Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Components Of Net Periodic Cost (Benefit)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5,238	$ 4,456	$ 4,633
Interest cost	19,986	21,325	21,649
Expected return on plan assets	(28,755)	(31,804)	(33,133)
Amortization of prior service cost (credit)	770	684	875
Amortization of actuarial loss	15,356	9,916	8,174
Net periodic cost (benefit)	12,595	4,577	2,198
Other Postretirement Employee Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	284	446	415
Interest cost	2,478	3,486	3,972
Expected return on plan assets	0	0	0
Amortization of prior service cost (credit)	(9,446)	(8,536)	(8,891)
Amortization of actuarial loss	3,127	3,967	4,631
Net periodic cost (benefit)	$ (3,557)	$ (637)	$ 127