Preferred Stock - Narrative (Details)		1 Months Ended	9 Months Ended
	Jan. 25, 2018 USD ($) $ / shares shares	Oct. 31, 2017 USD ($) member $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) $ / shares shares
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			5,000,000
Beneficial conversion amount | $			$ 24,000
Accrued dividends | $			68,000		$ 59,000
Proceeds from issuance of preferred stock gross | $			1,527,000	$ 0
Issuance of stock | $			$ 1,527,000
Conversion price below this fair value of the common stock (in dollars per share) | $ / shares			$ 1.16
Common Stock
Class of Stock [Line Items]
Stock issued for conversion of convertible preferred stock, shares (in shares)			3,518,000
Perpetual Series B-1 Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			100
Preferred stock, shares issued (in shares)			0
Preferred stock, shares outstanding (in shares)			0
Series A-2 Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			7,500		7,500
Preferred stock, shares issued (in shares)			32		32
Preferred stock, stated value | $			$ 7,500		$ 7,500
Preferred stock, shares outstanding (in shares)			32		32
Stock issued during period, conversion of convertible securities, price (in dollars per share) | $ / shares			$ 2.16		$ 2.40
Convertible preferred stock, shares issued upon conversion (in shares)			3,472
Preferred stock, cumulative dividend percentage rate, per annum			5.00%
Redemption price per share (in dollars per share) | $ / shares			$ 8,250
Redemption price per share, multiplier (in dollars per share) | $ / shares			$ 7,500
Redemption price per share, multiplier, percentage			110.00%
Stated value (in dollars per share) | $ / shares			$ 0.0001		$ 0.0001
Derivative liability | $			$ 0
Series A-2 Preferred Stock | Preferred Stock
Class of Stock [Line Items]
Stock issued for conversion of convertible preferred stock, shares (in shares)			0
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			2,800		2,800
Preferred stock, shares issued (in shares)			375		450
Preferred stock, stated value | $			$ 1,000		$ 1,000
Preferred stock, shares outstanding (in shares)			375		450
Stock issued during period, conversion of convertible securities, price (in dollars per share) | $ / shares		$ 0.28
Preferred stock, cumulative dividend percentage rate, per annum			0.00%
Proceeds from issuance of preferred stock gross | $		$ 2,800,000
Stated value (in dollars per share) | $ / shares		$ 1,000	$ 0.0001		$ 0.0001
Participation rights, future offerings, max percentage		100.00%
Expansion of board of director members | member		6
Series B Preferred Stock | Preferred Stock
Class of Stock [Line Items]
Issuance of stock (in shares)		2,800
Stock issued for conversion of convertible preferred stock, shares (in shares)			75
Series B Preferred Stock | Common Stock
Class of Stock [Line Items]
Stock issued for conversion of convertible preferred stock, shares (in shares)			268,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			1,750		1,750
Preferred stock, shares issued (in shares)			775		0
Preferred stock, stated value | $			$ 1,000		$ 1,000
Preferred stock, shares outstanding (in shares)			775		0
Stock issued during period, conversion of convertible securities, price (in dollars per share) | $ / shares	$ 0.30
Proceeds from issuance of preferred stock gross | $	$ 1,750,000
Stated value (in dollars per share) | $ / shares	$ 1,000		$ 0.0001		$ 0.0001
Participation rights, future offerings, max percentage	100.00%
Participation rights, future offerings, limitation on stated value outstanding | $	$ 500,000
Series C Preferred Stock | Preferred Stock
Class of Stock [Line Items]
Preferred stock, cumulative dividend percentage rate, per annum	0.00%
Issuance of stock (in shares)	1,750		1,750
Stock issued for conversion of convertible preferred stock, shares (in shares)			975
Issuance of stock | $	$ 1,527,000
Series C Preferred Stock | Common Stock
Class of Stock [Line Items]
Stock issued for conversion of convertible preferred stock, shares (in shares)			3,250,000
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			4,000
Preferred stock, shares issued (in shares)			0
Preferred stock, shares outstanding (in shares)			0
Perpetual Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, convertible, shares authorized (in shares)			100
Preferred stock, shares issued (in shares)			0
Preferred stock, shares outstanding (in shares)			0