Pension and Other Postretirement Benefit Plans Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	$ 200,000	$ 159,000	$ 159,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax		(734,000)	(853,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Transition Assets (Obligations), before Tax		259,000	324,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax		(1,264,000)	(5,678,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(1,739,000)	(6,207,000)
Defined Benefit Plan, Amortization of Net Transition Asset (Obligation)	$ 100,000