Summary of Business and Significant Accounting Policies - Accounts Receivable Allowance For Credit Loss Rollforward (Details) $ in Thousands	6 Months Ended
	Jul. 31, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 5,150
Provision for credit losses	13,723
Write-offs	(1,373)
Ending balance	$ 17,500