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, 2016 USD ($) contracts	Dec. 31, 2015 USD ($) contracts	Dec. 31, 2014 USD ($) contracts
Financing Receivables, Modifications [Line Items]
Total Count | contracts	21	12	21
Total Balance | $	$ 12,897	$ 2,034	$ 11,967
Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	19	12	14
Total Balance | $	$ 12,656	$ 2,034	$ 8,025
Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	9	5	14
Total Balance | $	$ 8,046	$ 674	$ 8,391
Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	4	5
Total Balance | $	$ 470	$ 420	$ 4,120
Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 275	$ 0	$ 0
Commercial | Commercial, industrial and other
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	0	2
Total Balance | $	$ 345	$ 0	$ 1,549
Commercial | Commercial, industrial and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	0	1
Total Balance | $	$ 345	$ 0	$ 88
Commercial | Commercial, industrial and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 1,461
Commercial | Commercial, industrial and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	2
Total Balance | $	$ 0	$ 0	$ 1,549
Commercial | Commercial, industrial and other | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	0
Total Balance | $	$ 275	$ 0	$ 0
Commercial | Leases
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	0	0
Total Balance | $	$ 2,949	$ 0	$ 0
Commercial | Leases | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	0	0
Total Balance | $	$ 2,949	$ 0	$ 0
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 | Commercial construction
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Commercial construction | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Commercial construction | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Commercial construction | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Commercial construction | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Land
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Land | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Land | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Land | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Land | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0
Total Balance | $	$ 0
Commercial real estate | Office
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	2
Total Balance | $	$ 450	$ 0	$ 1,510
Commercial real estate | Office | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	1	0	2
Total Balance | $	$ 450	$ 0	$ 1,510
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	6	1	2
Total Balance | $	$ 7,921	$ 169	$ 1,763
Commercial real estate | Industrial | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	6	1	2
Total Balance | $	$ 7,921	$ 169	$ 1,763
Commercial real estate | Industrial | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	3	0	1
Total Balance | $	$ 7,196	$ 0	$ 685
Commercial real estate | Industrial | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	1	1
Total Balance | $	$ 0	$ 169	$ 1,078
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 | Retail
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 202
Commercial real estate | Retail | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 202
Commercial real estate | Retail | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Retail | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Retail | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Multi-family
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 181
Commercial real estate | Multi-family | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Multi-family | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	1
Total Balance | $	$ 0	$ 0	$ 181
Commercial real estate | Multi-family | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0
Commercial real estate | Multi-family | 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	2	7
Total Balance | $	$ 150	$ 201	$ 4,926
Commercial real estate | Mixed use and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	2	3
Total Balance | $	$ 150	$ 201	$ 2,837
Commercial real estate | Mixed use and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	7
Total Balance | $	$ 0	$ 0	$ 4,926
Commercial real estate | Mixed use and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	2	1
Total Balance | $	$ 0	$ 201	$ 1,273
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	7	9	6
Total Balance | $	$ 1,082	$ 1,664	$ 1,836
Residential real estate and other | Extension at Below Market Terms
Financing Receivables, Modifications [Line Items]
Total Count | contracts	5	9	5
Total Balance | $	$ 841	$ 1,664	$ 1,625
Residential real estate and other | Reduction of Interest Rate
Financing Receivables, Modifications [Line Items]
Total Count | contracts	6	5	4
Total Balance | $	$ 850	$ 674	$ 1,138
Residential real estate and other | Modification To Interest Only Payments
Financing Receivables, Modifications [Line Items]
Total Count | contracts	2	1	1
Total Balance | $	$ 470	$ 50	$ 220
Residential real estate and other | Forgiveness of Debt
Financing Receivables, Modifications [Line Items]
Total Count | contracts	0	0	0
Total Balance | $	$ 0	$ 0	$ 0