Note 9 - Short-term Borrowings (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Short-term Debt [Table Text Block]

	2016		2015
Overnight repurchase agreements with customers	$	8,131,387	$	73,872,716
Federal funds purchased		31,840,000		70,790,000
	$	39,971,387	$	144,662,716

Schedule of Repurchase Agreements [Table Text Block]

	2016			2015
Average daily balance during the period	$	30,082,866		$	121,186,231
Average daily interest rate during the period		0.07	%		0.11	%
Maximum month-end balance during the period	$	59,833,229		$	159,407,193
Weighted average rate as of end of period		0.02	%		0.11	%

	2016			2015
Average daily balance during the period	$	19,105,595		$	32,826,489
Average daily interest rate during the period		0.56	%		0.41	%
Maximum month-end balance during the period	$	51,750,000		$	126,220,000
Weighted average rate as of end of period		0.70	%		0.57	%

Securities Sold under Agreements to Repurchase [Member]

Notes Tables

Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets [Table Text Block]

	2016		2015
U.S. govt. sponsored agency securities	$	630,077	$	29,499,803
Residential mortgage-backed and related securities		19,090,261		65,888,911
Total securities pledged to overnight customer repurchase agreements	$	19,720,338	$	95,388,714
Less: overcollateralized position		11,588,951		21,515,998
	$	8,131,387	$	73,872,716