Note 6 - Stock-Based Compensation (Details) - Changes In Shares Under Option Plans (USD $)	1 Months Ended	9 Months Ended
	Jan. 31, 2013	Sep. 30, 2013	Sep. 30, 2012
Changes In Shares Under Option Plans [Abstract]
Beginning Balance	722,155	722,155	919,371
Beginning Balance (in Dollars per share)	$ 10.18	$ 10.18	$ 10.23
Issued	3,300	3,300
Issued (in Dollars per share)		$ 20.03
Exercised		(117,791)	(74,933)
Exercised (in Dollars per share)		$ 10.58	$ 10.32
Forfeited		(1,870)	(2,640)
Forfeited (in Dollars per share)		$ 7.88	$ 5.76
Expired		(23,113)	(31,341)
Expired (in Dollars per share)		$ 10.05	$ 13.92
Ending Balance		582,681	810,457
Ending Balance (in Dollars per share)		$ 10.17	$ 10.09