Note 24 - Stock Yards Bancorp, Inc. (Parent Company Only) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract
Net income	$ 17,736	$ 14,533	$ 13,368	$ 13,232	$ 16,649	$ 17,234	$ 16,543	$ 15,641	$ 14,658	$ 13,876	$ 13,579	$ 13,404	$ 58,869	$ 66,067	$ 55,517
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on the disposal of premises and equipment													(150)	372	56
Stock compensation expense													3,262	3,578	4,027
Excess tax benefits from stock- based compensation arrangements													(452)	(812)	(549)
Net cash provided by operating activities													77,125	58,436	65,889
Cash flows from operating activities:
Proceeds from sale of fixed assets													1,240	2,907	230
Cash for acquisition, net of cash acquired													0	(24,686)	0
Net cash provided by (used in) investing activities													(804,718)	(163,173)	(11,570)
Cash flows from financing activities:
Repurchase of common stock													(2,265)	(11,817)	(2,004)
Share repurchases related to compensation plans													(224)	(272)	(154)
Cash dividends paid													(24,481)	(23,542)	(21,766)
Net cash used in financing activities													795,814	155,522	5,372
Parent Company [Member]
us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract
Net income													58,869	66,067	55,517
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed net income of subsidiaries													(42,978)	5,802	(37,207)
Loss on the disposal of premises and equipment													0	0	(10)
Stock compensation expense													3,262	3,578	4,027
Excess tax benefits from stock- based compensation arrangements													(452)	(812)	(549)
Change in other assets													(1,356)	(3,863)	(1,080)
Change in other liabilities													17	(82)	220
Net cash provided by operating activities													17,362	70,690	20,918
Cash flows from operating activities:
Proceeds from sale of fixed assets													0	0	13
Cash for acquisition, net of cash acquired													0	(28,000)	0
Net cash provided by (used in) investing activities													0	(28,000)	13
Cash flows from financing activities:
Repurchase of common stock													(2,265)	(11,817)	(2,004)
Share repurchases related to compensation plans													(224)	(272)	(154)
Cash dividends paid													(24,481)	(23,542)	(21,766)
Net cash used in financing activities													(26,970)	(35,631)	(23,924)
Net increase (decrease) in cash													(9,608)	7,059	(2,993)
Cash at beginning of year				$ 14,714				$ 7,655				$ 10,648	14,714	7,655	10,648
Cash at end of year	$ 5,106				$ 14,714				$ 7,655				$ 5,106	$ 14,714	$ 7,655