Loans and Leases (Delinquency Status) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	$ 43,915.5	$ 40,358.3
NONACCRUAL	76.4	122.3
TOTAL LOANS AND LEASES	43,991.9	40,480.6
NONACCRUAL WITH NO ALLOWANCE	58.6	97.3
Other Real Estate Owned	0.0	3.0
Total Nonaccrual Assets	76.4	125.3
CURRENT
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	43,234.5	39,980.5
30 – 59 DAYS PAST DUE
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	412.5	272.3
60 – 89 DAYS PAST DUE
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	217.0	77.2
90 DAYS OR MORE PAST DUE
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	51.5	28.3
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	22,729.0	18,401.3
NONACCRUAL	60.3	86.1
TOTAL LOANS AND LEASES	22,789.3	18,487.4
NONACCRUAL WITH NO ALLOWANCE	42.5	61.1
Commercial | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	12,395.1	11,469.7
NONACCRUAL	18.4	19.5
TOTAL LOANS AND LEASES	12,413.5	11,489.2
NONACCRUAL WITH NO ALLOWANCE	4.6	8.8
Commercial | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	4,528.9	4,259.7
NONACCRUAL	41.9	66.6
TOTAL LOANS AND LEASES	4,570.8	4,326.3
NONACCRUAL WITH NO ALLOWANCE	37.9	52.3
Commercial | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	4,617.3	1,990.2
NONACCRUAL	0.0	0.0
TOTAL LOANS AND LEASES	4,617.3	1,990.2
NONACCRUAL WITH NO ALLOWANCE	0.0	0.0
Commercial | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL		11.0
NONACCRUAL		0.0
TOTAL LOANS AND LEASES	0.0	11.0
NONACCRUAL WITH NO ALLOWANCE		0.0
Commercial | Other
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	1,187.7	670.7
NONACCRUAL	0.0	0.0
TOTAL LOANS AND LEASES	1,187.7	670.7
NONACCRUAL WITH NO ALLOWANCE	0.0	0.0
Commercial | CURRENT
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	22,246.9	18,363.2
Commercial | CURRENT | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	11,949.8	11,434.7
Commercial | CURRENT | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	4,517.5	4,256.6
Commercial | CURRENT | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	4,591.9	1,990.2
Commercial | CURRENT | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL		11.0
Commercial | CURRENT | Other
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	1,187.7	670.7
Commercial | 30 – 59 DAYS PAST DUE
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	299.8	35.6
Commercial | 30 – 59 DAYS PAST DUE | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	269.9	32.5
Commercial | 30 – 59 DAYS PAST DUE | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	4.5	3.1
Commercial | 30 – 59 DAYS PAST DUE | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	25.4	0.0
Commercial | 30 – 59 DAYS PAST DUE | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL		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	177.3	2.1
Commercial | 60 – 89 DAYS PAST DUE | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	174.0	2.1
Commercial | 60 – 89 DAYS PAST DUE | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	3.3	0.0
Commercial | 60 – 89 DAYS PAST DUE | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	0.0	0.0
Commercial | 60 – 89 DAYS PAST DUE | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL		0.0
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	5.0	0.4
Commercial | 90 DAYS OR MORE PAST DUE | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	1.4	0.4
Commercial | 90 DAYS OR MORE PAST DUE | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	3.6	0.0
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 | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL		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	21,186.5	21,957.0
NONACCRUAL	16.1	36.2
TOTAL LOANS AND LEASES	21,202.6	21,993.2
NONACCRUAL WITH NO ALLOWANCE	16.1	36.2
Personal | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	13,945.2	15,256.3
NONACCRUAL	0.0	0.0
TOTAL LOANS AND LEASES	13,945.2	15,256.3
NONACCRUAL WITH NO ALLOWANCE	0.0	0.0
Personal | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	6,429.8	6,283.7
NONACCRUAL	16.1	36.2
TOTAL LOANS AND LEASES	6,445.9	6,319.9
NONACCRUAL WITH NO ALLOWANCE	16.1	36.2
Personal | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	616.4	381.8
NONACCRUAL	0.0	0.0
TOTAL LOANS AND LEASES	616.4	381.8
NONACCRUAL WITH NO ALLOWANCE	0.0	0.0
Personal | Other
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	195.1	35.2
NONACCRUAL	0.0	0.0
TOTAL LOANS AND LEASES	195.1	35.2
NONACCRUAL WITH NO ALLOWANCE	0.0	0.0
Personal | CURRENT
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	20,987.6	21,617.3
Personal | CURRENT | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	13,750.8	14,927.3
Personal | CURRENT | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	6,425.3	6,273.2
Personal | CURRENT | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	616.4	381.6
Personal | CURRENT | Other
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	195.1	35.2
Personal | 30 – 59 DAYS PAST DUE
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	112.7	236.7
Personal | 30 – 59 DAYS PAST DUE | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	112.0	229.5
Personal | 30 – 59 DAYS PAST DUE | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	0.7	7.0
Personal | 30 – 59 DAYS PAST DUE | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	0.0	0.2
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	39.7	75.1
Personal | 60 – 89 DAYS PAST DUE | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	37.2	71.8
Personal | 60 – 89 DAYS PAST DUE | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	2.5	3.3
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	46.5	27.9
Personal | 90 DAYS OR MORE PAST DUE | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	45.2	27.7
Personal | 90 DAYS OR MORE PAST DUE | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	1.3	0.2
Personal | 90 DAYS OR MORE PAST DUE | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	0.0	0.0
Personal | 90 DAYS OR MORE PAST DUE | Other
Financing Receivable, Credit Quality Indicator [Line Items]
TOTAL ACCRUAL	$ 0.0	$ 0.0