Note 12 - Stock-based Compensation (Details) - Nonvested Option Shares and Changes - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Nonvested Option Shares and Changes [Abstract]
Nonvested at beginning of year	62,700	58,750
Nonvested at beginning of year	$ 6.14	$ 5.38
Granted	14,000	19,000
Granted	$ 8.01	$ 8.34
Forfeited	(5,250)	(3,500)
Forfeited	$ 7.22	$ 6.78
Vested	(18,150)	(11,550)
Vested	$ 5.71	$ 5.72
Nonvested at end of year	53,300	62,700
Nonvested at end of year	$ 6.67	$ 6.14