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, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	$ 17,422	$ 17,582	$ 35,011	$ 35,084
Expected return on plan assets	(23,005)	(21,095)	(45,662)	(42,206)
Amortization of actuarial loss	4,486	4,889	9,136	9,716
Amortization of prior-service costs	417	4	835	7
Net periodic benefit expense (income)	(680)	1,380	(680)	2,601
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligation	803	863	1,607	1,719
Amortization of actuarial loss	280	242	559	523
Amortization of prior-service costs	2	0	3	0
Net periodic benefit expense (income)	1,085	1,105	2,169	2,242
Postretirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	313	417	742	840
Interest cost on benefit obligation	848	1,138	1,739	2,159
Amortization of prior service credit	(263)	(301)	(526)	(603)
Net periodic benefit expense (income)	$ 898	$ 1,254	$ 1,955	$ 2,396