$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi

$sbsi Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000070543224000026 Filed on February 27, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$102.8M		$359.7M
YoY Change	27.1%		42.2%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$2.468M	$2.577M	$10.58M
YoY Change	-6.37%	-7.07%	-4.75%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$49.41M		$144.7M
YoY Change	79.71%		256.09%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$26.13M	$19.52M	$101.1M
YoY Change	-14.53%	-38.92%	-15.47%
Income Tax	$4.622M	$2.206M	$14.44M
% Of Pretax Income	17.69%	11.3%	14.28%
Net Earnings	$21.51M	$17.32M	$86.69M
YoY Change	-17.37%	-37.42%	-17.45%
Net Earnings / Revenue	20.93%		24.1%
Basic Earnings Per Share	$0.71		$2.82
Diluted Earnings Per Share	$0.71	$0.57	$2.82
COMMON SHARES
Basic Shares Outstanding	30.26M shares	30.20M shares	30.70M shares
Diluted Shares Outstanding	30.31M shares		30.76M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$469.4M	$560.5M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$154.4M	$139.0M	$139.0M
YoY Change	9.2%	-1.63%	-1.63%
Goodwill	$201.1M	$201.1M
YoY Change	0.0%	0.0%
Intangibles	$2.588M	$2.925M
YoY Change	-37.55%	-36.72%
Long-Term Investments	$9.554M	$9.691M	$9.691M
YoY Change	-3.58%	-13.33%	-13.33%
Other Assets	$29.88M	$30.43M	$30.43M
YoY Change	-11.58%	-12.3%	-12.3%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$8.354B	$8.285B	$8.285B
YoY Change	7.21%	9.61%	9.61%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$16.74M	$16.70M	$16.70M
YoY Change	-1.44%	-2.14%	-2.14%
Deferred Revenue
YoY Change
Short-Term Debt	$457.7M	$509.8M	$509.8M
YoY Change	-26.84%	130.53%	130.53%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$474.4M	$526.5M	$526.5M
YoY Change	-26.17%	2984.5%	2984.5%
LONG-TERM LIABILITIES
Long-Term Debt	$154.2M	$154.1M	$154.1M
YoY Change	-3.01%	-3.01%	-3.01%
Other Long-Term Liabilities	$79.10M	$85.33M	$85.33M
YoY Change	15.78%	5.13%	5.13%
Total Long-Term Liabilities	$233.3M	$239.5M	$239.5M
YoY Change	2.64%	-0.26%	-0.26%
TOTAL LIABILITIES
Total Short-Term Liabilities	$474.4M	$526.5M	$526.5M
Total Long-Term Liabilities	$233.3M	$239.5M	$239.5M
Total Liabilities	$7.566B	$7.512B	$7.512B
YoY Change	7.45%	10.26%	10.26%
SHAREHOLDERS EQUITY
Retained Earnings	$292.9M	$282.4M
YoY Change	15.05%	17.84%
Common Stock	$837.5M	$836.4M
YoY Change	0.47%	0.52%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$231.6M	$232.0M
YoY Change	13.62%	23.27%
Treasury Stock Shares
Shareholders Equity	$787.9M	$773.3M	$773.3M
YoY Change
Total Liabilities & Shareholders Equity	$8.354B	$8.285B	$8.285B
YoY Change	7.21%	9.61%	9.61%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$21.51M	$17.32M	$86.69M
YoY Change	-17.37%	-37.42%	-17.45%
Depreciation, Depletion And Amortization	$2.468M	$2.577M	$10.58M
YoY Change	-6.37%	-7.07%	-4.75%
Cash From Operating Activities	$58.29M	-$56.64M	$79.86M
YoY Change	146.68%	-411.99%	-64.74%
INVESTING ACTIVITIES
Capital Expenditures	$2.567M	$1.804M	$6.904M
YoY Change	17.59%	93.77%	-25.77%
Acquisitions
YoY Change
Other Investing Activities	-$180.4M	-$5.969M	-$320.2M
YoY Change	64.43%	-92.67%	-48.81%
Cash From Investing Activities	-$183.0M	-$7.773M	-$327.1M
YoY Change	63.51%	-90.57%	-48.47%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	33.52M	299.1M	$608.5M
YoY Change	-83.2%	337.46%	49.96%
NET CHANGE
Cash From Operating Activities	58.29M	-56.64M	$79.86M
Cash From Investing Activities	-183.0M	-7.773M	-$327.1M
Cash From Financing Activities	33.52M	299.1M	$608.5M
Net Change In Cash	-91.14M	234.7M	$361.3M
YoY Change	-181.93%	5588.68%	-14544.54%
FREE CASH FLOW
Cash From Operating Activities	$58.29M	-$56.64M	$79.86M
Capital Expenditures	$2.567M	$1.804M	$6.904M
Free Cash Flow	$55.73M	-$58.44M	$72.96M
YoY Change	159.81%	-439.33%	-66.41%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2023Q4	sbsi	Transferred Securities Unrealized Loss Before Tax TransferredSecuritiesUnrealizedLossBeforeTax	113500000	usd
CY2023Q4	sbsi	Securities Transferred Unrealized Loss Net Of Tax SecuritiesTransferredUnrealizedLossNetOfTax	89700000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4400000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	584000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	3900000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	4100000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	218000	usd
CY2021	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	usd
CY2023	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	5100000	usd
CY2023	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	5131000	usd
CY2022	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	-685000	usd
CY2021	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	-174000	usd
CY2022	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2021	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2021	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-174000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	1055361000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	422026000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	290975000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	128067000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	358920000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4147691000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4524510000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4147691000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	897000	usd
CY2023	sbsi	Financing Receivable Nonaccrual Interest Income Reversal FinancingReceivableNonaccrualInterestIncomeReversal	89000	usd
CY2022	sbsi	Financing Receivable Nonaccrual Interest Income Reversal FinancingReceivableNonaccrualInterestIncomeReversal	36000	usd
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0000705432
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest After Allowance For Credit Loss Statement Of Financial Position Extensible List DebtSecuritiesHeldToMaturityAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#InterestReceivable
CY2023Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss Statement Of Financial Position Extensible List DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#InterestReceivable
CY2023Q4	us-gaap	Derivative Liability Statement Of Financial Position Extensible Enumeration DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration	http://fasb.org/us-gaap/2023#OtherLiabilities
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	000-12247
CY2023	dei	Entity Registrant Name EntityRegistrantName	SOUTHSIDE BANCSHARES, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	TX
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	75-1848732
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	1201 S. Beckham Avenue,
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Tyler,
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	TX
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	75701
CY2023	dei	City Area Code CityAreaCode	903
CY2023	dei	Local Phone Number LocalPhoneNumber	531-7111
CY2023	dei	Security12b Title Security12bTitle	Common Stock, $1.25 par value
CY2023	dei	Trading Symbol TradingSymbol	SBSI
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	751300000	usd
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	30255576	shares
CY2023	dei	Auditor Firm AuditorFirmId	42
CY2023	dei	Auditor Name AuditorName	Ernst & Young LLP
CY2023	dei	Auditor Location AuditorLocation	Dallas, Texas
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	122021000	usd
CY2022Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	106143000	usd
CY2023Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	391719000	usd
CY2022Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	9276000	usd
CY2023Q4	us-gaap	Federal Funds Sold FederalFundsSold	46770000	usd
CY2022Q4	us-gaap	Federal Funds Sold FederalFundsSold	83833000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	560510000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	199252000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1332467000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1387874000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1296294000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1299014000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1166162000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1149156000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	1307053000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	1326729000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	11936000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	9190000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	9691000	usd
CY2022Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	11181000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	10894000	usd
CY2022Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	667000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4524510000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4147691000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	42674000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	36515000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	4481836000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	4111176000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	138950000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	141256000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	14837000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	15314000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	201116000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	201116000	usd
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	2925000	usd
CY2022Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	4622000	usd
CY2023Q4	us-gaap	Interest Receivable InterestReceivable	50489000	usd
CY2022Q4	us-gaap	Interest Receivable InterestReceivable	49350000	usd
CY2023Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	30426000	usd
CY2022Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	34695000	usd
CY2023Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	136330000	usd
CY2022Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	133911000	usd
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CY2022Q4	us-gaap	Other Assets OtherAssets	21163000	usd
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CY2022Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	4526457000	usd
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CY2023Q4	us-gaap	Other Liabilities OtherLiabilities	68626000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	64100000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	7511626000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	6812639000	usd
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CY2023Q4	us-gaap	Common Stock Value CommonStockValue	47550000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	47501000	usd
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CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	239610000	usd
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	7790276	shares
CY2022Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	6454192	shares
CY2023Q4	us-gaap	Treasury Stock Value TreasuryStockValue	231995000	usd
CY2022Q4	us-gaap	Treasury Stock Value TreasuryStockValue	188203000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-113462000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-137456000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	773288000	usd
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CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	7558636000	usd
CY2023	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	244803000	usd
CY2022	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	170410000	usd
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	144803000	usd
CY2023	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	31186000	usd
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CY2023	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	54629000	usd
CY2022	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	45001000	usd
CY2021	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	37730000	usd
CY2023	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	19450000	usd
CY2022	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	16639000	usd
CY2021	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	19534000	usd
CY2022	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	503000	usd
CY2021	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	530000	usd
CY2021	us-gaap	Interest Income Other InterestIncomeOther	78000	usd
CY2023	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Short Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm	6777000	usd
CY2023	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	3920000	usd
CY2022	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	4015000	usd
CY2023	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	4504000	usd
CY2022	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	2397000	usd
CY2021	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	1390000	usd
CY2023	us-gaap	Interest Expense Other InterestExpenseOther	21356000	usd
CY2022	us-gaap	Interest Expense Other InterestExpenseOther	1862000	usd
CY2021	us-gaap	Interest Expense Other InterestExpenseOther	42000	usd
CY2023	us-gaap	Interest Expense InterestExpense	144714000	usd
CY2022	us-gaap	Interest Expense InterestExpense	40640000	usd
CY2021	us-gaap	Interest Expense InterestExpense	26430000	usd
CY2023	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	215027000	usd
CY2022	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	212341000	usd
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	189557000	usd
CY2023	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	9154000	usd
CY2022	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	3241000	usd
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-16964000	usd
CY2023	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	205873000	usd
CY2022	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	209100000	usd
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	206521000	usd
CY2023	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	25497000	usd
CY2022	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	25843000	usd
CY2021	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	26368000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-15976000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3819000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	3862000	usd
CY2023	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	5058000	usd
CY2022	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2021	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2023	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	563000	usd
CY2022	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	531000	usd
CY2021	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	1641000	usd
CY2023	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	5910000	usd
CY2022	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	5992000	usd
CY2021	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	5959000	usd
CY2023	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	5823000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	2647000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	2618000	usd
CY2023	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3305000	usd
CY2022	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3335000	usd
CY2021	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3383000	usd
CY2023	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	5654000	usd
CY2022	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	6328000	usd
CY2021	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	5505000	usd
CY2023	us-gaap	Noninterest Income NoninterestIncome	35834000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	40857000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	49336000	usd
CY2023	us-gaap	Labor And Related Expense LaborAndRelatedExpense	85625000	usd
CY2022	us-gaap	Labor And Related Expense LaborAndRelatedExpense	82633000	usd
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	79892000	usd
CY2023	us-gaap	Occupancy Net OccupancyNet	14694000	usd
CY2022	us-gaap	Occupancy Net OccupancyNet	15130000	usd
CY2021	us-gaap	Occupancy Net OccupancyNet	14239000	usd
CY2023	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	4093000	usd
CY2022	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	3430000	usd
CY2021	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	2367000	usd
CY2023	sbsi	Atm Expense ATMExpense	1351000	usd
CY2022	sbsi	Atm Expense ATMExpense	1314000	usd
CY2021	sbsi	Atm Expense ATMExpense	1166000	usd
CY2023	us-gaap	Professional Fees ProfessionalFees	5351000	usd
CY2022	us-gaap	Professional Fees ProfessionalFees	4959000	usd
CY2021	us-gaap	Professional Fees ProfessionalFees	4015000	usd
CY2023	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9395000	usd
CY2022	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	6847000	usd
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	5675000	usd
CY2023	us-gaap	Communication Communication	1469000	usd
CY2022	us-gaap	Communication Communication	1896000	usd
CY2021	us-gaap	Communication Communication	2233000	usd
CY2023	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	3558000	usd
CY2022	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1945000	usd
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1807000	usd
CY2023	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1697000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2273000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2849000	usd
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	usd
CY2022	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	usd
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-1118000	usd
CY2023	us-gaap	Other Noninterest Expense OtherNoninterestExpense	13345000	usd
CY2022	us-gaap	Other Noninterest Expense OtherNoninterestExpense	9899000	usd
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	9669000	usd
CY2023	us-gaap	Noninterest Expense NoninterestExpense	140578000	usd
CY2022	us-gaap	Noninterest Expense NoninterestExpense	130326000	usd
CY2021	us-gaap	Noninterest Expense NoninterestExpense	125030000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	101129000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	119631000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	130827000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14437000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14611000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17426000	usd
CY2023	us-gaap	Profit Loss ProfitLoss	86692000	usd
CY2022	us-gaap	Profit Loss ProfitLoss	105020000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	113401000	usd
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.82
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.27
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.48
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.82
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.26
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.47
CY2023	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.42
CY2022	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.40
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.37
CY2023	us-gaap	Net Income Loss NetIncomeLoss	86692000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	105020000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	113401000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	28782000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	-179684000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax	-37199000	usd
CY2023	sbsi	Oci Debt Securities Available For Sale Transfer To Held To Maturity Gain Loss Before Adjustment And Tax OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax	0	usd
CY2022	sbsi	Oci Debt Securities Available For Sale Transfer To Held To Maturity Gain Loss Before Adjustment And Tax OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax	-125175000	usd
CY2021	sbsi	Oci Debt Securities Available For Sale Transfer To Held To Maturity Gain Loss Before Adjustment And Tax OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax	0	usd
CY2023	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-8004000	usd
CY2022	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-4968000	usd
CY2021	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-1363000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-15976000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-3819000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	3862000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	1222000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	44757000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	13648000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	24544000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	3638000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	-6395000	usd
CY2023	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	756000	usd
CY2022	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	895000	usd
CY2021	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	1264000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Finalization Of Pension And Non Pension Postretirement Plan Valuation Before Tax OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax	-16000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Finalization Of Pension And Non Pension Postretirement Plan Valuation Before Tax OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax	0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Finalization Of Pension And Non Pension Postretirement Plan Valuation Before Tax OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax	0	usd
CY2023	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	192000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	4487000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	6524000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	30372000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-249571000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-11867000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	6378000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-52410000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-2492000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	23994000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-197161000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-9375000	usd
CY2023	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	110686000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-92141000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	104026000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	875297000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	113401000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-9375000	usd
CY2021	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	34150	shares
CY2021	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1353000	usd
CY2021	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	938484	shares
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	34148000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3020000	usd
CY2021	us-gaap	Stock Issued During Period Shares Share Based Compensation StockIssuedDuringPeriodSharesShareBasedCompensation	305212	shares
CY2021	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	7193000	usd
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.37
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	44569000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	912172000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	105020000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-197161000	usd
CY2022	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	31853	shares
CY2022	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1233000	usd
CY2022	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	923775	shares
CY2022	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	33841000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3221000	usd
CY2022	us-gaap	Stock Issued During Period Shares Share Based Compensation StockIssuedDuringPeriodSharesShareBasedCompensation	86500	shares
CY2022	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	289000	usd
CY2022	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.40
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	44936000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	745997000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	86692000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	23994000	usd
CY2023	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	38884	shares
CY2023	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	1224000	usd
CY2023	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	1435193	shares
CY2023	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	45074000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3552000	usd
CY2023	us-gaap	Stock Issued During Period Shares Share Based Compensation StockIssuedDuringPeriodSharesShareBasedCompensation	99109	shares
CY2023	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	485000	usd
CY2023	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.42
CY2023	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	43582000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	773288000	usd
CY2023	us-gaap	Profit Loss ProfitLoss	86692000	usd
CY2022	us-gaap	Profit Loss ProfitLoss	105020000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	113401000	usd
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	10577000	usd
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11105000	usd
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11421000	usd
CY2023	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-4523000	usd
CY2022	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-18261000	usd
CY2021	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-22770000	usd
CY2023	us-gaap	Investment Income Net Amortization Of Discount And Premium InvestmentIncomeNetAmortizationOfDiscountAndPremium	-400000	usd
CY2022	us-gaap	Investment Income Net Amortization Of Discount And Premium InvestmentIncomeNetAmortizationOfDiscountAndPremium	52000	usd
CY2021	us-gaap	Investment Income Net Amortization Of Discount And Premium InvestmentIncomeNetAmortizationOfDiscountAndPremium	829000	usd
CY2023	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	9154000	usd
CY2022	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	3241000	usd
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-16964000	usd
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	3552000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	3221000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	3020000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2110000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-89000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4752000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-15976000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3819000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	3862000	usd
CY2023	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	5058000	usd
CY2022	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2021	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	0	usd
CY2023	sbsi	Available For Sale Securities Loss On Impairment AvailableForSaleSecuritiesLossOnImpairment	0	usd
CY2022	sbsi	Available For Sale Securities Loss On Impairment AvailableForSaleSecuritiesLossOnImpairment	38000	usd
CY2021	sbsi	Available For Sale Securities Loss On Impairment AvailableForSaleSecuritiesLossOnImpairment	0	usd
CY2023	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-342000	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-576000	usd
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-324000	usd
CY2023	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	17161000	usd
CY2022	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	23774000	usd
CY2021	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	45803000	usd
CY2023	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	19295000	usd
CY2022	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	22757000	usd
CY2021	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	43792000	usd
CY2023	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	61000	usd
CY2022	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	40000	usd
CY2021	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	174000	usd
CY2023	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	587000	usd
CY2022	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	0	usd
CY2021	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	-1118000	usd
CY2023	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	1139000	usd
CY2022	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	10205000	usd
CY2021	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	437000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-37874000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	5447000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	2672000	usd
CY2023	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	7422000	usd
CY2022	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	1378000	usd
CY2021	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-2257000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-85559000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	94674000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	24482000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	79864000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	226517000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	156104000	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2046010000	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	708307000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	692675000	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1125414000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	460765000	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	160498000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	960614000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	107787000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	315455000	usd
CY2023	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	usd
CY2022	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	1632000	usd
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	22563000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	12002000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	18304000	usd
CY2023	sbsi	Proceeds From Sales Of Equity Securities ProceedsFromSalesOfEquitySecurities	6679000	usd
CY2022	sbsi	Proceeds From Sales Of Equity Securities ProceedsFromSalesOfEquitySecurities	0	usd
CY2021	sbsi	Proceeds From Sales Of Equity Securities ProceedsFromSalesOfEquitySecurities	0	usd
CY2023	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	36919000	usd
CY2022	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	46812000	usd
CY2021	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	32174000	usd
CY2023	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	39796000	usd
CY2022	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	40967000	usd
CY2021	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	21221000	usd
CY2023	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	388304000	usd
CY2022	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	503647000	usd
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-11891000	usd
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	6904000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	9301000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	8365000	usd
CY2023	us-gaap	Payments For Proceeds From Life Insurance Policies PaymentsForProceedsFromLifeInsurancePolicies	-951000	usd
CY2022	us-gaap	Payments For Proceeds From Life Insurance Policies PaymentsForProceedsFromLifeInsurancePolicies	0	usd
CY2021	us-gaap	Payments For Proceeds From Life Insurance Policies PaymentsForProceedsFromLifeInsurancePolicies	13000000	usd
CY2023	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	430000	usd
CY2022	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	1365000	usd
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	1861000	usd
CY2023	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	203000	usd
CY2022	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	220000	usd
CY2021	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	816000	usd
CY2023	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	168000	usd
CY2022	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	124000	usd
CY2021	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	254000	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-327073000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-634779000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-194008000	usd
CY2023	us-gaap	Net Change Interest And Noninterest Bearing Deposits Domestic NetChangeInterestAndNoninterestBearingDepositsDomestic	351551000	usd
CY2022	us-gaap	Net Change Interest And Noninterest Bearing Deposits Domestic NetChangeInterestAndNoninterestBearingDepositsDomestic	475629000	usd
CY2021	us-gaap	Net Change Interest And Noninterest Bearing Deposits Domestic NetChangeInterestAndNoninterestBearingDepositsDomestic	789968000	usd
CY2023	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	288667000	usd
CY2022	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	197934000	usd
CY2021	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	47000	usd
CY2023	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	2019000000	usd
CY2022	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	3321000000	usd
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	14998118000	usd
CY2023	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	1959710000	usd
CY2022	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	3511680000	usd
CY2021	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	15486607000	usd
CY2023	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	0	usd
CY2022	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	0	usd
CY2021	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	95000	usd
CY2023	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	4365000	usd
CY2022	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
CY2021	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	100011000	usd
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1082000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	790000	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	7672000	usd
CY2023	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	597000	usd
CY2022	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	501000	usd
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	479000	usd
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	44803000	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	33708000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	34148000	usd
CY2023	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	1224000	usd
CY2022	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	1233000	usd
CY2021	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	1353000	usd
CY2023	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	43582000	usd
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	44936000	usd
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	44569000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	608467000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	405761000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	131249000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	361258000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-2501000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	93345000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	199252000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	201753000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	108408000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	560510000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	199252000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	201753000	usd
CY2023	us-gaap	Interest Paid Net InterestPaidNet	137292000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	39262000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	28687000	usd
CY2023	us-gaap	Income Taxes Paid IncomeTaxesPaid	15750000	usd
CY2022	us-gaap	Income Taxes Paid IncomeTaxesPaid	11950000	usd
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	10750000	usd
CY2023	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	226000	usd
CY2022	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	465000	usd
CY2021	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	740000	usd
CY2023	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	8093000	usd
CY2022	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	usd
CY2021	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	usd
CY2023	sbsi	Debt Securities Available For Sale Transfer To Held To Maturity DebtSecuritiesAvailableForSaleTransferToHeldToMaturity	0	usd
CY2022	sbsi	Debt Securities Available For Sale Transfer To Held To Maturity DebtSecuritiesAvailableForSaleTransferToHeldToMaturity	1369639000	usd
CY2021	sbsi	Debt Securities Available For Sale Transfer To Held To Maturity DebtSecuritiesAvailableForSaleTransferToHeldToMaturity	0	usd
CY2021Q4	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	18995000	usd
CY2023Q4	sbsi	Unsettled Trades To Repurchase Common Stock UnsettledTradesToRepurchaseCommonStock	0	usd
CY2022Q4	sbsi	Unsettled Trades To Repurchase Common Stock UnsettledTradesToRepurchaseCommonStock	-133000	usd
CY2021Q4	sbsi	Unsettled Trades To Repurchase Common Stock UnsettledTradesToRepurchaseCommonStock	0	usd
CY2023Q4	sbsi	Numberofbankingcenters Numberofbankingcenters	55	banking_offices
CY2023Q4	sbsi	Numberofbankingcentersingrocerystores Numberofbankingcentersingrocerystores	13	banking_offices
CY2023	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain prior period amounts may be reclassified to conform to current period presentation.
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">Use of Estimates</span>. In preparing consolidated financial statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and reported amounts of revenues and expenses during the reporting period. These estimates are subjective in nature and involve matters of judgment. Actual results could differ from these estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for credit losses. The status of contingencies are particularly subject to change.
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2023	us-gaap	Revenue Recognition Interest RevenueRecognitionInterest	<div style="margin-bottom:6pt;margin-top:6pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">Accrued Interest</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">. Accrued interest for our loans and debt securities, included in interest receivable on our consolidated balance sheets, is excluded from the estimate of allowance for credit losses.</span></div>
CY2023Q4	us-gaap	Financing Receivable Threshold Period Past Due FinancingReceivableThresholdPeriodPastDue	P90D
CY2023Q4	us-gaap	Financing Receivable Threshold Period Past Due Writeoff FinancingReceivableThresholdPeriodPastDueWriteoff	P120D
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2023	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2023Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0	usd
CY2022Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0	usd
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	14000	shares
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	9000	shares
CY2023	us-gaap	Net Income Loss NetIncomeLoss	86692000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	105020000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	113401000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	30704000	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	32120000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	32558000	shares
CY2023	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	55000	shares
CY2022	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	131000	shares
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	134000	shares
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	30759000	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	32251000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	32692000	shares
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.82
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.27
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.48
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.82
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.26
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.47
CY2023	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	570000	shares
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4077000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1332467000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	3658000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	39831000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1296294000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	1307053000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	10571000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	151462000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1166162000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1387874000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1282000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	90142000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1299014000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	1326729000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	4565000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	182138000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1149156000	usd
CY2023	sbsi	Securities Transferred From Available For Sale To Held To Maturity SecuritiesTransferredFromAvailableForSaleToHeldToMaturity	0	usd
CY2022	sbsi	Securities Transferred From Available For Sale To Held To Maturity SecuritiesTransferredFromAvailableForSaleToHeldToMaturity	1250000000	usd
CY2022Q4	sbsi	Transferred Securities Unrealized Loss Before Tax TransferredSecuritiesUnrealizedLossBeforeTax	121500000	usd
CY2022Q4	sbsi	Securities Transferred Unrealized Loss Net Of Tax SecuritiesTransferredUnrealizedLossNetOfTax	96000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	185339000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	1165000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	560939000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	38666000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	746278000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	39831000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	26505000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	1258000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	939087000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	150204000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	965592000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	151462000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	373	debt_security
CY2023Q4	sbsi	Financing Receivable Held To Maturity Number Of Bonds Below Investment Grade FinancingReceivableHeldToMaturityNumberOfBondsBelowInvestmentGrade	2	bonds
CY2023	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	0	usd
CY2022	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss	15400000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAccruedInterestAfterAllowanceForCreditLoss	13700000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss	16900000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAccruedInterestAfterAllowanceForCreditLoss	13600000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Nonaccrual DebtSecuritiesHeldToMaturityNonaccrual	0	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Nonaccrual DebtSecuritiesHeldToMaturityNonaccrual	0	usd
CY2023	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	11331000	usd
CY2022	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	271000	usd
CY2021	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	615000	usd
CY2023	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	67355000	usd
CY2022	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	57663000	usd
CY2021	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	46296000	usd
CY2023	us-gaap	Interest Income Securities Corporate Debt Operating InterestIncomeSecuritiesCorporateDebtOperating	7129000	usd
CY2022	us-gaap	Interest Income Securities Corporate Debt Operating InterestIncomeSecuritiesCorporateDebtOperating	6007000	usd
CY2021	us-gaap	Interest Income Securities Corporate Debt Operating InterestIncomeSecuritiesCorporateDebtOperating	4131000	usd
CY2023	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	19450000	usd
CY2022	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	16639000	usd
CY2023	us-gaap	Interest And Other Income InterestAndOtherIncome	105265000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-16000000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	24500000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	2000000	usd
CY2023	us-gaap	Gain Loss On Oil And Gas Hedging Activity GainLossOnOilAndGasHedgingActivity	6500000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3800000	usd
CY2022	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	usd
CY2023	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	139916000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	139935000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	4260000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	4242000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	22203000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	21689000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	591809000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	556697000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	758188000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	722563000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	574279000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	573731000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1332467000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1296294000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Rolling Within One Year DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateRollingWithinOneYear	15969000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	15092000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Rolling After One Through Five Years DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateRollingAfterOneThroughFiveYears	4868000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	4739000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Rolling After5 Through10 Years DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateRollingAfter5Through10Years	140774000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	126474000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Rolling After10 Years DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateRollingAfter10Years	1024541000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	908434000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDate	1186152000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	1054739000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Without Single Maturity Date DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityWithoutSingleMaturityDate	120901000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	111423000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	1307053000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1166162000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	9700000	usd
CY2022Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	11200000	usd
CY2023	sbsi	Equity Securities Realized Gain EquitySecuritiesRealizedGain	5058000	usd
CY2023	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	73000	usd
CY2022	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-685000	usd
CY2023Q4	sbsi	Other Than Temporarily Impaired Equity Investments OtherThanTemporarilyImpairedEquityInvestments	0	usd
CY2023Q4	sbsi	Fhlb Stock With Other Than Temporary Impairment FHLBStockWithOtherThanTemporaryImpairment	0	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4524510000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4147691000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	42674000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	36515000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	4481836000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	4111176000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	13700000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	14200000	usd
CY2023Q4	sbsi	Loans And Leases Receivable Related Parties As Percent Of Shareholders Equity LoansAndLeasesReceivableRelatedPartiesAsPercentOfShareholdersEquity	0.018	rate
CY2022Q4	sbsi	Loans And Leases Receivable Related Parties As Percent Of Shareholders Equity LoansAndLeasesReceivableRelatedPartiesAsPercentOfShareholdersEquity	0.019	rate
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	839785000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	1199738000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	961538000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	365469000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	217076000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	613986000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	326918000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	4524510000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff	2427000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff	586000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff	105000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff	46000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff	818000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff	222000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Writeoff FinancingReceivableExcludingAccruedInterestRevolvingWriteoff	0	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	4204000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	1262330000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	630012000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	506000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	1000000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	1600000	usd
CY2023Q4	sbsi	Financing Receivable Collateral Dependent FinancingReceivableCollateralDependent	7500000	usd
CY2022Q4	sbsi	Financing Receivable Collateral Dependent FinancingReceivableCollateralDependent	8100000	usd
CY2023Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	1000000	usd
CY2022Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	0	usd
CY2023Q4	sbsi	Financing Receivable Excluding Accrued Interest Modified In Period Number Of Loans Modified Nonaccrual FinancingReceivableExcludingAccruedInterestModifiedInPeriodNumberOfLoansModifiedNonaccrual	3	loans
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	506000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	36515000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	4204000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	1454000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff After Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery	2750000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	8909000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	42674000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	35273000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	2584000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	1888000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff After Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery	696000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	1938000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	36515000	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	49006000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	2751000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	1980000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff After Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery	771000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	-12962000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	35273000	usd
CY2023Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	21300000	usd
CY2022Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	18800000	usd
CY2023Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	189643000	usd
CY2022Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	185588000	usd
CY2023Q4	us-gaap	Furniture And Fixtures Gross FurnitureAndFixturesGross	44719000	usd
CY2022Q4	us-gaap	Furniture And Fixtures Gross FurnitureAndFixturesGross	44126000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	234362000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	229714000	usd
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	95412000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	88458000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	138950000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	141256000	usd
CY2023	us-gaap	Accumulated Depreciation Depletion And Amortization Sale Of Property Plant And Equipment1 AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1	1500000	usd
CY2022	us-gaap	Accumulated Depreciation Depletion And Amortization Sale Of Property Plant And Equipment1 AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1	1900000	usd
CY2023	us-gaap	Depreciation Depreciation	8400000	usd
CY2022	us-gaap	Depreciation Depreciation	8600000	usd
CY2021	us-gaap	Depreciation Depreciation	8200000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	1390407000	usd
CY2022Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	1671562000	usd
CY2023Q4	us-gaap	Interest Bearing Deposit Liabilities Domestic InterestBearingDepositLiabilitiesDomestic	5159274000	usd
CY2022Q4	us-gaap	Interest Bearing Deposit Liabilities Domestic InterestBearingDepositLiabilitiesDomestic	4526457000	usd
CY2023Q4	us-gaap	Deposits Deposits	6549681000	usd
CY2022Q4	us-gaap	Deposits Deposits	6198019000	usd
CY2023	sbsi	Interest Expense Time Deposits250000or More InterestExpenseTimeDeposits250000orMore	13000000	usd
CY2022	sbsi	Interest Expense Time Deposits250000or More InterestExpenseTimeDeposits250000orMore	2100000	usd
CY2021	sbsi	Interest Expense Time Deposits250000or More InterestExpenseTimeDeposits250000orMore	1400000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	758980000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	113907000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	6256000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	3627000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	6707000	usd
CY2023Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	0	usd
CY2023Q4	us-gaap	Time Deposits TimeDeposits	889477000	usd
CY2023	sbsi	Interest Bearing Domestic Deposit Brokered Maximum Balance Allowed Per Company Policy Percent InterestBearingDomesticDepositBrokeredMaximumBalanceAllowedPerCompanyPolicyPercent	0.20
CY2023Q4	us-gaap	Related Party Deposit Liabilities RelatedPartyDepositLiabilities	9800000	usd
CY2022Q4	us-gaap	Related Party Deposit Liabilities RelatedPartyDepositLiabilities	11000000	usd
CY2023Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	1300000	usd
CY2022Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	1200000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In The Next Rolling Twelve Months BorrowedFundsMaturitiesRepaymentsOfPrincipalInTheNextRollingTwelveMonths	714127000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In Rolling Year Two BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearTwo	7205000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In Rolling Year Three BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearThree	484000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In Rolling Year Four BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFour	406000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In Rolling Year Five BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFive	246000	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal In Rolling After Year Five BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingAfterYearFive	0	usd
CY2023Q4	sbsi	Borrowed Funds Maturities Repayments Of Principal BorrowedFundsMaturitiesRepaymentsOfPrincipal	722468000	usd
CY2023Q4	sbsi	Line Of Credit Facility Number Of Credit Lines Maintained By Company LineOfCreditFacilityNumberOfCreditLinesMaintainedByCompany	3	credit_line
CY2023Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	usd
CY2022Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	usd
CY2023Q4	sbsi	Letters Of Credit Fhlb As Collateral LettersOfCreditFhlbAsCollateral	0	usd
CY2023Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	92100000	usd
CY2022Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	33200000	usd
CY2023	sbsi	Repurchase Agreement Counterparty Maturityof Agreements RepurchaseAgreementCounterpartyMaturityofAgreements	P2Y
CY2023Q4	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Amount Of Available Unused Funds FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds	1950000000	usd
CY2023Q4	us-gaap	Subordinated Debt SubordinatedDebt	93877000	usd
CY2022Q4	us-gaap	Subordinated Debt SubordinatedDebt	98674000	usd
CY2023Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	60270000	usd
CY2022Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	60265000	usd
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	154147000	usd
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	158939000	usd
CY2023	sbsi	Health Care Costs HealthCareCosts	8100000	usd
CY2022	sbsi	Health Care Costs HealthCareCosts	8400000	usd
CY2021	sbsi	Health Care Costs HealthCareCosts	8600000	usd
CY2023	sbsi	Other Postretirement Benefits Health Insurance Coverage For Employees Retiring Requisite Service Period OtherPostretirementBenefitsHealthInsuranceCoverageForEmployeesRetiringRequisiteServicePeriod	P50Y
CY2021Q4	sbsi	Retireesparticipatinginhealthinsurance Retireesparticipatinginhealthinsurance	1	retiree
CY2023Q4	sbsi	Retireesparticipatinginhealthinsurance Retireesparticipatinginhealthinsurance	1	retiree
CY2022Q4	sbsi	Retireesparticipatinginhealthinsurance Retireesparticipatinginhealthinsurance	1	retiree
CY2022	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	1000000	usd
CY2023	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	1000000	usd
CY2021	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	1000000	usd
CY2023Q4	us-gaap	Employee Stock Ownership Plan Esop Shares In Esop EmployeeStockOwnershipPlanESOPSharesInESOP	366791	shares
CY2022Q4	us-gaap	Employee Stock Ownership Plan Esop Shares In Esop EmployeeStockOwnershipPlanESOPSharesInESOP	345847	shares
CY2023	sbsi	Supplemental Unemployment Benefits Disability Related Benefits Automatic Coverage Qualification Requisite Service Period SupplementalUnemploymentBenefitsDisabilityRelatedBenefitsAutomaticCoverageQualificationRequisiteServicePeriod	P3Y
CY2023	sbsi	Supplemental Unemployment Benefits Disability Related Benefits Automatic Coverage Qualification Minimum Annual Salary Level SupplementalUnemploymentBenefitsDisabilityRelatedBenefitsAutomaticCoverageQualificationMinimumAnnualSalaryLevel	50000	usd
CY2023	sbsi	Supplemental Unemployment Benefits Disability Related Benefits Maximum Benefit Provided Per Month SupplementalUnemploymentBenefitsDisabilityRelatedBenefitsMaximumBenefitProvidedPerMonth	15000	usd
CY2023	sbsi	Defined Contribution Plan Requisite Service Period DefinedContributionPlanRequisiteServicePeriod	P30D
CY2023	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	2200000	usd
CY2022	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	2000000	usd
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	2200000	usd
CY2023	sbsi	Adjustment To Pension Liability AdjustmentToPensionLiability	948000	usd
CY2022	sbsi	Adjustment To Pension Liability AdjustmentToPensionLiability	5400000	usd
CY2022Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	usd
CY2023Q4	us-gaap	Derivative Assets DerivativeAssets	2444000	usd
CY2023Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions	620506	shares
CY2023Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Exercise Price Beginning Balance1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1	33.76
CY2023	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2	P4Y3M
CY2023Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Exercisable Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions	620506	shares
CY2023Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1	33.76
CY2023	us-gaap	Gain Loss On Oil And Gas Hedging Activity GainLossOnOilAndGasHedgingActivity	6500000	usd
CY2023Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	13642000	usd
CY2022Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	21562000	usd
CY2023Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	46800000	usd
CY2022Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	82100000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	56639000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	25684000	usd
CY2022Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	82306000	usd
CY2022Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	21217000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	7435000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	7435000	usd
CY2022Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	171000	usd
CY2022Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	171000	usd
CY2023Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	46760000	usd
CY2023Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	usd
CY2022Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	82135000	usd
CY2023Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	18249000	usd
CY2022Q4	us-gaap	Derivative Assets DerivativeAssets	0	usd
CY2022Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	21046000	usd
CY2023	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.42
CY2022	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.40
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.37
CY2023	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	38884	shares
CY2023	sbsi	Stock Issued During Period Per Share Average Dividend Reinvestment Plan StockIssuedDuringPeriodPerShareAverageDividendReinvestmentPlan	31.48
CY2022	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	31853	shares
CY2021	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	34150	shares
CY2022	sbsi	Stock Issued During Period Per Share Average Dividend Reinvestment Plan StockIssuedDuringPeriodPerShareAverageDividendReinvestmentPlan	38.70
CY2021	sbsi	Stock Issued During Period Per Share Average Dividend Reinvestment Plan StockIssuedDuringPeriodPerShareAverageDividendReinvestmentPlan	39.64
CY2023	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	1435193	shares
CY2023	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	45100000	usd
CY2022	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	923775	shares
CY2022	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	33800000	usd
CY2021	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	938484	shares
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	34100000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P10Y
CY2023Q4	us-gaap	Lessee Operating Lease Lease Not Yet Commenced Term Of Contract1 LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1	P5Y4M24D
CY2023Q4	us-gaap	Net Rentable Area NetRentableArea	202000	sqft
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	16547000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	14700000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	12674000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2110000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-89000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4752000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14437000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14611000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17426000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	8962000	usd
CY2023Q4	sbsi	Deferred Tax Liabilities Pension Plan DeferredTaxLiabilitiesPensionPlan	2529000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	8852000	usd
CY2023Q4	sbsi	Deferred Tax Asset Operating Lease Liabilities DeferredTaxAssetOperatingLeaseLiabilities	3508000	usd
CY2023Q4	sbsi	Deferred Tax Liabilities Operating Lease Right Of Use Assets DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets	3116000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	292000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	31820000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	6268000	usd
CY2023Q4	sbsi	Deferred Tax Asset Fair Value Adjustmenton Acquired Loans DeferredTaxAssetFairValueAdjustmentonAcquiredLoans	436000	usd
CY2023Q4	sbsi	Deferred Tax Assets Unfunded Status Of Defined Benefit Plan DeferredTaxAssetsUnfundedStatusOfDefinedBenefitPlan	4988000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards General Business DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness	181000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	1294000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	294000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	51483000	usd
CY2023Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	21057000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	30426000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	7668000	usd
CY2022Q4	sbsi	Deferred Tax Liabilities Pension Plan DeferredTaxLiabilitiesPensionPlan	2435000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	9269000	usd
CY2022Q4	sbsi	Deferred Tax Asset Operating Lease Liabilities DeferredTaxAssetOperatingLeaseLiabilities	3585000	usd
CY2022Q4	sbsi	Deferred Tax Liabilities Operating Lease Right Of Use Assets DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets	3216000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	548000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	44299000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	12829000	usd
CY2022Q4	sbsi	Deferred Tax Asset Fair Value Adjustmenton Acquired Loans DeferredTaxAssetFairValueAdjustmentonAcquiredLoans	500000	usd
CY2022Q4	sbsi	Deferred Tax Assets Unfunded Status Of Defined Benefit Plan DeferredTaxAssetsUnfundedStatusOfDefinedBenefitPlan	5184000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards General Business DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness	242000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	1177000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	337000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	62992000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	28297000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	34695000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	20576000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	3872000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	16704000	usd
CY2023Q4	sbsi	Lessee Operating Lease Lease Not Yet Commenced Liability LesseeOperatingLeaseLeaseNotYetCommencedLiability	422000	usd
CY2023	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	21237000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2022	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	25123000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	27474000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2023	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsuranceAmount	6107000	usd
CY2023	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsurancePercent	0.060
CY2022	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsuranceAmount	10345000	usd
CY2022	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsurancePercent	0.086
CY2021	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsuranceAmount	9636000	usd
CY2021	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Other Than Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherThanLifeInsurancePercent	0.074
CY2023	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsuranceAmount	1222000	usd
CY2023	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsurancePercent	0.012
CY2022	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsuranceAmount	555000	usd
CY2022	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsurancePercent	0.005
CY2021	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Amount EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsuranceAmount	549000	usd
CY2021	sbsi	Effective Income Tax Rate Reconciliation Tax Exempt Income Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeLifeInsurancePercent	0.004
CY2023	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	89000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.001
CY2022	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-93000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.001
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	-392000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.003
CY2023	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	353000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.003
CY2022	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	312000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.003
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	366000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.003
CY2023	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	87000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2022	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	169000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	163000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14437000	usd
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.143
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14611000	usd
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.122
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17426000	usd
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.133
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	14837000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	15314000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	16704000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	17070000	usd
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	1802000	usd
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	1773000	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	1811000	usd
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	1716000	usd
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	1644000	usd
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	2016000	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	809000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	1531000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	1330000	usd
CY2021Q1	sbsi	Lessee Operating Lease Numberof Contracts LesseeOperatingLeaseNumberofContracts	1	contract
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P13Y
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P13Y9M18D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0327	rate
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0298	rate
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	1607000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1754000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	1737000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	1616000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	1581000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	12281000	usd
CY2023Q4	sbsi	Number Of Square Feet We Occupy NumberOfSquareFeetWeOccupy	39000	sqft
CY2023	sbsi	Operating Lease Income Comprehensive Income Extensible List Not Disclosed Flag OperatingLeaseIncomeComprehensiveIncomeExtensibleListNotDisclosedFlag	Gross rental income
CY2023	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	3584000	usd
CY2022	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	3173000	usd
CY2021	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	3288000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Next Twelve Months LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths	2962000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Two Years LessorOperatingLeasePaymentsToBeReceivedTwoYears	2297000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Three Years LessorOperatingLeasePaymentsToBeReceivedThreeYears	1964000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Four Years LessorOperatingLeasePaymentsToBeReceivedFourYears	1197000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Five Years LessorOperatingLeasePaymentsToBeReceivedFiveYears	509000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received Thereafter LessorOperatingLeasePaymentsToBeReceivedThereafter	794000	usd
CY2023Q4	us-gaap	Lessor Operating Lease Payments To Be Received LessorOperatingLeasePaymentsToBeReceived	9723000	usd
CY2022Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	3687000	usd
CY2021Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	2384000	usd
CY2020Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	6386000	usd
CY2023	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	245000	usd
CY2022	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	1303000	usd
CY2021	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	-4002000	usd
CY2023Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	3932000	usd
CY2022Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	3687000	usd
CY2021Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	2384000	usd
CY2023Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1093150000	usd
CY2022Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1323617000	usd
CY2022Q4	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	0	usd
CY2023Q4	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	0	usd
CY2022Q4	sbsi	Unsettled Trades To Sell Securities UnsettledTradesToSellSecurities	0	usd
CY2023Q4	sbsi	Unsettled Trades To Sell Securities UnsettledTradesToSellSecurities	0	usd
CY2022Q4	sbsi	Unsettled Issuancesof Brokered C Ds UnsettledIssuancesofBrokeredCDs	0	usd
CY2023Q4	sbsi	Unsettled Issuancesof Brokered C Ds UnsettledIssuancesofBrokeredCDs	0	usd
CY2023Q4	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false

Files In Submission

Name	View Source	Status
0000705432-24-000026-index-headers.html	Edgar Link	pending
0000705432-24-000026-index.html	Edgar Link	pending
0000705432-24-000026.txt	Edgar Link	pending
0000705432-24-000026-xbrl.zip	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
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sbsi-20231231_cal.xml	Edgar Link	unprocessable
sbsi-20231231_def.xml	Edgar Link	unprocessable
sbsi-20231231_lab.xml	Edgar Link	unprocessable
sbsi-20231231_pre.xml	Edgar Link	unprocessable
sbsi-20231231_htm.xml	Edgar Link	completed

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$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi

2024 Q1 Form 10-K Financial Statement

#000070543224000026 Filed on February 27, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SBSI SOUTHSIDE BANCSHARES INC Stock $sbsi

2024 Q1 Form 10-K Financial Statement

#000070543224000026 Filed on February 27, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi