Leasing Lease Balances (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 391	$ 0
Finance Lease, Right-of-Use Asset	38	0
Finance Lease, Right-Of-Use Asset, Accumulated Depreciation	5
Lease, Right-of-Use Asset	424
Operating Lease, Liability, Current	91
Finance Lease, Liability, Current	10
Operating Lease, Liability, Noncurrent	369	$ 0
Finance Lease, Liability, Noncurrent	25
Lease, Liability	$ 495