Pension And Other Postretirement Benefits (Schedule Of Fair Value Of Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 1,975		$ 1,907
Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	633		1,316
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,177		441
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	165		150		107
Significant Unobservable Inputs (Level 3) [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	27		30
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	9		3		12
Significant Unobservable Inputs (Level 3) [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	64		62		55
Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	65		55		40
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,694		1,632		1,500
Pension Benefits [Member] | Equity Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	411	[1]	573	[1]
Pension Benefits [Member] | Equity International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	196	[2]	270	[2]
Pension Benefits [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	939	[3]	604	[3]
Pension Benefits [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	64		62
Pension Benefits [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	65	[4]	55	[4]
Pension Benefits [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	19	[4]	68	[4]
Pension Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	376		1,064
Pension Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Equity Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	165	[1]	334	[1]
Pension Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Equity International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	192	[2]	265	[2]
Pension Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			397	[3]
Pension Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	19	[4]	68	[4]
Pension Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,153		418
Pension Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	221	[1]	212	[1]
Pension Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2	[2]	2	[2]
Pension Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	930	[3]	204	[3]
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	165		150
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	25	[1]	27	[1]
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2	[2]	3	[2]
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	9	[3]	3	[3]
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	64		62
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	65	[4]	55	[4]
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	281		275		242
Other Postretirement Benefits [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	174	[5]	168	[5]
Other Postretirement Benefits [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	101	[6]	96	[6]
Other Postretirement Benefits [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	6		11
Other Postretirement Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	257		252
Other Postretirement Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	150	[5]	145	[5]
Other Postretirement Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	101	[6]	96	[6]
Other Postretirement Benefits [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	6		11
Other Postretirement Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	24		23
Other Postretirement Benefits [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 24	[5]	$ 23	[5]

[1] Predominantly includes domestic common stock and commingled funds.

[2] Predominantly includes foreign common and preferred stock and warrants.

[3] Predominantly includes corporate bonds, government bonds, municipal/provincial bonds, collateralized mortgage obligations, asset backed securities and commingled funds.

[4] Predominantly includes cash investment in short term investment funds.

[5] Includes domestic and international commingled funds.

[6] Includes fixed income commingled funds.