XML 61 R45.htm IDEA: XBRL DOCUMENT
v3.22.1

Loans and Allowance for Loan Losses - Aging of Past Due Loans by Class of Loan (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Financing Receivable, Past Due [Line Items] |  |
Loans | $ 3,800,916 | $ 3,645,162
Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 3,794,206 | 3,636,828
30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 5,098 | 6,507
60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 816 | 956
Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 796 | 871
Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 6,710 | 8,334
Construction Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 490,166 | 447,860
Construction Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 490,116 | 447,720
Construction Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 38 | 82
Construction Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 12 | 58
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 | 50 | 140
1-4 Family Residential Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 647,837 | 651,140
1-4 Family Residential Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 644,106 | 647,081
1-4 Family Residential Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 3,040 | 3,226
1-4 Family Residential Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 437 | 606
1-4 Family Residential Real Estate Loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 254 | 227
1-4 Family Residential Real Estate Loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 3,731 | 4,059
Commercial Real Estate Loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,722,577 | 1,598,172
Commercial Real Estate Loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,721,708 | 1,596,882
Commercial Real Estate Loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 747 | 1,191
Commercial Real Estate Loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 122 | 0
Commercial Real Estate Loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 99
Commercial Real Estate Loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 869 | 1,290
Commercial loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 401,144 | 418,998
Commercial loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 399,287 | 416,687
Commercial loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,100 | 1,523
Commercial loans | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 245 | 251
Commercial loans | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 512 | 537
Commercial loans | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 1,857 | 2,311
Municipal loans |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 455,155 | 443,078
Municipal loans | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 455,155 | 442,908
Municipal loans | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 170
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 | 170
Loans to individuals |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 84,037 | 85,914
Loans to individuals | Financial Asset, Current |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 83,834 | 85,550
Loans to individuals | 30-59 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 173 | 315
Loans to individuals | 60-89 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 0 | 41
Loans to individuals | Greater than 90 Days Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | 30 | 8
Loans to individuals | Financial Asset, Past Due |  |
Financing Receivable, Past Due [Line Items] |  |
Loans | $ 203 | $ 364

X
- Definition Amount excluding accrued interest, before allowance for credit loss, of financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + 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 No definition available. + 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: |