Shareholders' Equity - Before and after-tax components of other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Pension and postretirement benefits adjustments, pre-tax:
Amortization of net actuarial loss, pre-tax	$ 24	$ 39	$ 49	$ 77
Amortization of prior service cost, pre-tax	3	2	4	4
Pension and postretirement benefits adjustments, net, pre-tax	27	41	53	81
Deferred gains (losses) on hedge contracts, pre-tax:
Current deferrals, pre-tax	2	(4)	6	(2)
Reclassification adjustments, pre-tax	(1)	(1)	(2)	(1)
Deferred gains (losses) on hedge contracts, net, pre-tax	1	(5)	4	(3)
Foreign currency translation adjustments, pre-tax:
Foreign currency translation adjustments, pre-tax	3	(66)	4	(26)
Other comprehensive income (loss), pre-tax	31	(30)	61	52
Pension and postretirement benefits adjustments, tax:
Amortization of net actuarial loss, tax	(6)	(9)	(11)	(18)
Amortization of prior service cost, tax	(1)	(1)	(1)	(1)
Pension and postretirement benefits adjustments, net, tax	(7)	(10)	(12)	(19)
Deferred gains (losses) on hedge contracts, tax:
Current deferrals, tax	(1)	1	(2)
Deferred gains (losses) on hedge contracts, net, tax	(1)	1	(2)
Foreign currency translation adjustments, tax:
Foreign currency translation adjustments, tax	(2)	(3)		(1)
Other comprehensive income (loss), tax	(10)	(12)	(14)	(20)
Pension and postretirement benefits adjustments, after-tax:
Amortization of net actuarial loss, after-tax	18	30	38	59
Amortization of prior service cost, after-tax	2	1	3	3
Pension and postretirement benefits adjustments, net, after-tax	20	31	41	62
Deferred gains (losses) on hedge contracts, after-tax:
Current deferrals, after-tax	1	(3)	4	(2)
Reclassification adjustments, after-tax	(1)	(1)	(2)	(1)
Deferred gains (losses) on hedge contracts, net, after-tax		(4)	2	(3)
Foreign currency translation adjustments, after-tax:
Foreign currency translation adjustments, after-tax	1	(69)	4	(27)
Other comprehensive income (loss)	$ 21	$ (42)	$ 47	$ 32