Employee Benefits (Schedule Of Change In Benefit Obligation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation, beginning of year	$ 59,876	$ 54,033
Service cost	1,005	930	938
Interest cost	2,580	2,723	2,751
Actuarial loss (gain)	9,481	4,358
Benefits paid	(2,145)	(2,168)
Curtailment	(5,484)	0	0
Benefit obligation, end of year	65,313	59,876	54,033
Post-Retirement Healthcare Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation, beginning of year	20,212	20,047
Service cost	9	16	45
Interest cost	745	840	919
Actuarial loss (gain)	2,021	816
Benefits paid	(1,604)	(1,507)
Curtailment	0	0
Benefit obligation, end of year	$ 21,383	$ 20,212	$ 20,047