Pensions and Other Postretirement Benefits (Tables)

3 Months Ended

Jul. 31, 2011

Pensions and Other Postretirement Benefits (Tables) [Abstract]

Net periodic benefit cost

	Three Months Ended July 31,
	Defined Benefit Pension Plans						Other Postretirement Benefits
	2011			2010			2011			2010
Service cost	$	2,062		$	1,858		$	525		$	405
Interest cost		6,523			6,346			780			690
Expected return on plan assets		(6,885	)		(6,657	)		0			0
Recognized net actuarial loss (gain)		2,201			1,727			(25	)		(134	)
Termination benefit cost		0			7,462			0			2,413
Curtailment		0			3,910			0			0
Other		300			288			(100	)		(122	)
Net periodic benefit cost	$	4,201		$	14,934		$	1,180		$	3,252