Employee Benefit Plans (Components Of Net Periodic Benefit Expense (Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	$ 17,582	$ 17,685	$ 35,084	$ 35,655
Expected return on plan assets	(21,095)	(21,426)	(42,206)	(42,968)
Amortization of net loss	4,893	2,534	9,723	5,273
Net periodic benefit expense (income)	1,380	(1,207)	2,601	(2,040)
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	863	957	1,719	1,894
Amortization of net loss	242	182	523	339
Net periodic benefit expense (income)	1,105	1,139	2,242	2,233
Postretirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	417	316	840	721
Interest cost on benefit obligation	1,138	1,125	2,159	2,246
Amortization of prior service credit	(301)	(303)	(603)	(606)
Net periodic benefit expense (income)	$ 1,254	$ 1,138	$ 2,396	$ 2,361