Financial Instruments (Narrative) (Details)		1 Months Ended					12 Months Ended
	Aug. 01, 2016 USD ($) $ / shares shares	Oct. 31, 2017 shares	Sep. 30, 2017 shares	Mar. 31, 2017 USD ($) $ / shares shares	Aug. 31, 2015 USD ($)	Oct. 31, 2011 shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($) $ / shares	Jun. 30, 2016 $ / shares	Sep. 30, 2015 $ / shares	Oct. 31, 2014 $ / shares	Apr. 16, 2013 USD ($) $ / shares shares
Fair value of liability							$ 1,952,000	$ 3,305,000
Warrants reclassified from liabilities to equity							1,700,000
Change in fair value of warrant								(200,000)	$ (1,300,000)
Price per share of common stock at IPO date | $ / shares	$ 12.00
Long-term secured term debt fair value								28,700,000
Loss on extinguishment of debt								(11,176,000)	(2,934,000)
Debt discount							1,030,000	$ 3,306,000
Number of tranches | item								3
Warrants [Member]
Fair value of liability							$ 1,952,000	$ 3,305,000
Risk-free interest rate							2.20%
Expected life							4 years 7 months 28 days
Volatility							74.90%
Expected dividend yield							0.00%
Success Fee [Member]
Fair value of liability	$ 0
Change in fair value of liability								(100,000)	$ (200,000)
Risk-free interest rate									0.49%
Expected life									6 months
Volatility									79.20%
Unit price | $ / shares									$ 32.50
Strike price | $ / shares									$ 74.17
Expected dividend yield									0.00%
Equity Issued from Credit Agreement [Member]
Fair value of liability							$ 1,200,000	3,300,000
Risk-free interest rate									0.49%
Expected life									6 months
Volatility									79.20%
Unit price | $ / shares									$ 32.50
Strike price | $ / shares									$ 61.75
Expected dividend yield									0.00%
Class E Redeemable Convertible Units [Member]
Unit price | $ / shares										$ 11.50
Class A Units [Member]
Shares used for underlying value of equity instrument | shares						536,065
Unit price | $ / shares											$ 32.50	$ 39.00
2015 Credit Agreement [Member]
Fair value of liability							$ 1,200,000
Strike price | $ / shares	$ 10.20						$ 10.20
Common units converted to warrants | shares	617,651
Change in fair value of warrant							$ (1,100,000)	$ (4,300,000)
Third Amended and Restated Convertible Credit Agreement [Member]
Strike price | $ / shares	$ 10.20
Common units converted to warrants | shares	351,992
Other Warrants [Member]
Fair value of liability				$ 1,600,000			700,000
Change in fair value of liability							(900,000)
Strike price | $ / shares	$ 138.06			$ 4.50									$ 21.24
Warrants reclassified from liabilities to equity							$ 22,800,000
Common units converted to warrants | shares	46,163
Warrants to purchase				$ 2,707,138
Warrants issued													$ 1,400,000
Number of units for purchase | shares													30,000
Risk-free interest rate							1.39%
Expected life							3 months 7 days
Volatility							71.50%
Expected dividend yield							0.00%
Secured Term Debt [Member] | 2015 Credit Agreement [Member]
Strike price | $ / shares							$ 10.20
Debt discount							$ 1,500,000
Secured Term Debt [Member] | Class A Warrants [Member] | 2015 Credit Agreement [Member]
Warrants to purchase					$ 6,300,000		6,300,000
Strike price, percent for calculation					85.00%
Loss on extinguishment of debt					$ 900,000
Debt discount					$ 5,400,000		$ 5,400,000
2017 Public Offering [Member]
Warrants issued | shares		1,800,000	8,910,000				10,710,000
Strike price | $ / shares							$ 3.35
Warrant exercise price term							5 years
Price per share of common stock at IPO date | $ / shares							$ 3.001
Warrants to purchase							$ 10,687,200
2017 Private Placement [Member]
Warrants issued | shares				2,707,138			2,707,138
Strike price | $ / shares				$ 4.50			$ 4.50
Warrant exercise price term				13 months			13 months
Price per share of common stock at IPO date | $ / shares				$ 3.36			$ 3.36