Accumulated Other Comprehensive Loss and Other Comprehensive Income (Loss) - Components of accumulated other comprehensive loss (Details) - USD ($) $ in Millions	6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015
Components of Accumulated other comprehensive loss
Beginning of the period	$ (1,398)	$ (1,506)
Other comprehensive income (loss) before reclassifications	23	2
Reclassified from Accumulated other comprehensive loss	42	55
Other comprehensive income (loss)	65	57
End of the period	(1,333)	(1,449)
Pension and Postretirement Benefits Adjustments
Components of Accumulated other comprehensive loss
Beginning of the period	(1,327)	(1,511)
Other comprehensive income (loss) before reclassifications	5	62
Reclassified from Accumulated other comprehensive loss	31	49
Other comprehensive income (loss)	36	111
End of the period	(1,291)	(1,400)
Deferred Gains (Losses) on Hedge Contracts
Components of Accumulated other comprehensive loss
Beginning of the period	(24)	(13)
Other comprehensive income (loss) before reclassifications	14	(14)
Reclassified from Accumulated other comprehensive loss	11	6
Other comprehensive income (loss)	25	(8)
End of the period	1	(21)
Foreign Currency Translation Adjustments
Components of Accumulated other comprehensive loss
Beginning of the period	(47)	18
Other comprehensive income (loss) before reclassifications	4	(46)
Other comprehensive income (loss)	4	(46)
End of the period	$ (43)	$ (28)