Regulatory Capital Requirements - Schedule of Regulatory Requirements (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Red River Bank
Total Risk-Based Capital
Actual Amount	$ 245,488	$ 238,021
Actual Ratio	16.45%	16.23%
Regulatory Requirements, Minimum To Be Adequately Capitalized, Amount	$ 119,363	$ 117,325
Regulatory Requirements, Minimum To Be Adequately Capitalized, Ratio	8.00%	8.00%
Regulatory Requirements, Under Prompt Corrective Action Provisions, Amount	$ 156,664	$ 153,989
Regulatory Requirements, Under Prompt Corrective Action Provisions, Ratio	10.50%	10.50%
Tier I Risk-Based Capital
Actual Amount	$ 231,095	$ 224,084
Actual Ratio	15.49%	15.28%
Regulatory Requirements, Minimum To Be Adequately Capitalized, Amount	$ 89,522	$ 87,994
Regulatory Requirements, Minimum To Be Adequately Capitalized, Ratio	6.00%	6.00%
Regulatory Requirements, Under Prompt Corrective Action Provisions, Amount	$ 126,823	$ 124,658
Regulatory Requirements, Under Prompt Corrective Action Provisions, Ratio	8.50%	8.50%
Common Equity Tier I Capital
Actual Amount	$ 231,095	$ 224,084
Actual Ratio	15.49%	15.28%
Regulatory Requirements, Minimum To Be Adequately Capitalized, Amount	$ 67,142	$ 65,995
Regulatory Requirements, Minimum To Be Adequately Capitalized, Ratio	4.50%	4.50%
Regulatory Requirements, Under Prompt Corrective Action Provisions, Amount	$ 104,443	$ 102,660
Regulatory Requirements, Under Prompt Corrective Action Provisions, Ratio	7.00%	7.00%
Tier I Leverage Capital
Actual Amount	$ 231,095	$ 224,084
Actual Ratio	11.60%	11.47%
Regulatory Requirements, Minimum To Be Adequately Capitalized, Amount	$ 79,681	$ 78,114
Regulatory Requirements, Minimum To Be Adequately Capitalized, Ratio	4.00%	4.00%
Regulatory Requirements, Under Prompt Corrective Action Provisions, Amount	$ 79,681	$ 78,114
Regulatory Requirements, Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
Red River Bancshares, Inc.
Total Risk-Based Capital
Actual Amount	$ 271,234	$ 264,313
Actual Ratio	18.18%	18.02%
Tier I Risk-Based Capital
Actual Amount	$ 256,841	$ 250,376
Actual Ratio	17.21%	17.07%
Common Equity Tier I Capital
Actual Amount	$ 256,841	$ 250,376
Actual Ratio	17.21%	17.07%
Tier I Leverage Capital
Actual Amount	$ 256,841	$ 250,376
Actual Ratio	12.89%	12.82%

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

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Amount of Common Equity Tier One Risk-based Capital, 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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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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Tier 1 Risk Based Capital as defined in the regulations.

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