Stockholders' Equity - Additional Information (Details) - USD ($)			1 Months Ended	3 Months Ended
	Sep. 30, 2016	Jun. 21, 2016	Jul. 31, 2006	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Capitalization, Equity [Line Items]
Common stock, par value (in dollars per share)				$ 0.001		$ 0.001
Common stock, shares authorized (in shares)				125,000,000		125,000,000
Common stock, shares issued (in shares)				25,536,533		24,609,411
Common stock, shares outstanding (in shares)				25,536,533		24,609,411
Number of warrants issued to purchase common stock (in shares)				14,033		14,033
Warrant liability fair value adjustment				$ (1,523,000)	$ 0
Warrant liability				5,078,000		$ 6,601,000
Series C Convertible Preferred Stock
Schedule of Capitalization, Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)			196,923
Exercise price of warrants (in dollars per share)			$ 3.25
Fair value of warrants			$ 500,000
Common Stock
Schedule of Capitalization, Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)			14,033
Exercise price of warrants (in dollars per share)			$ 45.61
Series C-1 Convertible Preferred Stock
Schedule of Capitalization, Equity [Line Items]
Derivative liability				$ 0		$ 0
Warrants to purchase common stock associated with Loan Agreement
Schedule of Capitalization, Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)	122,435			122,435
Exercise price of warrants (in dollars per share)	$ 3.6754			$ 3.6754
Warrants issued, expiration period (in years)	5 years			5 years
Warrants to purchase common stock associated with June 2016 Public Offering
Schedule of Capitalization, Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)		4,218,750
Exercise price of warrants (in dollars per share)		$ 3.00
Share available for each warrant purchased		0.45
Warrants issued, expiration period (in years)		5 years