Revenue - Performance Obligation (Details) - USD ($) $ in Millions	Jul. 31, 2020	Jan. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 727.8	$ 679.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-02-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage		51.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period		12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-08-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	47.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months