XML 57 R46.htm IDEA: XBRL DOCUMENT
v3.25.1

Loans and Allowance for Loan Losses - Aging of Past Due Loans by Class of Loan (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Financing Receivable, Past Due [Line Items] |  |
Loans | $ 4,567,239 | $ 4,661,597
Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 4,554,177 | 4,650,195
30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 9,310 | 8,352
60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,699 | 2,361
Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,053 | 689
Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 13,062 | 11,402
Construction Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 458,101 | 537,827
Construction Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 456,991 | 537,730
Construction Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,110 | 92
Construction Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 5
Construction Real Estate Loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 0
Construction Real Estate Loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,110 | 97
1-4 Family Residential Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 741,432 | 740,396
1-4 Family Residential Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 737,443 | 735,589
1-4 Family Residential Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 3,432 | 3,217
1-4 Family Residential Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 384 | 1,328
1-4 Family Residential Real Estate Loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 173 | 262
1-4 Family Residential Real Estate Loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 3,989 | 4,807
Commercial Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,577,229 | 2,579,735
Commercial Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,575,064 | 2,577,350
Commercial Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,048 | 2,054
Commercial Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 35 | 331
Commercial Real Estate Loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 82 | 0
Commercial Real Estate Loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,165 | 2,385
Commercial loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 371,643 | 363,167
Commercial loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 365,910 | 359,230
Commercial loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,655 | 2,881
Commercial loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 2,280 | 649
Commercial loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 798 | 407
Commercial loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 5,733 | 3,937
Municipal loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 371,271 | 390,968
Municipal loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 371,271 | 390,968
Municipal loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 0
Municipal loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 0
Municipal loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 0
Municipal loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 0
Loans to individuals |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 47,563 | 49,504
Loans to individuals | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 47,498 | 49,328
Loans to individuals | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 65 | 108
Loans to individuals | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 48
Loans to individuals | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 20
Loans to individuals | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | $ 65 | $ 176

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 80 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-80 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sbsi_MunicipalLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |