Leases (Lease Income Associated with Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Lessor, Lease, Description [Line Items]
Fixed payments	$ 4	$ 14	$ 8	$ 29
Variable payments	15	18	31	35
Total lease income under operating leases	19	32	39	64
Operating revenues
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	19	22	39	44
Other income
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	$ 0	$ 10	$ 0	$ 20