LOANS AND ALLOWANCE FOR PROBABLE LOAN LOSSES - Interest Income on Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified
|
12 Months Ended |
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
$ 10,986us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment |
[1] |
$ 11,970us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment |
$ 13,233us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment |
Interest income recognized |
193us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod |
[1] |
632us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod |
449us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod |
Construction |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
1,346us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
[1] |
1,707us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
3,222us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
Interest income recognized |
4us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
[1] |
0us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
2us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConstructionLoansMember |
1-4 Family Residential |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
3,511us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
[1] |
2,915us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
2,873us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
Interest income recognized |
67us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
[1] |
76us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
19us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialRealEstateMember |
Other |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
2,173us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
[1] |
1,972us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
1,734us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Interest income recognized |
52us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
[1] |
72us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
13us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Commercial Loans |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
1,286us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
[1] |
1,935us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
2,234us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
Interest income recognized |
26us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
[1] |
19us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
7us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialLoanMember |
Municipal Loans |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
750us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
[1] |
292us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
0us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
Interest income recognized |
41us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
[1] |
16us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
0us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = sbsi_MunicipalLoansMember |
Loans to Individuals |
|
|
|
|
Impaired Financing Receivable, Average Recorded Investment and Interest [Abstract] |
|
|
|
|
Average recorded investment |
1,920us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
[1] |
3,149us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
3,170us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Interest income recognized |
$ 3us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
[1] |
$ 449us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
$ 408us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
|
|