Note 13 - Junior Subordinated Debentures (Details)	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Oct. 01, 2017 USD ($) loan	May 13, 2013 USD ($) loan	Feb. 29, 2004 USD ($)
Debt Instrument, Face Amount	$ 40,210,000	$ 40,210,000
Debt Instrument, Interest Rate, Effective Percentage	2.43%	2.48%
Junior Subordinated Debt [Member]
Repayment period (in years)	30 years
Note Payable to QCR Holdings Capital Trust II [Member]
Debt Instrument, Face Amount					$ 12,372,000
Community National
Number of assumed junior subordinated debentures | loan				2
Other borrowings				$ 4,200,000
Guaranty Bank and Trust Company
Number of assumed junior subordinated debentures | loan			1
Other borrowings			$ 3,900,000