PURCHASED INTANGIBLE ASSETS - Changes in the balances of goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	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