REVENUE RECOGNITION REVENUE RECOGNITION - REMAINING PERFORMANCE OBLIGATIONS (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Jan. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 1,038,275	$ 1,074,212
Within One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	727,206	731,659
Greater than One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	311,069	342,553
Customer Engagement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	476,836	492,479
Customer Engagement | Within One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	363,496	374,982
Customer Engagement | Greater than One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	113,340	117,497
Cyber Intelligence
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	561,439	581,733
Cyber Intelligence | Within One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	363,710	356,677
Cyber Intelligence | Greater than One Year [Domain]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 197,729	$ 225,056