REVENUES FROM CONTRACTS WITH CUSTOMERS - Remaining Unsatisfied Performance Obligations (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-05-01 $ in Millions	Apr. 30, 2021 USD ($)
REVENUES FROM CONTRACTS WITH CUSTOMERS
Contract backlog amount	$ 478.7
Contract backlog (as percent)	58.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	21 months