Pension And Other Postretirement Benefit Plans (Components Of Net Periodic Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,495	$ 2,976
Interest cost	9,334	9,127
Expected return on plan assets	(12,830)	(11,807)
Amortization of prior service cost	100	102
Amortization of net loss (gain)	4,843	1,978
Settlements	(27)
Net periodic cost	4,915	2,376
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	29	115
Interest cost	127	603
Amortization of prior service cost	(59)	(102)
Amortization of net loss (gain)	(21)	(243)
Net periodic cost	$ 76	$ 373