Note 8 - Stock-Based Compensation (Details) - Changes In Shares Under Option Plans (USD $)	1 Months Ended	6 Months Ended
	Feb. 28, 2014	Jun. 30, 2014	Jun. 30, 2013
Changes In Shares Under Option Plans [Abstract]
Beginning Balance		501,334	722,155
Beginning Balance		$ 10.34	$ 10.18
Issued	21,000	21,000	3,300
Issued		$ 32.77	$ 20.03
Exercised		(24,897)	(89,911)
Exercised		$ 12.25	$ 8.43
Forfeited		(110)	(1,870)
Forfeited		$ 5.76	$ 7.88
Expired		(408)	(15,640)
Expired		$ 9.37	$ 10.79
Ending Balance		496,919	618,034
Ending Balance		$ 11.20	$ 10.48