XML 65 R54.htm IDEA: XBRL DOCUMENT v3.25.3
Investment Securities - Additional Information (Details)
 3 Months Ended 9 Months Ended
Sep. 30, 2025
USD ($)
security
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
security
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Summary of Investment Holdings [Line Items]          
Transferred from available-for-sale to held-for-maturity $ 97,900,000   $ 97,900,000   $ 110,000,000.0
Allowance for credit losses for available-for-sale debt securities $ 0   $ 0   $ 0
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest   Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest   Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest
Allowance for securities held-to-maturity $ 150,000   $ 150,000   $ 150,000
Accrued interest receivable $ 58,600,000   $ 58,600,000   55,300,000
Number of securities in security portfolio | security 3,197   3,197    
Number of securities in unrealized loss position | security 2,292   2,292    
Equity securities, at fair value $ 126,281,000   $ 126,281,000   91,996,000
Gains on equity securities 1,000,000.0 $ 1,500,000 400,000 $ 1,400,000  
Impairments on equity securities without readily determinable fair value     0 0  
Downward adjustments on equity securities without readily determinable fair value     0 $ 0  
Other Assets          
Summary of Investment Holdings [Line Items]          
Equity securities without readily determinable fair value 942,100,000   942,100,000   609,200,000
Other Assets | Partnership Interest          
Summary of Investment Holdings [Line Items]          
Equity securities without readily determinable fair value 553,700,000   553,700,000   318,500,000
Other Assets | Initiatives in Low-to-Moderate Income Neighborhoods          
Summary of Investment Holdings [Line Items]          
Equity securities without readily determinable fair value $ 388,300,000   $ 388,300,000   $ 290,700,000