Note 13 - Employee Stock Option and Retirement Plans (Details) - Summary of Stock Option Activity (USD $)	0 Months Ended		1 Months Ended	3 Months Ended			9 Months Ended
	Jan. 15, 2014	Jan. 15, 2013	Jul. 31, 2012	May 31, 2014	Feb. 28, 2014	Nov. 30, 2013	May 31, 2014
Note 13 - Employee Stock Option and Retirement Plans (Details) - Summary of Stock Option Activity [Line Items]
Number outstanding				4,814,000	4,655,000	4,729,000	4,729,000
Weighted average exercise price per share				$ 79.85	$ 76.94	$ 75.95	$ 75.95
Granted, Number outstanding	14,424	18,781	241,546				391,478
Granted, Weighted average exercise price per share							$ 106.73
Exercised, Number outstanding				(142,000)	(136,000)	(136,000)
Exercised, Weighted average exercise price per share				$ 59.17	$ 40.99	$ 59.38
Forfeited, Number outstanding				(16,000)	(24,000)	(10,000)
Forfeited, Weighted average exercise price per share				$ 94.48	$ 86.75	$ 79.22
Number outstanding				4,656,000	4,814,000	4,655,000	4,656,000
Weighted average exercise price per share				$ 80.42	$ 79.85	$ 76.94	$ 80.42
Non-Performance Based [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Summary of Stock Option Activity [Line Items]
Granted, Number outstanding					139,000	36,000
Granted, Weighted average exercise price per share					$ 102.01	$ 108.64
Performance Based [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Summary of Stock Option Activity [Line Items]
Granted, Number outstanding					166,000	36,000
Granted, Weighted average exercise price per share					$ 109.39	$ 110.31
Non-Employee Director Grant [Member]
Note 13 - Employee Stock Option and Retirement Plans (Details) - Summary of Stock Option Activity [Line Items]
Granted, Number outstanding					14,000
Granted, Weighted average exercise price per share					$ 107.65