Summary of Business and Significant Accounting Policies - Accounts Receivable Allowance For Credit Loss Rollforward (Details) $ in Thousands	3 Months Ended
	Apr. 30, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 5,150
Provision for credit losses	3,771
Write-offs	(621)
Ending balance	$ 8,300