Employee Postretirement Benefits Employee Postretirement Benefits (Details) $ in Thousands	3 Months Ended		7 Months Ended	9 Months Ended
	Oct. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Aug. 31, 2015 USD ($) participants	Oct. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Jan. 31, 2015 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit, number of plan participants with benefits terminated | participants			5
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 49	$ 49	$ 252	$ 265	$ 147
Interest cost	92	91	244	302	274
Defined Benefit Plan, Amortization of Gains (Losses)	(38)	(38)		(206)	(114)
Defined Benefit Plan, Net Periodic Benefit Cost	179	$ 178		$ 773	$ 535
Defined Benefit Plan, Effect of Plan Amendment on Accumulated Benefit Obligation			(958)
Defined Benefit Plan, Actuarial Gain (Loss)			(3,403)
Defined Benefit Plan, Benefits Paid			(89)
Defined Benefit Plan, Benefit Obligation			8,171			$ 12,125
Defined Benefit Plan, Fair Value of Plan Assets			0
Defined Benefit Plan, Funded Status of Plan			(8,171)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax			(2,710)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax			(958)
Defined benefit plan, Other postretirement benefit obligation, other than amount in Accumulated Other Comprehensive Income			$ (6,419)
Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period	8
Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period	$ 15