Fair Value Measurements (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis [Abstract]
Unrealized loss recognized	$ (32,119)	$ (184,272)
Recurring [Member]
Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis [Abstract]
Cash equivalents	46,336,000		$ 56,276,000
Warrant liability	(3,822,000)		(3,789,000)
Level I [Member] | Recurring [Member]
Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis [Abstract]
Cash equivalents	46,336,000		56,276,000
Warrant liability	0		0
Level II [Member] | Recurring [Member]
Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis [Abstract]
Cash equivalents	0		0
Warrant liability	0		0
Level III [Member] | Recurring [Member]
Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis [Abstract]
Cash equivalents	0		0
Warrant liability	$ (3,822,000)		$ (3,789,000)