Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Feb. 20, 2020	Jun. 30, 2019
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	ANI PHARMACEUTICALS INC
Entity Current Reporting Status	Yes
Entity Central Index Key	0001023024
Current Fiscal Year End Date	--12-31
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 657.7
Class C Special Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		10,864
Convertible Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		12,096,556