Leases Lease Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 172	$ 256
Finance Lease, Right-of-Use Asset	62	62
Lease Right of Use Assets	234	318
Operating Lease, Liability	79	79
Finance Lease, Liability, Current	11	10
Operating Lease, Liability, Noncurrent	196	213
Finance Lease, Liability, Noncurrent	52	54
Lease Liabilities	$ 338	$ 356