Employee Benefits (Schedule Of Net Benefit Costs And Amounts Recognized In Other Comprehensive Income) (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]
Service cost	$ 1,005	$ 930	$ 938
Interest cost	2,580	2,723	2,751
Expected return on plan assets	(2,490)	(2,279)	(1,935)
Net amortization	2,071	1,567	1,899
Net periodic benefit cost	3,166	2,941	3,653
Net loss (gain) emerging	7,765	5,804	(1,521)
Curtailment	(5,484)	0	0
Amortization of net loss	(1,774)	(1,271)	(1,602)
Amortization of transition obligations	0	0	0
Amortization of prior service cost	(297)	(296)	(297)
Total recognized in OCI	210	4,237	(3,420)
Total net periodic benefit cost and OCI	3,376	7,178	233
Post-Retirement Healthcare Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	16	45
Interest cost	745	840	919
Expected return on plan assets	0	0	0
Net amortization	269	418	377
Net periodic benefit cost	1,023	1,274	1,341
Net loss (gain) emerging	2,021	816	(656)
Curtailment	0	0
Amortization of net loss	(185)	(118)	(51)
Amortization of transition obligations	0	(114)	(114)
Amortization of prior service cost	(84)	(186)	(212)
Total recognized in OCI	1,752	398	(1,033)
Total net periodic benefit cost and OCI	$ 2,775	$ 1,672	$ 308