Note 2 - Per Share Data (Details) - Net Income Per Share (Parentheticals) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income Per Share [Abstract]
Hypothetical share repurchase	$ 20.15	$ 18.81	$ 19.97	$ 19.25