Leases - Maturities (Details) $ in Millions	Dec. 31, 2019 USD ($)
Operating Leases
2020	$ 460
2021	361
2023	308
2023	265
2024	194
Thereafter	686
Total lease payments	2,274
Less: interest	(516)
Total	1,758
Less: current portion	(416)
Noncurrent operating lease liabilities	1,342
Finance Leases
2020	47
2021	28
2022	22
2023	22
2024	21
Thereafter	170
Total lease payments	310
Less: interest	(90)
Total	220
Less: current portion	(35)
Long-term portion	$ 185