Employee Postretirement Benefits Employee Postretirement Benefits (Tables)

6 Months Ended

Jul. 31, 2018

Retirement Benefits [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, 2018			July 31, 2017			July 31, 2018			July 31, 2017
Service cost	$	7		$	21		$	14		$	43
Interest cost	79			82			158			164
Amortization of actuarial losses	32			30			64			60
Amortization of unrecognized gains in prior service cost	(40		)	(40		)	(80		)	(80		)
Net periodic benefit cost	$	78		$	93		$	156		$	187