Net Periodic Pension and Post-Retirement Costs (Details) (USD $)	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Pension
Net periodic pension and post-retirement costs
Service Cost	$ 542,000	$ 1,116,000
Interest Cost	2,201,000	2,414,000
Expected Return on Plan Assets	(3,490,000)	(3,128,000)
Amortization of Prior Service Costs	2,000
Amortization of Net Actuarial (Gain) Loss	2,415,000	1,782,000
Net Periodic Pension Cost	1,670,000	2,184,000
Total expected contribute and benefit payments during the fiscal year	6,800,000
Post-Retirement
Net periodic pension and post-retirement costs
Service Cost	280,000	160,000
Interest Cost	382,000	420,000
Amortization of Net Actuarial (Gain) Loss	57,000	(177,000)
Net Periodic Pension Cost	719,000	403,000
Employer's contribution	265,000
Total expected contribute and benefit payments during the fiscal year	1,300,000
Supplemental Executive Retirement Plans
Net periodic pension and post-retirement costs
Employer's contribution	25,000
Total expected contribute and benefit payments during the fiscal year	$ 99,000