Note 17 - Earnings Per Share (Details) - Earnings Per Share - Basic and Diluted - 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
Earnings Per Share, Basic and Diluted [Abstract]
Net income (in Dollars)										$ 16,927,881	$ 14,952,537	$ 14,938,245
Less: Preferred stock dividends (in Dollars)											1,081,877	3,168,302
Net income attributable to QCR Holdings, Inc. common stockholders (in Dollars)										$ 16,927,881	$ 13,870,660	$ 11,769,943
EPS attributable to QCR Holdings, Inc. common stockholders
Basic (in Dollars per share)		$ 0.58	$ 0.55	$ (0.05)	$ 0.52	$ 0.38	$ 0.51	$ 0.46	$ 0.40	$ 1.64	$ 1.75	$ 2.13
Diluted (in Dollars per share)		$ 0.57	$ 0.55	$ (0.05)	$ 0.52	$ 0.37	$ 0.50	$ 0.45	$ 0.40	$ 1.61	$ 1.72	$ 2.08
Weighted average common shares outstanding*	[1]									10,345,286	7,925,220	5,531,948
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan**	[2]									154,555	123,441	114,978
Weighted average common and common equivalent shares outstanding										10,499,841	8,048,661	5,646,926

[1] The increase in weighted average common shares outstanding from 2014 to 2015 was primarily due to the common stock issuance discussed in Note 12 to theConsolidated Financial Statements

[2] Excludes anti-dilutive shares of 36,572, 124,983, and 116,324 at December 31, 2015, 2014 and 2013, respectively.