Disclosures About Fair Value of Assets and Liabilities - Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements Other Than Goodwill (Details) - Significant Unobservable Inputs (Level 3) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
State and municipal securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 2,452	$ 2,858
State and municipal securities | Discounted cash flow | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maturity/Call date	1 month	1 month
US Muni BQ curve	A-	A-
State and municipal securities | Discounted cash flow | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maturity/Call date	15 years	15 years
US Muni BQ curve	BBB-	BBB-
Corporate obligations and U.S. Government-sponsored mortgage-backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 35	$ 35
Impaired loans (collateral dependent) | Collateral based measurements
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	34,418	5,653
Other real estate owned | Appraisals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 464	$ 194
Discount rate | State and municipal securities | Discounted cash flow | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.015	0.02
Discount rate | State and municipal securities | Discounted cash flow | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.04	0.05
Weighted-average coupon | State and municipal securities | Discounted cash flow | Weighted-average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.04	0.04
Weighted-average coupon | Corporate obligations and U.S. Government-sponsored mortgage-backed securities | Discounted cash flow | Weighted-average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0	0
Risk free rate | Corporate obligations and U.S. Government-sponsored mortgage-backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk free rate	3 month LIBOR	3 month LIBOR
Plus premium for illiquidity | Corporate obligations and U.S. Government-sponsored mortgage-backed securities | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount rate	0.02	0.02
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0	0
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	0.10	0.10
Discount to reflect current market conditions and ultimate collectability | Impaired loans (collateral dependent) | Collateral based measurements | Weighted-average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Discount to reflect current market conditions and ultimate collectability	7	0.01
Discount to reflect current market conditions | Other real estate owned | Appraisals | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0	0
Discount to reflect current market conditions | Other real estate owned | Appraisals | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0.72	0.37
Discount to reflect current market conditions | Other real estate owned | Appraisals | Weighted-average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	0.32	0.37