PURCHASED INTANGIBLE ASSETS - Goodwill and Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2018	Jan. 31, 2018	Apr. 30, 2017
Finite-Lived Intangible Assets
Intangible Assets - Gross Carrying Amount	$ 11,566
Accumulated Amortization	4,670
Other intangible assets, net	6,896	$ 7,149
Indefinite-Lived Intangible Assets
Goodwill	34,329	34,329	$ 34,913
GPS
Indefinite-Lived Intangible Assets
Goodwill	18,500	18,500
TRC
Indefinite-Lived Intangible Assets
Goodwill	13,800	13,800
APC
Indefinite-Lived Intangible Assets
Goodwill	$ 2,000	2,000
Trade names
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life	15 years
Finite Lived Intangible Assets - Gross Carrying Amount	$ 8,323
Accumulated Amortization	3,492
Finite Lived Intangible Assets - Net Amount	$ 4,831	4,966
Process certifications
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life	7 years
Finite Lived Intangible Assets - Gross Carrying Amount	$ 1,897
Accumulated Amortization	655
Finite Lived Intangible Assets - Net Amount	1,242	1,310
Customer relationships
Finite-Lived Intangible Assets
Finite Lived Intangible Assets - Gross Carrying Amount	1,346
Accumulated Amortization	523
Finite Lived Intangible Assets - Net Amount	$ 823	$ 873
Customer relationships | Maximum
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life	10 years
Customer relationships | Minimum
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets - Estimated Useful Life	4 years