Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Mar. 01, 2014	Jun. 30, 2013
Document and Entity Information
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Entity Registrant Name	HEMISPHERX BIOPHARMA INC
Entity Central Index Key	0000946644
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		179,340,426
Entity Current Reporting Status	Yes
Entity Public Float			$ 36,034,329
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No