Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 01, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	QCR HOLDINGS INC
Entity Central Index Key	0000906465
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		15,758,261
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1