Note 5 - Benefit Plans (Details) - Stock Option Activity	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Note 5 - Benefit Plans (Details) - Stock Option Activity [Line Items]
Balance outstanding as of January 1, 2016 (in Dollars per share) | $ / shares	$ 19.58
Balance outstanding as of March 31, 2016 (in Dollars per share) | $ / shares	20.92
Options exercisable as of March 31, 2016 (in Dollars per share) | $ / shares	20.92
Granted (in Dollars per share) | $ / shares	0
Exercised (in Dollars per share) | $ / shares	5.19
Forfeited (in Dollars per share) | $ / shares	$ 28.34
Incentive Stock Options [Member]
Note 5 - Benefit Plans (Details) - Stock Option Activity [Line Items]
Balance outstanding as of January 1, 2016	91,500
Balance outstanding as of March 31, 2016	76,500
Options exercisable as of March 31, 2016	76,500
Granted	0
Exercised	(10,000)
Forfeited	(5,000)
Non-Incentive Stock Options [Member]
Note 5 - Benefit Plans (Details) - Stock Option Activity [Line Items]
Balance outstanding as of January 1, 2016	57,500
Balance outstanding as of March 31, 2016	52,500
Options exercisable as of March 31, 2016	52,500
Granted	0
Exercised	(5,000)
Forfeited	0