Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Operating Leases:
Operating Lease, Right-of-Use Asset	$ 665	$ 738
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets, net of accumulated amortization of $1,518 and $1,392 at December 31, 2023 and 2022, respectively	Other assets, net of accumulated amortization of $1,518 and $1,392 at December 31, 2023 and 2022, respectively
Finance Leases:
Property and equipment	$ 9,511	$ 9,639
Less accumulated depreciation and amortization	(4,304)	(4,274)
Property and equipment, net	5,207	5,365
Current finance lease liabilities	$ 2	$ 3
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Current maturities of long-term debt	Current maturities of long-term debt
Long-term finance lease liabilities	$ 214	$ 220
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt	Long-term debt
Finance Lease ROU Assets
Finance Leases:
Property and equipment	$ 256	$ 273
Less accumulated depreciation and amortization	(55)	(56)
Property and equipment, net	201	217
Finance Lease ROU Assets | Building and Improvements
Finance Leases:
Property and equipment	246	261
Finance Lease ROU Assets | Equipment and Fixtures
Finance Leases:
Property and equipment	$ 10	$ 12