Legal Proceedings And Contingencies (Narrative) (Details)	9 Months Ended					9 Months Ended	0 Months Ended	9 Months Ended								9 Months Ended			9 Months Ended	12 Months Ended
	Sep. 25, 2011	Sep. 25, 2011 Currency, British Pound Sterling [Member] Soothsayer [Member] GBP (£)	Jun. 24, 2009 Currency, British Pound Sterling [Member] Soothsayer [Member] GBP (£)	Sep. 25, 2011 Other Assets [Member] Environmental Matters [Member] Government [Member] USD ($)	Dec. 31, 2010 Other Assets [Member] Environmental Matters [Member] Government [Member] USD ($)	Sep. 25, 2011 Soothsayer [Member] USD ($)	Nov. 30, 2007 Department Of Justice [Member] USD ($)	Sep. 25, 2011 N.Y. Metropolitan Transportation Authority [Member] USD ($)	Apr. 24, 2009 N.Y. Metropolitan Transportation Authority [Member] USD ($)	Sep. 25, 2011 Environmental Matters [Member] USD ($)	Dec. 31, 2010 Environmental Matters [Member] USD ($)	Sep. 25, 2011 Environmental Matters [Member] Government [Member] USD ($)	Dec. 31, 2010 Environmental Matters [Member] Government [Member] USD ($)	Sep. 25, 2011 Standby Letters Of Credit [Member] USD ($)	Dec. 31, 2010 Standby Letters Of Credit [Member] USD ($)	Sep. 25, 2011 United Launch Alliance [Member] USD ($)	Sep. 25, 2011 Other Liabilities [Member] USD ($)	Dec. 31, 2010 Other Liabilities [Member] USD ($)	Sep. 25, 2011 Third Party Guarantees [Member] USD ($)	Dec. 31, 2010 Third Party Guarantees [Member] USD ($)
Contract value			£ 144,000,000			$ 222,000,000			$ 323,000,000
Contract payments received to date		39,000,000				60,000,000		241,000,000
Liquidated damages, demanded on amount paid under contract		2,000,000				3,000,000	80,000,000
Liabilities recorded relative to environmental matters										948,000,000	935,000,000
Liabilities recorded relative to environmental matters recorded in other liabilities																	836,000,000	807,000,000
Environmental costs eligible for future recovery												821,000,000	810,000,000
Environmental costs eligible for future recovery recorded in other assets				723,000,000	699,000,000
Time period environmental costs and recovery of environmental costs are projected over, number of years	20 years
Percentage of expenditures for certain remediation activities	50.00%
Outstanding letters of credit, surety bonds and third-party guarantees														4,000,000,000	4,200,000,000
Third-party guarantees outstanding																			1,000,000,000	1,000,000,000
Percentage of total guarantees that relate to guarantees of contractual performance of joint ventures																			90.00%	85.00%
Ownership interest in affiliated entity																50.00%
Dividend distributions received																327,000,000
Revolving line of credit																$ 400,000,000