Leases (Payment Schedule for Operating Lease Obligations) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
2020	$ 149
2021	92
2022	47
2023	13
2024	8
Thereafter	18
Total lease payments	327
Less present value discount	(21)
Present value of lease liabilities	306	$ 325
2020	33
2021	33
2022	34
2023	35
2024	35
Thereafter	603
Total lease payments	773
Less present value discount	(201)
Present value of lease liabilities	$ 572	$ 0