Leases Lease Cost (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating Lease, Cost	$ 73	$ 146
Short-term Lease, Cost	24	47
Lease, Cost	$ 97	193
Operating Lease, Payments		98
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 168
Operating Lease, Weighted Average Remaining Lease Term	8 years	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.70%	4.70%