Employee Benefits (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
U.K.
Defined Benefit Plan Disclosure
Service cost		$ 0	$ 0	$ 0	$ 0
Interest cost		30	43	60	86
Expected return on plan assets, net of administration expenses		(49)	(65)	(97)	(129)
Amortization of prior-service cost		0	1	0	1
Amortization of net actuarial loss		8	9	15	17
Net periodic cost (benefit)		(11)	(12)	(22)	(25)
Loss on pension settlement		0	61	0	61
Total net periodic cost (benefit)		(11)	49	(22)	36
Estimate of contributions to defined benefit pension plans for the current fiscal year		80		80
Contributions made to defined benefit pension plans		26	17	42	34
U.S.
Defined Benefit Plan Disclosure
Service cost		0	0	0	0
Interest cost		24	28	48	55
Expected return on plan assets, net of administration expenses		(35)	(39)	(70)	(78)
Amortization of prior-service cost		1	1	1	1
Amortization of net actuarial loss		12	12	25	25
Net periodic cost (benefit)		2	2	4	3
Loss on pension settlement		0	0	0	0
Total net periodic cost (benefit)		2	2	4	3
Estimate of contributions to defined benefit pension plans for the current fiscal year		51		51
Contributions made to defined benefit pension plans		13	6	26	19
Other International Plan [Member]
Defined Benefit Plan Disclosure
Service cost		0	0	0	0
Interest cost		6	7	12	14
Expected return on plan assets, net of administration expenses		(11)	(12)	(22)	(24)
Amortization of prior-service cost		0	0	0	0
Amortization of net actuarial loss		3	3	6	5
Net periodic cost (benefit)		(2)	(2)	(4)	(5)
Loss on pension settlement		0	0	0	0
Total net periodic cost (benefit)		(2)	(2)	(4)	(5)
Estimate of contributions to defined benefit pension plans for the current fiscal year		18		18
Contributions made to defined benefit pension plans		$ 9	$ 3	$ 11	$ 10
Subsequent Event | U.S.
Defined Benefit Plan Disclosure
Non-cash contributions by employer	$ 80