Document And Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 12, 2013
Document Information [Line Items]
Entity Registrant Name	Synthetic Biologics, Inc.
Entity Central Index Key	0000894158
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Trading Symbol	SYN
Entity Common Stock, Shares Outstanding		44,654,414
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2013
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2013