Note 2 - Stock-based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($) $ / shares shares
Stock Option Plan 1999 [Member]
Outstanding (in shares)	20,500
Outstanding (in dollars per share) | $ / shares	$ 23
Exercised (in shares)	(4,000)
Exercised (in dollars per share) | $ / shares	$ 23
Forfeited or expired (in shares)	0
Forfeited or expired (in dollars per share) | $ / shares	$ 0
Outstanding (in shares)	16,500
Outstanding (in dollars per share) | $ / shares	$ 23
Outstanding	131 days
Outstanding | $	$ 103
Exercisable (in shares)	16,500
Exercisable (in dollars per share) | $ / shares	$ 23
Exercisable	131 days
Exercisable | $	$ 103
Exercised (in shares)	(4,000)