Leases Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Cost	$ 72	$ 73
Short-term Lease, Cost	29	23
Lease, Cost	101	96
Operating Lease, Payments	70	40
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 25	$ 61
Operating Lease, Weighted Average Remaining Lease Term	7 years		7 years
Operating Lease, Weighted Average Discount Rate, Percent	4.50%		4.60%