Pension and Postretirement Benefits Other than Pensions Postretirement Benefits (Details) (Defined Benefit Postretirement Health Coverage [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 47	$ 48	$ 141	$ 144
Interest cost	316	665	950	1,994
Amortization of Prior Service Cost	382	32	1,147	96
Amortization of net loss	452	464	1,355	1,391
Postretirement Benefit Expense	$ 433	$ 1,145	$ 1,299	$ 3,433