Pension and Post-Retirement Benefit Plans (Tables)

3 Months Ended

Nov. 30, 2012

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Cost

The components of the net periodic pension and post-retirement benefit costs are as follows:

	Three months ended November 30,
Defined benefit pension plans	2012			2011
	(in thousands)
Service cost	$	486		$	380
Interest cost		662			682
Expected return on plan assets		(717	)		(729	)
Amortization of prior service cost		60			57
Amortization of actuarial losses		483			193
Net periodic benefit cost	$	974		$	583

	Three months ended November 30,
Post-retirement health care plans	2012			2011
	(in thousands)
Service cost	$	59		$	57
Interest cost		215			243
Amortization of prior service credit		(38	)		(38	)
Amortization of actuarial losses		67			—
Net periodic benefit cost	$	303		$	262