CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2017	$ 155,120	$ 74,055	$ 229,175
Balance, shares at Dec. 31, 2017	16,352
Net Income		32,452	32,452
Dividend Reinvestment & Common Stock Purchase Plan	$ 1,150		1,150
Dividend Reinvestment & Common Stock Purchase Plan, shares	27,000
Restricted Stock Award, Net - Employees	$ 975		975
Restricted Stock Award, Net - Employees, shares	22,000
Stock Award - Board Of Directors	$ 147		147
Stock Award - Board Of Directors, shares	4,000
Shares Forefeited	$ (38)		(38)
Shares Forfeited, shares	(2,000)
Cash Dividends on Common Stock		(14,930)	(14,930)
Cash Dividends on Preferred Stock		(144)	(144)
Balance at Dec. 31, 2018	$ 157,354	91,433	248,787
Balance, shares at Dec. 31, 2018	16,403
Net Income		33,888	33,888
Dividend Reinvestment & Common Stock Purchase Plan	$ 12,738		12,738
Dividend Reinvestment & Common Stock Purchase Plan, shares	226,000
Restricted Stock Award, Net - Employees	$ 907		907
Restricted Stock Award, Net - Employees, shares	18,000
Stock Award - Board Of Directors	$ 196		196
Stock Award - Board Of Directors, shares	4,000
Shares Forefeited	$ (466)		(466)
Shares Forfeited, shares	(18,000)
Conversion of Convertible Preferred Stock	$ 350		350
Conversion of Convertible Preferred Stock, shares	41,000
Issuance of Common Stock	$ 44,046		44,046
Issuance of Common Stock, shares	760,000
Cash Dividends on Common Stock		(16,165)	(16,165)
Cash Dividends on Preferred Stock		(132)	(132)
Common Stock Expenses		(357)	(357)
Balance at Dec. 31, 2019	$ 215,125	108,667	323,792
Balance, shares at Dec. 31, 2019	17,434,000
Net Income		38,425	38,425
Dividend Reinvestment & Common Stock Purchase Plan	$ 1,230		1,230
Dividend Reinvestment & Common Stock Purchase Plan, shares	19,000
Restricted Stock Award, Net - Employees	$ 851		851
Restricted Stock Award, Net - Employees, shares	16,000
Stock Award - Board Of Directors	$ 245		245
Stock Award - Board Of Directors, shares	4,000
Cash Dividends on Common Stock		(18,178)	(18,178)
Cash Dividends on Preferred Stock		(120)	(120)
Common Stock Expenses		(37)	(37)
Balance at Dec. 31, 2020	$ 217,451	$ 128,757	$ 346,208
Balance, shares at Dec. 31, 2020	17,473,000