Commitments, Contingencies and Other Items - Right-of-Way Agreements (Details) $ in Millions	Dec. 31, 2019 USD ($)
Right-of-Way Agreements
Right-of-Way Agreements, 2020	$ 83
Right-of-Way Agreements, 2021	58
Right-of-Way Agreements, 2022	55
Right-of-Way Agreements, 2023	53
Right-of-Way Agreements, 2024	44
Right-of-Way Agreements, Thereafter	276
Right-of-Way Agreements, Total	$ 569