PURCHASED INTANGIBLE ASSETS - Goodwill and Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Apr. 30, 2019	Jul. 31, 2020	Jul. 31, 2019	Jan. 31, 2020
Indefinite-Lived Intangible Assets
Goodwill		$ 27,943	$ 30,766	$ 27,943
Goodwill changes		$ 0	0
Impairment loss			$ 2,072
Finite-Lived Intangible Assets - Estimated Useful Life		10 years
Intangible Assets - Gross Carrying Amount		$ 11,385
Accumulated Amortization		6,835
Finite Lived Intangible Assets - Net Amount		4,550		5,001
APC
Indefinite-Lived Intangible Assets
Impairment loss	$ 2,100
GPS
Indefinite-Lived Intangible Assets
Goodwill		18,500
TRC
Indefinite-Lived Intangible Assets
Goodwill		$ 9,500		9,500
Trade names
Indefinite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life		15 years
Intangible Assets - Gross Carrying Amount		$ 8,142
Accumulated Amortization		4,714
Finite Lived Intangible Assets - Net Amount		$ 3,428		3,699
Process certifications
Indefinite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life		7 years
Intangible Assets - Gross Carrying Amount		$ 1,897
Accumulated Amortization		1,264
Finite Lived Intangible Assets - Net Amount		633		768
Customer relationships
Indefinite-Lived Intangible Assets
Intangible Assets - Gross Carrying Amount		1,346
Accumulated Amortization		857
Finite Lived Intangible Assets - Net Amount		$ 489		$ 534
Customer relationships | Minimum
Indefinite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life		4 years