Employee Benefit Plans (Components Of Net Periodic Benefit Expense (Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	$ 17,502	$ 17,970
Expected return on plan assets	(21,111)	(21,542)
Amortization of net loss	4,830	2,739
Net periodic benefit expense (income)	1,221	(833)
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	856	937
Amortization of net loss	281	157
Net periodic benefit expense (income)	1,137	1,094
Postretirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	1,021	1,121
Service cost	423	405
Amortization of prior service credit	(302)	(303)
Net periodic benefit expense (income)	$ 1,142	$ 1,223