Business Dispositions and Discontinued Operations (Details 1) (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings from discontinued operations, net of tax	$ 0	$ 34
Shipbuilding Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales		1,646
Earnings from discontinued operations		59
Income tax expense		(26)
Earnings, net of tax		33
Gain on divestiture, net of income tax expense of $1		1
Earnings from discontinued operations, net of tax		34
Gain on divestiture, tax		$ 1