Employee Retirement Plans (Summary Of Changes In Fair Value Of The Defined Benefit Plans Level 3 Assets) (Details) (USD $) In Millions, unless otherwise specified									12 Months Ended								12 Months Ended						12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Level 3 [Member]	Dec. 31, 2011 Level 3 [Member]	Dec. 31, 2012 Private Equity [Member]		Dec. 31, 2011 Private Equity [Member]		Dec. 31, 2012 Private Equity [Member] Level 3 [Member]		Dec. 31, 2011 Private Equity [Member] Level 3 [Member]		Dec. 31, 2012 Real Estate [Member]		Dec. 31, 2011 Real Estate [Member]		Dec. 31, 2012 Real Estate [Member] Level 3 [Member]		Dec. 31, 2011 Real Estate [Member] Level 3 [Member]		Dec. 31, 2012 Insurance Contracts [Member]	Dec. 31, 2011 Insurance Contracts [Member]	Dec. 31, 2012 Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2010 Insurance Contracts [Member] Level 3 [Member]
Summary Of Changes In Fair Value Of The Defined Benefits Plans [Line Items]
Fair value of plan assets at beginning of year	$ 2,975	$ 2,770	$ 330	$ 337	$ 221	[1]	$ 241	[1]	$ 241	[1]	$ 234		$ 103	[2]	$ 91	[2]	$ 91	[2]	$ 74		$ 6	$ 5	$ 5	$ 5
Actual return on plan assets relating to assets still held at the reporting date									26		27						11		6
Transfers in and/or out of level 3									(46)		(20)						1		11				1
Fair value of plan assets at end of year	$ 2,975	$ 2,770	$ 330	$ 337	$ 221	[1]	$ 241	[1]	$ 221	[1]	$ 241	[1]	$ 103	[2]	$ 91	[2]	$ 103	[2]	$ 91	[2]	$ 6	$ 5	$ 6	$ 5

[1] This category includes venture capital, leverage buyouts and distressed debt limited partnerships invested primarily in U.S. companies. The inputs are valued by internally generated Discounted Cash Flow Analysis and comparable sale analysis

[2] This category includes industrial, office, apartments, hotels, infrastructure, and retail investments which are limited partnerships predominately in the U.S. The inputs are valued by internally generated Discounted Cash Flow Analysis; compare sale analysis and periodic external appraisals