Leases Lease Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating Lease, Cost	$ 166
Finance Lease, Right-of-Use Asset, Amortization	10
Finance Lease, Interest Expense	1
Finance Lease, Cost	11
Short-term Lease, Cost	17
Variable Lease, Cost	7
Total Lease Cost	$ 201