Note 2 - Available-for-sale Securities - Carrying Amount of Securities and Fair Value (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Available-for-sale Securities, Gross Amortized Cost	$ 27,043,648	$ 31,951,014
Available-for-sale Securities, Gross Unrealized Gains	33,218	53,689
Available-for-sale Securities, Gross Unrealized Losses	(361,357)	(505,571)
Available-for-sale Securities	26,715,509	31,499,132
Collateralized Mortgage Backed Securities [Member]
Available-for-sale Securities, Gross Amortized Cost	23,277,441	27,524,834
Available-for-sale Securities, Gross Unrealized Gains	24,527	45,866
Available-for-sale Securities, Gross Unrealized Losses	(307,542)	(442,303)
Available-for-sale Securities	22,994,426	27,128,397
US Government Agencies Debt Securities [Member]
Available-for-sale Securities, Gross Amortized Cost	2,083,027	2,588,843
Available-for-sale Securities, Gross Unrealized Gains	2,040	0
Available-for-sale Securities, Gross Unrealized Losses	(53,815)	(63,107)
Available-for-sale Securities	2,031,252	2,525,736
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale Securities, Gross Amortized Cost	1,683,180	1,837,337
Available-for-sale Securities, Gross Unrealized Gains	6,651	7,823
Available-for-sale Securities, Gross Unrealized Losses		(161)
Available-for-sale Securities	$ 1,689,831	$ 1,844,999

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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-Name Accounting Standards Codification
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