Employee Postretirement Benefits Employee Postretirement Benefits (Tables)

6 Months Ended

Jul. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Components of net periodic benefit cost for postretirement plan

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

	Three Months Ended					Six Months Ended
	July 31, 2016			July 31, 2015		July 31, 2016			July 31, 2015
Service cost	$	20		$	108	$	40		$	216
Interest cost	83			105		166			210
Amortization of actuarial losses	37			84		74			168
Amortization of unrecognized prior service cost	(40		)	—		$	(80	)	$	—
Net periodic benefit cost	$	100		$	297	$	200		$	594