Leases - Other information (Details) $ in Millions	6 Months Ended
	Jul. 31, 2019 USD ($)
Leases [Abstract]
Weighted average remaining lease term	5 years 3 months 18 days
Weighted average discount rate	7.80%
Cash paid for operating lease liabilities	$ 51.9
Right-of-use assets obtained in exchange for lease obligations	$ 15.6