Note 10 - Securities Sold Under Agreements to Repurchase and Other Short-term Borrowings (Details Textual)	12 Months Ended
Dec. 31, 2016
Short Term Debt Maturity, Period	1 day

Represents the maturity period of short-term debt securities from the transaction date.

No definition available.

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