v3.26.1
Stock-based Compensation Expense - Stock-based Compensation Expense (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Stock-based Compensation Expense [Abstract]        
Stock-based compensation expense, net of amounts capitalized $ 45,595 $ 29,690 $ 88,870 $ 59,408
Capitalized stock-based compensation expense 0 509 18 1,000
Total stock-based compensation expense 45,595 30,199 88,888 60,408
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold        
Stock-based Compensation Expense [Abstract]        
Stock-based compensation expense, net of amounts capitalized 176 610 323 710
Location, Statement of Income, Balance [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense        
Stock-based Compensation Expense [Abstract]        
Stock-based compensation expense, net of amounts capitalized 20,321 9,538 38,743 18,858
Location, Statement of Income, Balance [Axis]: ions:ResearchDevelopmentAndPatentExpense        
Stock-based Compensation Expense [Abstract]        
Stock-based compensation expense, net of amounts capitalized $ 25,098 $ 19,542 $ 49,804 $ 39,840