Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 28, 2018	Sep. 29, 2017
Pension
Net periodic benefit income
Service cost	$ 9	$ 10
Interest cost	52	48
Expected return on plan assets	(95)	(92)
Amortization of net actuarial loss (gain)	0	0
Total net periodic benefit income	(34)	(34)
Other Benefits
Net periodic benefit income
Service cost	0	0
Interest cost	2	2
Expected return on plan assets	(4)	(4)
Amortization of net actuarial loss (gain)	(2)	0
Total net periodic benefit income	$ (4)	$ (2)