Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
12 Months Ended
Dec. 31, 2023
Mar. 27, 2024
Jun. 30, 2023
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Financial Statement Error Correction [Flag] false    
Entity Interactive Data Current Yes    
ICFR Auditor Attestation Flag false    
Amendment Flag false    
Document Period End Date Dec. 31, 2023    
Document Fiscal Year Focus 2023    
Document Fiscal Period Focus FY    
Entity Information [Line Items]      
Entity Central Index Key 0001388320    
Entity File Number 001-36374    
Entity Tax Identification Number 74-2963609    
Entity Incorporation, State or Country Code DE    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Shell Company false    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Public Float     $ 200,262,958
Entity Contact Personnel [Line Items]      
Entity Address, Address Line One 100 Park Ave., 23rd Floor    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10017    
Entity Phone Fax Numbers [Line Items]      
City Area Code (646)    
Local Phone Number 677-3870    
Entity Listings [Line Items]      
Title of 12(b) Security Common stock, par value $0.001    
Trading Symbol ATNM    
Security Exchange Name NYSE    
Entity Common Stock, Shares Outstanding   29,396,411