Leases Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Cost	$ 75	$ 73	$ 147	$ 146
Short-term Lease, Cost	25	24	54	47
Lease, Cost	$ 100	$ 97	201	193
Operating Lease, Payments			142	98
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 169	$ 168
Operating Lease, Weighted Average Remaining Lease Term	7 years		7 years		8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.50%		4.50%		4.70%