Summary of Significant Accounting Policies - Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Renewal term	20 years
Lease, option to terminate	45 days
Operating lease, liability, extensible enumeration	Other liabilities and accrued expenses	Other liabilities and accrued expenses
Operating lease, right-of-use asset, extensible enumeration	Other assets, net	Other assets, net
Lease liability	$ 265	$ 343
Right of use asset	163	234
Lease, cost	102	131	$ 162
Variable lease, cost	$ 19	$ 23	$ 30
Minimum
Lessee, Lease, Description [Line Items]
Lease, term of contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease, term of contract	10 years