Note 23 - Parent Company Condensed Financial Information - Condensed Statements of Cash Flows (Details) - USD ($)	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net Income	$ 2,499,000	$ 2,527,000	$ 2,104,000	$ 2,136,000	$ 1,590,000	$ 2,112,000	$ 2,194,000	$ 1,556,000	$ 1,744,000	$ 1,761,000	$ 1,787,000	$ 1,585,000	$ 9,266,000	$ 7,452,000	$ 6,877,000
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Stock compensation expense													192,000	88,000	82,000
Unrealized loss on equity securities													207,000
Net change in other assets and liabilities													13,348,000	13,419,000	8,240,000
Investing Activities:
Proceeds from sale of cost method equity investment															856,000
Purchase of equity investment													1,922,000
Financing Activities:
Purchase of treasury stock													(34,000)	(18,000)	(34,000)
Dividends paid													(3,101,000)	(2,883,000)	(2,817,000)
Parent Company [Member]
Operating Activities:
Net Income													9,253,000	7,439,000	6,864,000
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Equity in undistributed net income of subsidiaries													(3,524,000)	(3,496,000)	(4,538,000)
Stock compensation expense													192,000	88,000	82,000
Gain on sale of cost method equity investment															(145,000)
Unrealized loss on equity securities													207,000
Net change in other assets and liabilities													(89,000)	(20,000)	(15,000)
Net cash provided by operating activities													6,039,000	4,011,000	2,248,000
Investing Activities:
Proceeds from sale of cost method equity investment															856,000
Purchase of equity investment													(1,922,000)
Net cash provided by (used in) investing activities													(1,922,000)		856,000
Financing Activities:
Purchase of treasury stock													(34,000)	(18,000)	(34,000)
Dividends paid													(3,088,000)	(2,870,000)	(2,804,000)
Net cash used in financing activities													(3,122,000)	(2,888,000)	(2,838,000)
Net increase in cash and cash equivalents													995,000	1,123,000	266,000
Cash and cash equivalents at beginning of year				$ 1,850,000				$ 727,000				$ 461,000	1,850,000	727,000	461,000
Cash and cash equivalents at end of year	$ 2,845,000				$ 1,850,000				$ 727,000				$ 2,845,000	$ 1,850,000	$ 727,000