Note 1 - Basis of Presentation and Accounting Policies - Impact of Restated Adjustments (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		Dec. 31, 2013
Prepaid expenses and other assets	$ 8,470,887				$ 8,348,385				$ 8,470,887	$ 8,348,385
Total assets	990,701,914				946,282,972				990,701,914	946,282,972
Retained earnings	49,560,595				43,691,073				49,560,595	43,691,073
Stockholders' equity	87,183,719				82,170,774				87,183,719	82,170,774	$ 80,002,576		$ 74,207,180
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]
Scenario, Previously Reported [Member]
Income tax receivable											$ 2,594,376		0
Prepaid expenses and other assets											6,898,192		9,599,143
Total assets											885,864,932		674,721,943
Retained earnings											41,303,204		38,849,326
Stockholders' equity											80,436,861		74,858,143
Income tax expense											1,565,687
Net income											$ 3,872,944
Basic earnings per share (in dollars per share)											$ 0.40
Diluted earnings per share (in dollars per share)											$ 0.40
Scenario, Actual [Member]
Income tax receivable											$ 1,591,105		0
Prepaid expenses and other assets											7,467,178		8,948,180
Total assets											885,430,647		674,070,980
Retained earnings											40,868,919		38,198,363
Stockholders' equity											80,002,576		$ 74,207,180
Income tax expense											1,349,009
Net income											$ 4,089,622
Basic earnings per share (in dollars per share)											$ 0.43
Diluted earnings per share (in dollars per share)											$ 0.42

[1] revised for prior period restatement

[2] revised for prior period restatement

[3] revised for prior period restatement