Accumulated Other Comprehensive Income (Loss) - Change in component of accumulated comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	$ (2,179)	$ (2,095)	$ (1,962)
Other comprehensive (loss) before reclassifications	(1,466)	(424)	(3)
Amounts reclassified from accumulated other comprehensive (loss) after tax benefit (expense)	(2,204)	340	(130)
Balance at end of period	(5,849)	(2,179)	(2,095)
Income tax (expense) benefit on postretirement benefits	1,187	(183)	70
Cumulative Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(282)	142	145
Other comprehensive (loss) before reclassifications	(1,466)	(424)	(3)
Amounts reclassified from accumulated other comprehensive (loss) after tax benefit (expense)	0	0	0
Balance at end of period	(1,748)	(282)	142
Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(1,897)	(2,237)	(2,107)
Other comprehensive (loss) before reclassifications	0	0	0
Amounts reclassified from accumulated other comprehensive (loss) after tax benefit (expense)	(2,204)	340	(130)
Balance at end of period	$ (4,101)	$ (1,897)	$ (2,237)