Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 01, 2020
Document and Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Entity Registrant Name	QCR HOLDINGS INC
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Current Fiscal Year End Date	--12-31
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		15,773,518
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000906465
Amendment Flag	false