Note 22 - Business Segment Information (Details) - Selected Financial Information on the Company’s Business Segments (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total revenue									$ 106,962,556	$ 107,685,786	$ 93,997,168
Net interest income	17,781,213	17,475,331	16,965,343	16,849,241	16,895,732	17,310,336	15,708,052	14,191,317	69,071,128	64,105,437	57,649,260
Net income attributable to QCR Holdings, Inc.	2,992,821	4,062,665	4,007,836	3,889,215	3,815,926	3,811,944	4,045,231	3,265,144	14,952,537	14,938,245	12,617,767
Total assets	2,524,958,100				2,394,952,924				2,524,958,100	2,394,952,924	2,093,730,492
Provision for loan/lease losses	3,647,636	1,063,323	1,001,879	1,094,162	1,985,517	1,366,984	1,520,137	1,057,782	6,807,000	5,930,420	4,370,767
Goodwill	3,222,688				3,222,688				3,222,688	3,222,688	3,222,688
Core deposit intangible	1,670,921				1,870,433				1,670,921	1,870,433
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenue									(456,646)	(402,040)	(379,946)
Net income attributable to QCR Holdings, Inc.											(10,752)
Total assets	(7,233,390)				(16,168,205)				(7,233,390)	(16,168,205)	(38,008,739)
Quad City Bank and Trust Company [Member]
Segment Reporting Information [Line Items]
Total revenue									48,542,678	48,742,635	47,984,123
Net interest income									36,539,635	33,892,035	33,770,092
Net income attributable to QCR Holdings, Inc.									9,065,183	9,310,779	9,915,267
Total assets	1,320,684,456				1,245,128,136				1,320,684,456	1,245,128,136	1,177,294,502
Provision for loan/lease losses									3,800,667	3,391,406	1,527,767
Goodwill	3,222,688				3,222,688				3,222,688	3,222,688	3,222,688
Cedar Rapids Bank and Trust [Member]
Segment Reporting Information [Line Items]
Total revenue									35,683,917	36,089,448	26,697,921
Net interest income									24,215,815	22,239,329	15,717,038
Net income attributable to QCR Holdings, Inc.									7,562,252	7,953,230	5,786,446
Total assets	840,331,777				804,223,453				840,331,777	804,223,453	625,713,218
Provision for loan/lease losses									1,855,333	1,531,014	1,275,000
Core deposit intangible	1,670,921				1,870,433				1,670,921	1,870,433
Rockford Bank and Trust [Member]
Segment Reporting Information [Line Items]
Total revenue									14,598,307	13,809,593	12,955,951
Net interest income									10,261,615	9,645,411	9,630,481
Net income attributable to QCR Holdings, Inc.									2,149,676	1,855,672	857,610
Total assets	353,448,134				339,375,139				353,448,134	339,375,139	313,824,607
Provision for loan/lease losses									1,151,000	1,008,000	1,568,000
Wealth Management [Member]
Segment Reporting Information [Line Items]
Total revenue									8,513,322	7,521,821	5,993,437
Net income attributable to QCR Holdings, Inc.									1,556,082	1,379,402	646,762
All Other [Member]
Segment Reporting Information [Line Items]
Total revenue									80,978	1,924,329	745,682
Net interest income									(1,945,937)	(1,671,338)	(1,468,351)
Net income attributable to QCR Holdings, Inc.									(5,380,656)	(5,560,838)	(4,577,566)
Total assets	$ 17,727,123				$ 22,394,401				$ 17,727,123	$ 22,394,401	$ 14,906,904