INTANGIBLE ASSETS AND GOODWILL INTANGIBLE ASSETS AND GOODWILL - AMORTIZATION AND IMPAIRMENT (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2015	Jul. 31, 2016	Jul. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill, Impairment Loss				$ 0
Impairment of Intangible Assets (Excluding Goodwill) [Abstract]
Impairment of acquired intangible assets		$ 2,300,000	$ 0	0
Amortization [Abstract]
Amortization of Intangible Assets	$ 20,600,000	$ 20,600,000		$ 41,100,000	$ 39,300,000