Contracts in Process - General and Administrative, Independent Research and Development and Bids and Proposal Costs (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2015	Jun. 27, 2014	Jun. 26, 2015	Jun. 27, 2014
Inventory Disclosure [Abstract]
Amounts included in inventoried contract costs at beginning of the period	$ 149	$ 141	$ 138	$ 138
Contract costs incurred:
IRAD and B&P	75	72	140	143
Other G&A	217	217	421	415
Total	292	289	561	558
Amounts charged to cost of sales	(292)	(279)	(550)	(545)
Amounts included in inventoried contract costs at end of the period	$ 149	$ 151	$ 149	$ 151