Note 8 - Income Taxes (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Unrecognized Tax Benefits, Including Interest and Penalties	$ 40	$ 40

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns, including penalties and interest accrued.

No definition available.

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