Note 7 - Income Taxes - Schedule of Unfunded Contributions (Details) $ in Thousands	Mar. 31, 2025 USD ($)
Remainder of 2025	$ 73,146
2026	52,979
2027	15,625
2028	1,160
2029	1,324
Thereafter	7,248
Total unfunded contributions	$ 151,482

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

No definition available.

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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

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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

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