CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 1,593	$ 5,974	$ 4,163	$ 1,910	$ 1,828	$ 3,734	$ 3,470	$ 2,268	$ 13,640	$ 11,300	$ 9,798
Other Comprehensive Income, net of tax
Qualified Cash Flow Hedging Instrument Expense, net of tax benefit of $1 for three months ended September 30, 2012 and 2011 and $1 for nine months ended September 30, 2012 and 2011									3	3	3
Reclassification to Pension and Post-Retirement Benefits Other Than Pension, net of tax benfit of $15 and $3 for the three months ended September 30, 2012 and 2011 and $46 and $8 for the nine months ended September 30, 2012 and 2011									(566)	(361)	16
Unrealized gain (loss) on investments, net of tax (expense) benefit of $(20) and $49 for the three months ended September 30, 2012 and 2011 and $(41) and $50 for the nine months ended September 30, 2012 and 2011									60	(31)	47
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(503)	(389)	66
Comprehensive Income									$ 13,099	$ 10,873	$ 9,826