Loans and Leases (Credit Quality Indicator At Amortized Cost By Origination Year) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 7,448.6
2019	3,667.9
2018	1,352.6
2017	1,123.1
2016	1,254.8
PRIOR	3,128.5
REVOLVING LOANS	15,453.6
REVOLVING LOANS CONVERTED TO TERM LOANS	330.6
Lease Financing, net	33,759.7	$ 31,409.6
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,772.7
2019	2,187.7
2018	990.3
2017	725.0
2016	749.9
PRIOR	1,285.8
REVOLVING LOANS	5,490.9
REVOLVING LOANS CONVERTED TO TERM LOANS	59.7
Lease Financing, net	15,262.0	14,001.3
Commercial | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,491.5
2019	1,170.9
2018	596.0
2017	544.2
2016	553.6
PRIOR	622.1
REVOLVING LOANS	5,042.2
REVOLVING LOANS CONVERTED TO TERM LOANS	37.8
Lease Financing, net	10,058.3	9,091.1
Commercial | Commercial and Institutional | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	663.8
2019	546.0
2018	204.6
2017	96.0
2016	396.0
PRIOR	448.8
REVOLVING LOANS	3,742.4
REVOLVING LOANS CONVERTED TO TERM LOANS	5.5
Lease Financing, net	6,103.1
Commercial | Commercial and Institutional | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	793.4
2019	505.1
2018	354.1
2017	405.4
2016	134.6
PRIOR	167.3
REVOLVING LOANS	1,238.7
REVOLVING LOANS CONVERTED TO TERM LOANS	32.3
Lease Financing, net	3,630.9
Commercial | Commercial and Institutional | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	34.3
2019	119.8
2018	37.3
2017	42.8
2016	23.0
PRIOR	6.0
REVOLVING LOANS	61.1
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	324.3
Commercial | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,124.7
2019	976.2
2018	392.3
2017	169.7
2016	196.3
PRIOR	494.4
REVOLVING LOANS	184.7
REVOLVING LOANS CONVERTED TO TERM LOANS	20.1
Lease Financing, net	3,558.4	3,104.3
Commercial | Commercial Real Estate | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	406.3
2019	109.2
2018	27.6
2017	36.5
2016	11.8
PRIOR	99.4
REVOLVING LOANS	124.3
REVOLVING LOANS CONVERTED TO TERM LOANS	8.7
Lease Financing, net	823.8
Commercial | Commercial Real Estate | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	703.1
2019	811.8
2018	332.7
2017	107.4
2016	184.5
PRIOR	382.8
REVOLVING LOANS	60.4
REVOLVING LOANS CONVERTED TO TERM LOANS	11.4
Lease Financing, net	2,594.1
Commercial | Commercial Real Estate | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	15.3
2019	55.2
2018	32.0
2017	25.8
2016	0.0
PRIOR	12.2
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	140.5
Commercial | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
2020	868.3
2019	40.6
2018	2.0
2017	11.1
2016	0.0
PRIOR	157.9
REVOLVING LOANS	264.0
REVOLVING LOANS CONVERTED TO TERM LOANS	1.8
Lease Financing, net	1,345.7	1,576.3
Commercial | Non-U.S. | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	555.2
2019	16.8
2018	0.0
2017	11.1
2016	0.0
PRIOR	0.0
REVOLVING LOANS	78.5
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	661.6
Commercial | Non-U.S. | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	313.1
2019	0.7
2018	2.0
2017	0.0
2016	0.0
PRIOR	157.9
REVOLVING LOANS	39.2
REVOLVING LOANS CONVERTED TO TERM LOANS	1.8
Lease Financing, net	514.7
Commercial | Non-U.S. | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0.0
2019	23.1
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	146.3
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	169.4
Commercial | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0.0
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	11.4
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	11.4	65.6
Commercial | Lease Financing, net | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0.0
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	11.4
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	11.4
Commercial | Other
Financing Receivable, Credit Quality Indicator [Line Items]
2020	288.2
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	288.2	164.0
Commercial | Other | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	81.7
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	81.7
Commercial | Other | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	206.5
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	206.5
Personal
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,675.9
2019	1,480.2
2018	362.3
2017	398.1
2016	504.9
PRIOR	1,842.7
REVOLVING LOANS	9,962.7
REVOLVING LOANS CONVERTED TO TERM LOANS	270.9
Lease Financing, net	18,497.7	17,408.3
Personal | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,166.7
2019	754.1
2018	191.1
2017	124.0
2016	87.7
PRIOR	213.6
REVOLVING LOANS	9,021.2
REVOLVING LOANS CONVERTED TO TERM LOANS	256.7
Lease Financing, net	11,815.1	11,071.4
Personal | Private Client | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	668.6
2019	273.7
2018	51.7
2017	60.4
2016	10.2
PRIOR	136.1
REVOLVING LOANS	5,392.8
REVOLVING LOANS CONVERTED TO TERM LOANS	47.9
Lease Financing, net	6,641.4
Personal | Private Client | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	492.1
2019	479.9
2018	117.3
2017	60.4
2016	77.5
PRIOR	77.5
REVOLVING LOANS	3,564.7
REVOLVING LOANS CONVERTED TO TERM LOANS	207.3
Lease Financing, net	5,076.7
Personal | Private Client | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	6.0
2019	0.5
2018	22.1
2017	3.2
2016	0.0
PRIOR	0.0
REVOLVING LOANS	63.7
REVOLVING LOANS CONVERTED TO TERM LOANS	1.5
Lease Financing, net	97.0
Personal | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,424.2
2019	685.2
2018	159.4
2017	273.6
2016	416.7
PRIOR	1,619.1
REVOLVING LOANS	448.4
REVOLVING LOANS CONVERTED TO TERM LOANS	9.1
Lease Financing, net	6,035.7	6,095.0
Personal | Residential Real Estate | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,554.3
2019	317.4
2018	42.9
2017	109.9
2016	205.1
PRIOR	627.8
REVOLVING LOANS	152.8
REVOLVING LOANS CONVERTED TO TERM LOANS	1.7
Lease Financing, net	3,011.9
Personal | Residential Real Estate | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	854.6
2019	359.5
2018	115.8
2017	163.2
2016	209.7
PRIOR	896.5
REVOLVING LOANS	273.1
REVOLVING LOANS CONVERTED TO TERM LOANS	7.4
Lease Financing, net	2,879.8
Personal | Residential Real Estate | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	15.3
2019	8.3
2018	0.7
2017	0.5
2016	1.9
PRIOR	94.8
REVOLVING LOANS	22.5
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	144.0
Personal | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
2020	36.0
2019	40.9
2018	11.8
2017	0.5
2016	0.5
PRIOR	10.0
REVOLVING LOANS	493.1
REVOLVING LOANS CONVERTED TO TERM LOANS	5.1
Lease Financing, net	597.9	174.8
Personal | Non-U.S. | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	23.3
2019	14.9
2018	0.0
2017	0.0
2016	0.0
PRIOR	1.8
REVOLVING LOANS	275.6
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	315.6
Personal | Non-U.S. | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	12.7
2019	26.0
2018	11.8
2017	0.5
2016	0.5
PRIOR	7.9
REVOLVING LOANS	217.5
REVOLVING LOANS CONVERTED TO TERM LOANS	5.1
Lease Financing, net	282.0
Personal | Non-U.S. | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0.0
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.3
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	0.3
Personal | Other
Financing Receivable, Credit Quality Indicator [Line Items]
2020	49.0
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	49.0	$ 67.1
Personal | Other | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	34.6
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	34.6
Personal | Other | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2020	14.4
2019	0.0
2018	0.0
2017	0.0
2016	0.0
PRIOR	0.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
Lease Financing, net	$ 14.4