Legal Proceedings, Commitments, and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended									12 Months Ended	72 Months Ended
	Dec. 31, 2012 Y	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Other Noncurrent Liabilities	Dec. 31, 2011 Other Noncurrent Liabilities	Dec. 31, 2012 Other Noncurrent Assets	Dec. 31, 2011 Other Noncurrent Assets	Dec. 31, 2012 N.Y. Metropolitan Transportation Authority	Apr. 24, 2009 N.Y. Metropolitan Transportation Authority	Dec. 31, 2012 United Launch Alliance Y	Dec. 31, 2012 United Launch Alliance	Dec. 31, 2011 United Launch Alliance
Site Contingency [Line Items]
Contract value									$ 323,000,000
Contract payments received to date								241,000,000
Liabilities recorded relative to environmental matters	950,000,000	932,000,000		844,000,000	814,000,000
Environmental costs eligible for future recovery	821,000,000	808,000,000				730,000,000	706,000,000
Time period environmental costs and recovery of environmental costs are projected over, years	20
Percentage of expenditures that are reimbursed for certain remediation activities	50.00%
Total rental expense under operating leases	302,000,000	347,000,000	399,000,000
Future minimum lease commitments, total	859,000,000
Future minimum lease commitments, due in 2013	229,000,000
Future minimum lease commitments, due in 2014	161,000,000
Future minimum lease commitments, due in 2015	118,000,000
Future minimum lease commitments, due in 2016	91,000,000
Future minimum lease commitments, due in 2017	60,000,000
Future minimum lease commitments, due in later years	200,000,000
Outstanding letters of credit, surety bonds, and third-party guarantees	2,200,000,000	3,900,000,000
Third-party guarantees outstanding	816,000,000	907,000,000
Percentage of total guarantees that relate to guarantees of contractual performance of joint ventures	85.00%	85.00%
Percentage of ownership interest in affiliated entity										50.00%	50.00%
Dividends that are subject to contingency											494,000,000
Revolving line of credit										560,000,000	560,000,000
Amount of net assets that exceeded book value of investment that is being recognized ratably over 10 years										395,000,000	395,000,000
Number of years the difference between book value and underlying equity in equity method investment is being recognized ratably										10
Total equity method investment	$ 749,000,000	$ 697,000,000								$ 572,000,000	$ 572,000,000	$ 574,000,000