Stock Options and Equity-Classified Warrants (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Vesting period	3 years
Average vesting period	6 years
Number of Options (Employees and Non-Employees) [Abstract]
Exercised (in shares)	(900,000)
Employees [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Estimated annualized forfeiture rate		10.00%	10.00%
Employees [Member] | Maximum [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Expected lives	10 years
Non-employees [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Unrecognized compensation expense related to unvested stock options, granted	$ 0
Weighted-Average Exercise Price Options [Abstract]
Issuance of stock options to certain consultants in exchange for services	422,000	$ 0	$ 0
Senior Management [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Estimated annualized forfeiture rate		2.00%	2.00%
Employees and Directors [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Unrecognized compensation expense related to unvested stock options, granted	$ 1,800,000
Unrecognized compensation cost, recognized as expense over a weighted-average period	1 year 1 month 24 days
Directors [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Estimated annualized forfeiture rate		0.00%	0.00%
Stock Options [Member] | Employees [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Expected dividend yield	0.00%	0.00%	0.00%
Stock Options [Member] | Employees [Member] | Minimum [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Risk-free interest rate	2.04%	1.20%	1.74%
Expected volatility	86.00%	74.00%	74.00%
Expected lives	6 years	6 years	6 years
Stock Options [Member] | Employees [Member] | Maximum [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Risk-free interest rate	2.35%	2.26%	2.12%
Expected volatility	92.00%	88.00%	85.00%
Expected lives	10 years	10 years	10 years
Stock Options [Member] | Non-employees [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Risk-free interest rate		0.00%	0.00%
Expected volatility	92.00%	0.00%	0.00%
Expected lives	10 years	0 years	0 years
Expected dividend yield	0.00%	0.00%	0.00%
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding - beginning of year (in shares)	100,000	105,952	115,357
Granted (in shares)	273,333	0	0
Exercised (in shares)	0	0	0
Expired/Forfeited (in shares)	0	(5,952)	(9,405)
Outstanding - end of year (in shares)	373,333	100,000	105,952
Exercisable at end of year (in shares)	373,333	100,000	105,952
Weighted average fair value of stock options granted during the year (in dollars per share)	$ 1.54	$ 0	$ 0
Weighted-Average Exercise Price Options [Abstract]
Outstanding - beginning of year (in dollars per share)	16.41	18.12	20.82
Granted (in dollars per share)	1.78	0	0
Exercised (in dollars per share)	0	0	0
Expired/Forfeited (in dollars per share)	0	46.62	51.24
Outstanding - end of year (in dollars per share)	5.70	16.41	18.12
Exercisable at end of year (in dollars per share)	$ 5.70	$ 16.41	$ 18.12
Stock Options [Member] | Non-employees [Member] | Minimum [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Risk-free interest rate	2.30%
Stock Options [Member] | Non-employees [Member] | Maximum [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Risk-free interest rate	2.35%
Stock Options [Member] | Employees and Directors [Member]
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding - beginning of year (in shares)	2,813,280	2,263,977	1,559,765
Granted (in shares)	591,369	809,500	765,000
Exercised (in shares)	(19,213)	(55,000)	(47,857)
Forfeited (in shares)	(874,210)	(196,054)	0
Expired (in shares)	(19,047)	(9,143)	(12,931)
Outstanding - end of year (in shares)	2,492,179	2,813,280	2,263,977
Exercisable at end of year (in shares)	1,701,445	1,811,320	1,336,694
Weighted average fair value of stock options granted during the year (in dollars per share)	$ 1.47	$ 2.58	$ 11.28
Weighted-Average Exercise Price Options [Abstract]
Outstanding - beginning of year (in dollars per share)	14.14	18.66	16.98
Granted (in dollars per share)	1.87	3.54	15.66
Exercised (in dollars per share)	2.58	12.84	12.30
Forfeited (in dollars per share)	13.11	20.94	0
Expired (in dollars per share)	56.88	48.18	33.48
Outstanding - end of year (in dollars per share)	11.35	14.14	18.66
Exercisable at end of year (in dollars per share)	$ 14.85	$ 17.70	$ 20.70
Warrants [Member]
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding - beginning of year (in shares)	5,417,155	1,204,245	1,224,960
Granted (in shares)	584,554	5,284,263	0
Exercised (in shares)	(861,581)	(9,393)	(1,667)
Forfeited (in shares)	0	0	0
Expired (in shares)	(1,159,347)	(1,061,960)	(19,048)
Outstanding - end of year (in shares)	3,980,781	5,417,155	1,204,245
Exercisable at end of year (in shares)	3,626,613	5,031,715	1,204,245
Weighted average fair value of stock options granted during the year (in dollars per share)	$ 1.65	$ 1.56	$ 0
Weighted-Average Exercise Price Options [Abstract]
Outstanding - beginning of year (in dollars per share)	4.08	25.68	25.62
Granted (in dollars per share)	6.31	3.72	0
Exercised (in dollars per share)	3.66	4.20	15.00
Forfeited (in dollars per share)	0	0	0
Expired (in dollars per share)	4.92	26.88	22.92
Outstanding - end of year (in dollars per share)	4.26	4.08	25.68
Exercisable at end of year (in dollars per share)	$ 4.23	$ 4.02	$ 25.68
Issuance of stock options to certain consultants in exchange for services	$ 41,865	$ 157,797
Restricted Stock [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Share based compensation arranged by share based payment award restricted stock granted (in shares)			0
Restricted Stock [Member] | Chairman and Chief Executive Officer [Member]
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Vesting period	3 years	3 years
Share based compensation arranged by share based payment award restricted stock granted (in shares)	387,597	387,597
Share based compensation of fair value of the restricted stock on the grant	$ 679,000	$ 1,000,000
2000 Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	233,334
Expiration date	Aug. 06, 2010
Share-based compensation, shares available for future grant (in shares)	0
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding - end of year (in shares)	44,371
2008 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	5,000,000
Share-based compensation, shares available for future grant (in shares)	1,200,000
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding - end of year (in shares)	2,800,000
2008 Stock Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, outstanding stock options (in shares)	800,000