Lease Commitments Lease Commitments - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Paid for Lease Liabilities [Abstract]
Operating cash flows from operating leases	$ 424	$ 434	$ 460
Operating cash flows from finance leases	14	15	6
Financing cash flows from finance leases	52	105	35
Operating leases	441	304	527
Finance leases	$ 192	$ 306	$ 43