Accumulated Other Comprehensive Loss and Other Comprehensive Income - Before and after-tax components of other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Pension and postretirement benefits adjustments, pre-tax:
Amortization of net actuarial loss, pre-tax	$ 26	$ 36	$ 78	$ 114
Amortization of prior service credit, pre-tax	(2)	(2)	(6)	(4)
Unrealized gains, pre-tax			7	98
Pension and postretirement benefits adjustments, net, pre-tax	24	34	79	208
Deferred gains (losses) on hedge contracts, pre-tax:
Current deferrals, pre-tax	(3)	(10)	17	(28)
Reclassification adjustments, pre-tax	1	9	16	18
Deferred gains (losses) on hedge contracts, net, pre-tax	(2)	(1)	33	(10)
Foreign currency translation adjustments, pre-tax	13	4	24	(39)
Other comprehensive income (loss), pre-tax	35	37	136	159
Pension and postretirement benefits adjustments, tax:
Amortization of net actuarial loss, tax	(9)	(12)	(28)	(40)
Amortization of prior service credit, tax	1		3	1
Unrealized gains, tax			(2)	(36)
Pension and postretirement benefits adjustments, net, tax	(8)	(12)	(27)	(75)
Deferred gains (losses) on hedge contracts, tax:
Current deferrals, tax		2	(6)	6
Reclassification adjustments, tax		(2)	(4)	(5)
Deferred gains (losses) on hedge contracts, net, tax			(10)	1
Foreign currency translation adjustments, tax	(9)	(3)	(16)	(6)
Other comprehensive income (loss), tax	(17)	(15)	(53)	(80)
Pension and postretirement benefits adjustments, after-tax:
Amortization of net actuarial loss, after-tax	17	24	50	74
Amortization of prior service credit, after-tax	(1)	(2)	(3)	(3)
Unrealized gains, after-tax			5	62
Pension and postretirement benefits adjustments net, after-tax	16	22	52	133
Deferred gains (losses) on hedge contracts, after-tax:
Current deferrals, after-tax	(3)	(8)	11	(22)
Reclassification adjustments, after-tax	1	7	12	13
Deferred gains (losses) on hedge contracts, net, after-tax	(2)	(1)	23	(9)
Foreign currency translation adjustments, after-tax	4	1	8	(45)
Other comprehensive income	$ 18	$ 22	$ 83	$ 79