Loans and Leases (Troubled Debt Restructurings) (Details) - Lease Financing, net $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) Contract	Sep. 30, 2018 USD ($) Contract	Sep. 30, 2019 USD ($) Contract	Sep. 30, 2018 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	5	12	34	41
Recorded Investment	$ 3.1	$ 5.1	$ 28.2	$ 24.3
Unpaid Principal Balance	$ 3.1	$ 5.7	$ 29.6	$ 27.4
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	0	1	3	3
Recorded Investment	$ 0.0	$ 1.5	$ 7.6	$ 3.1
Unpaid Principal Balance	$ 0.0	$ 1.5	$ 8.8	$ 3.3
Commercial | Commercial and Institutional
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	0	0	1	1
Recorded Investment	$ 0.0	$ 0.0	$ 7.6	$ 0.3
Unpaid Principal Balance	$ 0.0	$ 0.0	$ 8.8	$ 0.5
Commercial | Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	0	1	2	2
Recorded Investment	$ 0.0	$ 1.5	$ 0.0	$ 2.8
Unpaid Principal Balance	$ 0.0	$ 1.5	$ 0.0	$ 2.8
Personal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	5	11	31	38
Recorded Investment	$ 3.1	$ 3.6	$ 20.6	$ 21.2
Unpaid Principal Balance	$ 3.1	$ 4.2	$ 20.8	$ 24.1
Personal | Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract	5	11	31	37
Recorded Investment	$ 3.1	$ 3.6	$ 20.6	$ 21.2
Unpaid Principal Balance	$ 3.1	$ 4.2	$ 20.8	$ 24.0
Personal | Private Client
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases | Contract		0		1
Recorded Investment		$ 0.0		$ 0.0
Unpaid Principal Balance		$ 0.0		$ 0.1