Employee Benefits (Components Of Net Periodic Benefit Cost And Changes In Plan Assets And Benefit Obligations Recognized In OCI) (Details) (Postretirement Benefit Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 1,178	$ 1,378	$ 1,644
Interest cost on projected benefit obligation	5,861	6,468	6,166
Net amortization and deferrals	(2,552)	(2,232)	(2,012)
Net periodic benefit cost	4,487	5,614	5,798
Net actuarial loss (gain)	16,909	(5,426)
Recognized actuarial loss	(2,167)	(2,487)
Recognized prior service credit	4,719	4,719
Total recognized in OCI (before tax effects)	$ 19,461	$ (3,194)