Note 23 - Business Segment Information - (Details) $ in Thousands	Dec. 31, 2019 USD ($) subsidiary
Number of subsidiaries commercial banks	4
Assets allocated \| $	$ 0
Commercial Banking
Number of subsidiaries commercial banks	4
Wealth Management Segment [Member]
Number of subsidiaries commercial banks	3

The amount of assets of subsidiary banks allocated to other segments.

No definition available.

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