v3.24.2.u1
FAIR VALUE MEASUREMENTS - Fair Value of Assets Measured on a Recurring Basis (Detail) - USD ($)
$ in Thousands
Jun. 30, 2024
Dec. 31, 2023
Financial assets    
Cash equivalents $ 42,615 $ 34,159
Marketable debt securities 1,688,883 1,649,675
Marketable equity securities 9,889 11,178
Recurring    
Financial assets    
Marketable equity securities 9,889 11,178
Total financial assets 1,858,456 1,828,122
Financial liabilities    
Development derivative liability 390,939 324,941
Recurring | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Marketable equity securities 9,889 11,178
Total financial assets 169,573 178,447
Financial liabilities    
Development derivative liability 0 0
Recurring | Significant Observable Inputs (Level 2)    
Financial assets    
Marketable equity securities 0 0
Total financial assets 1,688,883 1,649,675
Financial liabilities    
Development derivative liability 0 0
Recurring | Significant Unobservable Inputs (Level 3)    
Financial assets    
Marketable equity securities 0 0
Total financial assets 0 0
Financial liabilities    
Development derivative liability 390,939 324,941
Recurring | Money market funds    
Financial assets    
Cash equivalents 158,467 166,059
Restricted cash (money market funds) 1,217 1,210
Recurring | Money market funds | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Cash equivalents 158,467 166,059
Restricted cash (money market funds) 1,217 1,210
Recurring | Money market funds | Significant Observable Inputs (Level 2)    
Financial assets    
Cash equivalents 0 0
Restricted cash (money market funds) 0 0
Recurring | Money market funds | Significant Unobservable Inputs (Level 3)    
Financial assets    
Cash equivalents 0 0
Restricted cash (money market funds) 0 0
Recurring | U.S. treasury securities    
Financial assets    
Cash equivalents 36,315 30,712
Marketable debt securities 882,671 862,022
Recurring | U.S. treasury securities | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Cash equivalents 0 0
Marketable debt securities 0 0
Recurring | U.S. treasury securities | Significant Observable Inputs (Level 2)    
Financial assets    
Cash equivalents 36,315 30,712
Marketable debt securities 882,671 862,022
Recurring | U.S. treasury securities | Significant Unobservable Inputs (Level 3)    
Financial assets    
Cash equivalents 0 0
Marketable debt securities 0 0
Recurring | Commercial paper    
Financial assets    
Cash equivalents 6,300 2,685
Marketable debt securities 70,079 56,216
Recurring | Commercial paper | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Cash equivalents 0 0
Marketable debt securities 0 0
Recurring | Commercial paper | Significant Observable Inputs (Level 2)    
Financial assets    
Cash equivalents 6,300 2,685
Marketable debt securities 70,079 56,216
Recurring | Commercial paper | Significant Unobservable Inputs (Level 3)    
Financial assets    
Cash equivalents 0 0
Marketable debt securities 0 0
Recurring | Municipal securities    
Financial assets    
Marketable debt securities 5,014  
Recurring | Municipal securities | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Marketable debt securities 0  
Recurring | Municipal securities | Significant Observable Inputs (Level 2)    
Financial assets    
Marketable debt securities 5,014  
Recurring | Municipal securities | Significant Unobservable Inputs (Level 3)    
Financial assets    
Marketable debt securities 0  
Recurring | Corporate notes    
Financial assets    
Cash equivalents   762
Marketable debt securities 305,003 252,350
Recurring | Corporate notes | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Cash equivalents   0
Marketable debt securities 0 0
Recurring | Corporate notes | Significant Observable Inputs (Level 2)    
Financial assets    
Cash equivalents   762
Marketable debt securities 305,003 252,350
Recurring | Corporate notes | Significant Unobservable Inputs (Level 3)    
Financial assets    
Cash equivalents   0
Marketable debt securities 0 0
Recurring | U.S. government-sponsored enterprise securities    
Financial assets    
Marketable debt securities 383,501 441,341
Recurring | U.S. government-sponsored enterprise securities | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Marketable debt securities 0 0
Recurring | U.S. government-sponsored enterprise securities | Significant Observable Inputs (Level 2)    
Financial assets    
Marketable debt securities 383,501 441,341
Recurring | U.S. government-sponsored enterprise securities | Significant Unobservable Inputs (Level 3)    
Financial assets    
Marketable debt securities $ 0 0
Recurring | Certificates of deposit    
Financial assets    
Marketable debt securities   3,587
Recurring | Certificates of deposit | Quoted Prices in Active Markets (Level 1)    
Financial assets    
Marketable debt securities   0
Recurring | Certificates of deposit | Significant Observable Inputs (Level 2)    
Financial assets    
Marketable debt securities   3,587
Recurring | Certificates of deposit | Significant Unobservable Inputs (Level 3)    
Financial assets    
Marketable debt securities   $ 0