Employee Benefit Plans (Summary Of Components Of Net Periodic Benefit Expense (Income)) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	$ 17,827	$ 17,284	$ 53,482	$ 51,852
Expected return on plan assets	(21,483)	(18,760)	(64,451)	(56,279)
Amortization of net loss	2,636	2,268	7,909	6,803
Net periodic benefit expense (income)	(1,020)	792	(3,060)	2,376
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	946	969	2,840	2,909
Amortization of net loss	170	113	509	339
Net periodic benefit expense (income)	1,116	1,082	3,349	3,248
Postretirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	360	351	1,081	1,054
Interest cost on benefit obligation	1,123	1,208	3,369	3,624
Amortization of prior service credit	(303)	(301)	(909)	(902)
Net periodic benefit expense (income)	$ 1,180	$ 1,258	$ 3,541	$ 3,776