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PURCHASED INTANGIBLE ASSETS - Changes in the balances of goodwill (Details) - USD ($) $ in Thousands | 12 Months Ended
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Jan. 31, 2020 | Jan. 31, 2019 | Jan. 31, 2018
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | $ 32,838 | $ 34,329 | $ 34,913
Impairment loss | (4,895) | (1,491) | (584)
Goodwill, Ending Balance | 27,943 | 32,838 | 34,329
GPS |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | 18,476 | 18,476 | 18,476
Goodwill, Ending Balance | 18,476 | 18,476 | 18,476
TRC |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | 12,290 | 13,781 | 14,365
Impairment loss | (2,823) | (1,491) | (584)
Goodwill, Ending Balance | 9,467 | 12,290 | 13,781
APC |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | 2,072 | 2,072 | 2,072
Impairment loss | $ (2,072) |  |
Goodwill, Ending Balance |  | $ 2,072 | $ 2,072

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
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- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266 + Details
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