Loans - Troubled Debt Restructuring (Details)	12 Months Ended
Dec. 31, 2019 USD ($) contract loan	Dec. 31, 2018 USD ($) contract loan	Dec. 31, 2017 USD ($) contract loan
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	1	1	8
Pre-Modification Outstanding Recorded Investment	$ 207,000	$ 11,000	$ 305,000
Post-Modification Outstanding Recorded Investment	$ 207,000	$ 11,000	305,000
Number of loans that subsequently defaulted within 12 months of modification \| loan	0	0
Type of modification	$ 207,000	$ 11,000	$ 305,000
Loans in the process of foreclosure	161,000	112,000
Residential OREO	$ 285,000	$ 719,000
Commercial
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	0	0	5
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 212,000
Post-Modification Outstanding Recorded Investment	0	0	212,000
Allowance for loan losses for loans modified			$ 137,000
Number of loans that subsequently defaulted within 12 months of modification \| loan			3
Loans that defaulted within twelve months of modification			$ 109,000,000
Type of modification	$ 0	$ 0	$ 212,000
Commercial Real Estate \| Real estate
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	0	0	0
Type of modification	$ 0	$ 0	$ 0
Residential Real Estate \| Real estate
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 207,000	$ 11,000	$ 36,000
Post-Modification Outstanding Recorded Investment	207,000	11,000	36,000
Allowance for loan losses for loans modified	24,000	0	$ 0
Number of loans that subsequently defaulted within 12 months of modification \| loan			1
Loans that defaulted within twelve months of modification			$ 143,000,000
Type of modification	$ 207,000	$ 11,000	$ 36,000
Residential Real Estate \| Home equity
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	0	0	2
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 57,000
Post-Modification Outstanding Recorded Investment	0	0	57,000
Allowance for loan losses for loans modified			1,000
Type of modification	$ 0	$ 0	$ 57,000
Consumer
Loans modified as TDRs [Abstract]
Number of Contracts \| contract	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	0	0	0
Type of modification	$ 0	$ 0	$ 0

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Amount of increase (decrease) in allowance for credit loss on financing receivable.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

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