Premises and Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Finance leases	$ 3.4	$ 4.6
Depreciation and amortization expense	51.6	49.2	$ 42.6
Premises and equipment transferred to/(from) other assets, net	$ 7.0	$ 6.1