|
Note 6 - Fair Value Measurement and Financial Instruments (Tables)
|
12 Months Ended |
|
Dec. 31, 2014
|
| Note 6 - Fair Value Measurement and Financial Instruments (Tables) [Line Items] |
|
| Fair Value, Assets Measured on Recurring Basis [Table Text Block] |
|
|
|
December 31,
2014
|
|
|
Level 1
|
|
|
Level 2
|
|
|
Level 3
|
|
|
Assets:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market funds
|
|
$
|
99
|
|
|
$
|
99
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
Commercial paper
|
|
|
12,398
|
|
|
|
—
|
|
|
|
12,398
|
|
|
|
—
|
|
|
U.S. government sponsored enterprise securities
|
|
|
6,308
|
|
|
|
—
|
|
|
|
6,308
|
|
|
|
—
|
|
|
Corporate debt securities
|
|
|
3,166
|
|
|
|
—
|
|
|
|
3,166
|
|
|
|
—
|
|
|
Total assets
|
|
$
|
21,971
|
|
|
$
|
99
|
|
|
$
|
21,872
|
|
|
$
|
—
|
|
|
Liabilities:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Warrant liability
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
Stock-based compensation liability
|
|
|
22
|
|
|
|
—
|
|
|
|
—
|
|
|
|
22
|
|
|
Total liabilities
|
|
$
|
22
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
22
|
|
|
|
|
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] |
|
|
|
For the Years Ended December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
2012
|
|
|
Expected Life of the Option Term (years)
|
|
|
3.7
|
|
|
|
3.9
|
|
|
|
3.9
|
|
|
Risk-free interest rate
|
|
|
1.2
|
%
|
|
|
0.9
|
%
|
|
|
1.2
|
%
|
|
Dividend rate
|
|
|
0
|
%
|
|
|
0
|
%
|
|
|
0
|
%
|
|
Volatility
|
|
|
76.2
|
%
|
|
|
83.8
|
%
|
|
|
73.9
|
%
|
|
Forfeiture rate
|
|
|
5.3
|
%
|
|
|
8.1
|
%
|
|
|
9.0
|
%
|
|
| 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] |
|
|
|
December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Stock price at the end of each reporting period
|
|
$
|
0.54
|
|
|
$
|
3.70
|
|
|
Weighted average exercise price
|
|
$
|
29.14
|
|
|
$
|
25.45
|
|
|
Risk-free interest rate
|
|
|
0.25
|
%
|
|
|
0.62
|
%
|
|
Volatility
|
|
|
425.17
|
%
|
|
|
115.09
|
%
|
|
Dividend yield
|
|
|
0.00
|
%
|
|
|
0.00
|
%
|
|
Expected life in years
|
|
|
0.21
|
|
|
|
2.51
|
|
|
Calculated fair value per common share purchase warrant
|
|
$
|
—
|
|
|
$
|
0.96
|
|
|
| Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] |
|
|
|
For the Years Ended December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Liabilities:
|
|
|
|
|
|
|
|
|
|
Balance at beginning of period:
|
|
$
|
883
|
|
|
$
|
—
|
|
|
Calculation of initial warrant liability fair value
|
|
|
—
|
|
|
|
1,572
|
|
|
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 expense, net
|
|
|
(49
|
)
|
|
|
(689
|
)
|
|
Balance at end of period:
|
|
$
|
—
|
|
|
$
|
883
|
|
|
| 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] |
|
|
|
December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Stock price at the end of each reporting period
|
|
$
|
0.54
|
|
|
$
|
3.70
|
|
|
Weighted average exercise price
|
|
$
|
15.83
|
|
|
$
|
17.66
|
|
|
Risk-free interest rate
|
|
|
0.88
|
%
|
|
|
1.00
|
%
|
|
Volatility
|
|
|
138.38
|
%
|
|
|
94.53
|
%
|
|
Dividend yield
|
|
|
0.00
|
%
|
|
|
0.00
|
%
|
|
Expected life in years
|
|
|
2.49
|
|
|
|
3.42
|
|
|
Calculated fair value per stock option
|
|
$
|
0.10
|
|
|
$
|
1.17
|
|
|
| Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] |
|
|
|
For the Years Ended December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Liabilities:
|
|
|
|
|
|
|
|
|
|
Balance at beginning of period
|
|
$
|
202
|
|
|
$
|
—
|
|
|
Calculation of initial stock-based compensation liability fair value
|
|
|
|
|
|
|
163
|
|
|
Change in fair value of stock-based compensation liability recorded as an adjustment to contributed surplus
|
|
|
(180
|
)
|
|
|
39
|
|
|
Balance at end of period:
|
|
$
|
22
|
|
|
$
|
202
|
|
|