Pension and Postretirement Benefits other than Pensions Postretirement Expected Benefits Payments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year	$ 11,701
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	12,219
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	13,172
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	13,817
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	14,316
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	81,064
Postretirement Benefit Costs [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year	3,190
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	3,232
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	3,235
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	3,220
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	3,072
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 12,157