Regulatory Capital Requirements (Details) $ in Thousands	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Red River Bancshares, Inc.
Total Risk-Based Capital
Actual Amount	$ 389,245	$ 384,577
Actual Ratio (as a percent)	0.1801	0.1828
Regulatory Requirements, Minimum, Amount	$ 226,894	$ 220,905
Regulatory Requirements, Minimum, Ratio (as a percent)	0.1050	0.1050
Tier I Risk-Based Capital
Actual Amount	$ 367,176	$ 362,799
Actual Ratio (as a percent)	0.1699	0.1724
Regulatory Requirements, Minimum, Amount	$ 183,676	$ 178,828
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0850	0.0850
Common Equity Tier I Capital
Actual Amount	$ 367,176	$ 362,799
Actual Ratio (as a percent)	0.1699	0.1724
Regulatory Requirements, Minimum, Amount	$ 151,263	$ 147,270
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0700	0.0700
Tier I Leverage Capital
Actual Amount	$ 367,176	$ 362,799
Actual Ratio (as a percent)	0.1174	0.1156
Regulatory Requirements, Minimum, Amount	$ 125,098	$ 125,575
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0400	0.0400
Red River Bank
Total Risk-Based Capital
Actual Amount	$ 381,452	$ 378,582
Actual Ratio (as a percent)	0.1766	0.1800
Regulatory Requirements, Minimum, Amount	$ 226,818	$ 220,850
Regulatory Requirements, Minimum, Ratio (as a percent)	0.1050	0.1050
Regulatory Requirements, Minimum Plus CCB, Amount	$ 216,017	$ 210,333
Regulatory Requirements, Minimum Plus CCB, Ratio (as a percent)	0.1000	0.1000
Tier I Risk-Based Capital
Actual Amount	$ 359,383	$ 356,804
Actual Ratio (as a percent)	0.1664	0.1696
Regulatory Requirements, Minimum, Amount	$ 183,615	$ 178,783
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0850	0.0850
Regulatory Requirements, Minimum, Amount	$ 172,814	$ 168,266
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0800	0.0800
Common Equity Tier I Capital
Actual Amount	$ 359,383	$ 356,804
Actual Ratio (as a percent)	0.1664	0.1696
Regulatory Requirements, Minimum, Amount	$ 151,212	$ 147,233
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0700	0.0700
Regulatory Requirements, Minimum Plus CCB, Amount	$ 140,411	$ 136,716
Regulatory Requirements, Minimum Plus CCB, Ratio (as a percent)	0.0650	0.0650
Tier I Leverage Capital
Actual Amount	$ 359,383	$ 356,804
Actual Ratio (as a percent)	0.1149	0.1137
Regulatory Requirements, Minimum, Amount	$ 125,062	$ 125,538
Regulatory Requirements, Minimum, Ratio (as a percent)	0.0400	0.0400
Regulatory Requirements, Minimum Plus CCB, Amount	$ 156,328	$ 156,923
Regulatory Requirements, Minimum Plus CCB, Ratio (as a percent)	0.0500	0.0500