Represents the amount that the entity would have been required to pay, if an event of default on all contracts had occurred.

No definition available.

+ Details

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

- Definition

Represents the term of agreements entered into by the entity for undertaking guarantee obligation.

+ References

No definition available.

+ Details

Name:	sybt_GuaranteeObligationsAgreementTerm
Namespace Prefix:	sybt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121611286&loc=d3e11927-110247

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82919202-210446

+ Details

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

- Definition

Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

+ Details

Name:	us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_PerformanceGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sybt_CommonwealthMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 12 - Commitments and Contingent Liabilities (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 07, 2022
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	$ (400,000)
Standby Letters of Credit [Member] \| Minimum [Member]
Guarantee Obligations, Agreement Term (Year)		1 year
Standby Letters of Credit [Member] \| Maximum [Member]
Guarantee Obligations, Agreement Term (Year)		2 years
Performance Guarantee [Member]
Guarantee Obligation, Estimated Payment Under Default on Contract	3,000,000
Commonwealth [Member]
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance			$ 500,000
Other Liabilities [Member]
Off-Balance-Sheet, Credit Loss, Liability, Ending Balance	$ 3,600,000	$ 3,500,000