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Financial Condition (Details Narrative) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Cumulated net losses		$ (273,665,247)	$ (261,781,888)
Cash, investment securities and interest receivable		27,700,000
Common Stock Sales Agreement [Member] | Aspire Capital Fund, LLC [Member]
Proceeds from available future sale of equity under common stock purchase agreement		31,000,000
New Jersey [Member]
Tax benefits of EDA		11,100,000
New Jersey [Member] | Maximum [Member]
Tax benefits of EDA	$ (12,500,000)
New Jersey [Member]
Tax benefits of EDA		11,100,000
Unrecognized tax benefits		$ 3,900,000

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