CONDENSED 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	16,352,000
Net Income		13,169	13,169
Dividend Reinvestment & Common Stock Purchase Plan	$ 596		$ 596
Dividend Reinvestment & Common Stock Purchase Plan, shares	15,000		15,026
Restricted Stock Award, Net - Employees	$ 388		$ 388
Restricted Stock Award, Net - Employees, shares	23,000
Stock Award - Board Of Directors	$ 147		147
Stock Award - Board Of Directors, shares	4,000
Shares Forfeited
Shares Forfeited, shares	(2,000)
Cash Dividends on Common Stock		(7,325)	(7,325)
Cash Dividends on Common Stock, shares
Cash Dividends on Preferred Stock		(72)	(72)
Cash Dividends on Preferred Stock, shares
Balance at Jun. 30, 2018	$ 156,251	79,828	236,079
Balance, shares at Jun. 30, 2018	16,392,000
Balance at Mar. 31, 2018	$ 155,580	74,855	230,435
Balance, shares at Mar. 31, 2018	16,358,000
Net Income		8,675	8,675
Dividend Reinvestment & Common Stock Purchase Plan	$ 310		310
Dividend Reinvestment & Common Stock Purchase Plan, shares	7,000
Restricted Stock Award, Net - Employees	$ 214		214
Restricted Stock Award, Net - Employees, shares	23,000
Stock Award - Board Of Directors	$ 147		147
Stock Award - Board Of Directors, shares	4,000
Cash Dividends on Common Stock		(3,666)	(3,666)
Cash Dividends on Common Stock, shares
Cash Dividends on Preferred Stock		(36)	(36)
Cash Dividends on Preferred Stock, shares
Balance at Jun. 30, 2018	$ 156,251	79,828	236,079
Balance, shares at Jun. 30, 2018	16,392,000
Balance at Dec. 31, 2018	$ 157,354	91,433	248,787
Balance, shares at Dec. 31, 2018	16,403,000
Net Income		14,696	14,696
Dividend Reinvestment & Common Stock Purchase Plan	$ 7,081		$ 7,081
Dividend Reinvestment & Common Stock Purchase Plan, shares	130,000		129,675
Restricted Stock Award, Net - Employees	$ 507		$ 507
Restricted Stock Award, Net - Employees, shares	17,000
Stock Award - Board Of Directors	$ 196		196
Stock Award - Board Of Directors, shares	4,000
Cash Dividends on Common Stock		(7,906)	(7,906)
Cash Dividends on Common Stock, shares
Cash Dividends on Preferred Stock		(72)	(72)
Cash Dividends on Preferred Stock, shares
Common Stock Expenses		(5)	(5)
Common Stock Expenses, shares
Balance at Jun. 30, 2019	$ 165,138	98,146	263,284
Balance, shares at Jun. 30, 2019	16,554,000
Balance at Mar. 31, 2019	$ 160,142	94,000	254,142
Balance, shares at Mar. 31, 2019	16,451,000
Net Income		8,146	8,146
Dividend Reinvestment & Common Stock Purchase Plan	$ 4,522		4,522
Dividend Reinvestment & Common Stock Purchase Plan, shares	82,000
Restricted Stock Award, Net - Employees	$ 278		278
Restricted Stock Award, Net - Employees, shares	17,000
Stock Award - Board Of Directors	$ 196		196
Stock Award - Board Of Directors, shares	4,000
Cash Dividends on Common Stock		(3,964)	(3,964)
Cash Dividends on Common Stock, shares
Cash Dividends on Preferred Stock		(36)	(36)
Cash Dividends on Preferred Stock, shares
Balance at Jun. 30, 2019	$ 165,138	$ 98,146	$ 263,284
Balance, shares at Jun. 30, 2019	16,554,000