Pensions And Other Employee Benefits Plans (Reconciliation Of Changes In Plans' Benefit Obligations And Fair Value Of Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	$ 20,207	$ 299,292
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	12,113	12,265	10,677
Interest cost	21,675	25,504	24,673
Employer contributions	34,700
Funded status at end of period	(42,281)	(249,721)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	447	522	672
Interest cost	2,597	3,198	3,411
Employer contributions	1,000
Funded status at end of period	(1,051)	(66,022)
Reconciliation Of Benefit Obligation [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Obligation at beginning of period	549,013	476,031
Service cost	12,113	12,265
Interest cost	21,675	25,504
Participant contributions	1,252	1,469
Plan amendment	(1,497)
Actuarial loss (gain)	7,690	57,824
Benefit payments	(21,200)	(24,080)
Transfer due to sale	(506,558)
Obligation at December 31	62,488	549,013
Reconciliation Of Benefit Obligation [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Obligation at beginning of period	66,049	62,840
Service cost	447	522
Interest cost	2,597	3,198
Participant contributions	1,646	2,014
Actuarial loss (gain)	(967)	1,755
Benefit payments	(2,662)	(4,280)
Transfer due to sale	(66,059)
Obligation at December 31	1,051	66,049
Reconciliation Of Fair Value Of Plan Assets [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Participant contributions	1,252	1,469
Benefit payments	(19,985)	(22,870)
Transfer due to sale	(323,919)
Fair value of plan assets at beginning of period	299,292	289,036
Actual return on plan assets	28,821	(2,453)
Employer contributions	34,746	34,110
Fair value of plan assets at December 31	20,207	299,292
Reconciliation Of Fair Value Of Plan Assets [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Participant contributions	1,646	2,014
Benefit payments	(2,662)	(4,280)
Fair value of plan assets at beginning of period	27	269
Actual return on plan assets	1	(2)
Employer contributions	988	2,026
Fair value of plan assets at December 31		$ 27