Note 22 - Business Segment Information (Details) - Selected Financial Information on the Company’s Business Segments - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenue									$ 114,532,976	$ 107,122,613	$ 108,717,634
Net interest income	$ 19,886,145	$ 20,137,526	$ 18,490,836	$ 17,782,217	$ 17,781,213	$ 17,475,331	$ 16,965,343	$ 16,849,241	76,296,724	69,071,128	64,105,437
Net income attributable to QCR Holdings, Inc.	6,784,823	6,488,987	(523,818)	4,177,889	2,992,821	4,062,665	4,007,836	3,889,215	16,927,881	14,952,537	14,938,245
Total assets	2,593,198,275				2,524,958,100				2,593,198,275	2,524,958,100	2,394,952,924
Provision for loan/lease losses	1,176,516	$ 1,635,263	$ 2,348,665	$ 1,710,456	3,647,636	$ 1,063,323	$ 1,001,879	$ 1,094,162	6,870,900	6,807,000	5,930,420
Goodwill	3,222,688				3,222,688				3,222,688	3,222,688	3,222,688
Core deposit intangible	1,471,409				1,670,921				1,471,409	1,670,921	1,870,433
Operating Segments [Member] | Wealth Management Segment [Member]
Segment Reporting Information [Line Items]
Total revenue									9,103,173	8,513,322	7,521,821
Net income attributable to QCR Holdings, Inc.									1,627,586	1,556,082	1,379,402
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Total revenue									663,432	80,978	1,924,329
Net interest income									(1,610,135)	(1,945,937)	(1,671,338)
Net income attributable to QCR Holdings, Inc.									(5,131,205)	(5,380,656)	(5,560,838)
Total assets	27,605,704				17,727,123				27,605,704	17,727,123	22,394,401
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenue									(424,688)	(485,860)	(108,214)
Total assets	(5,323,168)				(7,233,390)				(5,323,168)	(7,233,390)	(16,168,205)
Quad City Bank and Trust Company [Member] | Operating Segments [Member] | Commercial Banking Segment [Member]
Segment Reporting Information [Line Items]
Total revenue									52,859,118	48,827,714	49,701,389
Net interest income									40,416,563	36,539,635	33,892,035
Net income attributable to QCR Holdings, Inc.									10,333,111	9,065,183	9,310,779
Total assets	1,336,571,694				1,320,684,456				1,336,571,694	1,320,684,456	1,245,128,136
Provision for loan/lease losses									4,367,234	3,800,667	3,391,406
Goodwill	3,222,688				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									37,515,641	35,899,702	35,946,233
Net interest income									26,635,659	24,215,815	22,239,329
Net income attributable to QCR Holdings, Inc.									7,695,867	7,562,252	7,953,230
Total assets	866,872,406				840,331,777				866,872,406	840,331,777	804,223,453
Provision for loan/lease losses									1,750,000	1,855,333	1,531,014
Core deposit intangible	1,471,409				1,670,921				1,471,409	1,670,921	1,870,433
Rockford Bank and Trust [Member] | Operating Segments [Member] | Commercial Banking Segment [Member]
Segment Reporting Information [Line Items]
Total revenue									14,816,300	14,286,757	13,732,076
Net interest income									10,854,637	10,261,615	9,645,411
Net income attributable to QCR Holdings, Inc.									2,402,522	2,149,676	1,855,672
Total assets	$ 367,471,639				$ 353,448,134				367,471,639	353,448,134	339,375,139
Provision for loan/lease losses									$ 753,666	$ 1,151,000	$ 1,008,000