XML 75 R1.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2019
Feb. 20, 2020
Jun. 30, 2019
Cover [Abstract]      
Entity Registrant Name Ionis Pharmaceuticals, Inc.    
Entity Central Index Key 0000874015    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Shell Company false    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Public Float     $ 7,483,343,134
Entity Common Stock, Shares Outstanding   139,219,800  
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Document Annual Report true    
Document Transition Report false    
Entity File Number 000-19125    
Entity Tax Identification Number 33-0336973    
Entity Incorporation, State or Country Code DE    
Entity Address, Address Line One 2855 Gazelle Court    
Entity Address, City or Town Carlsbad    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 92010    
City Area Code 760    
Local Phone Number 931-9200    
Title of 12(b) Security Common Stock, $.001 Par Value    
Trading Symbol IONS    
Security Exchange Name NASDAQ