Shareholders Equity and Regulatory Matters - Schedule of comparison of the actual capital amounts and ratios (Details) $ in Thousands	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Actual, Amount	$ 532,849	$ 512,024
Total capital (to risk weighted assets), Actual, Ratio	0.1278	0.1266
Total capital (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 437,756	$ 424,563
Total capital (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.105	0.105
Tier 1 capital (to risk weighted assets), Actual, Amount	$ 411,870	$ 392,037
Tier 1 capital (to risk weighted assets), Actual, Ratio	0.0988	0.097
Tier 1 capital (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 354,374	$ 343,694
Tier 1 capital (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.085	0.085
Tier 1 capital (to average assets), Actual, Amount	$ 411,870	$ 392,037
Tier 1 capital (to average assets), Actual, Ratio	0.0924	0.0923
Tier 1 capital (to average assets), For Capital Adequacy Purposes, Amount	$ 178,275	$ 169,917
Tier 1 capital (to average assets), For Capital Adequacy Purposes, Ratio	0.04	0.04
Common equity tier 1 (to risk weighted assets), Actual, Amount	$ 345,645	$ 325,812
Common equity tier 1 (to risk weighted assets), Actual, Ratio	0.0829	0.0806
Common equity tier 1 (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 291,837	$ 283,042
Common equity tier 1 (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.07	0.07
THIRD COAST BANK
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Actual, Amount	$ 561,184	$ 544,624
Total capital (to risk weighted assets), Actual, Ratio	0.1349	0.1349
Total capital (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 436,918	$ 423,829
Total capital (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.105	0.105
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 416,112	$ 403,647
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.10	0.10
Tier 1 capital (to risk weighted assets), Actual, Amount	$ 520,861	$ 505,190
Tier 1 capital (to risk weighted assets), Actual, Ratio	0.1252	0.1252
Tier 1 capital (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 353,695	$ 343,100
Tier 1 capital (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.085	0.085
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 332,890	$ 322,918
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.08	0.08
Tier 1 capital (to average assets), Actual, Amount	$ 520,861	$ 505,190
Tier 1 capital (to average assets), Actual, Ratio	0.1171	0.1191
Tier 1 capital (to average assets), For Capital Adequacy Purposes, Amount	$ 177,976	$ 169,649
Tier 1 capital (to average assets), For Capital Adequacy Purposes, Ratio	0.04	0.04
Tier 1 capital (to average assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 222,470	$ 212,062
Tier 1 capital (to average assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.05	0.05
Common equity tier 1 (to risk weighted assets), Actual, Amount	$ 520,861	$ 505,190
Common equity tier 1 (to risk weighted assets), Actual, Ratio	0.1252	0.1252
Common equity tier 1 (to risk weighted assets), For Capital Adequacy Purposes, Amount	$ 291,278	$ 282,553
Common equity tier 1 (to risk weighted assets), For Capital Adequacy Purposes, Ratio	0.07	0.07
Common equity tier 1 (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 270,473	$ 262,371
Common equity tier 1 (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065

Tier one risk based capital required for capital adequacy with buffer.

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Ratio of minimum Common Equity Tier 1 risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
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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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