Commitments and Contingencies Environmental (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accrual for Environmental Loss Contingencies [Roll Forward]
Number of sites the Company participates in environmental studies, cleanup or both	200
Environmental Issue
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 298	$ 317	$ 342
Accruals / changes in estimates	5	0	5
Payments	(21)	(19)	(30)
Ending balance	282	298	317
Current portion of ending balance	40	$ 40	$ 40
Environmental Issue | Minimum
Accrual for Environmental Loss Contingencies [Roll Forward]
Future costs to settle claims and associated liability	230
Environmental Issue | Maximum
Accrual for Environmental Loss Contingencies [Roll Forward]
Future costs to settle claims and associated liability	$ 380