Note 11 - Stock-based Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2014

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

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
Research and development	$	153	$	60	$	346	$	124
General and administrative		391		213		807		401
Total	$	544	$	273	$	1,153	$	525

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

	Six Months Ended June 30,
	2014			2013
Expected life of the option term (years)		3.7			4.2
Risk-free interest rate		1.2	%		1.4	%
Dividend rate		0	%		0	%
Volatility		76.2	%		69.1	%
Forfeiture rate		5.3	%		8.8	%

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

	Options outstanding			Weighted average exercise price		Currency
Outstanding at January 1, 2014		1,362		$	7.10	US
Options granted		87			2.57	US
Options forfeited		(9	)		4.17	CND
Options forfeited		(54	)		3.79	US
Outstanding at June 30, 2014		1,386		$	3.51	US