Note 4 - Loans Leases Receivable - Aging of the Loan Lease Portfolio (Details) - USD ($)		Dec. 31, 2017	Dec. 31, 2016
Current		$ 2,929,430,446	$ 2,378,270,983
Accruing Past Due 90 Days or More		88,671	966,814
Financing Receivable, Recorded Investment, Nonaccrual Status		11,441,234	13,919,066
Loans		$ 2,956,713,493	$ 2,397,414,282
Current as a percentage of total loan/lease portfolio		99.08%	99.20%
Accruing past due 90 days or more as a percentage of total loan/lease portfolio		0.00%	0.04%
Nonaccrual Loans/Leases as a percentage of total loan/lease portfolio		0.39%	0.58%
Loans and leases as a percentage of total loan/lease portfolio		100.00%	100.00%
Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		$ 14,795,578	$ 3,000,574
Past due as a percentage of total loan/lease portfolio		0.50%	0.13%
Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		$ 957,563	$ 1,256,845
Past due as a percentage of total loan/lease portfolio		0.03%	0.05%
Commercial Portfolio Segment [Member]
Current		$ 1,124,734,486	$ 821,637,507
Accruing Past Due 90 Days or More			346,234
Financing Receivable, Recorded Investment, Nonaccrual Status		1,231,353	4,187,786	[1]
Loans	[2]	1,134,516,315	827,637,263
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		8,306,829	1,455,185
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		243,647	10,551
Commercial Real Estate Portfolio Segment [Member]
Loans		1,303,491,882	1,093,458,860
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Current		331,868,142	331,812,571
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		333,900	332,148	[1]
Loans		332,742,477	332,387,621
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Current		181,558,092	160,760,034
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		4,844,312	4,353,819	[1]
Loans		186,402,404	165,149,491
Commercial Real Estate Portfolio Segment [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Current		782,526,249	594,384,926
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		1,243,728	1,436,149	[1]
Loans		784,347,000	595,921,748
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Past Due		540,435
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Past Due			35,638
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Past Due		572,877	100,673
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Past Due			242,902
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Past Due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Past Due		4,146
Finance Leases Portfolio Segment [Member]
Current		137,708,397	161,452,627
Accruing Past Due 90 Days or More			215,225
Financing Receivable, Recorded Investment, Nonaccrual Status		2,175,044	2,446,181	[1]
Loans	[3]	141,448,232	165,419,360
Finance Leases Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		1,305,191	730,627
Finance Leases Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		259,600	574,700
Residential Portfolio Segment [Member]
Current		253,261,821	227,023,552
Accruing Past Due 90 Days or More		74,519	294,854
Financing Receivable, Recorded Investment, Nonaccrual Status		1,363,806	1,075,639	[1]
Loans	[4]	258,646,265	229,233,104
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		3,552,709	473,478
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		393,410	365,581
Consumer Portfolio Segment [Member]
Current		117,773,259	81,199,766
Accruing Past Due 90 Days or More		14,152	110,501
Financing Receivable, Recorded Investment, Nonaccrual Status		249,091	87,344	[1]
Loans		118,610,799	81,665,695
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		517,537	204,973
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		$ 56,760	$ 63,111

[1] At December 31, 2016, nonaccrual loans/leases included $2,300,479 of TDRs, including $48,501 in C&I loans, $1,380,047 in CRE loans, $816,149 in direct financing leases, $43,579 in residential real estate loans, and $12,203 in installment loans.

[2] 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.

[3] 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.

[4] Includes residential real estate loans held for sale totaling $645,001 and $1,135,500 as of December 31, 2017 and 2016, respectively.