Note 3 - Loans Leases Receivable - Composition of the Loan Lease Portfolio (Details) - USD ($)		Sep. 30, 2017		Jun. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Loans		$ 2,669,013,113			$ 2,397,414,282
Plus deferred loan/lease origination costs, net of fees		7,741,698			8,072,703
Gross loans/leases receivable		2,676,754,811			2,405,486,985
Less allowance		(34,982,341)		$ (33,356,632)	(30,757,448)		$ (28,826,835)	$ (28,097,490)	$ (26,140,906)
Net loans/leases receivable		2,641,772,470			2,374,729,537
Commercial Portfolio Segment [Member]
Loans	[1]	1,034,530,786			827,637,263
Less allowance		(14,402,715)		(14,207,733)	(12,545,110)		(11,557,966)	(10,724,506)	(10,484,080)
Commercial Real Estate Portfolio Segment [Member]
Loans		1,157,855,663			1,093,458,860
Less allowance		(14,359,374)		(12,999,233)	(11,670,609)		(11,002,524)	(10,987,062)	(9,375,117)
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Loans		327,144,766			332,387,621
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans		168,992,704			165,149,491
Commercial Real Estate Portfolio Segment [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Loans		661,718,193			595,921,748
Finance Leases Portfolio Segment [Member]
Loans	[2],[3]	147,062,893			165,419,360
Plus deferred loan/lease origination costs, net of fees	[2]	4,800,719			5,881,778
Gross loans/leases receivable	[2]	151,863,612			171,301,138
Less allowance		(2,652,758)	[2]	(2,638,301)	(3,111,898)	[2]	(3,041,962)	(3,226,194)	(3,395,088)
Net loans/leases receivable	[2]	149,210,854			168,189,240
Net minimum lease payments to be received	[2]	162,728,461			184,274,802
Estimated unguaranteed residual values of leased assets	[2]	1,085,154			1,085,154
Unearned lease/residual income	[2]	(16,750,722)			(19,940,596)
Residential Portfolio Segment [Member]
Loans	[3],[4]	239,957,916			229,233,104
Less allowance		(2,398,978)		(2,430,454)	(2,342,344)		(2,055,654)	(2,014,987)	(1,790,150)
Consumer Portfolio Segment [Member]
Loans	[3]	89,605,855			81,665,695
Less allowance		$ (1,168,516)		$ (1,080,911)	$ (1,087,487)		$ (1,168,729)	$ (1,144,741)	$ (1,096,471)

[1] Includes loans outstanding at QCBT's wholly-owned subsidiary, m2, totaling $60,981,381 and $38,668,209 as of September 30, 2017 and December 31, 2016, respectively.

[2] Management performs an evaluation of the estimated unguaranteed residual values of leased assets on an annual basis, at a minimum. The evaluation consists of discussions with reputable and current vendors, which is combined with management's expertise and understanding of the current states of particular industries to determine informal valuations of the equipment. As necessary and where available, management will utilize valuations by independent appraisers. The large majority of leases with residual values contain a lease options rider, which requires the lessee to pay the residual value directly, finance the payment of the residual value, or extend the lease term to pay the residual value. In these cases, the residual value is protected and the risk of loss is minimal. There were no losses related to residual values for the three and nine months ended September 30, 2017 and 2016.

[3] Performing = loans/leases accruing and less than 90 days past due. Nonperforming = loans/leases on nonaccrual, accruing loans/leases that are greater than or equal to 90 days past due, and accruing TDRs.

[4] Includes residential real estate loans held for sale totaling $290,320 and $1,135,500 as of September 30, 2017, and December 31, 2016, respectively.