v3.24.3
Investments and Fair Value Measurements - Summary Of Assets And Liabilities That Are Measured At Fair Value On A Recurring And Nonrecurring Basis (Detail) - USD ($)
$ in Thousands
Sep. 30, 2024
Dec. 31, 2023
Marketable securities:    
Debt securities $ 3,787,649 $ 2,834,940
Total 4,337,663 3,435,491
Level 1    
Marketable securities:    
Total 545,200 594,836
Level 2    
Marketable securities:    
Total 3,792,463 2,840,655
Level 3    
Marketable securities:    
Total 0 0
U.S. Treasury securities    
Marketable securities:    
Debt securities 3,787,649 2,834,940
Cash and Cash Equivalents | Money market funds    
Cash and cash equivalents:    
Cash and cash equivalents 536,900 576,565
Cash and Cash Equivalents | Money market funds | Level 1    
Cash and cash equivalents:    
Cash and cash equivalents 536,900 576,565
Cash and Cash Equivalents | Money market funds | Level 2    
Cash and cash equivalents:    
Cash and cash equivalents 0 0
Cash and Cash Equivalents | Money market funds | Level 3    
Cash and cash equivalents:    
Cash and cash equivalents 0 0
Cash and Cash Equivalents | U.S. Treasury securities    
Cash and cash equivalents:    
Cash and cash equivalents   10,079
Marketable securities:    
Debt securities   10,079
Cash and Cash Equivalents | U.S. Treasury securities | Level 1    
Cash and cash equivalents:    
Cash and cash equivalents   0
Cash and Cash Equivalents | U.S. Treasury securities | Level 2    
Cash and cash equivalents:    
Cash and cash equivalents   10,079
Cash and Cash Equivalents | U.S. Treasury securities | Level 3    
Cash and cash equivalents:    
Cash and cash equivalents   0
Cash and Cash Equivalents | Certificates of deposit    
Cash and cash equivalents:    
Cash and cash equivalents   938
Cash and Cash Equivalents | Certificates of deposit | Level 1    
Cash and cash equivalents:    
Cash and cash equivalents   0
Cash and Cash Equivalents | Certificates of deposit | Level 2    
Cash and cash equivalents:    
Cash and cash equivalents   938
Cash and Cash Equivalents | Certificates of deposit | Level 3    
Cash and cash equivalents:    
Cash and cash equivalents   0
Prepaid Expenses and Other Current Assets and Other Assets | Certificates of deposit    
Prepaid expenses and other current assets and other assets:    
Certificates of deposit 4,814 4,777
Prepaid Expenses and Other Current Assets and Other Assets | Certificates of deposit | Level 1    
Prepaid expenses and other current assets and other assets:    
Certificates of deposit 0 0
Prepaid Expenses and Other Current Assets and Other Assets | Certificates of deposit | Level 2    
Prepaid expenses and other current assets and other assets:    
Certificates of deposit 4,814 4,777
Prepaid Expenses and Other Current Assets and Other Assets | Certificates of deposit | Level 3    
Prepaid expenses and other current assets and other assets:    
Certificates of deposit 0 0
Marketable Securities | U.S. Treasury securities    
Marketable securities:    
Debt securities 3,787,649 2,824,861
Marketable Securities | U.S. Treasury securities | Level 1    
Marketable securities:    
Debt securities 0 0
Marketable Securities | U.S. Treasury securities | Level 2    
Marketable securities:    
Debt securities 3,787,649 2,824,861
Marketable Securities | U.S. Treasury securities | Level 3    
Marketable securities:    
Debt securities 0 0
Marketable Securities | Publicly-traded equity securities    
Marketable securities:    
Publicly-traded equity securities 8,300 18,271
Marketable Securities | Publicly-traded equity securities | Level 1    
Marketable securities:    
Publicly-traded equity securities 8,300 18,271
Marketable Securities | Publicly-traded equity securities | Level 2    
Marketable securities:    
Publicly-traded equity securities 0 0
Marketable Securities | Publicly-traded equity securities | Level 3    
Marketable securities:    
Publicly-traded equity securities $ 0 $ 0