Balance Sheet Offsetting (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets [Line Items]
Derivative Asset, Not Offset	[1],[2]	$ 0	$ 0
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Gross		18,239	7,871
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Liability		0	0
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed		18,239	7,871
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Not Offset, Policy Election Deduction	[1]	0	0
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Collateral, Obligation to Return Cash	[1]	(483)	(4,404)
Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Amount Offset Against Collateral		17,756	3,467
Derivative Liability, Not Offset	[1],[2]	0	0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross		25,943	13,523
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset		0	0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned		25,943	13,523
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Not Offset, Policy Election Deduction	[1]	0	0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash	[1]	25,429	5,682
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Amount Offset Against Collateral		514	7,841
Securities Sold under Agreements to Repurchase, Gross		237,984	245,868
Securities Sold under Agreements to Repurchase, Asset		0	0
Securities Sold under Agreements to Repurchase		237,984	245,868
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Securities	[1]	237,984	245,868
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	[1]	0	0
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral		0	0
Customer Loan Swap - Dealer Bank
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		17,242	4,374
Derivative Asset, Fair Value, Gross Liability		0	0
Derivative Asset		17,242	4,374
Derivative, Collateral, Obligation to Return Cash	[1]	17,242	(4,374)
Derivative, Collateral, Obligation to Return Cash		0	0
Customer Loan Swap - Commercial Customer
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]	17,756	3,467
Derivative Asset, Fair Value, Gross Liability	[2]	0	0
Derivative Asset	[2]	17,756	3,467
Derivative, Collateral, Obligation to Return Cash	[1],[2]	0	0
Derivative, Collateral, Obligation to Return Cash	[2]	17,756	3,467
Derivative Liability, Fair Value, Gross Liability	[2]	514	7,841
Derivative Liability, Fair Value, Gross Asset	[2]	0	0
Derivative Liability	[2]	514	7,841
Derivative, Collateral, Right to Reclaim Cash	[1],[2]	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	[2]	514	7,841
Interest Rate Swap On Loans [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		483
Derivative Asset, Fair Value, Gross Liability		0
Derivative Asset		483
Derivative, Collateral, Obligation to Return Cash	[1]	(483)
Derivative, Collateral, Obligation to Return Cash		0
FHLBB Advance Interest Rate Swap
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset			30
Derivative Asset, Fair Value, Gross Liability			0
Derivative Asset			30
Derivative, Collateral, Obligation to Return Cash	[1]		(30)
Derivative, Collateral, Obligation to Return Cash			0
Junior Subordinated Debt Interest Rate Swap
Offsetting Assets [Line Items]
Derivative Liability, Fair Value, Gross Liability		8,187	5,682
Derivative Liability, Fair Value, Gross Asset		0	0
Derivative Liability		8,187	5,682
Derivative, Collateral, Right to Reclaim Cash	[1]	8,187	5,682
Derivative Liability, Fair Value, Amount Offset Against Collateral		$ 0	$ 0

[1] (1) The amount presented was the lesser of the amount pledged (received) or the net amount presented in the consolidated statements of condition.

[2] (2)The Company manages its net exposure on its commercial customer loan swaps by obtaining collateral as part of the normal loan policy and underwriting practices.