Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	Total	Common stock	Paid-in capital	Retained earnings	Accumulated other comprehensive loss
Beginning of Year at Dec. 31, 2011		$ 254	$ 3,873	$ 9,699	$ (3,490)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		(9)	(548)
Stock awards and options		3	118
Shipbuilding spin-off adjustment			0
Net earnings	986			986
Dividends declared				(266)
Other comprehensive income, net of tax	95				95
Cash dividends declared per share (in dollars per share)	$ 1.05
End of Period at Jun. 30, 2012	10,715	248	3,443	10,419	(3,395)
Beginning of Year at Dec. 31, 2012	9,514	239	2,924	11,138	(4,787)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		(13)	(907)
Stock awards and options		5	112
Shipbuilding spin-off adjustment			(5)
Net earnings	977			977
Dividends declared				(277)
Other comprehensive income, net of tax	152				152
Cash dividends declared per share (in dollars per share)	$ 1.16
End of Period at Jun. 30, 2013	$ 9,558	$ 231	$ 2,124	$ 11,838	$ (4,635)