Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Leases with options to extend	20 years
Leases with options to terminate	7 years
Operating leases that have not yet commenced	$ 190
Operating lease costs	121	$ 133	$ 153
Short-term lease costs	74	80	96
Net investment income
Income and Expenses, Lessor [Abstract]
Lease Income	79	85	100
Other Income
Income and Expenses, Lessor [Abstract]
Lease Income	$ 11	$ 12	$ 15
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 year
Operating lease term not yet commenced	5 years
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	25 years
Operating lease term not yet commenced	15 years