CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net Income	$ 4,310	$ 4,163	$ 6,923	$ 6,073
Other Comprehensive Income, net of tax
Qualified Cash Flow Hedging Instrument Expense, net of tax expense of $0 and $0 for three months ended June 30, 2013 and 2012, respectively, and $0 and $0 for six months ended June 30, 2013 and 2012, respectively	1	1	1	1
Reclassification to Pension and Post-Retirement Benefits Other Than Pension, net of tax (expense) benefit of $(28) and $19 for the three months ended June 30, 2013 and 2012 and $(45) and $31 for the six months ended June 30, 2013 and 2012, respectively	92	(29)	67	(35)
Unrealized gain (loss) on investments, net of tax (expense) benefit of $(3) and $19 for the three months ended June 30, 2013 and 2012, repectively, and $(35) and $(21) for the six months ended June 30, 2013 and 2012, repectively	5	(30)	53	31
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	98	(58)	121	(3)
Comprehensive Income	$ 4,408	$ 4,105	$ 7,044	$ 6,070