Regulatory Capital Matters - Summary of Actual and Required Capital Amounts and Ratios, Exclusive of Capital Conservation Buffer (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2016
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital conservation buffer	0.625%	2.50%		0.625%
Consolidated
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount		$ 144,216	$ 139,593
Tier 1 capital (to risk-weighted assets), Actual Amount		134,528	129,893
Common equity Tier 1 capital (to risk-weighted assets), Actual Amount		134,528	129,893
Tier 1 capital (to average assets), Actual Amount		$ 134,528	$ 129,893
Total capital (to risk-weighted assets), Actual Ratio		16.02%	16.26%
Tier 1 capital (to risk-weighted assets), Actual Ratio		14.94%	15.13%
Common equity Tier 1 capital (to risk-weighted assets), Actual Ratio		14.94%	15.13%
Tier 1 capital (to average assets), Actual Ratio		12.96%	12.88%
Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount		$ 140,411	$ 139,538
Tier 1 capital (to risk-weighted assets), Actual Amount		130,723	129,838
Common equity Tier 1 capital (to risk-weighted assets), Actual Amount		130,723	129,838
Tier 1 capital (to average assets), Actual Amount		$ 130,723	$ 129,838
Total capital (to risk-weighted assets), Actual Ratio		15.60%	16.25%
Tier 1 capital (to risk-weighted assets), Actual Ratio		14.52%	15.12%
Common equity Tier 1 capital (to risk-weighted assets), Actual Ratio		14.52%	15.12%
Tier 1 capital (to average assets), Actual Ratio		12.60%	12.87%
Total capital (to risk-weighted assets), Amount, Required for Capital Adequacy Purposes		$ 72,009	$ 68,686
Tier 1 capital (to risk-weighted assets), Amount, Required for Capital Adequacy Purposes		54,007	51,514
Common equity Tier 1 capital (to risk-weighted assets), Amount, Required for Capital Adequacy Purposes		40,505	38,636
Tier 1 capital (to average assets), Amount, Required for Capital Adequacy Purposes		$ 41,509	$ 40,346
Capital conservation buffer		8.00%	8.00%
Tier 1 capital (to risk-weighted assets), Ratio, Required for Capital Adequacy Purposes		6.00%	6.00%
Common equity Tier 1 capital (to risk-weighted assets), Ratio, Required for Capital Adequacy Purposes		4.50%	4.50%
Tier 1 capital (to average assets), Ratio, Required for Capital Adequacy Purposes		4.00%	4.00%
Total capital (to risk-weighted assets), Amount, Minimum To be Considered "Well Capitalized"		$ 90,012	$ 85,857
Tier 1 capital (to risk-weighted assets), Amount, Minimum To be Considered "Well Capitalized"		72,009	68,686
Common equity Tier 1 capital (to risk-weighted assets), Amount, Minimum To be Considered "Well Capitalized"		58,508	55,807
Tier 1 capital (to average assets), Amount, Minimum To be Considered "Well Capitalized"		$ 51,886	$ 50,432
Total capital (to risk-weighted assets), Ratio, Minimum To be Considered "Well Capitalized"		10.00%	10.00%
Tier 1 capital (to risk-weighted assets), Ratio, Minimum To be Considered "Well Capitalized"		8.00%	8.00%
Common equity Tier 1 capital (to risk-weighted assets), Ratio, Minimum To be Considered "Well Capitalized"		6.50%	6.50%
Tier 1 capital (to average assets), Ratio, Minimum To be Considered "Well Capitalized"		5.00%	5.00%

Common equity tier one capital required for capital adequacy to risk weighted assets.

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Common equity tier one capital required to be well capitalized to risk weighted assets.

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Amount of Common Equity Tier One Risk-based Capital, as defined by regulatory framework.

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Percentage of Common Equity Tier One Risk-based Capital to total risk-weighted assets, as defined by regulatory framework.

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Amount of Common Equity Tier 1 Risk-based Capital required to be categorized as adequately capitalized under regulatory framework for prompt corrective action.

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Amount of Common Equity Tier 1 Risk-based Capital required to be categorized as well-capitalized under regulatory framework for prompt corrective action.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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