Shareholders' Equity - Before and after-tax components of other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Pension and postretirement benefits adjustments, pre-tax:
Amortization of net actuarial loss, pre-tax	$ 25	$ 38
Amortization of prior service cost, pre-tax	1	2
Pension and postretirement benefits adjustments, net, pre-tax	26	40
Deferred gains on hedge contracts, pre-tax:
Current deferrals, pre-tax	4	2
Reclassification adjustments, pre-tax	(1)
Deferred gains on hedge contracts, net, pre-tax	3	2
Foreign currency translation adjustments, pre-tax:
Foreign currency translation adjustments, pre-tax	1	40
Other comprehensive income (loss), pre-tax	30	82
Pension and postretirement benefits adjustments, tax:
Amortization of net actuarial loss, tax	(5)	(9)
Pension and postretirement benefits adjustments, net, tax	(5)	(9)
Deferred gains on hedge contracts, tax:
Current deferrals, tax	(1)	(1)
Deferred gains on hedge contracts, net, tax	(1)	(1)
Foreign currency translation adjustments, tax:
Foreign currency translation adjustments, tax	2	2
Other comprehensive income (loss), tax	(4)	(8)
Pension and postretirement benefits adjustments, after-tax:
Amortization of net actuarial loss, after-tax	20	29
Amortization of prior service cost, after-tax	1	2
Pension and postretirement benefits adjustments, net, after-tax	21	31
Deferred gains on hedge contracts, after-tax:
Current deferrals, after-tax	3	1
Reclassification adjustments, after-tax	(1)
Deferred gains on hedge contracts, net, after-tax	2	1
Foreign currency translation adjustments, after-tax:
Foreign currency translation adjustments, after-tax	3	42
Other comprehensive income	$ 26	$ 74