Employee Benefit Plans (Summary Of Components Of Net Periodic Benefit Expense (Income)) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Qualified Pension Plans [Member]
Interest cost on benefit obligation	$ 17,685	$ 17,204	$ 35,655	$ 34,568
Expected return on plan assets	(21,426)	(18,138)	(42,968)	(37,519)
Amortization of net loss	2,534	2,307	5,273	4,535
Net periodic benefit expense	(1,207)	1,373	(2,040)	1,584
Non-Qualified Pension Plans [Member]
Interest cost on benefit obligation	957	966	1,894	1,940
Amortization of net loss	182	115	339	226
Net periodic benefit expense	1,139	1,081	2,233	2,166
Postretirement Medical Plan [Member]
Service cost	316	305	721	703
Interest cost on benefit obligation	1,125	1,195	2,246	2,416
Amortization of prior service credit	(303)	(300)	(606)	(601)
Net periodic benefit expense	$ 1,138	$ 1,200	$ 2,361	$ 2,518