Leases (Operating and Finance Leases Liabilities and Related ROU Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Leases
Current portion of lease liabilities	$ 258	$ 262
Long-term lease liabilities	1,085	1,149
ROU assets	$ 1,257	$ 1,328
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Finance Leases
Current portion of lease liabilities	$ 79	$ 68
Long-term lease liabilities	258	255
ROU assets	$ 319	$ 333
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets