Commitments And Contingencies (Narrative) (Details) $ in Millions	Jun. 30, 2021 USD ($) item
Commitments and Contingencies [Line Items]
Sites identified which we are or may be liable for remediation costs	385
Sites subject of actions taken by the U.S. government	28
Sites on the Superfund National Priorities List	18
Personal Injury [Member]
Commitments and Contingencies [Line Items]
Percent of liability recorded related to asserted claims	95.00%
Percent of liability recorded related to unasserted claims	5.00%
Personal Injury [Member] | Minimum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims | $	$ 301
Personal Injury [Member] | Maximum [Member]
Commitments and Contingencies [Line Items]
Reasonably possible outcome of related claims | $	$ 330