Note 12 - Stock-based Compensation - RSUs Activity (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	3 Months Ended
	Apr. 30, 2021 $ / shares shares
Outstanding (in shares) | shares	698
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 41.56
Granted (in shares) | shares	12
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 71.65
Released (in shares) | shares	(8)	[1]
Released, weighted average grant date fair value (in dollars per share) | $ / shares	$ 30.97	[1]
Forfeited (in shares) | shares	(11)
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 40.56
Outstanding (in shares) | shares	691
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 42.23

[1] The number of RSUs released includes shares withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements.