Note 6 - Fair Value Measurement and Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2014

Note 6 - Fair Value Measurement and Financial Instruments (Tables) [Line Items]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	June 30, 2014		Level 1		Level 2		Level 3
Assets:
Money market funds	$	1,793	$	1,793	$	—	$	—
Commercial paper		21,297		—		21,297		—
U.S. government sponsored enterprise securities		2,006		—		2,006		—
Corporate debt securities		2,875		—		2,875		—
Total assets	$	27,971	$	1,793	$	26,178	$	—
Liabilities:
Warrant liability	$	—	$	—	$	—	$	—
Stock-based compensation liability		84		—		—		84
Total liabilities	$	84	$	—	$	—	$	84

	December 31, 2013		Level 1		Level 2		Level 3
Assets:
Money market funds	$	55	$	55	$	—	$	—
Commercial paper		23,570		—		23,570		—
U.S. government sponsored enterprise securities		17,005		—		17,005		—
Corporate debt securities		6,507		—		6,507		—
Total assets	$	47,137	$	55	$	47,082	$	—
Liabilities:
Warrant liability	$	883	$	—	$	—	$	883
Stock-based compensation liability		202		—		—		202
Total liabilities	$	1,085	$	—	$	—	$	1,085

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	%

Warrant Liability [Member]

Note 6 - Fair Value Measurement and Financial Instruments (Tables) [Line Items]

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

	June 30, 2014			December 31, 2013
Stock price	$	2.24		$	3.70
Weighted average exercise price	$	31.68		$	25.45
Risk-free interest rate		0.11	%		0.62	%
Volatility		51.24	%		115.09	%
Dividend yield		0.00	%		0.00	%
Expected life in years		0.71			2.51
Calculated fair value per common share purchase warrant	$	-		$	0.96

Condensed Cash Flow Statement [Table Text Block]

	Three Months Ended June 30, 2014			Six Months Ended June 30, 2014
Liabilities:
Balance at beginning of period:	$	20		$	883
Reclassification of fair value of warrant liability to equity as a result of the amendment to convert the exercise price of certain warrants from Canadian dollars to U.S dollars of the underlying common share purchase warrants		-			(834	)
Change in fair value of warrant liability included in other income (expense), net		(20	)		(49	)
Balance at end of period:	$	-		$	-

Stock-based Compensation Liability [Member]

Note 6 - Fair Value Measurement and Financial Instruments (Tables) [Line Items]

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

	June 30, 2014			December 31, 2013
Stock price	$	2.24		$	3.70
Weighted average exercise price	$	17.53		$	17.66
Risk-free interest rate		0.85	%		1.00	%
Volatility		95.37	%		94.53	%
Dividend yield		0.00	%		0.00	%
Expected life in years		2.93			3.42
Calculated fair value per stock option	$	0.41		$	1.17

Condensed Cash Flow Statement [Table Text Block]

	Three Months Ended June 30, 2014			Six Months Ended June 30, 2014
Liabilities:
Balance at beginning of period:	$	181		$	202
Change in fair value of stock-based compensation liability recorded as an adjustment to contributed surplus		(97	)		(118	)
Balance at end of period:	$	84		$	84