Note 2 - Stock-Based Compensation (Details) - Stock Option Activity (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Stock Option Activity [Abstract]
Outstanding, January 1	79,693	88,774
Outstanding, January 1 (in Dollars per share)	$ 26.81	$ 26.81
Exercised	(19,761)	0
Exercised (in Dollars per share)	$ 24.09	$ 0
Forfeited	0	(9,081)
Forfeited (in Dollars per share)	$ 0	$ 22.94
Outstanding, June 30	59,932	79,693
Outstanding, June 30 (in Dollars per share)	$ 28.29	$ 27.25
Exercisable June 30	59,932	79,693
Exercisable June 30 (in Dollars per share)	$ 28.29	$ 27.25