Note 25 - Quarterly Financial Data (Unaudited) - Quarterly Financial Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income	$ 9,336,000	$ 9,210,000	$ 8,998,000	$ 8,672,000	$ 8,569,000	$ 8,217,000	$ 7,901,000	$ 7,764,000
Interest expense	920,000	911,000	898,000	882,000	841,000	794,000	711,000	708,000	$ 3,610,879	$ 3,054,309	$ 2,750,843
Net interest income	8,416,000	8,299,000	8,100,000	7,790,000	7,728,000	7,423,000	7,190,000	7,056,000	32,605,336	29,396,294	26,427,020
Provision for credit losses	200,000	220,000	325,000	225,000	325,000	335,000	140,000		970,000	800,000	1,100,000
Non-interest income	3,372,000	3,691,000	3,548,000	3,576,000	3,736,000	3,766,000	3,616,000	3,180,000	14,187,504	14,297,975	8,585,186
Non-interest expense	8,819,000	8,928,000	9,047,000	9,106,000	9,087,000	9,007,000	9,026,000	9,254,000	35,900,439	36,373,727	28,473,575
Income tax expense	775,000	948,000	664,000	574,000	484,000	610,000	486,000	257,000	2,961,139	1,837,329	1,349,009	[1]
Net income	$ 1,994,000	$ 1,894,000	$ 1,612,000	$ 1,461,000	$ 1,568,000	$ 1,237,000	$ 1,154,000	$ 725,000	$ 6,961,262	$ 4,683,213	$ 4,089,622	[1],[2],[3]
Basic earnings per share (in dollars per share)	$ 0.21	$ 0.20	$ 0.17	$ 0.15	$ 0.17	$ 0.13	$ 0.12	$ 0.08	$ 0.73	$ 0.49	$ 0.43	[1]
Diluted earnings per share (in dollars per share)	0.21	0.20	0.17	0.15	0.16	0.13	0.12	0.08	0.73	0.49	0.42	[1]
Dividends per share (in dollars per share)	$ 0.03	$ 0.03	$ 0.03	$ 0.025	$ 0.025	$ 0.025	$ 0.025	$ 0.025	$ 0.115	$ 0.10	$ 0.10

[1] revised for prior period restatement

[2] revised for prior period restatement

[3] revised for prior period restatement