Note 6 - Employee Benefit Plans - Stock Options Activity (Details) $ / shares in Units, shares in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Outstanding (in shares) | shares	745
Outstanding, weighted average exercise price (in dollars per share)	$ 10.64
Granted (in shares) | shares	13
Granted, weighted average exercise price (in dollars per share)	$ 15.76
Exercised (in shares) | shares	(21)
Exercised, weighted average exercise price (in dollars per share)	$ 7.68
Canceled (in shares) | shares	(2)
Canceled, weighted average exercise price (in dollars per share)	$ 10.66
Expired (in shares) | shares	(9)
Expired, weighted average exercise price (in dollars per share)	$ 8.86
Outstanding, weighted average exercise price (in dollars per share)	$ 10.84
Outstanding, weighted average remaining contractual (Year)	4 years 160 days
Outstanding, aggregate intrinsic value | $	$ 1,566
Vested and expected to vest (in shares) | shares	713
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 10.79
Vested and expected to vest, weighted average remaining contractual term (Year)	4 years 127 days
Vested and expected to vest, aggregate intrinsic value | $	$ 1,560,000
Exercisable (in shares) | shares	562
Exercisable, weighted average exercise price (in dollars per share)	$ 10.10
Exercisable, weighted average remaining contractual term (Year)	3 years 65 days
Exercisable, aggregate intrinsic value | $	$ 1,484,000