Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Other Amounts Recognized in the Consolidated Statemetns of Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amortization of prior service (cost) credit	$ 5,230	$ 4,790	$ 4,695
Pension Plans, Defined Benefit [Member]
Net loss (gain)	20,180	57,220	(6,682)
Prior service cost (credit)	510	0	0
Amortization of prior service (cost) credit	(770)	(684)	(875)
Amortization of actuarial loss	(15,356)	(9,916)	(8,174)
Total recognized in other comprehensive loss (income)	4,564	46,620	(15,731)
Total recognized in net periodic cost (benefit) and other comprehensive loss (income)	17,159	51,197	(13,533)
Pre-tax net periodic benefit cost (benefit)	12,595	4,577	2,198
Other Postretirement Benefit Plans, Defined Benefit [Member]
Net loss (gain)	(4,878)	(913)	(6,477)
Prior service cost (credit)	(5,942)	(5,805)	715
Amortization of prior service (cost) credit	9,343	8,536	8,571
Amortization of actuarial loss	(3,127)	(3,967)	(4,631)
Total recognized in other comprehensive loss (income)	(4,604)	(2,149)	(1,822)
Total recognized in net periodic cost (benefit) and other comprehensive loss (income)	(8,161)	(2,786)	(1,695)
Pre-tax net periodic benefit cost (benefit)	$ (3,557)	$ (637)	$ 127