Income taxes	3 Months Ended
Mar. 31, 2013
Income taxes [Abstract]
Income taxes	10. Income taxes The Company has incurred net losses since its inception, and therefore, no current income tax liabilities have been incurred for the periods presented. However, the Company does have franchise tax obligations in certain states. This expense and related liability is included in the accompanying financial statements as income tax provision and accounts payable, respectively. The amount of federal operating loss carryforwards was approximately $43,100,000 at March 31, 2013. A valuation allowance is recorded to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that a portion or none of the deferred tax assets will be realized. After consideration of all the evidence, including reversal of deferred tax liabilities, future taxable income and other factors, management has determined that a full valuation allowance is necessary as of March 31, 2013. Additionally, the Company has various tax credit carryforwards of approximately $1,400,000 as of March 31, 2013.

Income taxes

3 Months Ended

Mar. 31, 2013

10. Income taxes

The Company has incurred net losses since its inception, and therefore, no current income tax liabilities have been incurred for the periods presented. However, the Company does have franchise tax obligations in certain states. This expense and related liability is included in the accompanying financial statements as income tax provision and accounts payable, respectively. The amount of federal operating loss carryforwards was approximately $43,100,000 at March 31, 2013. A valuation allowance is recorded to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that a portion or none of the deferred tax assets will be realized. After consideration of all the evidence, including reversal of deferred tax liabilities, future taxable income and other factors, management has determined that a full valuation allowance is necessary as of March 31, 2013. Additionally, the Company has various tax credit carryforwards of approximately $1,400,000 as of March 31, 2013.