Quarterly report [Sections 13 or 15(d)]

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

v3.25.3
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, 2025
Dec. 31, 2024
Sep. 30, 2024
Dec. 31, 2023
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Cash and cash equivalents $ 305.5 $ 415.3    
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows 328.0 438.1 $ 417.9 $ 595.5
Prepaid expenses and other current assets [Member]        
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Restricted cash 3.7 4.3    
Other Assets [Member]        
Cash, Cash Equivalents and Restricted Cash [Line Items]        
Restricted cash $ 18.8 $ 18.5