Employee Retirement And Postretirement Benefits (Schedule Of Net Benefit Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,126	$ 710
Interest cost	3,631	3,803
Expected return on plan assets	(4,402)	(4,241)
Unrecognized transition obligation	28	28
Prior service cost/(credit)	194	191
Unrecognized net loss	2,918	2,265
Net periodic benefit cost	3,495	2,756
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	147	7
Interest cost	337	190
Prior service cost/(credit)	6	(16)
Unrecognized net loss	32	124
Net periodic benefit cost	$ 522	$ 305