Accumulated Other Comprehensive Loss and Other Comprehensive Income - Components of accumulated other comprehensive loss (Details) - USD ($) $ in Millions	9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015
Components of Accumulated other comprehensive loss
Beginning of the period	$ (1,398)	$ (1,506)
Other comprehensive income (loss) before reclassifications	24	(5)
Reclassified from Accumulated other comprehensive loss	59	84
Other comprehensive income (loss)	83	79
End of the period	(1,315)	(1,427)
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	47	71
Other comprehensive income (loss)	52	133
End of the period	(1,275)	(1,378)
Deferred Gains (Losses) on Hedge Contracts
Components of Accumulated other comprehensive loss
Beginning of the period	(24)	(13)
Other comprehensive income (loss) before reclassifications	11	(22)
Reclassified from Accumulated other comprehensive loss	12	13
Other comprehensive income (loss)	23	(9)
End of the period	(1)	(22)
Foreign Currency Translation Adjustments
Components of Accumulated other comprehensive loss
Beginning of the period	(47)	18
Other comprehensive income (loss) before reclassifications	8	(45)
Other comprehensive income (loss)	8	(45)
End of the period	$ (39)	$ (27)