Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 01, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Trading Symbol	ATRS
Security Exchange Name	NASDAQ
Entity Registrant Name	ANTARES PHARMA, INC.
Entity Central Index Key	0001016169
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Entity Common Stock, Shares Outstanding		165,560,401
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity File Number	1-32302
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-1350192
Entity Address, Address Line One	100 Princeton South
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Ewing
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08628
City Area Code	609
Local Phone Number	359-3020
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false