Note 3 - Investment Securities (Tables)

12 Months Ended

Dec. 31, 2014

Note 3 - Investment Securities (Tables) [Line Items]

Unrealized Gain (Loss) on Investments [Table Text Block]

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		(Losses)			Value
December 31, 2014:
Securities held to maturity:
Municipal securities	$	198,829,574	$	2,420,298	$	(1,186,076	)	$	200,063,796
Other securities		1,050,000		-		-			1,050,000
	$	199,879,574	$	2,420,298	$	(1,186,076	)	$	201,113,796
Securities available for sale:
U.S. govt. sponsored agency securities	$	312,959,760	$	173,685	$	(5,263,873	)	$	307,869,572
Residential mortgage-backed and related securities		110,455,925		1,508,331		(541,032	)		111,423,224
Municipal securities		29,408,740		1,053,713		(62,472	)		30,399,981
Other securities		1,342,554		625,145		(846	)		1,966,853
	$	454,166,979	$	3,360,874	$	(5,868,223	)	$	451,659,630
December 31, 2013:
Securities held to maturity:
Municipal securities	$	144,401,895	$	299,789	$	(7,111,579	)	$	137,590,105
Other securities		1,050,000		-		-			1,050,000
	$	145,451,895	$	299,789	$	(7,111,579	)	$	138,640,105
Securities available for sale:
U.S. govt. sponsored agency securities	$	376,574,132	$	41,696	$	(20,142,841	)	$	356,472,987
Residential mortgage-backed and related securities		160,110,199		1,153,409		(3,834,157	)		157,429,451
Municipal securities		35,813,866		923,315		(778,324	)		35,958,857
Other securities		1,372,365		524,798		-			1,897,163
	$	573,870,562	$	2,643,218	$	(24,755,322	)	$	551,758,458

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than 12 Months					12 Months or More					Total
			Gross					Gross					Gross
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
	Value		Losses			Value		Losses			Value		Losses
December 31, 2014:
Securities held to maturity:
Municipal securities	$	20,419,052	$	(587,992	)	$	38,779,545	$	(598,084	)	$	59,198,597	$	(1,186,076	)
Securities available for sale:
U.S. govt. sponsored agency securities	$	23,970,085	$	(102,695	)	$	255,743,056	$	(5,161,178	)	$	279,713,141	$	(5,263,873	)
Residential mortgage-backed and related securities		10,710,671		(10,139	)		37,570,774		(530,893	)		48,281,445		(541,032	)
Municipal securities		920,935		(1,773	)		4,425,337		(60,699	)		5,346,272		(62,472	)
Other securities		243,004		(846	)		-		-			243,004		(846	)
	$	35,844,695	$	(115,453	)	$	297,739,167	$	(5,752,770	)	$	333,583,862	$	(5,868,223	)
December 31, 2013:
Securities held to maturity:
Municipal securities	$	101,983,602	$	(6,711,240	)	$	2,697,375	$	(400,339	)	$	104,680,977	$	(7,111,579	)
Securities available for sale:
U.S. govt. sponsored agency securities	$	333,194,820	$	(19,141,077	)	$	10,978,390	$	(1,001,764	)	$	344,173,210	$	(20,142,841	)
Residential mortgage-backed and related securities		94,723,092		(2,947,770	)		14,117,719		(886,387	)		108,840,811		(3,834,157	)
Municipal securities		13,890,692		(724,939	)		985,687		(53,385	)		14,876,379		(778,324	)
	$	441,808,604	$	(22,813,786	)	$	26,081,796	$	(1,941,536	)	$	467,890,400	$	(24,755,322	)

Realized Gain (Loss) on Investments [Table Text Block]

	2014			2013			2012
Proceeds from sales of securities	$	78,476,422		$	37,393,047		$	19,215,075
Gross gains from sales of securities		517,116			523,071			104,600
Gross losses from sales of securities		(424,753	)		(90,579	)		-

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized Cost		Fair Value
Securities held to maturity:
Due in one year or less	$	13,233,202	$	13,236,032
Due after one year through five years		18,369,970		18,455,551
Due after five years		168,276,402		169,422,213
	$	199,879,574	$	201,113,796
Securities available for sale:
Due in one year or less	$	1,465,251	$	1,472,292
Due after one year through five years		92,324,465		91,274,581
Due after five years		248,578,784		245,522,680
	$	342,368,500	$	338,269,553
Residential mortgage-backed and related securities		110,455,925		111,423,224
Other securities		1,342,554		1,966,853
	$	454,166,979	$	451,659,630

	Amortized Cost		Fair Value
Securities held to maturity:
Municipal securities	$	110,251,899	$	111,121,516
Securities available for sale:
U.S. govt. sponsored agency securities		232,619,254		228,580,781
Municipal securities		17,823,260		18,324,081
	$	250,442,514	$	246,904,862

Schedule of Debt [Table Text Block]

	2014		2013
Wholesale structured repurchase agreements	$	130,000,000	$	130,000,000
Term note		17,625,000		9,800,000
Series A subordinated notes		2,657,492		2,648,362
	$	150,282,492	$	142,448,362

Bonds [Member]

Note 3 - Investment Securities (Tables) [Line Items]

Schedule of Debt [Table Text Block]

December 31, 2014:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Iowa		14	$	20,156,969	$	20,446,655	$	1,460,475
Missouri		11		8,424,928		8,426,047		766,004
Illinois		10		22,447,799		22,784,638		2,278,464
Other		42		16,838,719		17,110,831		407,401
Total general obligation bonds		77	$	67,868,415	$	68,768,171	$	893,093

December 31, 2013:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Iowa		16	$	17,946,059	$	17,444,045	$	1,090,253
Illinois		12		15,063,325		15,264,718		1,272,060
Other		56		22,166,026		21,512,582		384,153
Total general obligation bonds		84	$	55,175,410	$	54,221,345	$	645,492

December 31, 2014:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Missouri		30	$	62,358,276	$	62,584,516	$	2,086,151
Iowa		20		59,417,246		60,402,941		3,020,147
Indiana		8		17,991,200		17,925,721		2,240,715
Kansas		2		12,307,866		12,332,528		6,166,264
Other		4		8,295,311		8,449,900		2,112,475
Total revenue bonds		64	$	160,369,899	$	161,695,606	$	2,526,494

December 31, 2013:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Iowa		17	$	47,903,572	$	46,257,997	$	2,721,059
Missouri		21		42,085,249		40,054,613		1,907,363
Indiana		7		15,020,000		14,324,717		2,046,388
Kansas		2		11,022,382		9,997,068		4,998,534
Other		5		9,009,148		8,693,222		1,738,644
Total revenue bonds		52	$	125,040,351	$	119,327,617	$	2,294,762