Leases Leases - Summary (Details) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 553
Finance Lease, Right-of-Use Asset	509
Total Right-of-Use Asset	1,062
Operating Lease, Liability	597
Finance Lease, Liability	523
Total Lease Liabilities	$ 1,120