Selected Balance Sheet Information - USD ($) $ in Thousands	Apr. 30, 2020	Jan. 31, 2020
Accounts receivable, net:
Trade accounts	$ 59,459	$ 56,978
Unbilled receivables	2,739	6,954
Allowance for doubtful accounts	(1,862)	(1,380)
Accounts receivable, net	60,336	62,552
Inventories:
Finished goods	9,266	6,309
In process	1,491	3,287
Materials	46,344	44,303
Inventories	57,101	53,899
Other current assets:
Insurance policy benefit	38	38
Income tax receivable	1,560	1,370
Prepaid Expense and other	4,670	4,028
Other current assets	6,268	5,436
Property, plant and equipment, net:
Property, plant and equipment, net	102,061	100,850
Other Assets (Noncurrent):
Equity investments	1,325	1,289
Operating Lease, Right-of-Use Asset	8,022	4,275
Deferred Income Taxes	112	16
Other	2,093	1,507
Other assets	11,552	7,087
Accrued liabilities:
Salaries and related	4,178	4,188
Benefits	6,190	5,339
Insurance obligations	1,763	1,680
Warranties	1,606	2,019
Income Taxes	1,049	293
Other taxes	1,563	1,734
Acquisition-related contingent consideration liability, current	580	763
Lease liability, current	2,117	2,530
Other	1,790	2,197
Accrued And Other Liabilities, Current	20,836	20,743
Other liabilities:
Postretirement benefits	8,739	8,741
Acquisition-related contingent consideration liability, long-term	2,198	2,171
Lease liability, noncurrent	6,404	2,627
Deferred Income Tax Liabilities, Net	5,213	7,080
Uncertain tax positions	2,627	2,606
Other, Noncurrent	8,758	5,936
Other Liabilities, Noncurrent	33,939	29,161
Land [Member]
Property, plant and equipment, net:
Property, plant and equipment	3,117	3,117
Building and Building Improvements [Member]
Property, plant and equipment, net:
Property, plant and equipment	81,114	80,330
Machinery and Equipment [Member]
Property, plant and equipment, net:
Property, plant and equipment	162,160	158,354
Right-of-use Assets, Financing Leases [Member]
Property, plant and equipment, net:
Property, plant and equipment	866	881
Property, plant and equipment, Owned and Right-of-Use Assets for financing lease [Member]
Property, plant and equipment, net:
Accumulated depreciation	(145,196)	(141,832)
Property, plant and equipment, net	$ 102,061	$ 100,850