Business Dispositions (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total debt	$ 3,940,000,000	$ 4,714,000,000
Aggregate principal amount	2,000,000,000
Term loan	3,929,000,000
Advisory Services Division
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposition			1,650,000,000
Gain from discontinued operations, net of tax			15,000,000
Sales and service revenues			1,500,000,000
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
Total debt	1,200,000,000
Aggregate principal amount	650,000,000
Term loan	575,000,000
Debt proceeds used for cash contribution	1,429,000,000
Non-deductible transaction costs incurred from spin-off Shipbuilding business	28,000,000	28,000,000	4,000,000
Shipbuilding spinoff total transaction costs	60,000,000
Gain from discontinued operations, net of tax	1,000,000	15,000,000	18,000,000
Sales and service revenues	1,646,000,000	6,711,000,000	7,740,000,000
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	$ 568,000,000