Leases Maturities of lease liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 42
2021	36
2022	28
2023	23
2024	15
Later years	126
Total lease payments	270
Less amounts representing interest	(33)
Total lease obligations	237
Finance Lease, Liability, Payment, Due [Abstract]
2020	36
2021	31
2022	28
2023	24
2024	22
Later years	101
Total lease payments	242
Less amounts representing interest	(69)
Total lease obligations	$ 173	$ 201