Note 7 - Income Taxes - Schedule of Unfunded Contributions (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Remainder of 2024	$ 35,791
2025	62,830
2026	33,634
2027	7,136
2028	793
Thereafter	13,117
Total unfunded contributions	$ 153,301

Represents tax credit partnership payments due in the remainder of the current fiscal year.

No definition available.

Name:	sybt_TaxCreditPartnershipsCommitmentPaymentsRemainderOfFiscalYear
Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents tax credit partnership commitment payments due during year five and after.

+ References

No definition available.

+ Details

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Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents tax credit partnership payments due in year four.

+ References

No definition available.

+ Details

Name:	sybt_TaxCreditPartnershipsCommitmentPaymentsYearFour
Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents tax credit partnerships commitment payments due in year one.

+ References

No definition available.

+ Details

Name:	sybt_TaxCreditPartnershipsCommitmentPaymentsYearOne
Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents tax credit partnership payments due in year three.

+ References

No definition available.

+ Details

Name:	sybt_TaxCreditPartnershipsCommitmentPaymentsYearThree
Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents tax credit partnership payments due in year two.

+ References

No definition available.

+ Details

Name:	sybt_TaxCreditPartnershipsCommitmentPaymentsYearTwo
Namespace Prefix:	sybt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of commitment and contingent commitment, including amount of delayed equity contribution, for investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, commitment and contingent commitment related to investment under tax credit program not meeting condition for accounting under proportional amortization method.

+ References

Reference 1: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478156/740-323-50-2

+ Details

Name:	us-gaap_QualifiedAffordableHousingProjectInvestmentsCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant