Leases and Commitments Maturity of Operating Lease Liabilities (Details) $ in Millions	Dec. 31, 2020 USD ($)
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Year One	$ 148
Lessee, Operating Lease, Liability, Payments, Due Year Two	126
Operating Leases, Future Minimum Payments, Due in Three Years	100
Operating Leases, Future Minimum Payments, Due in Four Years	76
Operating Leases, Future Minimum Payments, Due in Five Years	63
Operating Leases, Future Minimum Payments, Due Thereafter	90
Lessee, Operating Lease, Liability, Payments, Due	603
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	$ 47