Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease ROU assets	$ 630	$ 894
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Finance lease ROU assets	$ 84	$ 66
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Equipment, office facilities, and property — net	Equipment, office facilities, and property — net
Operating lease liabilities	$ 892	$ 994
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Finance lease liabilities	$ 85	$ 68
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt	Long-term debt