Leases Lease cash flow information (Details) $ in Thousands	3 Months Ended
	Apr. 30, 2019 USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 8,114
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	$ 2,327
Weighted-average remaining lease term (years)	5 years 5 months 1 day
Weighted-average discount rate (as a percent)	6.45%