Note 2 - Acquisition - Summary of Assets Acquired and Liabilities Assumed (Details) - USD ($)					3 Months Ended		9 Months Ended
		Jun. 01, 2021		May 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Goodwill, Ending Balance					$ 135,830,000	$ 12,513,000	$ 135,830,000	$ 12,513,000	$ 136,529,000	$ 12,513,000	$ 12,513,000	$ 12,513,000
Consideration paid in acquisition							28,276,000
Total consideration paid							232,946,000
Goodwill					0	$ 0	124,016,000	$ 0
Kentucky Bancshares [Member]
Mortgage loans held for sale		$ 3,071,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities		395,862,000		$ 396,000,000
Federal Home Loan Bank stock, at cost		7,072,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans, Gross		755,175,000		755,000,000
Allowance for credits losses on loans		(6,757,000)
Net loans		748,418,000
Premises and equipment, net		21,040,000
Bank owned life insurance		18,909,000
Accrued interest receivable		4,939,000
Goodwill, Ending Balance		0		123,000,000	123,000,000		$ 123,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		4,403,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	[1]	999,000
Other real estate owned		551,000
Mortgage servicing rights		1,662,000
Deferred income taxes, net		2,341,000
Deferred income taxes, net	[2]	(230,000)
Other assets		4,485,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Prepaid and Other Assets		(70,000)	[3]		$ (70,000)
Total assets acquired		1,266,010,000
Total assets acquired, adjustment		699,000
Non-interest bearing		359,544,000
Interest bearing		679,674,000
Total deposits		1,039,218,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Securities Sold under Repurchase Agreement		11,360,000		11,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Federal Home Loan Bank Advances		91,071,000		91,000,000
Accrued interest payable		505,000
Other liabilities		14,227,000
Total liabilities assumed		1,156,381,000
Net assets acquired		109,629,000
Consideration for common stock		204,670,000
Consideration paid in acquisition		28,276,000
Total consideration paid		232,946,000		$ 233,000,000
Goodwill		123,317,000
Kentucky Bancshares [Member] | Cash [Member]
Cash and due from banks		53,257,000
Kentucky Bancshares [Member] | As Recorded By Acquiree [Member]
Mortgage loans held for sale		3,071,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities		396,157,000
Federal Home Loan Bank stock, at cost		7,072,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans, Gross		755,932,000
Allowance for credits losses on loans		(9,491,000)
Net loans		746,441,000
Premises and equipment, net		27,401,000
Bank owned life insurance		18,909,000
Accrued interest receivable		4,939,000
Goodwill, Ending Balance		14,001,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		0
Other real estate owned		674,000
Mortgage servicing rights		1,628,000
Deferred income taxes, net		1,856,000
Other assets		6,421,000
Total assets acquired		1,281,827,000
Non-interest bearing		359,544,000
Interest bearing		678,528,000
Total deposits		1,038,072,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Securities Sold under Repurchase Agreement		11,360,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Federal Home Loan Bank Advances		88,581,000
Accrued interest payable		505,000
Other liabilities		16,231,000
Total liabilities assumed		1,154,749,000
Net assets acquired		127,078,000
Kentucky Bancshares [Member] | As Recorded By Acquiree [Member] | Cash [Member]
Cash and due from banks		53,257,000
Kentucky Bancshares [Member] | As Adjusted By Acquirer [Member]
Mortgage loans held for sale	[4]	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[4],[5]	(295,000)
Federal Home Loan Bank stock, at cost	[4]	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans, Gross	[4],[6]	(757,000)
Allowance for credits losses on loans	[4],[7]	(2,734,000)
Net loans	[4]	1,977,000
Premises and equipment, net	[4],[8]	(6,361,000)
Bank owned life insurance	[4]	0
Accrued interest receivable	[4]	0
Goodwill, Ending Balance	[4],[9]	(14,001,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	[1],[4]	3,404,000
Other real estate owned	[4],[10]	(123,000)
Mortgage servicing rights	[4],[11]	34,000
Deferred income taxes, net	[2],[4]	715,000
Other assets	[3],[4]	(1,866,000)
Total assets acquired	[4]	(16,516,000)
Non-interest bearing	[4]	0
Interest bearing	[4],[12]	1,146,000
Total deposits	[4]	1,146,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Securities Sold under Repurchase Agreement	[4]	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Federal Home Loan Bank Advances	[4],[13]	2,490,000
Accrued interest payable	[4]	0
Other liabilities	[4],[14]	(2,004,000)
Total liabilities assumed	[4]	1,632,000
Net assets acquired	[4]	(18,148,000)
Kentucky Bancshares [Member] | As Adjusted By Acquirer [Member] | Cash [Member]
Cash and due from banks	[4]	$ 0

[1] Calculation of core deposit intangible related to the acquisition. During the third quarter of 2021, a recast adjustment of $999,000 was recorded based on revised inputs used in the calculation of the CDI attributed to KB, resulting in an increased intangible value.

[2] Adjustment to net deferred tax assets associated with the effects of the purchase accounting adjustments.

[3] Adjustment to other assets to reflect the estimated fair value of prepaid and other assets. During the third quarter of 2021, a recast adjustment of $70,000 was recorded for the write off of miscellaneous mortgage servicing fees accrued in other assets by KB at acquisition, resulting in a reduction to other assets.

[4] See the following page for explanations or individual fair value adjustments.

[5] Adjustment based on Bancorp’s evaluation of the acquired investment portfolio. Approximately $91 million in AFS debt securities were sold by Bancorp shortly after acquisition.

[6] Adjustments to loans to reflect estimated fair value adjustments, including the following: (in thousands) Fair value adjustment - acquired non PCD loans $ 228 Fair value adjustment - acquired PCD loans (735) Eliminate unrecognized loan fees on acquired loans and fair value hedge (250) Net loan fair value adjustments $ (757)

[7] On January 1, 2020, Stock Yards Bancorp adopted ASC 326, “Financial Instruments – Credit Losses,” which required that loans held for investment be accounted for under the CECL framework. In accordance with ASC 326, “Financial Instruments – Credit Losses,” Kentucky Bancshares was not required to adopt CECL as of January 1, 2020. The net adjustment to allowance for credit losses includes the following: (in thousands) Reversal of historical KB allowance for credit losses on loans $ 9,491 Estimate of lifetime credit losses for PCD loans (6,757) Net change in allowance for credit losses $ 2,734

[8] Adjustment to premises and equipment to reflect the estimated fair value of acquired premises and equipment and right of use assets.

[9] Elimination of the historical KB goodwill of $14.0 million at the closing date.

[10] Adjustment to reflect the estimated fair value of other real estate owned.

[11] Adjustment to reflect the estimated fair value of mortgage servicing rights.

[12] Adjustment to deposits to reflect the estimated fair value of time deposits in interest rates, which was based primarily on an analysis of current market interest rates and maturity dates.

[13] Adjustment to reflect the estimated fair value of Federal Home Loan Bank advances for differences in interest rates, which was based primarily on an analysis of current market interest rates and maturity dates. All KB FHLB advances were paid off immediately upon acquisition.

[14] Adjustment to other liabilities to establish the reserve for unfunded loan commitments under CECL and various accrual adjustments.