Basis of Presentation and Summary of Significant Accounting Policies - Antidilutive shares excluded from earnings per share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of earnings per share	31,542,178	25,473,682	31,542,193	23,753,932
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of earnings per share	4,583,133	3,088,292	4,583,148	1,368,542
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of earnings per share	1,890,489	1,890,489	1,890,489	1,890,489
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of earnings per share	0	639,129	0	639,129
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of earnings per share	25,068,556	19,855,772	25,068,556	19,855,772