Note 1 - Stock Option Activity (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Outstanding (in shares)			946,546
Outstanding (in dollars per share)			$ 8.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	11,000	11,000	120,332	103,308
Granted (in dollars per share)			$ 16.55
Exercised (in shares)			(141,022)
Exercised (in dollars per share)			$ 6.97
Lapsed (in shares)			(1,592)
Lapsed (in dollars per share)			$ 5.62
Cancelled (in shares)			(660)
Cancelled (in dollars per share)			$ 14.21
Outstanding (in shares)	923,604		923,604
Outstanding (in dollars per share)	$ 9.67		$ 9.67