Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 26, 2014	Sep. 27, 2013
Inventory Disclosure [Abstract]
Amounts included in inventoried contract costs at beginning of the period:	$ 151	$ 115	$ 138	$ 110
IRAD and B&P costs	70	66	215	219
Other G&A costs	239	216	658	653
Total contract costs incurred	309	282	873	872
Amounts charged to cost of sales	(309)	(271)	(860)	(856)
Amounts included in inventoried contract costs at end of the period	$ 151	$ 126	$ 151	$ 126