STOCK-BASED COMPENSATION STOCK-BASED COMPENSATION - STOCK-BASED COMPENSATION - BY LINE ITEM (Details) - USD ($)
$ in Thousands
3 Months Ended
Apr. 30, 2018
Apr. 30, 2017
Stock-Based Compensation Plans    
Stock-based compensation expense $ 16,459 $ 17,683
Cost of revenue - product    
Stock-Based Compensation Plans    
Stock-based compensation expense 117 341
Cost of revenue - service and support    
Stock-Based Compensation Plans    
Stock-based compensation expense 729 1,252
Research and development, net    
Stock-Based Compensation Plans    
Stock-based compensation expense 1,509 3,031
Selling, general and administrative    
Stock-Based Compensation Plans    
Stock-based compensation expense $ 14,104 $ 13,059