Summary of Nonaccrual Loans (Details) - USD ($) $ in Thousands		Dec. 31, 2018		Dec. 31, 2017
Financing Receivable Impaired [Line Items]
TDRs on nonaccrual status		$ 29,348	[1]	$ 6,067
Financing Receivable, Recorded Investment, Nonaccrual Status	[2]	45,413		49,630
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		26,310		32,055
Commercial Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		3,015		3,123
Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		311		0
Small Business [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		235		230
Residential Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		8,251		8,129
Home Equity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		7,278		6,022
Consumer Portfolio Segment [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		$ 13		$ 71

[1] (1)During the fourth quarter of 2018 nonaccrual loans associated with a large commercial loan customer that had previously declared bankruptcy were modified when a court confirmed the customer's bankruptcy reorganization plan. That revision to loan terms required the Company to deem loans associated with the customer as troubled debt restructures as of December 31, 2018 which amounted to $25.9 million.

[2]
(1) Included in these amounts were $29.3 million and $6.1 million of nonaccruing TDRs at December 31, 2018 and 2017, respectively. During the fourth quarter of 2018 nonaccrual loans associated with a large commercial loan customer that had previously declared bankruptcy were modified when a court confirmed the customer's bankruptcy reorganization plan. That revision to loan terms required the Company to deem loans associated with the customer as troubled debt restructures as of December 31, 2018 which amounted to $25.9 million.