Debt (Narrative) (Details)		1 Months Ended	12 Months Ended
	Aug. 01, 2016 $ / shares shares	Aug. 31, 2015 USD ($) item	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2017 USD ($)	Nov. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Debt Instrument [Line Items]
Debt discount			$ 1,030,000	$ 3,306,000
Debt Instrument, Unamortized Premium			345,000
Loss on extinguishment of debt				(11,176,000)	$ (2,934,000)
Deferred financing costs			$ 228,000	737,000
2015 Second-Lien Convertible Debt [Member]
Debt Instrument [Line Items]
Shares converted | shares	19,034,467
Total borrowings				15,000,000				$ 92,000,000
2015 Credit Agreement [Member]
Debt Instrument [Line Items]
Deferred principal payments						$ 380,000	$ 380,000
Additional equity capital to be raised						17,000,000	$ 40,000,000
Warrants exercise price | $ / shares	$ 10.20		$ 10.20
Secured Term Debt [Member] | 2015 Credit Agreement [Member]
Debt Instrument [Line Items]
Total borrowings		$ 35,000,000
Fees		$ 788,000
Monthly principal payments			$ 380,000
Maturity date			Jun. 17, 2018
Number of lenders | item		2
Debt discount			$ 1,500,000
Deferred financing cost write-offs			390,000
Deferred financing costs			1,300,000
Unamortized deferred financing costs			$ 200,000	700,000
Debt term			3 years
Interest expense			$ 500,000	$ 400,000	$ 400,000
Warrants exercise price | $ / shares			$ 10.20
Secured Term Debt [Member] | 2015 Credit Agreement [Member] | Class A Warrants [Member]
Debt Instrument [Line Items]
Warrants to purchase		$ 6,300,000	$ 6,300,000
Debt discount		5,400,000	5,400,000
Loss on extinguishment of debt		$ 900,000
Secured Term Debt [Member] | 2015 Credit Agreement [Member] | One Exsisting Lender [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt			113,000
Secured Term Debt [Member] | 2015 Credit Agreement, Third Amendment [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Premium						$ 900,000
Interest expense			$ 600,000
Warrants issued | shares			617,651
Warrants exercise price | $ / shares			$ 4.50
Expected proceeds if warrants are exercised			$ 2,800,000
Secured Term Debt [Member] | London Interbank Offered Rate (LIBOR) [Member] | 2015 Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument spread		9.375%
Secured Term Debt [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | 2015 Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument spread		1.00%