Loans and Leases (Troubled Debt Restructurings) (Details) - Lease Financing, net $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	17	24	38	55
Recorded Investment	$ 8.1	$ 6.9	$ 13.4	$ 21.9
Unpaid Principal Balance	$ 8.4	$ 7.4	$ 13.8	$ 27.3
Commercial
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	0	3	1	10
Recorded Investment	$ 0.0	$ 1.9	$ 1.4	$ 11.4
Unpaid Principal Balance	$ 0.0	$ 2.0	$ 1.3	$ 15.7
Commercial | Commercial and Institutional
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	0	2	0	4
Recorded Investment	$ 0.0	$ 0.1	$ 0.0	$ 4.1
Unpaid Principal Balance	$ 0.0	$ 0.2	$ 0.0	$ 6.2
Commercial | Real Estate
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	0	1	1	6
Recorded Investment	$ 0.0	$ 1.8	$ 1.4	$ 7.3
Unpaid Principal Balance	$ 0.0	$ 1.8	$ 1.3	$ 9.5
Personal
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	17	21	37	45
Recorded Investment	$ 8.1	$ 5.0	$ 12.0	$ 10.5
Unpaid Principal Balance	$ 8.4	$ 5.4	$ 12.5	$ 11.6
Personal | Real Estate
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	17	20	36	44
Recorded Investment	$ 8.1	$ 3.0	$ 12.0	$ 8.5
Unpaid Principal Balance	$ 8.4	$ 3.4	$ 12.4	$ 9.6
Personal | Private Client
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | Contract	0	1	1	1
Recorded Investment	$ 0.0	$ 2.0	$ 0.0	$ 2.0
Unpaid Principal Balance	$ 0.0	$ 2.0	$ 0.1	$ 2.0