Note 12 - Summary of Option Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Outstanding (in shares)	1,118,058	1,114,058
Outstanding (in dollars per share)	$ 6.63	$ 5.76
Granted (in shares)	153,618	397,218
Granted (in dollars per share)	$ 18.11	$ 8.30
Exercised (in shares)	(309,230)	(360,318)
Exercised (in dollars per share)	$ 6.90	$ 5.70
Lapsed (in shares)	(10,900)	(20,400)
Lapsed (in dollars per share)	$ 6	$ 7.92
Cancelled (in shares)	(5,000)	(12,500)
Cancelled (in dollars per share)	$ 11.22	$ 6.43
Outstanding (in shares)	946,546	1,118,058
Outstanding (in dollars per share)	$ 8.39	$ 6.63