The percent of financial receivable loans modified and not treated as troubled debt restructuring.

No definition available.

Name:	qcrh_FinancialReceivablesLoanModificationPercent
Namespace Prefix:	qcrh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of financing receivable modified not treated as troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	qcrh_FinancingReceivableLoanModificationNotTreatedAsTroubledDebtRestructuring
Namespace Prefix:	qcrh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivables that have been modified and not treated as troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	qcrh_FinancingReceivableModificationNumberOfContracts
Namespace Prefix:	qcrh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percent of financial receivable loans, leases.

+ References

No definition available.

+ Details

Name:	qcrh_LoansAndLeasesReceivableNetOfDeferredIncomePercent
Namespace Prefix:	qcrh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of leases.

+ References

No definition available.

+ Details

Name:	qcrh_NumberOfLeases
Namespace Prefix:	qcrh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of trouble debt restructurings restructured and written off.

+ References

No definition available.

+ Details

Name:	qcrh_NumberOfTroubledDebtRestructuringsRestructuredAndWrittenOff
Namespace Prefix:	qcrh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of loans restructured loans that were nonaccrual.

+ References

No definition available.

+ Details

Name:	qcrh_RestructuredLoansNonaccrualStatusNumber
Namespace Prefix:	qcrh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of financing receivable 90 days or more past due and still accruing.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5111-111524

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable on nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=120238483&loc=d3e48678-111004

+ Details

Name:	us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_ConsolidatedEntitiesAxis=qcrh_M2LeaseFundsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationNameAxis=qcrh_LoanReliefProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=qcrh_OneCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=qcrh_NonaccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=qcrh_TroubledDebtRestructuringsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=qcrh_M2LeaseFundsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_FinanceLeasesPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

NOTE 3 - LOANS/LEASES RECEIVABLE (Details) $ in Thousands	3 Months Ended				9 Months Ended
NOTE 3 - LOANS/LEASES RECEIVABLE (Details) $ in Thousands	Sep. 30, 2020 USD ($) item loan	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($) loan	Mar. 31, 2019 USD ($)	Sep. 30, 2020 USD ($) loan item contract	Sep. 30, 2019 USD ($) loan item
Loans and leases	$ 4,243,278	$ 3,681,346			$ 4,243,278
Loans receivable held for sale	8,811	3,673			8,811
Nonaccrual Loans/Leases	17,597	7,902			17,597
Accruing TDRs	$ 1,300	1,700			$ 1,300
Nonaccrual Loans/Leases \| loan	3		4		8	9
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 197	55	$ 172		$ 453	$ 831
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| item	1				3	2
Number of nonaccrual restructured loans \| loan	0				0
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 128				$ 482	$ 108
Number of TDRs restructured and written off \| item	3				10	3
Accruing Past Due 90 Days or More	$ 86	33			$ 86
Financing Receivable, Modification, Number of Contracts \| contract					2,451
Financing Receivable, Loan Modification, Not Treated as Troubled Debt Restructuring	575,000				$ 575,000
m2 Lease Funds, LLC
Financing Receivable, Modification, Number of Contracts \| contract					953
Financing Receivable, Loan Modification, Not Treated as Troubled Debt Restructuring	53,000				$ 53,000
Loan Relief Program
Number of Leases \| loan					238
Loans and leases	$ 83,000				$ 83,000
Loans and leases, Percent	1.95%				1.95%
Financing Receivable, Modification, Number of Contracts \| contract					1,498
Financing Receivable, Loan Modification, Not Treated as Troubled Debt Restructuring	$ 522,000				$ 522,000
Financial Receivables Loan Modification, Percent	13.53%				13.53%
One Customer [Member]
Financing Receivable, Modifications, Post-Modification Recorded Investment		32		$ 66
Nonaccrual [Member]
Nonaccrual Loans/Leases \| loan						3
Financing Receivable, Modifications, Post-Modification Recorded Investment						$ 121
Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases	$ 204	747,000			$ 204
Residential Portfolio Segment [Member]
Loans and leases	245,032	239,904			245,032
Loans receivable held for sale	8,800	3,700			8,800
Nonaccrual Loans/Leases	814	706			814
Accruing Past Due 90 Days or More	60				60
Residential Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		31
Commercial Portfolio Segment [Member]
Loans and leases	1,823,049	1,507,825			1,823,049
Nonaccrual Loans/Leases	4,981	1,236			4,981
Financing Receivable, Modifications, Post-Modification Recorded Investment		48
Commercial Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases	48	98			48
Commercial Portfolio Segment [Member] \| m2 Lease Funds, LLC
Loans and leases	162,100	142,000			162,100
Commercial Real Estate Portfolio Segment [Member]
Loans and leases	1,999,715	1,736,396			1,999,715
Commercial Real Estate Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases	50	269,000			50
Finance Leases Portfolio Segment [Member]
Loans and leases	73,011	87,869			73,011
Nonaccrual Loans/Leases	649	1,517			649
Finance Leases Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		294
Consumer Portfolio Segment [Member]
Loans and leases	102,471	109,352			102,471
Nonaccrual Loans/Leases	221	556			221
Accruing Past Due 90 Days or More	26	33			26
Consumer Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases	$ 106	$ 55			$ 106