Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Amounts Recognized in Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Net loss	$ 261,359	$ 256,536
Prior service cost (credit)	3,670	3,929
Net amount recognized	265,029	260,465
Other Postretirement Benefit Plans, Defined Benefit [Member]
Net loss	37,788	45,793
Prior service cost (credit)	(66,983)	(70,384)
Net amount recognized	$ (29,195)	$ (24,591)