Leases (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jul. 31, 2019 USD ($) Rate	Jul. 31, 2019 USD ($) Rate
Leases [Abstract]
Operating Lease, Weighted Average Remaining Lease Term	4 years 8 months 12 days	4 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent | Rate	4.80%	4.80%
Operating Leases, Rent Expense | $	$ 21.8	$ 43.4