Basis of Presentation (Details) (Contracts accounted for under percentage of completion method, USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Contracts accounted for under percentage of completion method
Change in accounting estimate
Income from continuing operations before income taxes	$ 4	$ (6)	$ 13	$ 10
Change in Accounting Estimate Financial Effect Increase in Income from Continuing Operations after taxes	2	(4)	8	6
Income from continuing operations per diluted share	$ 0.01	$ (0.02)	$ 0.03	$ 0.02
Basis of Presentation
Gross favorable program profit adjustments	12	12	30	52
Gross unfavorable program profit adjustments	$ 8	$ 18	$ 17	$ 42