Divestitures and Acquisitions - Statement of Operations Data Classified as Discontinued Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 25, 2016	Mar. 27, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations, net of income taxes	$ 63	$ 4
NSS [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	86	238
Cost of sales	(92)	$ (225)
Gain related to business divestiture	64
Operating income from discontinued operations	$ 58	$ 13
Interest expense allocated to discontinued operations		(5)
Income from discontinued operations before income taxes	$ 58	8
Income tax benefit (expense)	5	(4)
Income from discontinued operations, net of income taxes	$ 63	$ 4