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		(14)	(831)
Stock awards and options		6	249
Shipbuilding spin-off adjustment			5
Net earnings	1,445			1,445
Dividends declared				(405)
Other comprehensive income, net of tax	156				156
Cash dividends declared per share (in dollars per share)	$ 1.60
End of Period at Sep. 30, 2012	10,947	246	3,296	10,739	(3,334)
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		(21)	(1,652)
Stock awards and options		6	212
Shipbuilding spin-off adjustment			(5)
Net earnings	1,474			1,474
Dividends declared				(416)
Other comprehensive income, net of tax	244				244
Cash dividends declared per share (in dollars per share)	$ 1.77
End of Period at Sep. 30, 2013	$ 9,356	$ 224	$ 1,479	$ 12,196	$ (4,543)