Note 9 - Summary of the Weighted-Average Characteristics of Outstanding Stock Options (Details) - Jun. 30, 2015 - $ / shares	Total
Range 01 [Member]
Range of Exercise Prices (Minimum) (in dollars per share)	$ 1.60
Range of Exercise Prices (Maximum) (in dollars per share)	$ 3.70
Outstanding Options Number of Shares (in shares)	395,820
Outstanding Options Remaining Life	5 years 73 days
Outstanding Options Weighted-Average Price (in dollars per share)	$ 2.93
Exercisable Options Number of Shares (in shares)	395,820
Exercisable Options Weighted-Average Price (in dollars per share)	$ 2.93
Range 02 [Member]
Range of Exercise Prices (Minimum) (in dollars per share)	3.71
Range of Exercise Prices (Maximum) (in dollars per share)	$ 4.42
Outstanding Options Number of Shares (in shares)	695,396
Outstanding Options Remaining Life	6 years 73 days
Outstanding Options Weighted-Average Price (in dollars per share)	$ 3.82
Exercisable Options Number of Shares (in shares)	291,480
Exercisable Options Weighted-Average Price (in dollars per share)	$ 3.82
Range 03 [Member]
Range of Exercise Prices (Minimum) (in dollars per share)	4.43
Range of Exercise Prices (Maximum) (in dollars per share)	$ 5.40
Outstanding Options Number of Shares (in shares)	117,500
Outstanding Options Remaining Life	7 years 219 days
Outstanding Options Weighted-Average Price (in dollars per share)	$ 5
Exercisable Options Number of Shares (in shares)	41,000
Exercisable Options Weighted-Average Price (in dollars per share)	$ 5.18
Range 04 [Member]
Range of Exercise Prices (Minimum) (in dollars per share)	5.41
Range of Exercise Prices (Maximum) (in dollars per share)	$ 7.08
Outstanding Options Number of Shares (in shares)	223,000
Outstanding Options Remaining Life	7 years 36 days
Outstanding Options Weighted-Average Price (in dollars per share)	$ 6.42
Exercisable Options Number of Shares (in shares)	90,500
Exercisable Options Weighted-Average Price (in dollars per share)	$ 6.23
Outstanding Options Number of Shares (in shares)	1,431,716
Outstanding Options Remaining Life	6 years 73 days
Outstanding Options Weighted-Average Price (in dollars per share)	$ 4.08
Exercisable Options Number of Shares (in shares)	818,800
Exercisable Options Weighted-Average Price (in dollars per share)	$ 3.73