Note 12 - Summary of Information About Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Option Set 1 [Member] | Minimum [Member]
Range of Exercise Price (in dollars per share)	$ 3.82
Option Set 1 [Member] | Maximum [Member]
Range of Exercise Price (in dollars per share)	$ 4.71
Option Set 1 [Member]
Shares (in shares) | shares	53,166
Weighted Average Remaining Contractual Life	3 years 142 days
Weighted Average Exercise Price (in dollars per share)	$ 4.44
Option Set 2 [Member] | Minimum [Member]
Range of Exercise Price (in dollars per share)	5.55
Option Set 2 [Member] | Maximum [Member]
Range of Exercise Price (in dollars per share)	$ 7.36
Option Set 2 [Member]
Shares (in shares) | shares	665,722
Weighted Average Remaining Contractual Life	2 years 149 days
Weighted Average Exercise Price (in dollars per share)	$ 6.37
Option Set 3 [Member] | Minimum [Member]
Range of Exercise Price (in dollars per share)	7.96
Option Set 3 [Member] | Maximum [Member]
Range of Exercise Price (in dollars per share)	$ 18.66
Option Set 3 [Member]
Shares (in shares) | shares	227,658
Weighted Average Remaining Contractual Life	4 years 313 days
Weighted Average Exercise Price (in dollars per share)	$ 15.20
Minimum [Member]
Range of Exercise Price (in dollars per share)	3.82
Maximum [Member]
Range of Exercise Price (in dollars per share)	$ 18.66
Shares (in shares) | shares	946,546
Weighted Average Remaining Contractual Life	3 years 21 days
Weighted Average Exercise Price (in dollars per share)	$ 8.39