Summary Of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 04, 2015	Sep. 28, 2014	Oct. 04, 2015	Sep. 28, 2014
Accounting Policies [Abstract]
Length of fiscal quarters, weeks			91 days
Net increase in operating earnings from the quarterly impact of revisions in contract	$ 44	$ 13	$ 152	$ 103
Net increase in operating earnings per share from the quarterly impact of revisions in contract	$ 0.09	$ 0.02	$ 0.30	$ 0.20