The amount of gain (loss) on loans and leases receivable.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of trouble debt restructurings restructured and written off.

+ References

No definition available.

+ Details

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Namespace Prefix:	qcrh_
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Period Type:	instant

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

+ Details

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ 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=82895541&loc=d3e18845-111554

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

+ Details

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

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

+ Details

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

- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ 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=84173941&loc=d3e5111-111524

+ Details

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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

+ Details

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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=82891408&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=84173941&loc=d3e5074-111524

+ Details

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

- Definition

Amount, after allowance for bad debt, of mortgage loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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- Details

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- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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- Details

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- Details

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Balance Type:
Period Type:

- Details

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Data Type:	na
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Period Type:

- Details

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- Details

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Note 4 - Loans Leases Receivable - Textual (Details)	3 Months Ended				9 Months Ended		12 Months Ended
Note 4 - Loans Leases Receivable - Textual (Details)	Sep. 30, 2018 USD ($) item	Sep. 30, 2017 USD ($) item	Jun. 30, 2017 USD ($) item	Dec. 31, 2016 USD ($) item	Sep. 30, 2018 USD ($) lease item	Sep. 30, 2017 USD ($) lease item	Dec. 31, 2017 USD ($) item
Loans and leases	$ 3,644,099,503				$ 3,644,099,503		$ 2,956,713,493
Loans and leases receivable loss	0	$ 0			0	$ 0
Financing Receivable, Recorded Investment, Nonaccrual Status	23,576,285				23,576,285		11,441,234
Financing Receivable, Modifications, Recorded Investment	$ 7,276,337				$ 7,276,337		9,394,967
Financing Receivable, Modifications, Number of Contracts	8	8			11	36
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 4,309,980	$ 1,037,049			$ 4,403,824	$ 2,795,032
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| item	2	4			2	4
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 774,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down					$ 577,377		$ 65,623
Number of TDRs restructured and written off \| item	8				8		2
One Customer [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| item			2
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down			$ 112,000
Other Customers [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| item				2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment				$ 195,000
Nonaccrual [Member]
Financing Receivable, Modifications, Number of Contracts \| item					4	3
Financing Receivable, Modifications, Post-Modification Recorded Investment					$ 1,300,424	$ 1,384,680
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 3,036,422				3,036,422		$ 2,282,495
Residential Portfolio Segment [Member]
Loans and leases	309,287,535				309,287,535		258,646,265
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	2,557,907				2,557,907		645,001
Financing Receivable, Recorded Investment, Nonaccrual Status	973,947				973,947		1,363,806
Residential Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	82,151				82,151		115,190
Commercial Portfolio Segment [Member]
Loans and leases	1,380,542,524				1,380,542,524		1,134,516,315
Financing Receivable, Recorded Investment, Nonaccrual Status	8,046,588				8,046,588		1,231,353
Commercial Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	336,168				336,168		122,598
Commercial Portfolio Segment [Member] \| m2 Lease Funds, LLC [Member]
Loans and leases	98,823,351				98,823,351		66,758,397
Commercial Real Estate Portfolio Segment [Member]
Loans and leases	1,727,326,190				1,727,326,190		1,303,491,882
Commercial Real Estate Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,026,376				2,026,376		1,336,871
Finance Leases Portfolio Segment [Member]
Loans and leases	126,751,783				126,751,783		141,448,232
Financing Receivable, Recorded Investment, Nonaccrual Status	1,966,716				1,966,716		2,175,044
Finance Leases Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	587,613				587,613		700,255
Consumer Portfolio Segment [Member]
Loans and leases	100,191,471				100,191,471		118,610,799
Financing Receivable, Recorded Investment, Nonaccrual Status	230,616				230,616		249,091
Consumer Portfolio Segment [Member] \| Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 4,114				$ 4,114		$ 7,581