Note 8 - FAIR VALUE - Quantitative Information About Level Fair Value Measurements (Details) $ in Thousands	Mar. 31, 2024 USD ($) item	Dec. 31, 2023 USD ($)
Loans receivable held for sale in preparation for securitization	$ 274,816
Fair Value, Measurements, Nonrecurring
Fair value	310,694	$ 35,111
Loans receivable held for sale in preparation for securitization	274,816
Impaired Loans Leases | Fair Value, Measurements, Nonrecurring
Fair value	33,949	33,656
Other repossessed assets | Fair Value, Measurements, Nonrecurring
Fair value	1,082
Other Real Estate Owned | Fair Value, Measurements, Nonrecurring
Fair value	847	1,455
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair value	310,694	35,111
Loans receivable held for sale in preparation for securitization	274,816
Fair Value, Inputs, Level 3 | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
Loans receivable held for sale in preparation for securitization	$ 33,949	$ 33,656
Loans receivable held-for-sale, Valuation Technique	us-gaap:MarketApproachValuationTechniqueMember	us-gaap:MarketApproachValuationTechniqueMember
Loans receivable held-for-sale, Measurement Input	us-gaap:MeasurementInputComparabilityAdjustmentMember	us-gaap:MeasurementInputComparabilityAdjustmentMember
Fair Value, Inputs, Level 3 | Minimum | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
Loans receivable held-for-sale, Measurement Input | item	(0.1000)
Fair Value, Inputs, Level 3 | Maximum | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
Loans receivable held-for-sale, Measurement Input | item	(0.3000)
Fair Value, Inputs, Level 3 | Impaired Loans Leases | Fair Value, Measurements, Nonrecurring
Fair value	$ 33,949	$ 33,656
Fair Value, Inputs, Level 3 | Other repossessed assets | Fair Value, Measurements, Nonrecurring
Fair value	1,082
Fair Value, Inputs, Level 3 | Other repossessed assets | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
Fair value	$ 1,082
Loans receivable held-for-sale, Valuation Technique	qcrh:AverageAuctionPricesMember	qcrh:AverageAuctionPricesMember
Unobservable input, OREO	us-gaap:MeasurementInputComparabilityAdjustmentMember	us-gaap:MeasurementInputComparabilityAdjustmentMember
Fair Value, Inputs, Level 3 | Other Real Estate Owned | Fair Value, Measurements, Nonrecurring
Fair value	$ 847	$ 1,455
Fair Value, Inputs, Level 3 | Other Real Estate Owned | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
Fair value	$ 847	$ 1,455
Valuation technique, OREO	Valuation Technique, Appraisal of Collateral	Valuation Technique, Appraisal of Collateral
Unobservable input, OREO	Measurement Input, Appraised Value	Measurement Input, Appraised Value
Fair Value, Inputs, Level 3 | Other Real Estate Owned | Minimum | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
OREO, measurement input | item	0.0000
Fair Value, Inputs, Level 3 | Other Real Estate Owned | Maximum | Valuation Technique, Appraisal of Collateral | Measurement Input, Appraised Value
OREO, measurement input | item	(0.3500)