items]
Vesting percentage	100.00%
Total unamortized stock-based compensation expense	15,990
One-time adjustment	6,200	[1]
Average remaining quarterly expense to be recognized	$ 1,020

[1] Amounts represent the cumulative catch-up adjustment to be recorded if there was a change in the vesting percentage as of November 30, 2013.