Pensions And Other Employee Benefits (Reconciliation Of Changes In Plans' Benefit Obligations And Fair Value Of Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31,	$ 299,292	$ 289,036
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	12,265	10,677	9,436
Interest cost	25,504	24,673	24,447
Employer contributions	34,100
Funded status at end of period	(249,721)	(186,995)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	522	672	863
Interest cost	3,198	3,411	3,965
Employer contributions	2,000
Funded status at end of period	(66,022)	(62,571)
Reconciliation Of Benefit Obligation [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Obligation at beginning of period	476,031	420,076
Service cost	12,265	10,677
Interest cost	25,504	24,673
Participant contributions	1,469	1,507
Actuarial loss (gain)	57,824	41,826
Benefit payments	(24,080)	(22,728)
Obligation at December 31,	549,013	476,031
Reconciliation Of Benefit Obligation [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Obligation at beginning of period	62,840	67,392
Service cost	522	672
Interest cost	3,198	3,411
Participant contributions	2,014	1,968
Plan amendment		(1,386)
Actuarial loss (gain)	1,755	(5,085)
Benefit payments	(4,280)	(4,132)
Obligation at December 31,	66,049	62,840
Reconciliation Of Fair Value Of Plan Assets [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of period	289,036	256,166
Actual return on plan assets	(2,453)	28,133
Employer contributions	34,110	24,932
Participant contributions	1,469	1,507
Benefit payments	(22,870)	(21,702)
Fair value of plan assets at December 31,	299,292	289,036
Reconciliation Of Fair Value Of Plan Assets [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of period	269	507
Actual return on plan assets	(2)	2
Employer contributions	2,026	1,924
Participant contributions	2,014	1,968
Benefit payments	(4,280)	(4,132)
Fair value of plan assets at December 31,	$ 27	$ 269