Leases Lease Balance Sheet (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 280
Finance Lease, Right-of-Use Asset	58
Lease Right of Use Assets	338
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	35
Operating Lease, Liability	95
Finance Lease, Liability, Current	10
Operating Lease, Liability, Noncurrent	209
Finance Lease, Liability, Noncurrent	64
Lease Liabilities	$ 378