Allowance for Doubtful Accounts (Activity in Allowance for Credit Losses) (Details) $ in Thousands	3 Months Ended
	Apr. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Beginning balance	$ (710)
Provision for credit losses	(9,737)
Ending balance	(10,447)
Wholesale
Segment Reporting Information [Line Items]
Beginning balance	(628)
Provision for credit losses	(9,791)
Ending balance	(10,419)
Retail
Segment Reporting Information [Line Items]
Beginning balance	(82)
Provision for credit losses	54
Ending balance	$ (28)