Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation – The consolidated financial statements include the accounts of Stock Yards Bancorp, Inc. and its wholly-owned subsidiary, SYB&T. All significant inter-company transactions and accounts have been eliminated in consolidation. All companies are collectively referred to as “Bancorp” or the “Company.” The Bank, chartered in 1904, is a Louisville, Kentucky-based, state-chartered non-member financial institution that provides services in the Louisville, Kentucky, Indianapolis, Indiana and Cincinnati, Ohio MSAs through 42 full service banking center locations. As a result of its acquisition of KSB on May 1, 2019, Bancorp became the 100% successor owner of KBST, an unconsolidated finance subsidiary. As permitted under the terms of KBST’s governing documents, Bancorp redeemed the TPS at the par amount of approximately $4 million on June 17, 2019. Bancorp is divided into two reportable segments: Commercial Banking and WM&T: Commercial Banking provides a full range of loan and deposit products to individual consumers and businesses through commercial lending, retail lending, deposit services, treasury management services, private banking, online banking, mobile banking, merchant services, international banking, correspondent banking and other banking services. The Bank also offers securities brokerage services via its banking center network through an arrangement with a third party broker-dealer. WM&T provides custom-tailored financial planning, investment management, retirement planning and trust and estate services in all markets in which Bancorp operates. The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the financial statements do not include all the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for fair presentation have been included. Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. For further information, refer to the consolidated financial statements and footnotes thereto included in Bancorp’s Annual Report on Form 10-K for the year ended December 31, 2018. Certain reclassifications have been made in the prior year financial statements to conform to current year classifications.
New Accounting Pronouncements, Policy [Policy Text Block]	Accounting Standards Updates – Generally, if an issued-but-not-yet-effective ASU with an expected immaterial impact to Bancorp has been disclosed in prior SEC filings, it will not be re-disclosed. The following ASU was issued prior to September 30, 2019 and is considered relevant to Bancorp’s financial statements. In June 2016, FASB issued ASU 2016-13, CECL. This ASU significantly changes the way entities recognize impairment of many financial assets by requiring immediate recognition of estimated credit losses expected to occur over their remaining life. The guidance is effective for annual and interim reporting periods beginning after December 15, 2019. Bancorp expects to recognize a one-time cumulative-effect adjustment to the allowance. Interagency guidance issued in December 2018 allows for a three year phase-in of the cumulative-effect adjustment for regulatory capital reporting. As a result of this ASU, Bancorp expects to increase its allowance. Bancorp has formed a committee to oversee its transition to the CECL methodology. Bancorp has devoted internal resources and purchased a third party software solution to analyze, compute and report upon the CECL disclosure requirements. In addition, Bancorp has analyzed loan-level data and is determining its CECL loan segmentation and initial segment calculation methodologies. Bancorp continues to analyze forecast scenarios and stress test the volatility of the model. The Company expects to quantify the approximate January 1, 2020 impact of this ASU upon its consolidated financial statements in the filing of its 2019 Annual Report on Form 10-K. Recently Adopted Accounting Standards - Bancorp adopted ASU 2016-02, Leases and related amendments using an alternative transition method, effective January 1, 2019 and upon adoption recorded $17 million in right-of-use lease assets and $18 million of operating lease liabilities on its balance sheet. Prior periods have not been restated. The right-of-use lease asset and operating lease liability are recorded in premises and equipment and other liabilities on the consolidated balance sheet. Bancorp elected all applicable practical expedients, including the option to expense short-term leases, which are defined as leases with a term of one year or less. Bancorp also elected not to separate lease components from non-lease components. The adoption of this ASU did not have a meaningful impact on Bancorp's performance metrics, including regulatory capital ratios and ROA. Additionally, Bancorp does not believe that the adoption of this ASU by its clients will have a significant impact on Bancorp's ability to underwrite credit when client financial statements are presented inclusive of the requirements of this ASU. See the Footnote titled “Leases” for additional information on lease activities.

Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2019

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation – The consolidated financial statements include the accounts of Stock Yards Bancorp, Inc. and its wholly-owned subsidiary, SYB&T. All significant inter-company transactions and accounts have been eliminated in consolidation. All companies are collectively referred to as “Bancorp” or the “Company.”

The Bank, chartered in 1904, is a Louisville, Kentucky-based, state-chartered non-member financial institution that provides services in the Louisville, Kentucky, Indianapolis, Indiana and Cincinnati, Ohio MSAs through 42 full service banking center locations.

As a result of its acquisition of KSB on May 1, 2019, Bancorp became the 100% successor owner of KBST, an unconsolidated finance subsidiary. As permitted under the terms of KBST’s governing documents, Bancorp redeemed the TPS at the par amount of approximately $4 million on June 17, 2019.

Bancorp is divided into two reportable segments: Commercial Banking and WM&T:

Commercial Banking provides a full range of loan and deposit products to individual consumers and businesses through commercial lending, retail lending, deposit services, treasury management services, private banking, online banking, mobile banking, merchant services, international banking, correspondent banking and other banking services. The Bank also offers securities brokerage services via its banking center network through an arrangement with a third party broker-dealer.

WM&T provides custom-tailored financial planning, investment management, retirement planning and trust and estate services in all markets in which Bancorp operates.

The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the financial statements do not include all the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for fair presentation have been included. Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. For further information, refer to the consolidated financial statements and footnotes thereto included in Bancorp’s Annual Report on Form 10-K for the year ended December 31, 2018. Certain reclassifications have been made in the prior year financial statements to conform to current year classifications.

New Accounting Pronouncements, Policy [Policy Text Block]

Accounting Standards Updates – Generally, if an issued-but-not-yet-effective ASU with an expected immaterial impact to Bancorp has been disclosed in prior SEC filings, it will not be re-disclosed.

The following ASU was issued prior to September 30, 2019 and is considered relevant to Bancorp’s financial statements.

In June 2016, FASB issued ASU 2016-13, CECL. This ASU significantly changes the way entities recognize impairment of many financial assets by requiring immediate recognition of estimated credit losses expected to occur over their remaining life. The guidance is effective for annual and interim reporting periods beginning after December 15, 2019. Bancorp expects to recognize a one-time cumulative-effect adjustment to the allowance. Interagency guidance issued in December 2018 allows for a three year phase-in of the cumulative-effect adjustment for regulatory capital reporting.

As a result of this ASU, Bancorp expects to increase its allowance. Bancorp has formed a committee to oversee its transition to the CECL methodology. Bancorp has devoted internal resources and purchased a third party software solution to analyze, compute and report upon the CECL disclosure requirements. In addition, Bancorp has analyzed loan-level data and is determining its CECL loan segmentation and initial segment calculation methodologies. Bancorp continues to analyze forecast scenarios and stress test the volatility of the model. The Company expects to quantify the approximate January 1, 2020 impact of this ASU upon its consolidated financial statements in the filing of its 2019 Annual Report on Form 10-K.

Recently Adopted Accounting Standards - Bancorp adopted ASU 2016-02, Leases and related amendments using an alternative transition method, effective January 1, 2019 and upon adoption recorded $17 million in right-of-use lease assets and $18 million of operating lease liabilities on its balance sheet. Prior periods have not been restated. The right-of-use lease asset and operating lease liability are recorded in premises and equipment and other liabilities on the consolidated balance sheet. Bancorp elected all applicable practical expedients, including the option to expense short-term leases, which are defined as leases with a term of one year or less. Bancorp also elected not to separate lease components from non-lease components.

The adoption of this ASU did not have a meaningful impact on Bancorp's performance metrics, including regulatory capital ratios and ROA. Additionally, Bancorp does not believe that the adoption of this ASU by its clients will have a significant impact on Bancorp's ability to underwrite credit when client financial statements are presented inclusive of the requirements of this ASU. See the Footnote titled “Leases” for additional information on lease activities.