Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash for Balance Sheets and Cash Flows (Detail)

v3.24.3
Significant Accounting Policies - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash for Balance Sheets and Cash Flows (Detail) - USD ($)
$ in Millions
Sep. 30, 2024
Dec. 31, 2023
Sep. 30, 2023
Dec. 31, 2022
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Cash and cash equivalents $ 402.5 $ 575.2    
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows 417.9 595.5 $ 516.0 $ 516.3
Prepaid expenses and other current assets [Member]        
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Restricted cash 10.3 15.3    
Other Assets [Member]        
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Restricted cash $ 5.1 $ 5.0