Stockholders' Equity - Summary of the Company's Actual Capital Amounts and Ratios (Detail) - Company [Member] - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 415,863	$ 377,359
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	386,308	348,816
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	351,308	313,816
Tier 1 Capital (to 4th Qtr. Average Assets), Actual Amount	$ 386,308	$ 348,816
Total Capital (to Risk-Weighted Assets), Ratio	13.97%	13.62%
Tier 1 Capital (to Risk-Weighted Assets), Ratio	12.98%	12.59%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Ratio	11.80%	11.32%
Tier 1 Capital (to 4th Qtr. Average Assets), Ratio	7.25%	6.91%
Total Capital (to Risk-Weighted Assets), Capital Adequacy Amount	$ 238,132	$ 221,690
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Amount	178,599	166,268
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Amount	133,949	124,701
Tier 1 Capital (to 4th Qtr. Average Assets), Capital Adequacy Amount	$ 213,222	$ 201,913
Total Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	6.00%	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Capital Adequacy Ratio	4.50%	4.50%
Tier 1 Capital (to 4th Qtr. Average Assets), Capital Adequacy Ratio	4.00%	4.00%
Total Capital (to Risk-Weighted Assets), Well Capitalized Amount	$ 297,665	$ 277,113
Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Amount	238,132	221,690
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Amount	193,482	180,123
Tier 1 Capital (to 4th Qtr. Average Assets), Well Capitalized Amount	$ 266,528	$ 252,391
Total Capital (to Risk-Weighted Assets), Well Capitalized Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Ratio	8.00%	8.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Well Capitalized Ratio	6.50%	6.50%
Tier 1 Capital (to 4th Qtr. Average Assets), Well Capitalized Ratio	5.00%	5.00%

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Common Equity Tier One Risk Based Capital Required For Capital Adequacy

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Common Equity Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets

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

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Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets

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Common Equity Tier One Risk Based Capital To Risk Weighted Assets

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The amount of total capital as defined in the regulations.

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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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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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