Note 2 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2016

Notes Tables

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

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		(Losses)			Value
September 30, 2016:
Securities HTM:
Municipal securities	$	305,690,174	$	5,533,151	$	(778,982	)	$	310,444,343
Other securities		1,050,000		-		-			1,050,000
	$	306,740,174	$	5,533,151	$	(778,982	)	$	311,494,343
Securities AFS:
U.S. govt. sponsored agency securities	$	66,966,328	$	992,084	$	(73,463	)	$	67,884,949
Residential mortgage-backed and related securities		131,496,011		1,824,345		(147,552	)		133,172,804
Municipal securities		53,887,898		816,063		(63,499	)		54,640,462
Other securities		2,002,113		492,980		(3,227	)		2,491,866
	$	254,352,350	$	4,125,472	$	(287,741	)	$	258,190,081
December 31, 2015:
Securities HTM:
Municipal securities	$	252,624,159	$	3,190,558	$	(1,173,432	)	$	254,641,285
Other securities		1,050,000		-		-			1,050,000
	$	253,674,159	$	3,190,558	$	(1,173,432	)	$	255,691,285
Securities AFS:
U.S. govt. sponsored agency securities	$	216,281,416	$	104,524	$	(2,848,561	)	$	213,537,379
Residential mortgage-backed and related securities		81,442,479		511,095		(1,283,439	)		80,670,135
Municipal securities		26,764,981		872,985		(59,378	)		27,578,588
Other securities		1,108,124		540,919		(163	)		1,648,880
	$	325,597,000	$	2,029,523	$	(4,191,541	)	$	323,434,982

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
September 30, 2016:
Securities HTM:
Municipal securities	$	23,632,888	$	(251,558	)	$	14,150,396	$	(527,424	)	$	37,783,284	$	(778,982	)
Securities AFS:
U.S. govt. sponsored agency securities	$	9,547,746	$	(73,463	)	$	-	$	-		$	9,547,746	$	(73,463	)
Residential mortgage-backed and related securities		9,326,000		(78,305	)		8,464,738		(69,247	)		17,790,738		(147,552	)
Municipal securities		25,921,780		(49,087	)		846,894		(14,412	)		26,768,674		(63,499	)
Other securities		641,430		(3,227	)		-		-			641,430		(3,227	)
	$	45,436,956	$	(204,082	)	$	9,311,632	$	(83,659	)	$	54,748,588	$	(287,741	)
December 31, 2015:
Securities HTM:
Municipal securities	$	14,803,408	$	(294,438	)	$	19,927,581	$	(878,994	)	$	34,730,989	$	(1,173,432	)
Securities AFS:
U.S. govt. sponsored agency securities	$	112,900,327	$	(1,397,591	)	$	64,476,661	$	(1,450,970	)	$	177,376,988	$	(2,848,561	)
Residential mortgage-backed and related securities		40,356,921		(730,466	)		19,836,637		(552,973	)		60,193,558		(1,283,439	)
Municipal securities		2,220,800		(31,807	)		848,329		(27,571	)		3,069,129		(59,378	)
Other securities		411		(163	)		-		-			411		(163	)
	$	155,478,459	$	(2,160,027	)	$	85,161,627	$	(2,031,514	)	$	240,640,086	$	(4,191,541	)

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

	Three Months Ended						Nine Months Ended
	September 30, 2016			September 30, 2015			September 30, 2016			September 30, 2015
Proceeds from sales of securities*	$	58,775,764		$	11,922,915		$	119,850,909		$	65,889,838
Pre-tax gross gains from sales of securities		4,281,828			102,766			4,815,373			672,317
Pre-tax gross losses from sales of securities		(30,055	)		(46,186	)		(187,090	)		(198,804	)

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized Cost		Fair Value
Securities HTM:
Due in one year or less	$	9,333,827	$	9,382,178
Due after one year through five years		30,899,427		31,047,261
Due after five years		266,506,920		271,064,904
	$	306,740,174	$	311,494,343
Securities AFS:
Due in one year or less	$	2,345,063	$	2,347,195
Due after one year through five years		55,691,033		56,456,647
Due after five years		62,818,130		63,721,569
	$	120,854,226	$	122,525,411
Residential mortgage-backed and related securities		131,496,011		133,172,804
Other securities		2,002,113		2,491,866
	$	254,352,350	$	258,190,081

	Amortized Cost		Fair Value
Securities HTM:
Municipal securities	$	178,052,716	$	180,307,064
Securities AFS:
U.S. govt. sponsored agency securities		11,042,867		11,073,088
Municipal securities		41,062,791		37,443,219
	$	52,105,658	$	48,516,307

Schedule of Investment in Bond Securities [Table Text Block]

September 30, 2016:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Iowa		27	$	32,289,974	$	32,746,465	$	1,212,832
Illinois		19		30,063,690		30,437,115		1,601,953
North Dakota		6		19,403,728		19,906,421		3,317,737
Missouri		13		8,304,022		8,448,994		649,923
Other		49		23,934,196		24,247,257		494,842
Total general obligation bonds		114	$	113,995,610	$	115,786,252	$	1,015,669

December 31, 2015:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Iowa		15	$	19,974,939	$	20,247,108	$	1,349,807
Illinois		9		10,928,700		11,264,348		1,251,594
North Dakota		5		10,890,000		11,050,235		2,210,047
Missouri		12		7,924,800		7,986,856		665,571
Other		41		16,965,393		17,229,485		420,231
Total general obligation bonds		82	$	66,683,832	$	67,778,032	$	826,561

September 30, 2016:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Missouri		44	$	90,171,820	$	91,084,628	$	2,070,105
Iowa		30		75,440,709		77,216,784		2,573,893
Indiana		20		43,994,737		44,605,536		2,230,277
Kansas		6		13,480,269		13,587,744		2,264,624
North Dakota		4		8,114,931		8,175,230		2,043,808
Other		8		14,379,998		14,628,631		1,828,579
Total revenue bonds		112	$	245,582,464	$	249,298,553	$	2,225,880

December 31, 2015:
U.S. State:	Number of Issuers		Amortized Cost		Fair Value		Average Exposure Per Issuer (Fair Value)
Missouri		41	$	78,593,590	$	79,015,378	$	1,927,204
Iowa		26		70,773,660		71,659,410		2,756,131
Indiana		17		40,018,381		40,210,320		2,365,313
Kansas		3		11,748,679		11,821,055		3,940,352
Other		5		11,570,998		11,735,678		2,347,136
Total revenue bonds		92	$	212,705,308	$	214,441,841	$	2,330,890