Basis of presentation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019	Jan. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities (included in Current portion of debt and finance leases)	$ (2,573)		$ (2,573)
Current portion of debt and finance lease liabilities	4,939		4,939		$ 2,324
Lease liabilities, noncurrent (included in Long-term debt and finance leases)	(3,396)		(3,396)
Long term debt and finance lease liabilities	23,131		23,131		21,540
Deferred contract acquisition costs amortization	$ 1,250	$ 489	$ 1,775	$ 974
Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities (included in Current portion of debt and finance leases)					2,300
Current portion of debt and finance lease liabilities					2,300
Lease liabilities, noncurrent (included in Long-term debt and finance leases)					2,100
Long term debt and finance lease liabilities					$ 2,100
Change in deferred contract acquisition costs				1,000
Deferred contract acquisition costs amortization				$ 1,000