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
	Mar. 30, 2013	Mar. 31, 2012
Contracts accounted for under percentage of completion method
Change in accounting estimate
Income from continuing operations before income taxes	$ 7	$ 4
Change in Accounting Estimate Financial Effect Increase in Income from Continuing Operations after taxes	5	2
Income from continuing operations per diluted share	$ 0.02	$ 0.01
Basis of Presentation
Gross favorable program profit adjustments	9	17
Gross unfavorable program profit adjustments	$ 2	$ 13