STOCK-BASED COMPENSATION STOCK-BASED COMPENSATION - BONUS SHARE PROGRAM (Details) - USD ($)
$ in Millions
Apr. 30, 2016
Jan. 31, 2016
Mar. 31, 2015
Stock-Based Compensation Plans      
Total accrued liability $ 8.0 $ 6.6  
2016 Plan | Bonus Share Program      
Stock-Based Compensation Plans      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     75,000
2016 Plan | Combined Stock Bonus Program and Bonus Share Program      
Stock-Based Compensation Plans      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     200,000
2017 Plan | Bonus Share Program      
Stock-Based Compensation Plans      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 81,250    
2017 Plan | Combined Stock Bonus Program and Bonus Share Program      
Stock-Based Compensation Plans      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 206,250