Pension Plans and Other Postretirement Employee Benefits (Components Of Net Periodic Cost (Benefit)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,413	$ 1,282
Interest cost	4,454	4,981
Expected return on plan assets	(6,524)	(7,173)
Amortization of prior service cost (credit)	195	193
Amortization of actuarial loss	4,944	3,703
Net periodic cost (benefit)	4,482	2,986
Other Postretirement Employee Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	23	123
Interest cost	458	751
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	(2,427)	(2,279)
Amortization of actuarial loss	815	982
Net periodic cost (benefit)	$ (1,131)	$ (423)