Employee Postretirement Benefits Employee Postretirement Benefits (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 7	$ 7
Interest cost	83	79
Amortization of actuarial losses	24	32
Amortization of unrecognized prior service cost (Credit)	(40)	(40)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 74	$ 78