Employee Benefit Plans And Other Postretirement Benefits (Schedule Of Obligation And Funded Status) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension And SERPA Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation, beginning of period	$ 1,390,374	$ 1,284,722
Service cost	37,341	42,889	47,308
Interest cost	80,805	77,996	74,578
Plan amendments		1,855
Actuarial losses (gains)	127,259	46,035
Plan participant contributions	3,441	3,840
Benefits paid, net of Medicare Part D subsidy	(68,525)	(81,188)
Net curtailments and settlements	235	14,225
Benefit obligation, end of period	1,570,930	1,390,374	1,284,722
Balance, beginning of period	1,105,487	1,026,124
Actual return on plan assets	8,129	136,711
Company contributions	205,383	20,000
Plan participant contributions	3,441	3,840
Benefits paid	(68,524)	(81,188)
Balance, end of period	1,253,916	1,105,487	1,026,124
Funded status of the plans, December 31	(317,014)	(284,887)
Accrued benefit liability (other current liabilities)	(14,531)	(2,802)
Accrued benefit liability (other long-term liabilities)	(302,483)	(282,085)
Net amount recognized	(317,014)	(284,887)
Postretirement Healthcare Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation, beginning of period	378,341	377,283
Service cost	7,630	9,957	11,390
Interest cost	19,644	20,774	22,449
Plan amendments		(22,282)
Actuarial losses (gains)	(1,364)	(231)
Plan participant contributions	1,527	1,431
Early Retirement Reinsurance Program Proceeds	2,249
Benefits paid, net of Medicare Part D subsidy	(27,402)	(23,729)
Net curtailments and settlements		15,138
Benefit obligation, end of period	380,625	378,341	377,283
Balance, beginning of period	121,064	109,143
Actual return on plan assets	820	15,151
Company contributions	14,111	19,957
Plan participant contributions	1,527	1,431
Benefits paid	(28,362)	(24,618)
Balance, end of period	109,160	121,064	109,143
Funded status of the plans, December 31	(271,465)	(257,277)
Accrued benefit liability (other current liabilities)	(2,883)	(2,515)
Accrued benefit liability (other long-term liabilities)	(268,582)	(254,762)
Net amount recognized	$ (271,465)	$ (257,277)