Note 4 - Earnings Per Share (Detail) - Earnings Per Share - Basic and Diluted (USD $)	3 Months Ended							9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2012	Sep. 30, 2011
Net income	$ 3,184,510	$ 3,273,379	$ 3,402,849	$ 2,266,601		$ 2,773,214	$ 2,231,484	$ 9,860,738	$ 7,271,299
Less: Net income attributable to noncontrolling interests	127,177			103,446				494,431	308,215
Net income attributable to QCR Holdings, Inc.	3,057,333			2,163,155				9,366,307	6,963,084
Less: Preferred stock dividends and discount accretion	810,837			2,188,058	[1]			2,685,248	4,256,171	[1]
Net income attributable to QCR Holdings, Inc. common stockholders	$ 2,246,496			$ (24,903)				$ 6,681,059	$ 2,706,913
Earnings per common share attributable to QCR Holdings, Inc. common stockholders
Basic (in Dollars per share)	$ 0.45			$ (0.01)				$ 1.37	$ 0.56
Diluted (in Dollars per share)	$ 0.44			$ (0.01)				$ 1.35	$ 0.56
Weighted average common shares outstanding (in Shares)	4,978,699			4,866,692				4,871,626	4,795,382
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan (in Shares)	101,589				[2]			66,888	52,051
Weighted average common and common equivalent shares outstanding (in Shares)	5,080,288			4,866,692				4,938,514	4,847,433

[1] For the three and nine months ended September 30, 2011, includes approximately $1.2 million of accelerated accretion of discount on the Treasury Captial Purchase Program preferred shares repurchased during the third quarter of 2011.

[2] In accordance with U.S. GAAP, the common equivalent shares are not considered in the calculation of diluted earnings per share as the numerator is a loss.