Note 11 - Business Segment Information (Details) - Selected Financial Information on the Company’s Business Segments - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenue	$ 27,702,218	$ 26,449,589	$ 55,853,889	$ 52,231,641
Net interest income	18,490,836	16,965,343	36,273,053	33,814,584
Net income attributable to QCR Holdings, Inc.	(523,818)	4,007,836	3,654,071	7,897,051
Total assets	2,542,968,846	2,464,839,483	2,542,968,846	2,464,839,483	$ 2,524,958,100
Provision for loan/lease losses	2,348,665	1,001,879	4,059,121	2,096,041
Goodwill	3,222,688	3,222,688	3,222,688	3,222,688	3,222,688
Core deposit intangible	1,571,165	1,770,677	1,571,165	1,770,677	$ 1,670,921
Operating Segments [Member] | Wealth Management Segment [Member]
Segment Reporting Information [Line Items]
Total revenue	2,269,609	2,155,272	4,613,047	4,304,606
Net income attributable to QCR Holdings, Inc.	438,530	386,913	897,860	846,207
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Total revenue	908,697	5,266,342	6,553,303	10,490,207
Net interest income	(457,904)	(431,222)	(943,104)	(880,760)
Net income attributable to QCR Holdings, Inc.	(523,818)	4,007,836	3,654,071	7,897,051
Total assets	268,874,722	208,242,778	268,874,722	208,242,778
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenue	(994,731)	(5,347,439)	(6,720,641)	(10,663,220)
Net income attributable to QCR Holdings, Inc.	(881,107)	(5,237,586)	(6,490,013)	(10,443,972)
Total assets	(248,915,854)	(199,192,145)	(248,915,854)	(199,192,145)
Quad City Bank and Trust Company [Member] | Operating Segments [Member] | Commercial Banking Segment [Member]
Segment Reporting Information [Line Items]
Total revenue	12,992,397	11,962,820	25,785,576	23,900,953
Net interest income	9,741,899	9,080,775	19,016,937	18,001,813
Net income attributable to QCR Holdings, Inc.	229,577	2,454,422	2,792,190	4,795,705
Total assets	1,299,556,911	1,278,200,724	1,299,556,911	1,278,200,724
Provision for loan/lease losses	1,673,665	560,879	2,556,121	1,170,041
Goodwill	3,222,688	3,222,688	3,222,688	3,222,688
Cedar Rapids Bank and Trust [Member] | Operating Segments [Member] | Commercial Banking Segment [Member]
Segment Reporting Information [Line Items]
Total revenue	8,753,178	8,710,753	18,181,672	17,014,378
Net interest income	6,522,511	5,739,056	12,880,808	11,641,115
Net income attributable to QCR Holdings, Inc.	(316,567)	1,781,987	1,751,739	3,716,757
Total assets	860,403,296	826,278,230	860,403,296	826,278,230
Provision for loan/lease losses	500,000	250,000	1,100,000	550,000
Core deposit intangible	1,571,165	1,770,677	1,571,165	1,770,677
Rockford Bank and Trust [Member] | Operating Segments [Member] | Commercial Banking Segment [Member]
Segment Reporting Information [Line Items]
Total revenue	3,773,068	3,701,841	7,440,932	7,184,717
Net interest income	2,684,330	2,576,734	5,318,412	5,052,416
Net income attributable to QCR Holdings, Inc.	529,567	614,264	1,048,224	1,085,303
Total assets	363,049,771	351,309,896	363,049,771	351,309,896
Provision for loan/lease losses	$ 175,000	$ 191,000	$ 403,000	$ 376,000