STOCKHOLDERS' EQUITY - TREASURY STOCK (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Jan. 31, 2020
Stockholders' Equity Note [Abstract]
Treasury stock aquired (in shares)	613,000	8,000
Treasury stock acquired (in dollars)	$ 33,990	$ 474
Treasury stock, (in shares)	4,404,000		3,791,000
Treasury stock (in dollars)	$ 208,124		$ 174,134