Statements of Common Stockholders' Equity (Unaudited) (USD $) In Thousands, except Share data	Common Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2012	$ 79,299	$ 20,526	$ 99,825
Balance (in shares) at Dec. 31, 2012	12,918,633
Net income	0	2,139	2,139
Dividends	0	(1,790)	(1,790)
Retirement of common stock	(197)	0	(197)
Retirement of common stock (in shares)	(10,639)		(10,639)
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans	776	0	776
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans (in shares)	42,761
Balance at Mar. 31, 2013	79,878	20,875	100,753
Balance (in shares) at Mar. 31, 2013	12,950,755
Balance at Dec. 31, 2013	80,545	22,966	103,511
Balance (in shares) at Dec. 31, 2013	12,979,281		12,979,281
Net income	0	2,111	2,111
Dividends	0	(1,860)	(1,860)
Retirement of common stock	(572)	0	(572)
Retirement of common stock (in shares)	(27,980)		(27,980)
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans	782	0	782
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans (in shares)	38,890
Balance at Mar. 31, 2014	$ 80,755	$ 23,217	$ 103,972
Balance (in shares) at Mar. 31, 2014	12,990,191		12,990,191