Note 13 - Employee Stock Option and Retirement Plans (Tables)

6 Months Ended

Feb. 28, 2019

Notes Tables

Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block]

(in thousands, except per share data)	Number of Stock Options Outstanding			Weighted Average Exercise Price Per Share
Balance at August 31, 2018		3,143		$	153.05
Granted – non-performance-based		455			221.93
Exercised		(117	)		132.81
Forfeited		(24	)		169.47
Balance at November 30, 2018		3,457		$	162.68
Granted – non-performance-based		6			207.84
Granted – non-employee Directors’ grant		21			207.88
Exercised		(207	)		136.30
Forfeited		(61	)		152.19
Balance at February 28, 2019		3,216		$	164.42

Schedule of Share-based Compensation Vesting Percentage and Related Expenses [Table Text Block]

Vesting Percentage (in thousands)	Cumulative Catch-up Adjustment*		Remaining Expense to be Recognized
0% (current expectation)	$	—	$	—
80%	$	2,369	$	4,738
90%	$	2,665	$	5,331
100%	$	2,961	$	5,923

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

(in thousands, except per award data)	Number Outstanding			Weighted Average Grant Date Fair Value Per Award
Balance at August 31, 2018		143			$	139.34
Granted		41			$	212.66
Forfeited		(1	)		$	200.18
Vested		(52	) (1)		$	113.44
Balance at November 30, 2018		131			$	172.48
Granted		—			$	—
Forfeited		(1	)		$	184.64
Vested		(23	) (2)		$	136.58
Balance at February 28, 2019		107			$	187.62

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

(in thousands)	Share-based Awards Available for Grant under the Employee Stock Option Plan			Share-based Awards Available for Grant under the Non-Employee Stock Option Plan
Balance at August 31, 2018		6,298			282
Granted – non-performance-based options		(455	)		—
Restricted stock awards granted (1)		(103	)		—
Share-based awards canceled/forfeited (2)		25			—
Balance at November 30, 2018		5,765			282
Granted – non-performance-based options		(6	)		(21	)
Share-based awards canceled/forfeited (2)		65			3
Balance at February 28, 2019		5,824			264