Employee Benefit Plans (Pension And Other Postretirement Benefit Costs) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pension Plans, Defined Benefit [Member]
Service cost	$ 3,926	$ 4,062	$ 8,245	$ 7,935
Interest cost	3,996	3,790	8,127	7,911
Expected return on plan assets	(5,438)	(5,530)	(10,906)	(9,696)
Amortization of prior service cost (credit)	(142)	43	(95)	86
Amortization of other actuarial (gains) losses	2,235	1,161	4,374	3,566
Net benefit cost (credit)	4,577	3,526	9,745	9,802
Other Postretirement Benefit Plans, Defined Benefit [Member]
Service cost	518	308	923	754
Interest cost	529	394	1,027	1,042
Amortization of prior service cost (credit)	(546)	(679)	(1,137)	(1,182)
Amortization of other actuarial (gains) losses	(952)	(989)	(1,550)	(1,459)
Net benefit cost (credit)	$ (451)	$ (966)	$ (737)	$ (845)