CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2013	$ 146,185	$ 42,560	$ 188,745
Balance, shares at Dec. 31, 2013	15,963,000
Net Income		18,445	18,445
Dividend Reinvestment & Common Stock Purchase Plan	$ 1,493		1,493
Dividend Reinvestment & Common Stock Purchase Plan, shares	71,000
Restricted Stock Award, Net - Employees	$ 434		434
Restricted Stock Award, Net - Employees, shares	33,000
Stock Award - Board Of Directors	$ 105		105
Stock Award - Board Of Directors, shares	5,000
Conversion of $7.00 Convertible Preferred Stock	$ 451		451
Conversion of $7.00 Convertible Preferred Stock, shares	52,000
Cash Dividends on Common Stock		(12,231)	(12,231)
Cash Dividends on Preferred Stock		(151)	(151)
Balance at Dec. 31, 2014	$ 148,668	48,623	197,291
Balance, shares at Dec. 31, 2014	16,124,000
Net Income		20,028	20,028
Dividend Reinvestment & Common Stock Purchase Plan	$ 1,462		1,462
Dividend Reinvestment & Common Stock Purchase Plan, shares	63,000
Restricted Stock Award, Net - Employees	$ 528		528
Restricted Stock Award, Net - Employees, shares	33,000
Stock Award - Board Of Directors	$ 105		105
Stock Award - Board Of Directors, shares	5,000
Cash Dividends on Common Stock		(12,554)	(12,554)
Cash Dividends on Preferred Stock		(144)	(144)
Common Stock Expenses		(22)	(22)
Balance at Dec. 31, 2015	$ 150,763	55,931	206,694
Balance, shares at Dec. 31, 2015	16,225,000
Net Income		22,742	22,742
Dividend Reinvestment & Common Stock Purchase Plan	$ 1,453		1,453
Dividend Reinvestment & Common Stock Purchase Plan, shares	43,000
Restricted Stock Award, Net - Employees	$ 682		682
Restricted Stock Award, Net - Employees, shares	24,000
Stock Award - Board Of Directors	$ 147		147
Stock Award - Board Of Directors, shares	4,000
Cash Dividends on Common Stock		(13,137)	(13,137)
Cash Dividends on Preferred Stock		(144)	(144)
Balance at Dec. 31, 2016	$ 153,045	$ 65,392	$ 218,437
Balance, shares at Dec. 31, 2016	16,296,000