Summary of Business and Significant Accounting Policies (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of beginning of year	$ (9,259)
Amortization of prior service cost (credit)	795	$ 955
Net current period other comprehensive income	217	2,135
Balance as of end of year	(9,042)	(9,259)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of beginning of year	(9,259)	(11,394)
Other comprehensive (loss) income before reclassifications	(1,116)	1,180
Amortization of prior service cost (credit)	1,333	955
Net current period other comprehensive income	217	2,135
Balance as of end of year	$ (9,042)	$ (9,259)