Summary of Business and Significant Accounting Policies (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of beginning of year	$ (14,311)
Net current period other comprehensive income (loss)	726	$ (5,269)
Balance as of end of year	(13,585)	(14,311)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of beginning of year	(14,311)	(9,042)
Other comprehensive loss before reclassifications	(1,105)	(6,045)
Amortization of prior service cost (credit)	1,831	776
Net current period other comprehensive income (loss)	726	(5,269)
Balance as of end of year	$ (13,585)	$ (14,311)