Employee Postretirement Benefits Employee Postretirement Benefits (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 7	$ 7	$ 21	$ 21
Interest cost	83	79	250	237
Amortization of actuarial losses	24	32	72	96
Amortization of unrecognized prior service cost (Credit)	(40)	(40)	(120)	(120)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 74	$ 78	$ 223	$ 234