Employee Postretirement Benefits Employee Postretirement Benefits (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
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 (Credit)	(40)	0	(80)	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 100	$ 297	$ 200	$ 594