Summary of Business and Significant Accounting Policies (Concentration of Credit risk) (Details)	12 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Concentration Risk [Line Items]
Period of Manufacturing Operations	70 years
Foreign sales revenue by percent	10.00%
Revenue Benchmark \| Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Foreign sales revenue by percent	6.40%	6.70%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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