SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - COST OF REVENUE; CAPITALIZED SOFTWARE DEVELOPMENT (Details)	12 Months Ended
	Jan. 31, 2018 mo
Cost of Revenue [Abstract]
Maximum period of time for recognizing revenue for deferred cost of revenue classified as current (in months)	12
Software Development Costs
Software Development Costs
Estimated useful lives, (in years)	4 years
Internal-Use Software
Software Development Costs
Estimated useful lives, (in years)	4 years