Pension Plans And Other Postretirement Benefit Plans (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Contributions to pension plan	$ 26,000,000	$ 21,000,000	$ 48,000,000
Percentage point increases in accumulated postretirement benefit obligation	14,800,000
Percentage point increase in Service and interest cost	800,000
Percentage point decrease in accumulated postretirement benefit obligation	12,300,000
Percentage point decrease in service and interest cost	700,000
Amortization of transition obligation over a period of twenty years beginning in 1993	34,500,000
Amortization of transition obligation period	20
Target asset allocation of equity securities	51.00%	51.00%
Target asset allocation of debt securities	31.00%	31.00%
Executive deferral plan description	This plan allows executive officers and other key employees the opportunity to defer until the earlier of their retirement, termination, disability or death, up to 75 percent of their base salary and/or up to 100 percent of their incentive payments.
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to pension plan	26,000,000	21,000,000
Expected contributions to pension plan	44,000,000
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions to pension plan	5,300,000
Amortization of transition obligation over a period of twenty years beginning in 1993	$ 505,000	$ 505,000	$ 505,000
Target asset allocation of equity securities	62.00%	62.00%
Target asset allocation of debt securities	38.00%	38.00%