$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi

$sbsi Overview Financials Valuation SEC Filings Company Website

2019 Q2 Form 10-Q Financial Statement

#000070543219000088 Filed on August 01, 2019

Income Statement

Concept	2019 Q2	2018 Q2	2017 Q4
Revenue	$60.67M	$56.80M	$50.10M
YoY Change	6.82%	23.45%	14.71%
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	$3.100M	$3.500M	$2.900M
YoY Change	-11.43%	45.83%	16.0%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$17.54M	$13.69M	$11.80M
YoY Change	28.17%	29.3%	30.52%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$22.18M	$23.56M	$16.20M
YoY Change	-5.87%	32.12%	20.79%
Income Tax	$3.569M	$3.360M	$5.870M
% Of Pretax Income	16.09%	14.26%	36.23%
Net Earnings	$18.61M	$20.20M	$10.33M
YoY Change	-7.88%	39.51%	-10.73%
Net Earnings / Revenue	30.67%	35.57%	20.62%
Basic Earnings Per Share	$0.55	$0.58	$0.33
Diluted Earnings Per Share	$0.55	$0.57	$0.33
COMMON SHARES
Basic Shares Outstanding	33.73M shares	35.06M shares	29.43M shares
Diluted Shares Outstanding	33.88M shares	35.23M shares

Balance Sheet

Concept	2019 Q2	2018 Q2	2017 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$132.5M	$232.1M	$198.7M
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	$140.1M	$132.6M	$133.6M
YoY Change	5.68%	25.15%	26.07%
Goodwill	$201.1M	$201.2M	$201.2M
YoY Change	-0.07%	119.89%	119.89%
Intangibles	$15.47M	$20.29M	$22.99M
YoY Change	-23.74%	438.55%	398.98%
Long-Term Investments	$12.40M
YoY Change
Other Assets	$0.00	$15.40M	$12.20M
YoY Change	-100.0%	-31.25%	-57.79%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$6.373B	$6.250B	$6.498B
YoY Change	1.96%	12.04%	16.79%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$10.20M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$26.10M	$8.300M	$9.500M
YoY Change	214.46%	-99.19%	-98.91%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$10.20M	$8.300M	$9.500M
YoY Change	22.89%	-1.19%	33.8%
LONG-TERM LIABILITIES
Long-Term Debt	$158.7M	$158.6M	$158.5M
YoY Change	0.06%	0.13%	0.13%
Other Long-Term Liabilities	$82.10M	$46.30M	$43.20M
YoY Change	77.32%	-25.8%	15.82%
Total Long-Term Liabilities	$240.8M	$204.9M	$201.7M
YoY Change	17.52%	-7.2%	3.12%
TOTAL LIABILITIES
Total Short-Term Liabilities	$10.20M	$8.300M	$9.500M
Total Long-Term Liabilities	$240.8M	$204.9M	$201.7M
Total Liabilities	$5.585B	$5.498B	$5.744B
YoY Change	1.58%	9.28%	13.84%
SHAREHOLDERS EQUITY
Retained Earnings	$65.18M	$48.84M	$32.85M
YoY Change	33.45%	151.66%	9.15%
Common Stock	$811.6M	$806.8M	$804.7M
YoY Change	0.58%	34.02%	40.05%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$93.91M	$46.55M	$47.11M
YoY Change	101.73%	-2.68%	-1.64%
Treasury Stock Shares	4.118M shares	2.739M shares	2.802M shares
Shareholders Equity	$787.8M	$751.8M	$754.1M
YoY Change
Total Liabilities & Shareholders Equity	$6.373B	$6.250B	$6.498B
YoY Change	1.96%	12.04%	16.79%

Cashflow Statement

Concept	2019 Q2	2018 Q2	2017 Q4
OPERATING ACTIVITIES
Net Income	$18.61M	$20.20M	$10.33M
YoY Change	-7.88%	39.51%	-10.73%
Depreciation, Depletion And Amortization	$3.100M	$3.500M	$2.900M
YoY Change	-11.43%	45.83%	16.0%
Cash From Operating Activities	$14.30M	$28.80M	$14.30M
YoY Change	-50.35%	80.0%	-28.86%
INVESTING ACTIVITIES
Capital Expenditures	-$3.900M	-$3.200M	-$2.500M
YoY Change	21.88%	23.08%	92.31%
Acquisitions
YoY Change
Other Investing Activities	-$270.3M	$81.90M	$83.90M
YoY Change	-430.04%	36.5%	-141.39%
Cash From Investing Activities	-$274.2M	$78.90M	$81.30M
YoY Change	-447.53%	37.7%	-139.85%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	122.4M	-138.4M	-81.50M
YoY Change	-188.44%	63.79%	-152.75%
NET CHANGE
Cash From Operating Activities	14.30M	28.80M	14.30M
Cash From Investing Activities	-274.2M	78.90M	81.30M
Cash From Financing Activities	122.4M	-138.4M	-81.50M
Net Change In Cash	-137.5M	-30.70M	14.10M
YoY Change	347.88%	174.11%	-147.96%
FREE CASH FLOW
Cash From Operating Activities	$14.30M	$28.80M	$14.30M
Capital Expenditures	-$3.900M	-$3.200M	-$2.500M
Free Cash Flow	$18.20M	$32.00M	$16.80M
YoY Change	-43.13%	72.04%	-21.5%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2018Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.30
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
	dei	Entity Central Index Key EntityCentralIndexKey	0000705432
CY2018Q2	sbsi	Loans Receivable Modifications Commitmentto Lend LoansReceivableModificationsCommitmenttoLend	0	USD
	sbsi	Provision Reversalfor Pci Loans ProvisionReversalforPCILoans	358000	USD
CY2018	sbsi	Securities Transferred From Available For Sale To Held To Maturity SecuritiesTransferredFromAvailableForSaleToHeldToMaturity	0	USD
CY2018Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.28
CY2019Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.30
CY2018Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1.25
CY2019Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1.25
CY2018Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	80000000	shares
	dei	Amendment Flag AmendmentFlag	false
CY2019Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	80000000	shares
CY2018Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	37845224	shares
CY2019Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	37866359	shares
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	USD
CY2018Q4	us-gaap	Goodwill Goodwill	201100000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	0	USD
	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	USD
	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	USD
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	0-12247
	dei	Entity Registrant Name EntityRegistrantName	SOUTHSIDE BANCSHARES INC
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	TX
CY2018Q1	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	10035	shares
CY2018Q2	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	10397	shares
CY2019Q1	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	10565	shares
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CY2019Q1	us-gaap	Stock Issued During Period Shares Share Based Compensation StockIssuedDuringPeriodSharesShareBasedCompensation	23617	shares
CY2019Q2	us-gaap	Stock Issued During Period Shares Share Based Compensation StockIssuedDuringPeriodSharesShareBasedCompensation	20115	shares
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	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2019-06-30
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	75-1848732
	dei	Entity Address Address Line1 EntityAddressAddressLine1	1201 S. Beckham Avenue,
	dei	Entity Address City Or Town EntityAddressCityOrTown	Tyler,
	dei	Entity Address State Or Province EntityAddressStateOrProvince	TX
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	75701
	dei	City Area Code CityAreaCode	903
	dei	Local Phone Number LocalPhoneNumber	531-7111
	dei	Security12b Title Security12bTitle	Common Stock, $1.25 par value
	dei	Trading Symbol TradingSymbol	SBSI
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
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	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	1227000	USD
CY2019Q2	us-gaap	Interest Expense Other InterestExpenseOther	57000	USD
CY2018Q2	us-gaap	Interest Expense Other InterestExpenseOther	33000	USD
	us-gaap	Interest Expense Other InterestExpenseOther	132000	USD
	us-gaap	Interest Expense Other InterestExpenseOther	44000	USD
CY2019Q2	us-gaap	Interest Expense InterestExpense	17541000	USD
CY2018Q2	us-gaap	Interest Expense InterestExpense	13686000	USD
	us-gaap	Interest Expense InterestExpense	35443000	USD
	us-gaap	Interest Expense InterestExpense	26747000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	43131000	USD
CY2018Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	43111000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	84256000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	87244000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2506000	USD
CY2018Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1281000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1588000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	5016000	USD
CY2019Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	40625000	USD
CY2018Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	41830000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	82668000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	82228000	USD
CY2019Q2	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	6652000	USD
CY2018Q2	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	6261000	USD
	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	12638000	USD
	sbsi	Fee And Commissions Depositor Account FeeAndCommissionsDepositorAccount	12440000	USD
CY2019Q2	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	416000	USD
CY2018Q2	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-332000	USD
	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	672000	USD
	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-1159000	USD
CY2019Q2	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	181000	USD
CY2018Q2	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	173000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	274000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	288000	USD
CY2019Q2	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	1520000	USD
CY2018Q2	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	1931000	USD
	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	3061000	USD
	sbsi	Fees And Commissions Fiduciary And Trust Activity FeesAndCommissionsFiduciaryAndTrustActivity	3691000	USD
CY2019Q2	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	559000	USD
CY2018Q2	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1185000	USD
	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1103000	USD
	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1817000	USD
CY2019Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	477000	USD
CY2018Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	506000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	994000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	956000	USD
CY2019Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	1449000	USD
CY2018Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	1283000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2050000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2584000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	11254000	USD
CY2018Q2	us-gaap	Noninterest Income NoninterestIncome	11007000	USD
	us-gaap	Noninterest Income NoninterestIncome	20792000	USD
	us-gaap	Noninterest Income NoninterestIncome	20617000	USD
CY2019Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	17891000	USD
CY2018Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	16633000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	35937000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	35192000	USD
CY2019Q2	us-gaap	Occupancy Net OccupancyNet	3289000	USD
CY2018Q2	us-gaap	Occupancy Net OccupancyNet	3360000	USD
	us-gaap	Occupancy Net OccupancyNet	6464000	USD
	us-gaap	Occupancy Net OccupancyNet	6943000	USD
CY2019Q2	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2018Q2	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	1026000	USD
	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	1858000	USD
CY2019Q2	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	733000	USD
CY2018Q2	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	775000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	1580000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	1460000	USD
CY2019Q2	sbsi	Atm Expense ATMExpense	246000	USD
CY2018Q2	sbsi	Atm Expense ATMExpense	243000	USD
	sbsi	Atm Expense ATMExpense	426000	USD
	sbsi	Atm Expense ATMExpense	589000	USD
CY2019Q2	us-gaap	Professional Fees ProfessionalFees	1069000	USD
CY2018Q2	us-gaap	Professional Fees ProfessionalFees	952000	USD
	us-gaap	Professional Fees ProfessionalFees	2383000	USD
	us-gaap	Professional Fees ProfessionalFees	2022000	USD
CY2019Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	1086000	USD
CY2018Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	939000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	2162000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	1962000	USD
CY2019Q2	us-gaap	Communication Communication	489000	USD
CY2018Q2	us-gaap	Communication Communication	478000	USD
	us-gaap	Communication Communication	976000	USD
	us-gaap	Communication Communication	1016000	USD
	us-gaap	Noninterest Expense NoninterestExpense	60941000	USD
CY2019Q2	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	437000	USD
CY2018Q2	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	484000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	859000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	981000	USD
CY2019Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1129000	USD
CY2018Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1328000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2308000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2706000	USD
CY2019Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	3331000	USD
CY2018Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	3056000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	6232000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	6212000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	29700000	USD
CY2018Q2	us-gaap	Noninterest Expense NoninterestExpense	29274000	USD
	us-gaap	Noninterest Expense NoninterestExpense	59327000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	22179000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	23563000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	44133000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	41904000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3569000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3360000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6706000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5450000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	18610000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	20203000	USD
	us-gaap	Net Income Loss NetIncomeLoss	37427000	USD
	us-gaap	Net Income Loss NetIncomeLoss	36454000	USD
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.55
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.58
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.11
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.04
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.55
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.57
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.11
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2019Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.31
CY2018Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.30
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.61
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.58
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	18610000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	20203000	USD
	us-gaap	Net Income Loss NetIncomeLoss	37427000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	672000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-1159000	USD
	us-gaap	Net Income Loss NetIncomeLoss	36454000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	32196000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-10371000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	78822000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-48154000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred To Available For Sale Securities Before Tax OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesBeforeTax	0	USD
CY2018Q2	us-gaap	Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred To Available For Sale Securities Before Tax OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesBeforeTax	0	USD
	us-gaap	Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred To Available For Sale Securities Before Tax OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesBeforeTax	0	USD
	us-gaap	Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred To Available For Sale Securities Before Tax OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesBeforeTax	11881000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Transfers From Held To Maturity To Available For Sale Securities Net Of Tax OtherComprehensiveIncomeLossTransfersFromHeldToMaturityToAvailableForSaleSecuritiesNetOfTax	0	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Transfers From Held To Maturity To Available For Sale Securities Net Of Tax OtherComprehensiveIncomeLossTransfersFromHeldToMaturityToAvailableForSaleSecuritiesNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Transfers From Held To Maturity To Available For Sale Securities Net Of Tax OtherComprehensiveIncomeLossTransfersFromHeldToMaturityToAvailableForSaleSecuritiesNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Transfers From Held To Maturity To Available For Sale Securities Net Of Tax OtherComprehensiveIncomeLossTransfersFromHeldToMaturityToAvailableForSaleSecuritiesNetOfTax	401000	USD
CY2019Q2	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-80000	USD
CY2018Q2	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-1252000	USD
	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-571000	USD
	sbsi	Amortizationof Unrealized Gains Losseson Securities Transferred Between Availablefor Sale And Heldto Maturity Debt Securities Before Tax AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax	-1390000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	416000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-332000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-5653000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	1725000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-8773000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	5970000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	642000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	331000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	1310000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	458000	USD
CY2019Q2	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	648000	USD
CY2018Q2	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	618000	USD
	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	1189000	USD
	sbsi	Other Comprehensive Income Loss Defined Benefit Plan Gain Lossand Prior Service Cost Credit Reclassification Adjustmentfrom Aoc Ibefore Tax OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax	1091000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	26213000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-6775000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	69827000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-26720000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	5505000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-1423000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	14664000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-5611000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-5352000	USD
CY2018Q2	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	367000	USD
CY2018Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	509000	USD
CY2018Q2	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	204000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20708000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-5352000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	55163000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-21109000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	39318000	USD
CY2018Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	14851000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	92590000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	15345000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	754140000	USD
CY2018Q1	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0	USD
CY2018Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest Adjusted Balance1 StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	754140000	USD
CY2018Q1	us-gaap	Net Income Loss NetIncomeLoss	16251000	USD
CY2018Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-15757000	USD
CY2018Q1	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	353000	USD
CY2018Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	456000	USD
CY2018Q1	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	761000	USD
CY2018Q1	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	9808000	USD
CY2018Q1	us-gaap	Stockholders Equity StockholdersEquity	746396000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	20203000	USD
CY2018Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10517000	USD
CY2018Q2	us-gaap	Stockholders Equity StockholdersEquity	751810000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	731291000	USD
CY2019Q1	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	-16452000	USD
CY2019Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest Adjusted Balance1 StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	714839000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	18817000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	34455000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	355000	USD
CY2019Q1	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1325000	USD
CY2019Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	661000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	338000	USD
CY2019Q1	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10107000	USD
CY2019Q1	us-gaap	Stockholders Equity StockholdersEquity	758033000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	18610000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20708000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	349000	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	571000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-53000	USD
CY2019Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10453000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	787765000	USD
	us-gaap	Profit Loss ProfitLoss	37427000	USD
	us-gaap	Profit Loss ProfitLoss	36454000	USD
	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	6053000	USD
	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	7078000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-5946000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-7557000	USD
	us-gaap	Investment Income Net Amortization Of Discount And Premium InvestmentIncomeNetAmortizationOfDiscountAndPremium	940000	USD
	us-gaap	Investment Income Net Amortization Of Discount And Premium InvestmentIncomeNetAmortizationOfDiscountAndPremium	1712000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1588000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	5016000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	1232000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	965000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	142000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2438000	USD
	us-gaap	Availableforsale Securities Gross Realized Gain Loss Excluding Other Than Temporary Impairments AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments	672000	USD
	us-gaap	Availableforsale Securities Gross Realized Gain Loss Excluding Other Than Temporary Impairments AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments	-1159000	USD
	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-220000	USD
	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-132000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	9745000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	13578000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	10956000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	12159000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	90000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-258000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-2120000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-1391000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	89000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-16612000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	1617000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	247000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-18527000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-8484000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	34816000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	70530000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	784921000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	195005000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	713946000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	315656000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	60288000	USD
	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	8788000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	78042000	USD
	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	13377000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	15714000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	1767000	USD
	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	21210000	USD
	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	914000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	150798000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-19722000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	7900000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	5154000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	34000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	1905000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	490000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	771000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	227000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	287000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-165342000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	230454000	USD
	us-gaap	Net Change Interest And Noninterest Bearing Deposits Domestic NetChangeInterestAndNoninterestBearingDepositsDomestic	69276000	USD
	us-gaap	Net Change Interest And Noninterest Bearing Deposits Domestic NetChangeInterestAndNoninterestBearingDepositsDomestic	-6866000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-10746000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-1211000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	2959200000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	1718000000	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	2854506000	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	1958890000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	534000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1084000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	249000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	119000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1325000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	704000	USD
	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	720000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	20560000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	20325000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	142328000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-267607000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	11802000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	33377000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	120719000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	198692000	USD
CY2019Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	132521000	USD
CY2018Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	232069000	USD
	us-gaap	Interest Paid InterestPaid	33826000	USD
	us-gaap	Interest Paid InterestPaid	26499000	USD
CY2019Q2	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	38569000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	3500000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	0	USD
	sbsi	Loans Transferred To Other Repossessed Assets And Real Estate Through Foreclosure LoansTransferredToOtherRepossessedAssetsAndRealEstateThroughForeclosure	505000	USD
	sbsi	Loans Transferred To Other Repossessed Assets And Real Estate Through Foreclosure LoansTransferredToOtherRepossessedAssetsAndRealEstateThroughForeclosure	764000	USD
	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	USD
	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	3984000	USD
	us-gaap	Debt Securities Held To Maturity Transfer Amount DebtSecuritiesHeldToMaturityTransferAmount	0	USD
	us-gaap	Debt Securities Held To Maturity Transfer Amount DebtSecuritiesHeldToMaturityTransferAmount	743421000	USD
	sbsi	Adjustment To Pension Liability AdjustmentToPensionLiability	1189000	USD
	sbsi	Adjustment To Pension Liability AdjustmentToPensionLiability	1091000	USD
CY2018Q2	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	2279000	USD
CY2019Q2	us-gaap	Goodwill Goodwill	201100000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	18610000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	20203000	USD
	us-gaap	Net Income Loss NetIncomeLoss	37427000	USD
	us-gaap	Net Income Loss NetIncomeLoss	36454000	USD
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33726000	shares
CY2018Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	35062000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33711000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	35042000	shares
CY2019Q2	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	150000	shares
CY2018Q2	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	171000	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	151000	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	175000	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	33876000	shares
CY2018Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	35233000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	33862000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	35217000	shares
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.55
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.58
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.11
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.04
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.57
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.55
CY2018Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	246000	shares
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.11
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2019Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	480000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	485000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	216000	shares
CY2019Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	262000	USD
CY2018Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-1479000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	176000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-2515000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2045507000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	44665000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1385000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2088787000	USD
CY2019Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	147091000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	4516000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	300000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	151307000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2013485000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	10554000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	34603000	USD
CY2018Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1989436000	USD
CY2018Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	162931000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	360000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	3510000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	159781000	USD
CY2019Q2	sbsi	Transferred Securities Unrealized Loss Before Tax TransferredSecuritiesUnrealizedLossBeforeTax	4000000.0	USD
CY2019Q2	sbsi	Securitiestransferred Unrealized Loss Netof Tax SecuritiestransferredUnrealizedLossNetofTax	3100000	USD
CY2018Q4	sbsi	Transferred Securities Unrealized Loss Before Tax TransferredSecuritiesUnrealizedLossBeforeTax	15300000	USD
CY2018Q4	sbsi	Securitiestransferred Unrealized Loss Netof Tax SecuritiestransferredUnrealizedLossNetofTax	12100000	USD
	sbsi	Securities Transferred From Available For Sale To Held To Maturity SecuritiesTransferredFromAvailableForSaleToHeldToMaturity	0	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	5869000	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	53000	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	134769000	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	1332000	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	140638000	USD
CY2019Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	1385000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	17280000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	300000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	17280000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	300000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	115902000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	1247000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	1345243000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	33356000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	1461145000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	34603000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	5460000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	63000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	142236000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	3447000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	147696000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	3510000	USD
CY2019Q2	sbsi	Af Ssecuritiesand Ht Msecuritieswithotherthantemporaryimpairment AFSsecuritiesandHTMsecuritieswithotherthantemporaryimpairment	0
CY2019Q2	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	0	USD
CY2018Q2	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	23000	USD
CY2019Q2	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	3527000	USD
CY2018Q2	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	6353000	USD
CY2019Q2	sbsi	Interest Income Other Stocks And Bonds InterestIncomeOtherStocksAndBonds	27000	USD
CY2018Q2	sbsi	Interest Income Other Stocks And Bonds InterestIncomeOtherStocksAndBonds	28000	USD
CY2019Q2	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	13246000	USD
CY2018Q2	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	10210000	USD
CY2019Q2	us-gaap	Interest And Other Income InterestAndOtherIncome	16800000	USD
CY2018Q2	us-gaap	Interest And Other Income InterestAndOtherIncome	16614000	USD
	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	0	USD
	us-gaap	Interest Income Securities Us Treasury InterestIncomeSecuritiesUSTreasury	131000	USD
	us-gaap	Interest Income Securities Other Us Government InterestIncomeSecuritiesOtherUSGovernment	0	USD
	us-gaap	Interest Income Securities Other Us Government InterestIncomeSecuritiesOtherUSGovernment	89000	USD
	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	7645000	USD
	us-gaap	Interest Income Securities State And Municipal InterestIncomeSecuritiesStateAndMunicipal	12734000	USD
	sbsi	Interest Income Other Stocks And Bonds InterestIncomeOtherStocksAndBonds	55000	USD
	sbsi	Interest Income Other Stocks And Bonds InterestIncomeOtherStocksAndBonds	58000	USD
	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	25720000	USD
	us-gaap	Interest Income Securities Mortgage Backed InterestIncomeSecuritiesMortgageBacked	21104000	USD
	us-gaap	Interest And Other Income InterestAndOtherIncome	33420000	USD
	us-gaap	Interest And Other Income InterestAndOtherIncome	34116000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	672000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	5500000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4900000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-1200000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	2700000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	1500000	USD
	us-gaap	Proceeds From Sale Of Held To Maturity Securities ProceedsFromSaleOfHeldToMaturitySecurities	0	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	3349000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	3363000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	8406000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	8469000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	28488000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	29573000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	475332000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	490409000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	515575000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	531814000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	1529932000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	1556973000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2045507000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2088787000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	115000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	115000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	1658000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	1675000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount	1245000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1264000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	3018000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	3054000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount	144073000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	148253000	USD
CY2019Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	147091000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	151307000	USD
CY2019Q2	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	949200000	USD
CY2018Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	1080000000.00	USD
CY2019Q2	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	12400000	USD
	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	163000	USD
	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	-134000	USD
CY2018Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	12100000	USD
CY2019Q2	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	87000	USD
CY2018Q2	us-gaap	Unrealized Gain Loss On Investments UnrealizedGainLossOnInvestments	-42000	USD
CY2019Q2	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2018Q2	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2019Q2	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	87000	USD
CY2018Q2	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-42000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	163000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-134000	USD
CY2019Q2	sbsi	Equityinvestmentswithotherthantemporaryimpairment Equityinvestmentswithotherthantemporaryimpairment	0
CY2019Q2	sbsi	Federal Home Loan Bankstockwithotherthantemporaryimpairment FederalHomeLoanBankstockwithotherthantemporaryimpairment	0
CY2019Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3460143000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3312799000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	24705000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	27019000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	3435438000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	3285780000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24155000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2506000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	2397000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	441000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24705000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	27019000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1588000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	4682000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	780000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24705000	USD
CY2018Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24220000	USD
CY2018Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1281000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	917000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	488000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	25072000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	20781000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	5016000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	1684000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	959000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	25072000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2500000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1600000	USD
CY2019Q2	sbsi	Provision Reversalfor Pci Loans ProvisionReversalforPCILoans	-111000	USD
	sbsi	Provision Reversalfor Pci Loans ProvisionReversalforPCILoans	-163000	USD
CY2018Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1300000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	5000000.0	USD
CY2018Q2	sbsi	Provision Reversalfor Pci Loans ProvisionReversalforPCILoans	358000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	2369000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	22336000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24705000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	5908000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	21111000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	27019000	USD
CY2019Q2	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	25917000	USD
CY2019Q2	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	3393125000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet	41101000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3460143000	USD
CY2018Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	36247000	USD
CY2018Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	3230150000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet	46402000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3312799000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3460143000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3312799000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	16376000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	35770000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	11918000	USD
CY2018Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	5930000	USD
CY2019Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	1069000	USD
CY2018Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	1206000	USD
CY2019Q2	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	0	USD
CY2018Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	0	USD
CY2019Q2	us-gaap	Notes Receivable Net NotesReceivableNet	29363000	USD
CY2018Q4	us-gaap	Notes Receivable Net NotesReceivableNet	42906000	USD
CY2019Q2	sbsi	Restructured Nonaccrual Loans RestructuredNonaccrualLoans	8900000	USD
CY2018Q4	sbsi	Restructured Nonaccrual Loans RestructuredNonaccrualLoans	10900000	USD
CY2019Q2	sbsi	Purchase Credit Impaired Loans Restructured PurchaseCreditImpairedLoansRestructured	776000	USD
CY2018Q4	sbsi	Purchase Credit Impaired Loans Restructured PurchaseCreditImpairedLoansRestructured	3100000	USD
CY2019Q2	sbsi	Loansin Processof Foreclosure LoansinProcessofForeclosure	12000	USD
CY2018Q4	sbsi	Loansin Processof Foreclosure LoansinProcessofForeclosure	147000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	16376000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	35770000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	40143000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	35045000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	0	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2369000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	47274000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	44267000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	5908000	USD
CY2019Q2	sbsi	Purchase Credit Impaired Loanswith Deteriorationin Credit Quality After Acquisition PurchaseCreditImpairedLoanswithDeteriorationinCreditQualityAfterAcquisition	9100000	USD
CY2018Q4	sbsi	Purchase Credit Impaired Loanswith Deteriorationin Credit Quality After Acquisition PurchaseCreditImpairedLoanswithDeteriorationinCreditQualityAfterAcquisition	8000000.0	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	10986000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	3449157000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3460143000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	34314000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	3278485000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	3312799000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	35761000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	341000	USD
CY2018Q2	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	38779000	USD
CY2018Q2	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	82000	USD
	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	41033000	USD
	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	759000	USD
	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	27277000	USD
	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	157000	USD
CY2019Q2	sbsi	Loan Modification Related To Extending Amortization Period LoanModificationRelatedToExtendingAmortizationPeriod	0	USD
CY2019Q2	sbsi	Loanmodificationrelatedtointerestratesreductions Loanmodificationrelatedtointerestratesreductions	0	USD
CY2019Q2	sbsi	Loan Modification Extending Amortization Period Lowering Interest Rate And Principal Forgiveness LoanModificationExtendingAmortizationPeriodLoweringInterestRateAndPrincipalForgiveness	606000	USD
CY2019Q2	sbsi	Financing Receivable Modifications Total Modifications For Period FinancingReceivableModificationsTotalModificationsForPeriod	606000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	8	contract
	sbsi	Loan Modification Related To Extending Amortization Period LoanModificationRelatedToExtendingAmortizationPeriod	7650000	USD
	sbsi	Loanmodificationrelatedtointerestratesreductions Loanmodificationrelatedtointerestratesreductions	0	USD
	sbsi	Loan Modification Extending Amortization Period Lowering Interest Rate And Principal Forgiveness LoanModificationExtendingAmortizationPeriodLoweringInterestRateAndPrincipalForgiveness	731000	USD
	sbsi	Financing Receivable Modifications Total Modifications For Period FinancingReceivableModificationsTotalModificationsForPeriod	8381000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	13	contract
CY2018Q2	sbsi	Loan Modification Related To Extending Amortization Period LoanModificationRelatedToExtendingAmortizationPeriod	9000	USD
CY2018Q2	sbsi	Loanmodificationrelatedtointerestratesreductions Loanmodificationrelatedtointerestratesreductions	80000	USD
CY2018Q2	sbsi	Loan Modification Extending Amortization Period Lowering Interest Rate And Principal Forgiveness LoanModificationExtendingAmortizationPeriodLoweringInterestRateAndPrincipalForgiveness	103000	USD
CY2018Q2	sbsi	Financing Receivable Modifications Total Modifications For Period FinancingReceivableModificationsTotalModificationsForPeriod	192000	USD
CY2018Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	6	contract
	sbsi	Loan Modification Related To Extending Amortization Period LoanModificationRelatedToExtendingAmortizationPeriod	238000	USD
	sbsi	Loanmodificationrelatedtointerestratesreductions Loanmodificationrelatedtointerestratesreductions	80000	USD
	sbsi	Loan Modification Extending Amortization Period Lowering Interest Rate And Principal Forgiveness LoanModificationExtendingAmortizationPeriodLoweringInterestRateAndPrincipalForgiveness	103000	USD
	sbsi	Financing Receivable Modifications Total Modifications For Period FinancingReceivableModificationsTotalModificationsForPeriod	421000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	10	contract
CY2019Q2	sbsi	Loans Receivable Modifications Commitmentto Lend LoansReceivableModificationsCommitmenttoLend	0	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	45430000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	51388000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet	41101000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet	46402000	USD
CY2019Q1	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	14520000	USD
CY2018Q1	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	15818000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	15054000	USD
CY2017Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	18721000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	0	USD
CY2018Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	0	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	0	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	-1445000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	812000	USD
CY2018Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	1090000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	1074000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	770000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	776000	USD
CY2018Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	803000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	1572000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	1941000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	14556000	USD
CY2018Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	16105000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	14556000	USD
CY2018Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	16105000	USD
CY2019Q2	sbsi	Borrowed Funds Maturities Repaymentsof Principalinthe Next Twelve Months BorrowedFundsMaturitiesRepaymentsofPrincipalintheNextTwelveMonths	822696000	USD
CY2019Q2	sbsi	Borrowed Funds Maturingin Year Two BorrowedFundsMaturinginYearTwo	21507000	USD
CY2019Q2	sbsi	Borrowed Funds Maturingin Year Three BorrowedFundsMaturinginYearThree	0	USD
CY2019Q2	sbsi	Borrowed Funds Maturingin Year Four BorrowedFundsMaturinginYearFour	0	USD
CY2019Q2	sbsi	Borrowed Funds Maturingin Year Five BorrowedFundsMaturinginYearFive	0	USD
CY2019Q2	sbsi	Borrowed Funds Maturing After Year Five BorrowedFundsMaturingAfterYearFive	5618000	USD
CY2019Q2	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	849821000	USD
CY2019Q2	sbsi	Line Of Credit Facility Number Of Credit Lines Maintained By Company LineOfCreditFacilityNumberOfCreditLinesMaintainedByCompany	3	credit_line
CY2019Q2	us-gaap	Federal Funds Purchased FederalFundsPurchased	18000000.0	USD
CY2018Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	28000000.0	USD
CY2019Q2	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Amount Of Available Unused Funds FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds	1260000000	USD
CY2019Q2	sbsi	Letters Of Credit Fhlb As Collateral LettersOfCreditFhlbAsCollateral	0	USD
CY2019Q2	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	8100000	USD
CY2018Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	8800000	USD
	sbsi	Repurchase Agreement Counterparty Maturityof Agreements RepurchaseAgreementCounterpartyMaturityofAgreements	P13M
CY2019Q2	us-gaap	Subordinated Debt SubordinatedDebt	98490000	USD
CY2018Q4	us-gaap	Subordinated Debt SubordinatedDebt	98407000	USD
CY2019Q2	us-gaap	Other Long Term Debt OtherLongTermDebt	60248000	USD
CY2018Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	60246000	USD
CY2019Q2	us-gaap	Long Term Debt LongTermDebt	158738000	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	158653000	USD
CY2019Q2	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	270000000.0	USD
CY2019Q2	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	7400000	USD
CY2019Q2	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	8964000	USD
CY2019Q2	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	10072000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	11594000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	3320000	USD
CY2019Q2	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	2350000	USD
CY2019Q2	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	2350000	USD
CY2018Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	2201000	USD
CY2018Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	2201000	USD
CY2019Q2	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	0	USD
CY2019Q2	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	7420000	USD
CY2018Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	8306000	USD
CY2018Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	USD
CY2019Q2	us-gaap	Derivative Assets DerivativeAssets	6614000	USD
CY2019Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	302000	USD
CY2018Q4	us-gaap	Derivative Assets DerivativeAssets	1087000	USD
CY2018Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	1119000	USD
CY2019Q2	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3553000	USD
CY2018Q2	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	667000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	6564000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3012000	USD
CY2019Q2	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	16000	USD
CY2018Q2	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2693000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	142000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2438000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3569000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3360000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6706000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5450000	USD
CY2019Q2	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	5000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	9800000	USD
CY2019Q2	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3600000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6700000	USD
CY2019Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.161
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.152
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3400000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5500000	USD
CY2018Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.143
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.130
CY2019Q2	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	9812000	USD
CY2019Q2	us-gaap	Operating Lease Liability OperatingLeaseLiability	10204000	USD
CY2019Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	742000	USD
CY2019Q2	us-gaap	Operating Lease Cost OperatingLeaseCost	395000	USD
	us-gaap	Operating Lease Cost OperatingLeaseCost	789000	USD
CY2019Q2	us-gaap	Operating Lease Payments OperatingLeasePayments	360000	USD
	us-gaap	Operating Lease Payments OperatingLeasePayments	700000	USD
CY2019Q2	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	654000	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	654000	USD
CY2019Q2	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P12Y6M
CY2019Q2	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0388	Rate
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Remainder Of Fiscal Year LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear	625000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1338000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	1232000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	1193000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	1044000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	7866000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	13298000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	3094000	USD
CY2019Q2	us-gaap	Operating Lease Liability OperatingLeaseLiability	10204000	USD
CY2019Q2	sbsi	Lessee Operating Lease Lease Not Yet Commenced Payments Due LesseeOperatingLeaseLeaseNotYetCommencedPaymentsDue	9100000	USD
	sbsi	Lessee Operating Lease Not Yet Commenced Lease Term LesseeOperatingLeaseNotYetCommencedLeaseTerm	P20Y4M24D
CY2019Q2	us-gaap	Net Rentable Area NetRentableArea	202000	sqft
CY2019Q2	sbsi	Numberof Square Feet Occupied NumberofSquareFeetOccupied	41000	sqft
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	1487000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Remainder Of Fiscal Year LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear	1388000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Two Years LessorOperatingLeasePaymentsToBeReceivedTwoYears	2693000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Three Years LessorOperatingLeasePaymentsToBeReceivedThreeYears	1576000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Four Years LessorOperatingLeasePaymentsToBeReceivedFourYears	1553000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Five Years LessorOperatingLeasePaymentsToBeReceivedFiveYears	1316000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received Thereafter LessorOperatingLeasePaymentsToBeReceivedThereafter	4098000	USD
CY2019Q2	us-gaap	Lessor Operating Lease Payments To Be Received LessorOperatingLeasePaymentsToBeReceived	12624000	USD
CY2019Q2	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1051497000	USD
CY2018Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	901995000	USD
CY2019Q2	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	38600000	USD
CY2019Q2	sbsi	Unsettled Trades To Sell Securities UnsettledTradesToSellSecurities	0	USD
CY2018Q4	sbsi	Unsettled Trades To Purchase Securities Liability UnsettledTradesToPurchaseSecuritiesLiability	6400000	USD
CY2018Q4	sbsi	Unsettled Trades To Sell Securities UnsettledTradesToSellSecurities	0	USD
CY2019Q2	sbsi	Unsettled Issuancesof Brokered C Ds UnsettledIssuancesofBrokeredCDs	0	USD
CY2018Q4	sbsi	Unsettled Issuancesof Brokered C Ds UnsettledIssuancesofBrokeredCDs	15200000	USD

Files In Submission

Name	View Source	Status
0000705432-19-000088-index-headers.html	Edgar Link	pending
0000705432-19-000088-index.html	Edgar Link	pending
0000705432-19-000088.txt	Edgar Link	pending
0000705432-19-000088-xbrl.zip	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
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report.css	Edgar Link	pending
sbsi-20190630.xsd	Edgar Link	pending
sbsi-20190630_cal.xml	Edgar Link	unprocessable
sbsi-20190630_def.xml	Edgar Link	unprocessable
sbsi-20190630_lab.xml	Edgar Link	unprocessable
sbsi-20190630_pre.xml	Edgar Link	unprocessable
sbsi063019ex311.htm	Edgar Link	pending
sbsi063019ex312.htm	Edgar Link	pending
sbsi063019ex32.htm	Edgar Link	pending
sbsi10-q063019.htm	Edgar Link	pending
sbsi10-q063019_htm.xml	Edgar Link	completed
Show.js	Edgar Link	pending

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$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi

2019 Q2 Form 10-Q Financial Statement

#000070543219000088 Filed on August 01, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SBSI SOUTHSIDE BANCSHARES INC Stock $sbsi

2019 Q2 Form 10-Q Financial Statement

#000070543219000088 Filed on August 01, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SBSI
SOUTHSIDE BANCSHARES INC Stock $sbsi