Other Assets and Liabilites - Schedule of Right of Use Assets and Future Maturities of Lease Liabilities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Right of Use Assets
Right-of-Use Asset, Operating Lease	$ 842
Right-of-Use Asset, Finance Lease	18
Operating Lease Liabilities, Payments Due
2019, Operating Leases	86
2020, Operating Leases	195
2021, Operating Leases	172
2022, Operating Leases	148
2023, Operating Lease	118
2024, Operating Leases	92
Thereafter, Operating Leases	289
Total lease payments, Operating Leases	1,100
Less: imputed interest, Operating Lease	139
Total lease liabilities, Operating Leases	$ 961
Weighted Average Remaining Lease Term, Operating Lease	7 years 6 months
Weighted Average Discount Rate, Percent, Operating Lease	3.10%
Finance Lease Liabilities, Payments, Due
2019, Finance Leases	$ 4
2020, Finance Leases	7
2021, Finance Leases	6
2022, Finance Leases	5
2023, Finance Lease	3
2024, Finance Leases	2
Thereafter, Finance Leases	3
Total lease payments, Finance Leases	30
Less: imputed interest, Finance Leases	5
Total lease liabilities, Finance Leases	$ 25
Weighted Average Remaining Lease Term, Finance Lease	5 years
Weighted Average Discount Rate, Percent, Finance Lease	7.10%