v3.25.2
Loans (Delinquency Status) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL $ 43,230.6 $ 43,334.6
NONACCRUAL 92.8 56.0
TOTAL LOANS 43,323.4 43,390.6
NONACCRUAL WITH NO ALLOWANCE 52.5 34.6
CURRENT    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 42,913.8 43,110.9
30 – 59 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 170.0 122.6
60 – 89 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 106.9 18.8
90 DAYS OR MORE PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 39.9 82.3
Commercial    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 20,035.3 20,242.9
NONACCRUAL 50.2 35.9
TOTAL LOANS 20,085.5 20,278.8
NONACCRUAL WITH NO ALLOWANCE 21.4 16.1
Commercial | Commercial and Institutional    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 9,849.9 10,507.3
NONACCRUAL 44.1 29.8
TOTAL LOANS 9,894.0 10,537.1
NONACCRUAL WITH NO ALLOWANCE 21.4 10.5
Commercial | Commercial Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 5,260.4 5,308.6
NONACCRUAL 5.6 5.6
TOTAL LOANS 5,266.0 5,314.2
NONACCRUAL WITH NO ALLOWANCE 0.0 5.6
Commercial | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 2,540.3 2,113.4
NONACCRUAL 0.5 0.5
TOTAL LOANS 2,540.8 2,113.9
NONACCRUAL WITH NO ALLOWANCE 0.0 0.0
Commercial | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 2,384.7 2,313.6
NONACCRUAL 0.0 0.0
TOTAL LOANS 2,384.7 2,313.6
NONACCRUAL WITH NO ALLOWANCE 0.0 0.0
Commercial | CURRENT    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 19,956.2 20,218.4
Commercial | CURRENT | Commercial and Institutional    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 9,807.9 10,486.9
Commercial | CURRENT | Commercial Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 5,223.3 5,304.9
Commercial | CURRENT | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 2,540.3 2,113.0
Commercial | CURRENT | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 2,384.7 2,313.6
Commercial | 30 – 59 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 58.4 16.1
Commercial | 30 – 59 DAYS PAST DUE | Commercial and Institutional    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 36.7 12.8
Commercial | 30 – 59 DAYS PAST DUE | Commercial Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 21.7 3.3
Commercial | 30 – 59 DAYS PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Commercial | 30 – 59 DAYS PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Commercial | 60 – 89 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 6.0 1.1
Commercial | 60 – 89 DAYS PAST DUE | Commercial and Institutional    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.7
Commercial | 60 – 89 DAYS PAST DUE | Commercial Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 6.0 0.0
Commercial | 60 – 89 DAYS PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.4
Commercial | 60 – 89 DAYS PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Commercial | 90 DAYS OR MORE PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 14.7 7.3
Commercial | 90 DAYS OR MORE PAST DUE | Commercial and Institutional    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 5.3 6.9
Commercial | 90 DAYS OR MORE PAST DUE | Commercial Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 9.4 0.4
Commercial | 90 DAYS OR MORE PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Commercial | 90 DAYS OR MORE PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Personal    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 23,195.3 23,091.7
NONACCRUAL 42.6 20.1
TOTAL LOANS 23,237.9 23,111.8
NONACCRUAL WITH NO ALLOWANCE 31.1 18.5
Personal | Private Client    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 16,279.2 15,846.5
NONACCRUAL 11.7 2.3
TOTAL LOANS 16,290.9 15,848.8
NONACCRUAL WITH NO ALLOWANCE 5.0 0.7
Personal | Residential Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 6,051.9 6,092.1
NONACCRUAL 30.9 17.8
TOTAL LOANS 6,082.8 6,109.9
NONACCRUAL WITH NO ALLOWANCE 26.1 17.8
Personal | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 498.9 674.7
NONACCRUAL 0.0 0.0
TOTAL LOANS 498.9 674.7
NONACCRUAL WITH NO ALLOWANCE 0.0 0.0
Personal | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 365.3 478.4
NONACCRUAL 0.0 0.0
TOTAL LOANS 365.3 478.4
NONACCRUAL WITH NO ALLOWANCE 0.0 0.0
Personal | CURRENT    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 22,957.6 22,892.5
Personal | CURRENT | Private Client    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 16,049.5 15,677.6
Personal | CURRENT | Residential Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 6,048.6 6,063.4
Personal | CURRENT | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 494.2 673.1
Personal | CURRENT | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 365.3 478.4
Personal | 30 – 59 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 111.6 106.5
Personal | 30 – 59 DAYS PAST DUE | Private Client    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 110.5 87.7
Personal | 30 – 59 DAYS PAST DUE | Residential Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 17.2
Personal | 30 – 59 DAYS PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 1.1 1.6
Personal | 30 – 59 DAYS PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Personal | 60 – 89 DAYS PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 100.9 17.7
Personal | 60 – 89 DAYS PAST DUE | Private Client    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 98.1 15.2
Personal | 60 – 89 DAYS PAST DUE | Residential Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 2.8 2.5
Personal | 60 – 89 DAYS PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Personal | 60 – 89 DAYS PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.0 0.0
Personal | 90 DAYS OR MORE PAST DUE    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 25.2 75.0
Personal | 90 DAYS OR MORE PAST DUE | Private Client    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 21.1 66.0
Personal | 90 DAYS OR MORE PAST DUE | Residential Real Estate    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 0.5 9.0
Personal | 90 DAYS OR MORE PAST DUE | Non-U.S.    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL 3.6 0.0
Personal | 90 DAYS OR MORE PAST DUE | Other    
Financing Receivable, Credit Quality Indicator [Line Items]    
TOTAL ACCRUAL $ 0.0 $ 0.0