Pension Plans and Other Postretirement Employee Benefits (Components Of Net Periodic Cost (Benefit)) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,114	$ 1,158	$ 3,342	$ 3,474
Interest cost	5,331	5,412	15,994	16,237
Expected return on plan assets	(7,951)	(8,283)	(23,853)	(24,850)
Amortization of prior service cost (credit)	171	203	513	609
Amortization of actuarial loss	2,479	2,043	7,437	6,130
Curtailment loss (gain)			0	64
Net periodic cost (benefit)	1,144	533	3,433	1,664
Other Postretirement Employee Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	112	104	335	312
Interest cost	871	993	2,614	2,979
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(2,134)	(2,143)	(6,402)	(6,429)
Amortization of actuarial loss	992	1,158	2,975	3,474
Curtailment loss (gain)			0	(320)
Net periodic cost (benefit)	$ (159)	$ 112	$ (478)	$ 16