Leases - ASC 842 Quantitative Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Leases [Abstract]
Operating lease cost	$ 1,283	$ 1,472	$ 2,520	$ 2,912
Short-term lease cost	68	124	165	160
Short-term sublease income	(10)	(10)	(20)	(20)
Variable lease cost	77	(85)	607	370
Total lease cost	$ 1,418	$ 1,501	3,272	3,422
Cash paid for amounts included in the measurement of lease liabilities			2,712	2,201
Right-of-use assets obtained in exchange for new lease liabilities			$ 165	$ 398
Weighted-average remaining lease term (years)	3 years 7 months 6 days	4 years 6 months	3 years 7 months 6 days	4 years 6 months
Weighted-average discount rate	6.40%	6.40%	6.40%	6.40%