Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
General Obligation Bonds [Member]
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	78	77
Amortized cost	$ 56,989,724	$ 67,868,415
Fair value	57,299,775	68,768,171
Average exposure per issuer (fair value)	$ 734,613	$ 893,093
General Obligation Bonds [Member] | IOWA
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	16	14
Amortized cost	$ 19,725,988	$ 20,156,969
Fair value	19,629,187	20,446,655
Average exposure per issuer (fair value)	$ 1,226,824	$ 1,460,475
General Obligation Bonds [Member] | MISSOURI
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	12	11
Amortized cost	$ 7,903,655	$ 8,424,928
Fair value	7,859,378	8,426,047
Average exposure per issuer (fair value)	$ 654,948	$ 766,004
General Obligation Bonds [Member] | ILLINOIS
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	9	10
Amortized cost	$ 11,888,959	$ 22,447,799
Fair value	12,168,493	22,784,638
Average exposure per issuer (fair value)	$ 1,352,055	$ 2,278,464
General Obligation Bonds [Member] | Other States [Member]
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	41	42
Amortized cost	$ 17,471,122	$ 16,838,719
Fair value	17,642,717	17,110,831
Average exposure per issuer (fair value)	$ 430,310	$ 407,401
Revenue Bonds [Member]
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	81	64
Amortized cost	$ 194,248,658	$ 160,369,899
Fair value	193,095,109	161,695,606
Average exposure per issuer (fair value)	$ 2,383,890	$ 2,526,494
Revenue Bonds [Member] | IOWA
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	25	20
Amortized cost	$ 72,138,865	$ 59,417,246
Fair value	72,156,897	60,402,941
Average exposure per issuer (fair value)	$ 2,886,276	$ 3,020,147
Revenue Bonds [Member] | MISSOURI
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	34	30
Amortized cost	$ 66,832,018	$ 62,358,276
Fair value	66,174,793	62,584,516
Average exposure per issuer (fair value)	$ 1,946,317	$ 2,086,151
Revenue Bonds [Member] | Other States [Member]
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	4	4
Amortized cost	$ 7,893,263	$ 8,295,311
Fair value	8,006,048	8,449,900
Average exposure per issuer (fair value)	$ 2,001,512	$ 2,112,475
Revenue Bonds [Member] | INDIANA
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	15	8
Amortized cost	$ 35,440,200	$ 17,991,200
Fair value	35,161,046	17,925,721
Average exposure per issuer (fair value)	$ 2,344,070	$ 2,240,715
Revenue Bonds [Member] | KANSAS
Note 2 - Investment Securities (Details) - Amoritized Cost and Fair Values of General Obligation Bonds by Issuer's State [Line Items]
Number of issuers	3	2
Amortized cost	$ 11,944,312	$ 12,307,866
Fair value	11,596,325	12,332,528
Average exposure per issuer (fair value)	$ 3,865,442	$ 6,166,264