Pension And Postretirement Benefits (Schedule Of Components Of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,600	$ 2,973
Interest cost	5,941	5,862
Expected return on assets	(5,970)	(6,051)
Prior service cost (credit)	122	133
Actuarial loss (gain)	3,321	1,866
Settlement charge		14
Net periodic benefit cost (credit)	7,014	4,797
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	66	124
Interest cost	315	614
Prior service cost (credit)	(814)	(435)
Actuarial loss (gain)	(64)
Settlement charge
Net periodic benefit cost (credit)	$ (497)	$ 303