Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 05, 2021
Document and Entity Information
Entity Registrant Name	HUMANIGEN, INC
Entity Central Index Key	0001293310
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		59,083,706
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Entity File Number	001-35798
Document Quarterly Report	true
Document Transition Report	false
Entity Shell Company	false