Leases Maturity of Lease Liabilities (Details) $ in Millions	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating Lease, Year One	$ 154
Operating Lease, Year Two	120
Operating Lease, Year Three	93
Operating Lease, Year Four	67
Operating Lease, Year Five	47
Operating Lease, Due After Year Five	167
Operating Lease, Total Payments	648
Operating Lease, Interest	82
Total operating lease liabilities	566
Finance Lease, Year One	4
Finance Lease, Year Two	2
Finance Lease, Year Three	1
Finance Lease, Year Four	1
Finance Lease, Year Five	1
Finance Lease, Due After Year Five	1
Finance Lease, Total Payments	10
Finance Lease, Interest	1
Finance Lease, Liability	$ 9