Stockholders' Equity (Details 3) - $ / shares		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Common Shares Underlying Warrants		1,051,358	1,422,781	4,495,556
Expiration Date		Jan. 28, 2015
3.97 [Member] | Warrant [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Common Shares Underlying Warrants	[1]	100,778
Issue Date		Mar. 01, 2007
Exercisable Date		Mar. 01, 2007
Exercise Price		$ 3.97
Expiration Date		Mar. 01, 2017
1.63 [Member] | Derivative Instrument Warrants [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Common Shares Underlying Warrants	[2]	903,996
Issue Date		Jul. 01, 2010
Exercisable Date		Jan. 01, 2011
Exercise Price		$ 1.63
Expiration Date		Jan. 01, 2017
1.61 [Member] | Warrant [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Common Shares Underlying Warrants	[1]	46,584
Issue Date		Mar. 01, 2012
Exercisable Date		Mar. 01, 2012
Exercise Price		$ 1.61
Expiration Date		Mar. 01, 2022

[1] These warrants to purchase common stock are classified as equity.

[2] Because of the presence of net settlement provisions, these warrants to purchase common stock are classified as derivative liabilities. The fair value of these liabilities (see Note 3 – Fair Value Measurements) is remeasured at the end of every reporting period and the change in fair value is reported in the accompanying consolidated statements of operations as other income (expense).