|
Income taxes (Details 1)
|
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
| Income Taxes Disclosure [Line Items] | |||
| Federal statutory rate | (34.00%) | (34.00%) | (34.00%) |
| State income taxes, net of Federal benefits | (5.30%) | (5.00%) | (5.00%) |
| Warrant inducement expense | 9.90% | 0.00% | 0.00% |
| Other | 9.50% | (0.90%) | 1.40% |
| Valuation allowance | 19.90% | 39.90% | 37.60% |
| Total | 0.00% | 0.00% | 0.00% |