Leases Lease Cost (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating Lease, Cost	$ 51	$ 197
Short-term Lease, Cost	24	71
Lease, Cost	$ 75	268
Operating Lease, Payments		149
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 192
Operating Lease, Weighted Average Remaining Lease Term	8 years	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.70%	4.70%