Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 25, 2016	Mar. 27, 2015
Inventory Disclosure [Abstract]
Amounts included in inventoried contract costs at beginning of the period	$ 137	$ 117
Contract costs incurred:
IRAD and B&P	65	63
Other G&A	194	195
Total	259	258
Amounts charged to cost of sales	(239)	(247)
Amounts included in inventoried contract costs at end of the period	$ 157	$ 128