Note 12 - Stock-based Compensation - RSUs Activity (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	6 Months Ended
	Jul. 31, 2021 $ / shares shares
Restricted stock (in shares) | shares	698
Restricted stock, weighted average grant date fair value (in dollars per share) | $ / shares	$ 41.56
Granted (in shares) | shares	119
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 67.87
Released (in shares) | shares	(259)	[1]
Released, weighted average grant date fair value (in dollars per share) | $ / shares	$ 41.92	[1]
Forfeited (in shares) | shares	(21)
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares	$ 41.92
Restricted stock (in shares) | shares	537
Restricted stock, weighted average grant date fair value (in dollars per share) | $ / shares	$ 47.20

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