Borrowings (Schedule of Advances to the Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
FHLB advances, carrying value of residential real estate and commercial loans pledged as collateral	$ 1,300,000	$ 1,400,000
FHLB advances, securities pledged as collateral	38	150
Federal Home Loan Bank Advances	$ 25,000	$ 40,825
Long-term Debt [Member]
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Debt, Weighted Average Interest Rate	0.98%	1.87%
Short-term Debt
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Debt, Weighted Average Interest Rate	0.34%	1.28%
FHLBB Borrowing Maturing February 2020 \| Long-term Debt [Member]
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Debt, Weighted Average Interest Rate		1.87%
Federal Home Loan Bank Advances		$ 10,000
FHLBB Borrowing Maturing January 2020 \| Short-term Debt
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Debt, Weighted Average Interest Rate		1.79%
Federal Home Loan Bank Advances		$ 30,825
FHLBB Borrowing Maturing March 2025
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Federal Home Loan Bank Advances	$ 25,000
FHLBB Borrowing Maturing March 2025 \| Long-term Debt [Member]
Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]
Debt, Weighted Average Interest Rate	0.98%
Federal Home Loan Bank Advances	$ 25,000

Maturity Schedule Of Federal Home Loan Bank Advances [Line Items]

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Weighted average interest rate of debt outstanding.

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- Definition

Amount of Federal Home Loan Bank (FHLBank) advances to member financial institutions.

+ References

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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- Definition

The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for FHLB debt obligations, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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