XML 50 R41.htm IDEA: XBRL DOCUMENT
v3.23.2

Securities - Unrealized and Realized Gain (Loss) Recognized in Net Income on Equity Investments (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Investments, All Other Investments [Abstract] |  |  |  |
Net gains (losses) recognized during the period on equity investments | $ 2,558 | $ (191) | $ 5,058 | $ (466)
Less: Net gains recognized during the period on equity investments sold during the period | 2,642 | 0 | 5,058 | 0
Unrealized gains (losses) recognized during the reporting period on equity investments held at the reporting date | $ (84) | $ (191) | $ 0 | $ (466)

X
- Definition Equity Securities, Realized Gain + References No definition available. + Details
Name: | sbsi_EquitySecuritiesRealizedGain
Namespace Prefix: | sbsi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsAllOtherInvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of realized gain (loss) on investment. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 + Details
Name: | us-gaap_RealizedInvestmentGainsLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unrealized gain (loss) on investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_UnrealizedGainLossOnInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration