Accounts Payable, Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Jan. 31, 2019
Payables and Accruals [Abstract]
Accounts payable	$ 10,252		$ 8,025
Accrued employee compensation	15,111		19,029
Accrued Knowledge Network application provider fees	2,634		2,508
Accrued professional services and associated costs	3,064		2,198
Accrued employee stock purchase plan withholdings liability	1,085		2,635
Customer deposits	1,417		1,144
Other current liabilities	11,923		8,697
Total accounts payable, accrued expenses and other current liabilities	45,486		$ 44,236
Property, Plant and Equipment [Line Items]
Capital expenditures	7,347	$ 4,321
Accounts Payable and Accrued Liabilities
Property, Plant and Equipment [Line Items]
Capital expenditures	$ 2,200	$ 300