Note 7 - Employee Benefit Plans - Stock Options Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2019
Outstanding (in shares)	1,027
Outstanding, weighted average exercise price (in dollars per share)	$ 9.75
Granted (in shares)	66
Exercised (in shares)	(217)
Exercised, weighted average exercise price (in dollars per share)	$ 5.13
Canceled (in shares)	(75)
Canceled, weighted average exercise price (in dollars per share)	$ 14.53
Expired (in shares)	(55)
Expired, weighted average exercise price (in dollars per share)	$ 16.09
Outstanding (in shares)	746
Outstanding, weighted average exercise price (in dollars per share)	$ 9.79
Outstanding, weighted average remaining contractual term (Year)	4 years 197 days
Outstanding, aggregate intrinsic value	$ 2,521
Vested and expected to vest (in shares)	732
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 10.33
Vested and expected to vest, weighted average remaining contractual term (Year)	4 years 164 days
Vested and expected to vest, aggregate intrinsic value	$ 2,502
Exercisable (in shares)	582
Exercisable, weighted average exercise price (in dollars per share)	$ 9.79
Exercisable, weighted average remaining contractual term (Year)	3 years 120 days
Exercisable, aggregate intrinsic value	$ 2,291