XML 39 R33.htm IDEA: XBRL DOCUMENT v3.25.3
Organization and Summary of Significant Accounting Policies - Additional Information (Detail)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Jul. 02, 2025
USD ($)
$ / shares
shares
Jun. 08, 2025
Jun. 06, 2025
Dec. 02, 2024
USD ($)
Oct. 31, 2025
USD ($)
$ / shares
shares
Sep. 30, 2025
USD ($)
$ / shares
shares
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
$ / shares
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Cash and investments in marketable securities           $ 270,208   $ 270,208   $ 269,095
Aggregate maximum public offering amount               300,000    
Accounts receivable, credit loss expense (reversal)           $ 0 $ 0 $ 0 $ 0  
Reverse stock split, ratio             0.07   0.07 0.066667
Reverse stock split     Reverse Stock Split Amendment, to effect a reverse stock split of Nektar’s Common Stock at a ratio of one-for-fifteen, effective June 8, 2025.         one-for-fifteen reverse stock split   one-for-fifteen reverse stock split
Asset Purchase Agreement | Asset Acquisition By Ampersand Capital Partners                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Proceeds from sale of assets       $ 64,700            
Ownership interest received       20.00%            
Sales Agreement                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Aggregate maximum public offering amount               $ 75,000    
Percentage of gross sale of common stock sold through sales agents commission rate               3.00%    
At-the-Market Offering                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Net proceeds from issuance of common stock               $ 34,489 $ 0  
Common Stock                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Reverse stock split, ratio   0.07                
Common Stock | 2025 Offering                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Sale and issuance of shares | shares 4,893,618                  
Offering per share price | $ / shares $ 23.5                  
Net proceeds from issuance of common stock $ 107,200                  
Common Stock | At-the-Market Offering                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Sale and issuance of shares | shares [1]           600,198        
Offering per share price | $ / shares           $ 59.24   $ 59.24    
Net proceeds from issuance of common stock           $ 34,300        
Common Stock | At-the-Market Offering | Subsequent Event                    
Organization And Summary Of Significant Accounting Policies [Line Items]                    
Sale and issuance of shares | shares         673,725          
Offering per share price | $ / shares         $ 58.55          
Net proceeds from issuance of common stock         $ 38,300          
[1] All share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).