Pension And Other Post-Retirement Benefits (Schedule Of Components Of Net Periodic Benefit Cost For Pension And Other Post-Retirement Benefit Programs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (1,028)	$ (919)	$ (2,743)	$ (2,521)
Interest cost	(3,236)	(3,202)	(9,813)	(9,768)
Expected return on plan assets	4,709	5,123	14,331	15,336
Amortization of prior service costs, gains or losses and net transition asset	(2,529)	(1,612)	(7,782)	(4,769)
Curtailment charge	(99)		(99)
Net periodic benefit cost	(2,183)	(610)	(6,106)	(1,722)
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	(17)	(15)	(43)	(41)
Interest cost	(88)	(105)	(289)	(296)
Amortization of prior service costs, gains or losses and net transition asset	74	65	180	198
Net periodic benefit cost	$ (31)	$ (55)	$ (152)	$ (139)