Pension, Savings, And Other Employee Benefits (Schedule Of Components Of Net Periodic Benefit 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	$ 4,351	$ 4,301
Interest cost	8,295	8,147
Expected return on plan assets	(9,947)	(11,724)
Prior service cost/(credit)	100	104
Actuarial (gain)/loss	8,824	5,027
Net periodic benefit cost	11,623	5,855
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	124	144
Interest cost	556	552
Expected return on plan assets	(230)	(297)
Transition (asset)/obligation	184	246
Prior service cost/(credit)	(2)	(2)
Actuarial (gain)/loss	(153)	(260)
Net periodic benefit cost	$ 479	$ 383