INTANGIBLE ASSETS AND GOODWILL - GOODWILL (Details) - USD ($)
$ in Thousands
3 Months Ended
Apr. 30, 2018
Jan. 31, 2018
Goodwill activity    
Goodwill, gross at the beginning of the period $ 1,443,129 $ 1,455,164
Accumulated impairment losses (66,865) (66,865)
Goodwill, net at the beginning of the period 1,388,299  
Adjustments of prior period business combinations (335)  
Foreign currency translation and other (11,700)  
Goodwill, net, at the end of the period 1,376,264  
Customer Engagement    
Goodwill activity    
Goodwill, gross at the beginning of the period 1,295,575 1,307,136
Accumulated impairment losses (56,043) (56,043)
Goodwill, net at the beginning of the period 1,251,093  
Adjustments of prior period business combinations (335)  
Foreign currency translation and other (11,226)  
Goodwill, net, at the end of the period 1,239,532  
Cyber Intelligence    
Goodwill activity    
Goodwill, gross at the beginning of the period 147,554 148,028
Accumulated impairment losses (10,822) $ (10,822)
Goodwill, net at the beginning of the period 137,206  
Adjustments of prior period business combinations 0  
Foreign currency translation and other (474)  
Goodwill, net, at the end of the period $ 136,732