STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net Income	$ 8,298	$ 8,401	$ 12,592
Amount Included In Net Periodic Benefit Cost [Abstract]
Net actuarial gain (loss)	1,544	(1,205)	(448)
Prior service credit	7,230	161	(55)
Transition asset	60	60	60
Adjustment to post-retirement benefit plan	(1,034)	0	0
Income tax (benefit) expense	(3,106)	392	176
Change in post-retirement benefit plan	4,694	(592)	(267)
Comprehensive Income	$ 12,992	$ 7,809	$ 12,325