Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 23, 2016	Sep. 25, 2015	Sep. 23, 2016	Sep. 25, 2015
Inventory Disclosure [Abstract]
Amounts included in inventoried contract costs at beginning of the period	$ 163	$ 126	$ 137	$ 117
Contract costs incurred:
IRAD and B&P	76	69	213	204
Other G&A	201	217	611	611
Total	277	286	824	815
Amounts charged to cost of sales	(270)	(267)	(791)	(787)
Amounts included in inventoried contract costs at end of the period	$ 170	$ 145	$ 170	$ 145