Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 31, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Entity Registrant Name	Synthetic Biologics, Inc.
Entity Central Index Key	0000894158
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	SYN
Entity Common Stock, Shares Outstanding		128,247,070