The eligible age limit of employee for participation in the defined benefit plan.

No definition available.

Name:	qcrh_DefinedBenefitPlanEligibleAgeLimit
Namespace Prefix:	qcrh_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of discretionary contributions made by the entity.

+ References

No definition available.

+ Details

Name:	qcrh_DiscretionaryCompanyContributions
Namespace Prefix:	qcrh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest on deferred compensation amounts.

+ References

No definition available.

+ Details

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

- Definition

The number of monthly installment payments.

+ References

No definition available.

+ Details

Name:	qcrh_NumberOfMonthlyInstallmentPayments
Namespace Prefix:	qcrh_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contributions made by employer into fund established for purposes of making future disbursement to individual in accordance with deferred compensation arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=qcrh_CertainExecutiveOfficersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=qcrh_CertainManagementOfficersMembersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=qcrh_First3OfEmployeesWagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=qcrh_MatchAt100Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=qcrh_From4To45OfEmployeesWagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=qcrh_MatchedAt50Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 15 - Employee Benefit Plans (Details) - USD ($)	12 Months Ended
Note 15 - Employee Benefit Plans (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Percent of employee contributions matched	4.50%
Discretionary contributions	$ 0	$ 0	$ 0
Deferred compensation liability, current and noncurrent	24,713,000	19,474,000	15,029,000	$ 12,347,000
Deferred compensation matching contributions	$ 3,959,000	2,474,000	$ 1,407,000
Minimum
Defined benefit plan eligible age limit	18 years
Minimum \| Certain Executive Officers [Member]
Deferred compensation matching contributions	$ 10,000
Interest on deferred compensation amounts	4.00%
Maximum \| Certain Executive Officers [Member]
Deferred compensation matching contributions	$ 25,000
Interest on deferred compensation amounts	12.00%
Certain Management Officers [Member]
Deferred compensation liability, current and noncurrent	$ 24,700,000	$ 19,500,000
Number of monthly installment payments	180 months
Certain Management Officers [Member] \| Minimum
Company matching contribution percent (as a percent)	4.00%
Interest on deferred compensation amounts	4.00%
Certain Management Officers [Member] \| Maximum
Company matching contribution percent (as a percent)	10.00%
Interest on deferred compensation amounts	8.00%
First 3% of Employees Wages [Member]
Company matching contribution percent (as a percent)	100.00%
Match at 100% [Member]
Percent of employee contributions matched	3.00%
From 4% to 4.5% of Employees Wages [Member]
Company matching contribution percent (as a percent)	50.00%
Matched at 50% [Member]
Percent of employee contributions matched	3.00%