Nature of Business (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Nature of Business (Textual)
Cash and cash equivalents	$ 11,720,085	$ 4,999,153	$ 11,720,085	$ 4,999,153	$ 7,809,487	$ 8,772,567
Net decrease in cash and cash equivalents			$ 3,910,598	(3,773,414)
Percentage decrease in cash and cash equivalents			50.00%
Cash used in operations			$ (4,568,927)	(4,192,304)
Working capital	9,118,737		9,118,737		6,185,863
Increase in working capital			$ 2,932,874
Percentage of decrease in working capital			47.00%
Government contract and grant funding available			$ 15,200,000
Net proceeds from the sale of NJ NOL			416,810
Equity facility, available amount	10,100,000		$ 10,100,000
Equity facility expiration date			Mar. 31, 2019
Accumulated deficit	(163,065,201)		$ (163,065,201)		$ (157,270,045)
Net loss	$ (1,861,608)	$ (963,094)	$ (5,795,156)	$ (5,008,129)
Remaining from the ATM agreement with FBR,Description			The Company has up to $9.0 million remaining from the ATM agreement with FBR under the prospectus supplement updated October 3, 2018
Contracts from BARDA and NIAID, description			The Company is currently developing RiVax® under a NIH contract of up to $24.7 million, and SGX301 and SGX942 under two separate NIH grants of approximately $1.5 million each over two years.