Regulatory Matters - Capital Ratios (Details) $ in Thousands	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	7.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	8.50%
Total Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	10.50%
Tier I Capital (to Average Tangible Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	4.00%
Consolidated [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 Capital (to Risk Weighted Assets), Actual Amount	$ 3,908,497	$ 3,681,430
Tier I Capital (to Risk Weighted Assets), Actual Amount	3,908,497	3,681,430
Total Capital (to Risk Weighted Assets), Actual Amount	4,206,669	3,923,052
Tier I Capital (to Average Tangible Assets), Actual Amount	$ 3,908,497	$ 3,681,430
CET1 Capital (to Risk Weighted Assets), Actual Ratio	0.1642	0.1554
Tier I Capital (to Risk Weighted Assets), Actual Ratio	0.1642	0.1554
Total Capital (to Risk Weighted Assets), Actual Ratio	0.1767	0.1656
Tier I Capital (to Average Tangible Assets), Actual Ratio	0.1082	0.1039
CET1 Capital (to Risk Weighted Assets) , Minimum Required Amount For Capital Adequacy Purposes	$ 1,071,015	$ 1,065,744
Tier I Capital (to Risk Weighted Assets), Minimum Required Amount For Capital Adequacy Purposes	1,428,021	1,420,992
Total Capital (to Risk Weighted Assets), Minimum Required Amount For Capital Adequacy Purposes	1,904,028	1,894,656
Tier I Capital (to Average Tangible Assets), Minimum Required Amount For Capital Adequacy Purposes	$ 1,445,504	$ 1,417,440
CET1 Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	4.50%	4.50%
Tier I Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	0.06	0.06
Total Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	0.08	0.08
Tier I Capital (to Average Tangible Assets), Minimum Required Ratio For Capital Adequacy Purposes	0.04	0.04
CET1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	$ 1,666,024	$ 1,657,824
Tier I Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	2,023,029	2,013,072
Total Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	2,499,036	2,486,736
Tier I Capital (to Average Tangible Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	$ 1,445,504	$ 1,417,440
CET1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	7.00%	7.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	8.50%	8.50%
Total Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	10.50%	10.50%
Tier I Capital (to Average Tangible Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	4.00%	4.00%
Prosperity Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 Capital (to Risk Weighted Assets), Actual Amount	$ 3,893,275	$ 3,665,750
Tier I Capital (to Risk Weighted Assets), Actual Amount	3,893,275	3,665,750
Total Capital (to Risk Weighted Assets), Actual Amount	4,191,332	3,907,375
Tier I Capital (to Average Tangible Assets), Actual Amount	$ 3,893,275	$ 3,665,750
CET1 Capital (to Risk Weighted Assets), Actual Ratio	0.1636	0.1548
Tier I Capital (to Risk Weighted Assets), Actual Ratio	0.1636	0.1548
Total Capital (to Risk Weighted Assets), Actual Ratio	0.1762	0.165
Tier I Capital (to Average Tangible Assets), Actual Ratio	0.1078	0.1035
CET1 Capital (to Risk Weighted Assets) , Minimum Required Amount For Capital Adequacy Purposes	$ 1,070,586	$ 1,065,417
Tier I Capital (to Risk Weighted Assets), Minimum Required Amount For Capital Adequacy Purposes	1,427,448	1,420,556
Total Capital (to Risk Weighted Assets), Minimum Required Amount For Capital Adequacy Purposes	1,903,264	1,894,074
Tier I Capital (to Average Tangible Assets), Minimum Required Amount For Capital Adequacy Purposes	$ 1,445,188	$ 1,417,269
CET1 Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	4.50%	4.50%
Tier I Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	0.06	0.06
Total Capital (to Risk Weighted Assets), Minimum Required Ratio For Capital Adequacy Purposes	0.08	0.08
Tier I Capital (to Average Tangible Assets), Minimum Required Ratio For Capital Adequacy Purposes	400	0.04
CET1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	$ 1,665,356	$ 1,657,315
Tier I Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	2,022,219	2,012,454
Total Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	2,498,035	2,485,972
Tier I Capital (to Average Tangible Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Amount	$ 1,445,188	$ 1,417,269
CET1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	7.00%	7.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	8.50%	8.50%
Total Capital (to Risk Weighted Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	10.50%	10.50%
Tier I Capital (to Average Tangible Assets), Minimum Required Plus Capital Conservation Buffer for 2020 Ratio	4.00%	4.00%
CET1 Capital (to Risk Weighted Assets), Amount To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	$ 1,546,402	$ 1,538,935
Tier I Capital (to Risk Weighted Assets), Amount To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	1,903,264	1,894,074
Total Capital (to Risk Weighted Assets), Amount To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	2,379,081	2,367,593
Tier I Capital (to Average Tangible Assets), Amount To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	$ 1,806,485	$ 1,771,586
CET1 Capital (to Risk Weighted Assets), Ratio To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	6.50%	6.50%
Tier I Capital (to Risk Weighted Assets), Ratio To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	0.08	0.08
Total Capital (to Risk Weighted Assets), Ratio To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	0.10	0.10
Tier I Capital (to Average Tangible Assets), Ratio To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions	0.05	0.05

Capital minimum required plus capital conservation weighted assets.

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Amount of total capital as defined by regulatory framework.

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 505
-Name Accounting Standards Codification
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Amount of Common Equity Tier 1 risk-based capital as defined by regulatory framework.

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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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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of tangible capital as defined by regulatory framework.

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