Pension Plans And Defined Contribution Plan (Schedule Of Reconciliation Of Changes In Projected Benefit Obligation) (Details) (Pension Plans [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 151,137	$ 136,159
Service cost-benefit earned during the period	769	867	1,568
Interest cost on projected benefit obligation	8,482	8,221	8,091
Union plan amendments	564
Actuarial loss	17,254	9,015
Benefits paid	(7,184)	(3,125)
Benefit obligation at end of year	$ 171,022	$ 151,137	$ 136,159