Pension Plans And Other Postretirement Benefit Plans (Components Of Net Periodic Benefit Cost) (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]
Transition obligation recognition	$ 34,500
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	12,936	11,609	10,496
Interest cost	24,134	23,231	21,770
Expected return on plan assets	(23,115)	(21,381)	(17,612)
Amortization of prior service cost	475	650	654
Net loss recognition	9,493	7,189	10,539
Net periodic benefit cost	23,923	21,298	25,847
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,805	684	803
Interest cost	4,126	2,624	2,364
Expected return on plan assets	(1,601)	(1,581)	(1,364)
Transition obligation recognition	505	505	505
Amortization of prior service cost	(149)	(149)	(149)
Net loss recognition	3,458	1,379	1,279
Net periodic benefit cost	$ 8,144	$ 3,462	$ 3,438