Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2017	May 02, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
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		121,894,034