Allowance for Credit Losses (Collateral Dependent Loans and Leases) (Details) $ in Thousands	Jun. 30, 2020 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 22,671,455
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,343,150
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,589,484
Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,459,954
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,727,904
Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,265,092
Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	940,443
Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,522,369
Residential
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,246,016
Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,056,588
Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,189,428
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	106,186
Residential Real Estate [Member] | Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Residential Real Estate [Member] | Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	102
Residential Real Estate [Member] | Commercial real estate | Commercial Real Estate, Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Residential Real Estate [Member] | Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	763
Residential Real Estate [Member] | Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	952
Residential Real Estate [Member] | Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Residential Real Estate [Member] | Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,507
Residential Real Estate [Member] | Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	101,862
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	14,081
Commercial Real Estate [Member] | Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,328
Commercial Real Estate [Member] | Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,845
Commercial Real Estate [Member] | Commercial real estate | Commercial Real Estate, Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	840
Commercial Real Estate [Member] | Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Commercial Real Estate [Member] | Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	68
Commercial Real Estate [Member] | Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Commercial Real Estate [Member] | Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Commercial Real Estate [Member] | Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
General Business Assets [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	17,522
General Business Assets [Member] | Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
General Business Assets [Member] | Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
General Business Assets [Member] | Commercial real estate | Commercial Real Estate, Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
General Business Assets [Member] | Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	575
General Business Assets [Member] | Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,167
General Business Assets [Member] | Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,780
General Business Assets [Member] | Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
General Business Assets [Member] | Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,534
Other Collateral [Member] | Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member] | Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member] | Commercial real estate | Commercial Real Estate, Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member] | Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	671
Other Collateral [Member] | Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,863
Other Collateral [Member] | Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member] | Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Other Collateral [Member] | Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Collateral Pledged [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	141,323
Collateral Pledged [Member] | Commercial real estate | Non-owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,328
Collateral Pledged [Member] | Commercial real estate | Owner occupied term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,947
Collateral Pledged [Member] | Commercial real estate | Commercial Real Estate, Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	840
Collateral Pledged [Member] | Commercial | Term, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,009
Collateral Pledged [Member] | Commercial | Lines of credit & other, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	13,050
Collateral Pledged [Member] | Commercial | Leases & equipment finance, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,780
Collateral Pledged [Member] | Residential | Mortgage, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,507
Collateral Pledged [Member] | Residential | Home equity loans & lines, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 101,862