STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 7,732	$ 8,298	$ 8,401
Designated interest rate swaps:
Changes in fair value	(62)	0	0
Income tax benefit	25	0	0
Unrealized holding loss on designated interest rate swaps	(37)	0	0
Amounts Included In Net Periodic Benefit Cost [Abstract]
Amortization of net actuarial loss (gain)	1,255	1,544	(1,205)
Amortization of prior service (credit) cost	(944)	7,230	161
Amortization of transition obligation	0	60	60
Adjustment to post-retirement benefit plan	0	(1,034)	0
Income tax (expense) benefit	(124)	(3,106)	392
Change in post-retirement benefit plan	187	4,694	(592)
Other comprehensive income (loss)	150	4,694	(592)
Comprehensive income	$ 7,882	$ 12,992	$ 7,809