Note 9 - Stock Options - Exercise Price (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Outstanding at the end of the period (in shares) | shares	2,254
Options outstanding weighted average remaining contractual life (Year)	3 years 25 days
Options outstanding weighted average exercise price (in dollars per share)	$ 0.64
Options exercisable (in shares) | shares	2,079
Options exercisable weighted average exercise price (in dollars per share)	$ 0.59
Range 1 [Member]
Exercise price, low end of range (in dollars per share)	0.20
Exercise price, high end of range (in dollars per share)	$ 0.50
Outstanding at the end of the period (in shares) | shares	1,296
Options outstanding weighted average remaining contractual life (Year)	2 years 204 days
Options outstanding weighted average exercise price (in dollars per share)	$ 0.34
Options exercisable (in shares) | shares	1,228
Options exercisable weighted average exercise price (in dollars per share)	$ 0.34
Range 2 [Member]
Exercise price, low end of range (in dollars per share)	0.51
Exercise price, high end of range (in dollars per share)	$ 1
Outstanding at the end of the period (in shares) | shares	661
Options outstanding weighted average remaining contractual life (Year)	2 years 346 days
Options outstanding weighted average exercise price (in dollars per share)	$ 0.67
Options exercisable (in shares) | shares	661
Options exercisable weighted average exercise price (in dollars per share)	$ 0.67
Range 3 [Member]
Exercise price, low end of range (in dollars per share)	1.01
Exercise price, high end of range (in dollars per share)	$ 2.73
Outstanding at the end of the period (in shares) | shares	297
Options outstanding weighted average remaining contractual life (Year)	5 years 226 days
Options outstanding weighted average exercise price (in dollars per share)	$ 1.91
Options exercisable (in shares) | shares	190
Options exercisable weighted average exercise price (in dollars per share)	$ 1.89