Employee Benefit Plans (Pension And Other Postretirement Benefit Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7,700	$ 7,596
Interest cost	3,926	3,980
Expected return on plan assets	(5,806)	(5,538)
Amortization of prior service cost (credit)	(158)	(36)
Amortization of other actuarial (gains) losses	4,551	3,571
Total net benefit	10,213	9,573
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	556	549
Interest cost	431	491
Amortization of prior service cost (credit)	(2,750)	(2,995)
Amortization of other actuarial (gains) losses	77	(90)
Total net benefit	$ (1,686)	$ (2,045)