Loans, Allowance for Loan Losses and Credit Quality (Summary of Nonaccrual Loans) (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Tdrs Recorded Investment On Nonaccrual Status		$ 27,841	$ 29,348
Financing Receivable, Nonaccrual	[1]	42,966	45,413
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		24,895	26,310
Commercial Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		833	3,015
Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		0	311
Small Business [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		168	235
Residential Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		9,986	8,251
Consumer Home Equity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		6,973	7,278
Consumer - Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Nonaccrual		$ 111	$ 13

[1] (1)Included in these amounts were $27.8 million and $29.3 million of nonaccruing TDRs at June 30, 2019 and December 31, 2018, respectively.