Employee Retirement Benefits (Accumulated Benefit Obligation) (Details) - Other Postretirement Benefit Plan, Defined Benefit [Member] - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 12,125	$ 8,254	$ 8,307
Service cost	285	195	202
Interest cost	386	366	348
Amendments	(958)	0	0
Actuarial (gain) loss and assumption changes	(3,544)	3,543	(340)
Retiree benefits paid	(303)	(233)	(263)
Benefit obligation at end of year	$ 7,991	$ 12,125	$ 8,254