Allowance for Credit Losses (Accrued Interest Reversed Through Income) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable accrued interest income	$ 1.1	$ 3.5
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable accrued interest income	0.5	1.5
Personal
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable accrued interest income	$ 0.6	$ 2.0