| Cover | Aug. 20, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | This Form 8-K/A amends the Current Report on Form 8-K, dated and filed as of August 21, 2020 (the “Form 8-K”), to add Item 5.02 to the disclosure, which was inadvertently omitted. No other changes have been made to the Form 8-K. |
| Document Period End Date | Aug. 20, 2020 |
| Entity File Number | 000-22208 |
| Entity Registrant Name | QCR Holdings, Inc. |
| Entity Central Index Key | 0000906465 |
| Entity Tax Identification Number | 42-1397595 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 3551 Seventh Street |
| Entity Address, City or Town | Moline |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 61265 |
| City Area Code | (309) |
| Local Phone Number | 736-3584 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $1.00 Par Value |
| Trading Symbol | QCRH |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
