Note 5 - Business Segment Information (Details) - Selected Financial Information on the Company’s Business Segments (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenue	$ 28,151,671us-gaap_Revenues	$ 25,782,052us-gaap_Revenues
Net interest income	17,782,217us-gaap_InterestIncomeExpenseNet	16,849,241us-gaap_InterestIncomeExpenseNet
Net income attributable to QCR Holdings, Inc.	4,177,889us-gaap_NetIncomeLoss	3,889,215us-gaap_NetIncomeLoss
Total assets	2,491,659,006us-gaap_Assets	2,426,319,210us-gaap_Assets	2,524,958,100us-gaap_Assets
Provision for loan/lease losses	1,710,456us-gaap_ProvisionForLoanAndLeaseLosses	1,094,162us-gaap_ProvisionForLoanAndLeaseLosses
Goodwill	3,222,688us-gaap_Goodwill	3,222,688us-gaap_Goodwill	3,222,688us-gaap_Goodwill
Core deposit intangible	1,621,043us-gaap_FiniteLivedIntangibleAssetsNet	1,820,555us-gaap_FiniteLivedIntangibleAssetsNet	1,670,921us-gaap_FiniteLivedIntangibleAssetsNet
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenue	(5,725,910)	(5,315,781)
Net income attributable to QCR Holdings, Inc.	(5,608,906)	(5,206,386)
Total assets	(208,470,899)	(211,998,694)
Quad City Bank and Trust Company [Member]
Segment Reporting Information [Line Items]
Total revenue	12,793,179	11,938,133
Net interest income	9,275,038	8,921,038
Net income attributable to QCR Holdings, Inc.	2,562,613	2,341,283
Total assets	1,268,168,825	1,269,106,354
Provision for loan/lease losses	882,456	609,162
Goodwill	3,222,688	3,222,688
Cedar Rapids Bank and Trust [Member]
Segment Reporting Information [Line Items]
Total revenue	9,428,494	8,303,625
Net interest income	6,358,297	5,902,059
Net income attributable to QCR Holdings, Inc.	2,068,306	1,934,770
Total assets	855,417,474	819,179,681
Provision for loan/lease losses	600,000	300,000
Core deposit intangible	1,621,043	1,820,555
Rockford Bank and Trust [Member]
Segment Reporting Information [Line Items]
Total revenue	3,667,864	3,482,876
Net interest income	2,634,082	2,475,682
Net income attributable to QCR Holdings, Inc.	518,657	471,039
Total assets	354,993,941	346,365,023
Provision for loan/lease losses	228,000	185,000
Wealth Management [Member]
Segment Reporting Information [Line Items]
Total revenue	2,343,438	2,149,334
Net income attributable to QCR Holdings, Inc.	459,330	459,294
All Other [Member]
Segment Reporting Information [Line Items]
Total revenue	5,644,606	5,223,865
Net interest income	(485,200)	(449,538)
Net income attributable to QCR Holdings, Inc.	4,177,889	3,889,215
Total assets	$ 221,549,665	$ 203,666,846

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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