Note 2 - Long-Term Incentive Plans (Tables)

6 Months Ended

Jun. 30, 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	Six Months
	Ended June 30,	Ended June 30,
	2014	2014	2013
Expected volatility	79.30%	78.78%	76.23%
Risk-free interest rate	1.79%	1.91%	1.06%
Expected dividend yield	0.00%	0.00%	0.00%
Expected life (in years)	6.0	6.0	6.0
Estimated fair value per option granted	$1.49	$1.70	$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		866,250
Exercised		(473,789	)
Forfeited and cancelled		(47,870	)
Outstanding at June 30, 2014		6,339,379

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

	Shares
Nonvested at January 1, 2014		-
Granted		125,803
Forfeited and Cancelled		(27,956	)
Nonvested at June 30, 2014		97,847

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

	Three Months				Six Months
	Ended June 30,				Ended June 30,
	2014		2013		2014		2013
Cost of sales	$	25	$	11	$	49	$	28
Research and development		105		67		203		154
Selling, general and administrative		181		1,966		350		2,202
	$	311	$	2,044	$	602	$	2,384