Note 12 - Stock Based Compensation and Other Benefit Plans (Details) - Stock Options Activity (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options Activity [Abstract]
Outstanding at beginning of period	3,449,367
Outstanding at beginning of period	$ 6.94
Outstanding at end of period	3,342,015	3,449,367
Outstanding at end of period	$ 7.67	$ 6.94
Outstanding at end of period	6 years 178 days
Outstanding at end of period	$ 7,932,450
Vested or expected to vest at end of period	3,293,925
Vested or expected to vest at end of period	$ 7.62
Vested or expected to vest at end of period	6 years 164 days
Vested or expected to vest at end of period	7,920,816
Options exercisable at end of period	2,135,599
Options exercisable at end of period	$ 6.69
Options exercisable at end of period	5 years 131 days
Options exercisable at end of period	$ 6,361,350
Granted	554,641
Granted	$ 11.20	$ 11.43	$ 5.57
Exercised	(540,318)
Exercised	$ 6.37
Expired or cancelled	(121,675)
Expired or cancelled	$ 8.87