Note 4 - Earnings Per Share (Detail) - Earnings Per Share - Basic and Diluted (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 3,273,379	$ 3,402,849	$ 2,773,214	$ 2,231,484	$ 6,676,228	$ 5,004,698
Less: Net income attributable to noncontrolling interests	201,223		98,245		367,254	204,769
Net income attributable to QCR Holdings, Inc.	3,072,156		2,674,969		6,308,974	4,799,929
Less: Preferred stock dividends and discount accretion	935,786		1,035,742		1,874,411	2,068,113
Net income attributable to QCR Holdings, Inc. common stockholders	$ 2,136,370		$ 1,639,227		$ 4,434,563	$ 2,731,816
Earnings per common share attributable to QCR Holdings, Inc. common stockholders
Basic (in Dollars per share)	$ 0.44		$ 0.34		$ 0.92	$ 0.57
Diluted (in Dollars per share)	$ 0.44		$ 0.34		$ 0.91	$ 0.57
Weighted average common shares outstanding (in Shares)	4,835,773		4,847,740		4,818,090	4,759,728
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan (in Shares)	66,080		26,238		49,538	19,120
Weighted average common and common equivalent shares outstanding (in Shares)	4,901,853		4,873,978		4,867,628	4,778,848