Note 2 - Long-Term Incentive Plans (Tables)

3 Months Ended

Mar. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months
	Ended March 31,
	2014			2013
Expected volatility		78.39	%		76.23	%
Risk-free interest rate		2.00	%		1.06	%
Expected dividend yield		0.00	%		0.00	%
Expected life (in years)		6.0			6.0
Estimated fair value per option granted	$	1.86		$	0.87

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of
	Options
Outstanding at January 1, 2014		5,994,788
Granted		495,000
Exercised		(241,627	)
Forfeited and cancelled		(7,655	)
Outstanding at March 31, 2014		6,240,506

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

	Shares
Nonvested at January 1, 2014		-
Granted		125,803
Nonvested at March 31, 2014		125,803

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three Months
	Ended March 31,
	2014		2013
Cost of sales	$	24	$	17
Research and development		98		87
Selling, general and administrative		168		236
	$	290	$	340