Loans (Summary Of Commercial PCI Loans By Credit Quality) (Details) - Commercial PCI Loans - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 55.7	$ 113.2
Non-criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	21.8	41.0
Criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	33.9	72.2
Commercial Banking
Financing Receivable, Recorded Investment [Line Items]
Loans	10.6	42.7
Commercial Banking | Non-criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	0.0	5.4
Commercial Banking | Criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	10.6	37.3
Real Estate Finance
Financing Receivable, Recorded Investment [Line Items]
Loans	45.1	70.5
Real Estate Finance | Non-criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	21.8	35.6
Real Estate Finance | Criticized
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 23.3	$ 34.9