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		(4)	(256)
Stock awards and options		2	29
Shipbuilding spin-off adjustment			0
Net earnings	506			506
Dividends declared				(128)
Other comprehensive income, net of tax	56				56
Cash dividends declared per share	$ 0.50
End of Period at Mar. 31, 2012	10,541	252	3,646	10,077	(3,434)
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		(6)	(425)
Stock awards and options		2	(33)
Shipbuilding spin-off adjustment			(5)
Net earnings	489			489
Dividends declared				(131)
Other comprehensive income, net of tax	64				64
Cash dividends declared per share	$ 0.55
End of Period at Mar. 31, 2013	$ 9,469	$ 235	$ 2,461	$ 11,496	$ (4,723)