Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary of the Post-Modification Balance of Loans Restructured) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) contracts	Dec. 31, 2017 USD ($) contracts	Dec. 31, 2016 USD ($) contracts
Financing Receivables, Modifications [Line Items]
Total Count | contracts	71	21	21
Total Balance | $	$ 29,243	$ 24,325	$ 12,897
Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	67	12	19
Total Balance | $	$ 11,132	$ 4,265	$ 12,656
Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	28	9	9
Total Balance | $	$ 2,874	$ 4,915	$ 8,046
Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	7	2
Total Balance | $	$ 17,872	$ 17,719	$ 470
Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	1	1
Total Balance | $	$ 239	$ 69	$ 275
Commercial | Commercial, industrial and other
Financing Receivables, Modifications [Line Items]
Total Count | contracts	4	5	3
Total Balance | $	$ 13,441	$ 3,775	$ 345
Commercial | Commercial, industrial and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	1	3
Total Balance | $	$ 691	$ 95	$ 345
Commercial | Commercial, industrial and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	1	0
Total Balance | $	$ 0	$ 2,272	$ 0
Commercial | Commercial, industrial and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	3	0
Total Balance | $	$ 12,750	$ 1,408	$ 0
Commercial | Commercial, industrial and other | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 275
Commercial | Franchise
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	3	0
Total Balance | $	$ 5,157	$ 16,256	$ 0
Commercial | Franchise | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 35	$ 0	$ 0
Commercial | Franchise | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Franchise | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	3	0
Total Balance | $	$ 5,122	$ 16,256	$ 0
Commercial | Franchise | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Asset-based lending
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 130	$ 0	$ 0
Commercial | Asset-based lending | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 130	$ 0	$ 0
Commercial | Asset-based lending | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Asset-based lending | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Asset-based lending | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Leases
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	2
Total Balance | $	$ 239	$ 0	$ 2,949
Commercial | Leases | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	2
Total Balance | $	$ 239	$ 0	$ 2,949
Commercial | Leases | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Leases | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial | Leases | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Office
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	1
Total Balance | $	$ 59	$ 0	$ 450
Commercial real estate | Office | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	1
Total Balance | $	$ 59	$ 0	$ 450
Commercial real estate | Office | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Office | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Office | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Industrial
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	6
Total Balance | $	$ 0	$ 0	$ 7,921
Commercial real estate | Industrial | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	6
Total Balance | $	$ 0	$ 0	$ 7,921
Commercial real estate | Industrial | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	3
Total Balance | $	$ 0	$ 0	$ 7,196
Commercial real estate | Industrial | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Industrial | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Mixed use and other
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	1	2
Total Balance | $	$ 455	$ 1,245	$ 150
Commercial real estate | Mixed use and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	1	2
Total Balance | $	$ 455	$ 1,245	$ 150
Commercial real estate | Mixed use and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 85	$ 0	$ 0
Commercial real estate | Mixed use and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Mixed use and other | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Residential real estate and other
Financing Receivables, Modifications [Line Items]
Total Count | contracts	59	12	7
Total Balance | $	$ 9,762	$ 3,049	$ 1,082
Residential real estate and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	58	10	5
Total Balance | $	$ 9,523	$ 2,925	$ 841
Residential real estate and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	27	8	6
Total Balance | $	$ 2,789	$ 2,643	$ 850
Residential real estate and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	1	2
Total Balance | $	$ 0	$ 55	$ 470
Residential real estate and other | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	1	0
Total Balance | $	$ 239	$ 69	$ 0