Retirement And Other Postretirement Benefits (Components Of Net Other Postretirement Benefits) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	$ 37,691	$ 30,490
Interest cost on projected benefit obligation	65,232	59,248
Expected return on assets	(79,356)	(75,319)
Amortization of prior service cost (credit)	683	838
Amortization of loss	41,820	23,244
Net periodic benefit costs	66,070	38,501
Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	17,221	14,835
Interest cost on projected benefit obligation	20,640	18,631
Expected return on assets	(8,626)	(7,369)
Amortization of transition obligation	794	796
Amortization of prior service cost (credit)	(4,541)	(3,518)
Amortization of loss	9,113	5,298
Net periodic benefit costs	34,601	28,673
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit costs	$ 5,100	$ 4,900