Basis of Presentation (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Basis of Presentation
Gross favorable program profit adjustments	$ 12	$ 28	$ 52	$ 70
Gross unfavorable program profit adjustments	18	5	42	23
Contracts accounted for under percentage-of-completion method
Use of Estimates
Income from continuing operations before income taxes	(6)	23	10	47
Income from continuing operations after tax	$ (4)	$ 15	$ 6	$ 30
Income from continuing operations per diluted share (in dollars per share)	$ (0.02)	$ 0.04	$ 0.02	$ 0.09