Note 1 - Stock Option Activity (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Outstanding (in shares)	1,155,776	1,118,058
Outstanding (in dollars per share)	$ 7.54	$ 6.63
Granted (in shares)	92,308
Granted (in dollars per share)	$ 18.66
Exercised (in shares)	(54,590)
Exercised (in dollars per share)	$ 7.68