Note 3 - Stock-based Compensation and Shareholders' Equity (Details) - Stock Option Activity (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Stock Option Activity [Abstract]
Number of Options	115,800
Weighted Average Exercise Price	$ 23.51
Weighted Average Remaining Contractual Term	2 years 131 days
Exercisable at March 31, 2014	61,500
Exercisable at March 31, 2014	$ 25.61
Exercisable at March 31, 2014	343 days
Exercisable at March 31, 2014	$ 287
Granted	20,000
Granted	$ 25.16
Exercised	(12,500)
Exercised	$ 17.26
Number of Options	123,300
Weighted Average Exercise Price	$ 24.41
Weighted Average Remaining Contractual Term	2 years 131 days
Aggregate Intrinsic Value	$ 576