Leases (Summary of Operating Lease Components of Balance Sheet and Other Supplemental Information) (Details) $ in Millions	Jun. 30, 2020 USD ($)
Leases [Abstract]
ROU assets	$ 539
Lease liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherCurrentLiabilitiesMember
Current lease liabilities	$ 122
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherNoncurrentLiabilitiesMember
Non-current lease liabilities	$ 452
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesMember
Total lease liabilities	$ 574
Other supplemental information
Weighted average remaining lease term	8 years
Weighted average discount rate	3.00%