Leases Future Minimum Lease Payments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Capital Leases, Future Minimum Payments Due, Next Twelve Months		$ 6
Contractual Obligation, Due in Next Fiscal Year		11
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 8	4
Capital Leases, Future Minimum Payments Due in Two Years		6
Contractual Obligation, Due in Second Year		14
Operating Leases, Future Minimum Payments, Due in Two Years		5
Capital Leases, Future Minimum Payments Due in Three Years		6
Contractual Obligation, Due in Third Year		13
Operating Leases, Future Minimum Payments, Due in Three Years		5
Capital Leases, Future Minimum Payments Due in Four Years		6
Contractual Obligation, Due in Fourth Year		13
Operating Leases, Future Minimum Payments, Due in Four Years		6
Capital Leases, Future Minimum Payments Due in Five Years		5
Contractual Obligation, Due in Fifth Year		13
Operating Leases, Future Minimum Payments, Due in Five Years		7
Capital Leases, Future Minimum Payments Due Thereafter		67
Contractual Obligation, Due after Fifth Year		225
Operating Leases, Future Minimum Payments, Due Thereafter		97
Capital Leases, Future Minimum Payments Due		96
Contractual Obligation		289
Operating Leases, Future Minimum Payments Due		124
Capital Leases, Future Minimum Payments, Interest Included in Payments		(47)
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments		49
Capital Lease Obligations, Current	(2)	(2)
Purchase Commitment, Remaining Minimum Amount Committed	$ 47	$ 47