NOTE 3 - LOANS/LEASES RECEIVABLE - Loans Leases Nonperforming Loans Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accruing Past Due 90 Days or More	$ 58	$ 632
Nonaccrual Loans/Leases	13,148	14,260
Accruing TDRs	4,100	6,500
Loans and Leases Receivable, Net of Deferred Income	$ 3,901,736	$ 3,723,630
Percentage of Total NPLs	100.00%	100.00%
Nonperforming Financial Instruments [Member]
Accruing Past Due 90 Days or More	$ 58	$ 632
Nonaccrual Loans/Leases	13,148	14,260
Accruing TDRs	1,313	3,658
Loans and Leases Receivable, Net of Deferred Income	$ 14,519	$ 18,550
Percentage of Total NPLs	100.00%	100.00%
Commercial Portfolio Segment [Member]
Accruing Past Due 90 Days or More		$ 389
Nonaccrual Loans/Leases	$ 3,553	4,088
Loans and Leases Receivable, Net of Deferred Income	1,548,657	1,429,410
Commercial Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member]
Accruing Past Due 90 Days or More		389
Nonaccrual Loans/Leases	3,553	4,088
Accruing TDRs	1,112	454
Loans and Leases Receivable, Net of Deferred Income	$ 4,665	$ 4,931
Percentage of Total NPLs	32.13%	26.58%
Commercial Real Estate Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	$ 1,837,473	$ 1,766,111
Commercial Real Estate Portfolio Segment [Member] \| Owner Occupied Commercial Real Estate Loans [Member]
Accruing Past Due 90 Days or More		107
Nonaccrual Loans/Leases	190	216
Loans and Leases Receivable, Net of Deferred Income	494,638	500,654
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Nonaccrual Loans/Leases	194	319
Loans and Leases Receivable, Net of Deferred Income	312,578	236,787
Commercial Real Estate Portfolio Segment [Member] \| Other Non-owner Occupied Commercial Real Estate Loans [Member]
Nonaccrual Loans/Leases	5,410	5,522
Loans and Leases Receivable, Net of Deferred Income	1,030,257	1,028,670
Commercial Real Estate Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member] \| Owner Occupied Commercial Real Estate Loans [Member]
Accruing Past Due 90 Days or More		107
Nonaccrual Loans/Leases	190	216
Accruing TDRs	104
Loans and Leases Receivable, Net of Deferred Income	$ 294	$ 323
Percentage of Total NPLs	2.02%	1.74%
Commercial Real Estate Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member] \| Construction Loans [Member]
Nonaccrual Loans/Leases	$ 194	$ 319
Loans and Leases Receivable, Net of Deferred Income	$ 194	$ 319
Percentage of Total NPLs	1.34%	1.72%
Commercial Real Estate Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member] \| Other Non-owner Occupied Commercial Real Estate Loans [Member]
Nonaccrual Loans/Leases	$ 5,410	$ 5,522
Accruing TDRs		2,984
Loans and Leases Receivable, Net of Deferred Income	$ 5,410	$ 8,506
Percentage of Total NPLs	37.26%	45.86%
Finance Leases Portfolio Segment [Member]
Nonaccrual Loans/Leases	$ 1,548	$ 1,761
Loans and Leases Receivable, Net of Deferred Income	101,180	117,969
Finance Leases Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member]
Nonaccrual Loans/Leases	1,548	1,761
Accruing TDRs	97	111
Loans and Leases Receivable, Net of Deferred Income	$ 1,645	$ 1,872
Percentage of Total NPLs	11.33%	10.09%
Residential Portfolio Segment [Member]
Accruing Past Due 90 Days or More	$ 54	$ 89
Nonaccrual Loans/Leases	1,470	1,743
Loans and Leases Receivable, Net of Deferred Income	293,479	290,759
Residential Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member]
Accruing Past Due 90 Days or More	54	89
Nonaccrual Loans/Leases	1,470	1,743
Accruing TDRs		100
Loans and Leases Receivable, Net of Deferred Income	$ 1,524	$ 1,932
Percentage of Total NPLs	10.50%	10.41%
Consumer Portfolio Segment [Member]
Accruing Past Due 90 Days or More	$ 4	$ 47
Nonaccrual Loans/Leases	783	611
Loans and Leases Receivable, Net of Deferred Income	120,947	119,381
Consumer Portfolio Segment [Member] \| Nonperforming Financial Instruments [Member]
Accruing Past Due 90 Days or More	4	47
Nonaccrual Loans/Leases	783	611
Accruing TDRs		9
Loans and Leases Receivable, Net of Deferred Income	$ 787	$ 667
Percentage of Total NPLs	5.42%	3.60%

Amount of financing receivable modified as troubled debt restructuring.

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=118936363&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=118939409&loc=d3e18845-111554

+ Details

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

- 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=119407570&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=118936363&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=118955255&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=118936363&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=119407570&loc=SL82919258-210447

+ Details

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

- 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=118952595&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=118936363&loc=d3e5074-111524

+ Details

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

- Definition

Reflects the percentage derived from dividing impaired loans on which interest has ceased to be accrued by total loans.

+ References

No definition available.

+ Details

Name:	us-gaap_LoansAndLeasesReceivableRatioOfNonperformingLoansToAllLoans
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=qcrh_OwnerOccupiedCommercialRealEstateLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=qcrh_OtherNonownerOccupiedCommercialRealEstateLoansMember
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_ResidentialPortfolioSegmentMember
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: