Note 16 - Summary of Stock Option Activity (Details) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Outstanding (in shares)	2,070,672
Outstanding (in dollars per share)	$ 12.08
Exercisable (in shares)	709,255	971,797
Granted (in shares)	333,601
Granted (in dollars per share)	$ 39.76
Exercised (in shares)	(691,985)
Exercised (in dollars per share)	$ 8.40
Forfeited or expired (in shares)	(80,375)
Forfeited or expired (in dollars per share)	$ 14.48
Outstanding (in shares)	1,631,913	2,070,672
Outstanding (in dollars per share)	$ 19.17	$ 12.08
Exercisable (in dollars per share)	$ 12.30