Leases Supplemental Cash Flow Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating Lease, Payments	$ 7
Finance Lease, Interest Payment on Liability	5
Finance Lease, Principal Payments	4
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	56
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 154