Business Dispositions (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Shipbuilding Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pro rata shares	6
Total shares distributed	48,800,000
Debt proceeds used for cash contribution	$ 1,400,000,000
Non-deductible transaction costs incurred from spin-off Shipbuilding business	28,000,000	28,000,000
Sales and service revenues	1,646,000,000	6,711,000,000
National Security Technologies Deconsolidation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and service revenues		$ 579,000,000