Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Operating Leases:
Operating lease right-of-use assets	$ 715	$ 668
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets, net	Other assets, net
Finance Leases:
Property and equipment	$ 9,779	$ 9,757
Less accumulated depreciation and amortization	(4,223)	(4,204)
Property and equipment, net	5,556	5,553
Current finance lease liabilities	$ 3	$ 8
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	$ 258	$ 233
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt	Long-term debt
Finance Lease right-of-use Assets
Finance Leases:
Property and equipment	$ 336	$ 314
Less accumulated depreciation and amortization	(56)	(54)
Property and equipment, net	280	260
Finance Lease right-of-use Assets | Land and Improvements
Finance Leases:
Property and equipment	8	8
Finance Lease right-of-use Assets | Building and Improvements
Finance Leases:
Property and equipment	316	289
Finance Lease right-of-use Assets | Equipment and Fixtures
Finance Leases:
Property and equipment	$ 12	$ 17