Employee Benefit Plans (Components Of Net Periodic Benefit Expense (Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	$ 17,589	$ 17,502
Expected return on plan assets	(22,657)	(21,111)
Amortization of actuarial loss	4,650	4,827
Amortization of prior-service costs	418	3
Net periodic benefit expense	0	1,221
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	804	856
Expected return on plan assets	0	0
Amortization of actuarial loss	279	281
Amortization of prior-service costs	1	0
Net periodic benefit expense	1,084	1,137
Postretirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	429	423
Interest cost on benefit obligation	891	1,021
Amortization of prior service credit	(263)	(302)
Net periodic benefit expense	$ 1,057	$ 1,142