Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Jan. 06, 2018	Mar. 08, 2017	Mar. 07, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Class of Stock [Line Items]
Preferred stock, shares authorized (shares)				5,000,000		5,000,000
Number of units issued	2,045,454
Purchase price per unit (in usd per share)	$ 0.76
Preferred stock, par value (in dollars per share)				$ 0.001		$ 0.001
Proceeds from 2017 Series A Preferred Stock Offering, (net of offering costs of $377)				$ 0	$ 7,886
Deemed dividend on preferred stock				121	3,734
Dividend paid in-kind to preferred stockholders				$ 82	$ 20
2017 Private Placement
Class of Stock [Line Items]
Number of common shares authorized for purchase as a percent of conversion shares			100.00%
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (shares)				8,000	8,000	8,000
Preferred stock, shares issued (shares)				8,000		8,000
Dividend paid in-kind to preferred stockholders				$ 100	$ 25
Series A Convertible Preferred Stock | 2017 Private Placement
Class of Stock [Line Items]
Preferred stock, shares issued (shares)			1
Preferred stock, par value (in dollars per share)			$ 1,000
Conversion price (usd per share)			$ 2.3271
Proceeds from 2017 Series A Preferred Stock Offering, (net of offering costs of $377)		$ 8,000	$ 1,300
Dividend rate, preferred stock			4.00%
Dividend rate, period of initial rate			5 years
Increased dividend rate, preferred stock			8.00%
Risk-free interest rate			3.15%
Credit spread			31.27%
Market yield			34.42%
Proceeds from beneficial conversion feature			$ 3,700
Deemed dividend on preferred stock				100	$ 3,700
Ownership percentage, convertible preferred stock			70.00%
Units | 2017 Private Placement
Class of Stock [Line Items]
Number of units issued			8,000
Purchase price per unit (in usd per share)			$ 1,000
Warrant
Class of Stock [Line Items]
Discount on shares, preferred stock			$ 3,000
Deemed dividend on preferred stock				$ 100