Business Dispositions (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Discontinued Operations Income Statement Disclosures (Table Amounts)
Gain on divestitures	$ 0	$ 0	$ 10
Earnings (loss) from discontinued operations, net of tax	0	32	149
Shipbuilding Segment
Discontinued Operations Income Statement Disclosures (Table Amounts)
Sales and service revenues		1,646	6,711
Earnings from discontinued operations		59	229
Income tax expense		(28)	(95)
Earnings, net of tax		31	134
Gain on divestitures		1	15
Earnings (loss) from discontinued operations, net of tax		32
Discontinued Operations, Gain (Loss) on Disposal of Discontinued Operation, Tax		$ 1	$ 5