Loans and Leases (Credit Quality Indicator At Amortized Cost By Origination Year) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	$ 2,935.8	$ 7,724.7
2021/2020	6,077.6	3,571.3
2020/2019	3,414.8	2,863.1
2019/2018	2,504.6	1,226.4
2018/2017	1,103.6	836.4
PRIOR	4,183.8	3,588.4
REVOLVING LOANS	18,720.1	20,378.9
REVOLVING LOANS CONVERTED TO TERM LOANS	298.8	291.4
TOTAL LOANS AND LEASES	39,239.1	40,480.6
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	2,374.6	5,171.3
2021/2020	3,520.0	1,770.3
2020/2019	1,756.2	1,806.1
2019/2018	1,508.7	660.8
2018/2017	526.3	423.9
PRIOR	1,925.2	1,449.6
REVOLVING LOANS	7,555.8	7,147.0
REVOLVING LOANS CONVERTED TO TERM LOANS	57.9	58.4
TOTAL LOANS AND LEASES	19,224.7	18,487.4
Commercial | Commercial and Institutional
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	428.5	2,079.4
2021/2020	2,013.5	757.9
2020/2019	687.9	922.7
2019/2018	675.7	387.7
2018/2017	266.3	308.6
PRIOR	1,077.8	773.7
REVOLVING LOANS	6,574.1	6,226.0
REVOLVING LOANS CONVERTED TO TERM LOANS	32.8	33.2
TOTAL LOANS AND LEASES	11,756.6	11,489.2
Commercial | Commercial and Institutional | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	268.0	1,042.0
2021/2020	796.2	310.2
2020/2019	286.6	468.9
2019/2018	237.5	163.9
2018/2017	84.7	55.4
PRIOR	582.1	541.6
REVOLVING LOANS	5,285.9	4,946.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.1	0.1
TOTAL LOANS AND LEASES	7,541.1	7,528.1
Commercial | Commercial and Institutional | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	160.5	993.4
2021/2020	1,190.6	441.7
2020/2019	401.3	406.7
2019/2018	395.8	193.6
2018/2017	155.3	243.3
PRIOR	484.3	230.2
REVOLVING LOANS	1,248.6	1,217.8
REVOLVING LOANS CONVERTED TO TERM LOANS	32.7	33.1
TOTAL LOANS AND LEASES	4,069.1	3,759.8
Commercial | Commercial and Institutional | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	44.0
2021/2020	26.7	6.0
2020/2019	0.0	47.1
2019/2018	42.4	30.2
2018/2017	26.3	9.9
PRIOR	11.4	1.9
REVOLVING LOANS	39.6	62.2
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	146.4	201.3
Commercial | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	164.0	1,434.8
2021/2020	1,393.0	943.5
2020/2019	903.4	821.9
2019/2018	791.0	271.2
2018/2017	260.0	106.2
PRIOR	526.3	473.0
REVOLVING LOANS	234.2	252.3
REVOLVING LOANS CONVERTED TO TERM LOANS	23.3	23.4
TOTAL LOANS AND LEASES	4,295.2	4,326.3
Commercial | Commercial Real Estate | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	81.8	472.0
2021/2020	511.5	298.7
2020/2019	304.6	279.8
2019/2018	257.8	65.8
2018/2017	54.3	16.6
PRIOR	103.5	79.5
REVOLVING LOANS	62.5	67.5
REVOLVING LOANS CONVERTED TO TERM LOANS	2.2	2.9
TOTAL LOANS AND LEASES	1,378.2	1,282.8
Commercial | Commercial Real Estate | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	74.3	912.7
2021/2020	870.0	644.8
2020/2019	598.8	491.5
2019/2018	482.8	205.4
2018/2017	205.7	89.6
PRIOR	421.7	390.6
REVOLVING LOANS	169.2	182.3
REVOLVING LOANS CONVERTED TO TERM LOANS	21.1	20.5
TOTAL LOANS AND LEASES	2,843.6	2,937.4
Commercial | Commercial Real Estate | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	7.9	50.1
2021/2020	11.5	0.0
2020/2019	0.0	50.6
2019/2018	50.4	0.0
2018/2017	0.0	0.0
PRIOR	1.1	2.9
REVOLVING LOANS	2.5	2.5
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	73.4	106.1
Commercial | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	1,275.2	986.4
2021/2020	113.5	68.9
2020/2019	164.9	61.5
2019/2018	42.0	1.9
2018/2017	0.0	9.1
PRIOR	310.1	191.9
REVOLVING LOANS	747.5	668.7
REVOLVING LOANS CONVERTED TO TERM LOANS	1.8	1.8
TOTAL LOANS AND LEASES	2,655.0	1,990.2
Commercial | Non-U.S. | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	988.4	816.5
2021/2020	63.3	68.9
2020/2019	164.9	38.4
2019/2018	18.9	0.0
2018/2017	0.0	9.1
PRIOR	8.9	0.0
REVOLVING LOANS	657.3	582.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	1,901.7	1,514.9
Commercial | Non-U.S. | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	263.3	167.0
2021/2020	50.2	0.0
2020/2019	0.0	0.0
2019/2018	0.0	1.9
2018/2017	0.0	0.0
PRIOR	301.2	191.9
REVOLVING LOANS	72.8	73.3
REVOLVING LOANS CONVERTED TO TERM LOANS	1.8	1.8
TOTAL LOANS AND LEASES	689.3	435.9
Commercial | Non-U.S. | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	23.5	2.9
2021/2020	0.0	0.0
2020/2019	0.0	23.1
2019/2018	23.1	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	17.4	13.4
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	64.0	39.4
Commercial | Lease Financing, net
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	0.0
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	11.0	11.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	11.0	11.0
Commercial | Lease Financing, net | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021		0.0
2021/2020		0.0
2020/2019		0.0
2019/2018		0.0
2018/2017		0.0
PRIOR		11.0
REVOLVING LOANS		0.0
REVOLVING LOANS CONVERTED TO TERM LOANS		0.0
TOTAL LOANS AND LEASES		11.0
Commercial | Lease Financing, net | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0
2021/2020	0.0
2020/2019	0.0
2019/2018	0.0
2018/2017	0.0
PRIOR	11.0
REVOLVING LOANS	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0
TOTAL LOANS AND LEASES	11.0
Commercial | Other
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	506.9	670.7
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	506.9	670.7
Commercial | Other | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	363.2	551.5
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	363.2	551.5
Commercial | Other | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	143.7	119.2
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	143.7	119.2
Personal
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	561.2	2,553.4
2021/2020	2,557.6	1,801.0
2020/2019	1,658.6	1,057.0
2019/2018	995.9	565.6
2018/2017	577.3	412.5
PRIOR	2,258.6	2,138.8
REVOLVING LOANS	11,164.3	13,231.9
REVOLVING LOANS CONVERTED TO TERM LOANS	240.9	233.0
TOTAL LOANS AND LEASES	20,014.4	21,993.2
Personal | Private Client
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	159.7	1,002.2
2021/2020	1,075.2	454.2
2020/2019	400.9	490.2
2019/2018	452.2	248.6
2018/2017	264.3	94.3
PRIOR	260.1	169.7
REVOLVING LOANS	10,437.2	12,574.1
REVOLVING LOANS CONVERTED TO TERM LOANS	230.9	223.0
TOTAL LOANS AND LEASES	13,280.5	15,256.3
Personal | Private Client | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	113.2	432.5
2021/2020	376.9	116.6
2020/2019	87.7	90.3
2019/2018	17.5	14.9
2018/2017	69.1	39.3
PRIOR	186.4	129.8
REVOLVING LOANS	5,538.8	7,592.8
REVOLVING LOANS CONVERTED TO TERM LOANS	30.1	44.7
TOTAL LOANS AND LEASES	6,419.7	8,460.9
Personal | Private Client | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	46.5	567.8
2021/2020	697.3	335.2
2020/2019	313.0	396.9
2019/2018	434.7	213.3
2018/2017	175.3	55.0
PRIOR	73.7	39.9
REVOLVING LOANS	4,871.2	4,979.8
REVOLVING LOANS CONVERTED TO TERM LOANS	200.8	178.3
TOTAL LOANS AND LEASES	6,812.5	6,766.2
Personal | Private Client | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	1.9
2021/2020	1.0	2.4
2020/2019	0.2	3.0
2019/2018	0.0	20.4
2018/2017	19.9	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	27.2	1.5
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	48.3	29.2
Personal | Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	382.3	1,452.4
2021/2020	1,429.5	1,346.8
2020/2019	1,257.7	545.0
2019/2018	521.1	306.6
2018/2017	294.8	318.2
PRIOR	1,960.8	1,964.1
REVOLVING LOANS	371.8	384.6
REVOLVING LOANS CONVERTED TO TERM LOANS	2.2	2.2
TOTAL LOANS AND LEASES	6,220.2	6,319.9
Personal | Residential Real Estate | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	294.8	1,018.1
2021/2020	945.7	660.3
2020/2019	574.5	213.0
2019/2018	209.4	110.4
2018/2017	104.0	139.8
PRIOR	835.0	763.1
REVOLVING LOANS	132.5	161.5
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	3,095.9	3,066.2
Personal | Residential Real Estate | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	87.5	434.0
2021/2020	476.8	676.6
2020/2019	681.8	325.5
2019/2018	305.4	190.9
2018/2017	189.2	172.1
PRIOR	1,074.2	1,145.9
REVOLVING LOANS	237.4	218.1
REVOLVING LOANS CONVERTED TO TERM LOANS	2.2	2.2
TOTAL LOANS AND LEASES	3,054.5	3,165.3
Personal | Residential Real Estate | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	0.3
2021/2020	7.0	9.9
2020/2019	1.4	6.5
2019/2018	6.3	5.3
2018/2017	1.6	6.3
PRIOR	51.6	55.1
REVOLVING LOANS	1.9	5.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	69.8	88.4
Personal | Non-U.S.
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	2.1	63.6
2021/2020	52.9	0.0
2020/2019	0.0	21.8
2019/2018	22.6	10.4
2018/2017	18.2	0.0
PRIOR	37.7	5.0
REVOLVING LOANS	355.3	273.2
REVOLVING LOANS CONVERTED TO TERM LOANS	7.8	7.8
TOTAL LOANS AND LEASES	496.6	381.8
Personal | Non-U.S. | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	27.5
2021/2020	16.3	0.0
2020/2019	0.0	1.2
2019/2018	2.4	0.0
2018/2017	4.5	0.0
PRIOR	1.0	1.0
REVOLVING LOANS	124.2	44.1
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	148.4	73.8
Personal | Non-U.S. | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	2.1	36.1
2021/2020	36.6	0.0
2020/2019	0.0	20.6
2019/2018	20.2	10.4
2018/2017	13.7	0.0
PRIOR	36.5	3.8
REVOLVING LOANS	231.1	229.1
REVOLVING LOANS CONVERTED TO TERM LOANS	7.8	7.8
TOTAL LOANS AND LEASES	348.0	307.8
Personal | Non-U.S. | 6 to 9 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	0.0	0.0
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.2	0.2
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	0.2	0.2
Personal | Other
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	17.1	35.2
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	17.1	35.2
Personal | Other | 1 to 3 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	10.0	13.4
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	10.0	13.4
Personal | Other | 4 to 5 Category
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021	7.1	21.8
2021/2020	0.0	0.0
2020/2019	0.0	0.0
2019/2018	0.0	0.0
2018/2017	0.0	0.0
PRIOR	0.0	0.0
REVOLVING LOANS	0.0	0.0
REVOLVING LOANS CONVERTED TO TERM LOANS	0.0	0.0
TOTAL LOANS AND LEASES	$ 7.1	$ 21.8