Note 6 - Stockholders' Equity and Equity Compensation (Details) - Summary of Stock Option Activity (USD $)	9 Months Ended
	Sep. 30, 2013
Summary of Stock Option Activity [Abstract]
Outstanding at January 1, 2013	1,223,618
Outstanding at January 1, 2013 (in Dollars per share)	$ 18.49
Granted	29,025
Granted (in Dollars per share)	$ 25.11
Exercised	(29,511)
Exercised (in Dollars per share)	$ 20.14
Canceled/Expired	(7,729)
Canceled/Expired (in Dollars per share)	$ 24.52
Outstanding at September 30, 2013	1,215,403
Outstanding at September 30, 2013 (in Dollars per share)	$ 18.57
Exercisable at September 30, 2013	940,317
Exercisable at September 30, 2013 (in Dollars per share)	$ 17.89