Consolidated Statements of Income (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest and dividend income:
Loans/leases, including fees	$ 64,807,673	$ 67,999,191	$ 73,145,289
Securities:
Taxable	10,877,832	10,109,083	10,748,012
Nontaxable	983,040	907,085	967,940
Interest-bearing deposits at financial institutions	404,879	411,079	313,113
Restricted investment securities	557,698	497,214	302,756
Federal funds sold	92,126	173,714	133,723
Total interest and dividend income	77,723,248	80,097,366	85,610,833
Interest expense:
Deposits	8,939,056	12,681,625	18,374,065
Short-term borrowings	290,450	628,255	711,801
Federal Home Loan Bank advances	7,972,025	9,246,562	9,082,039
Other borrowings	5,149,022	5,732,142	4,764,812
Junior subordinated debentures	1,227,839	1,945,014	2,016,449
Total interest expense	23,578,392	30,233,598	34,949,166
Net interest income	54,144,856	49,863,768	50,661,667
Provision for loan/lease losses	6,616,014	7,463,618	16,975,517
Net interest income after provision for loan/lease losses	47,528,842	42,400,150	33,686,150
Noninterest income:
Trust department fees	3,368,995	3,290,844	2,883,482
Investment advisory and management fees, gross	2,108,918	1,812,903	1,507,557
Deposit service fees	3,493,001	3,478,743	3,319,967
Gains on sales of loans, net	2,565,043	3,169,514	1,677,312
Securities gains, net	1,472,528		1,488,391
Gains (losses) on sales of other real estate owned	(374,910)	(835,163)	177,736
Earnings on bank-owned life insurance	1,445,891	1,331,085	1,243,324
Credit card fees, net of processing costs	500,544	259,590	930,435
Other	2,881,868	2,898,372	2,318,843
Total noninterest income	17,461,878	15,405,888	15,547,047
Noninterest expenses:
Salaries and employee benefits	30,365,020	27,843,127	26,882,185
Occupancy and equipment expense	5,297,949	5,472,248	5,372,101
Professional and data processing fees	4,461,187	4,524,519	4,664,656
FDIC and other insurance	2,698,282	3,528,267	3,626,027
Loan/lease expense	2,160,674	1,657,552	1,997,583
Advertising and marketing	1,288,797	1,053,909	991,243
Postage and telephone	937,557	1,004,176	1,060,690
Stationery and supplies	516,873	491,252	528,959
Bank service charges	725,717	420,252	306,473
Prepayment fees on Federal Home Loan Bank advances	832,099
Other-than-temporary impairment losses on securities	118,847	113,800	206,369
Losses on lease residual values		617,000
Other	1,589,650	1,822,961	1,300,740
Total noninterest expenses	50,992,652	48,549,063	46,937,026
Income before income taxes	13,998,068	9,256,975	2,296,171
Federal and state income tax expense	3,868,199	2,449,249	247,340
Net income	10,129,869	6,807,726	2,048,831
Less: net income attributable to noncontrolling interests	438,221	221,047	276,923
Net income attributable to QCR Holdings, Inc.	9,691,648	6,586,679	1,771,908
Less: preferred stock dividends and discount accretion	5,283,885	4,128,104	3,843,924
Net income (loss) attributable to QCR Holdings, Inc. common stockholders	$ 4,407,763	$ 2,458,575	$ (2,072,016)
Basic earnings (loss) per common share (in Dollars per share)	$ 0.93	$ 0.54	$ (0.46)
Diluted earnings (loss) per common share (in Dollars per share)	$ 0.92	$ 0.53	$ (0.46)
Weighted average common shares outstanding (in Shares)	4,724,781	4,593,096	4,540,792
Weighted average common and common equivalent shares outstanding (in Shares)	4,789,026	4,618,242	4,540,792
Cash dividends declared per common share (in Dollars per share)	$ 0.08	$ 0.08	$ 0.08