Employee Retirement Benefits (Tables)

3 Months Ended

Apr. 30, 2012

Employee Retirement Benefits [Abstract]

The components of net periodic benefit cost for postretirement benefits

The components of net periodic benefit cost for postretirement benefits are as follows:

	Three Months Ended
	April 30, 2012		April 30, 2011
Service cost	$	47	$	30
Interest cost	84		84
Amortization of actuarial losses	58		32
Net periodic benefit cost	$	189	$	146