Contingencies and Commitments - Changes in Accrued Liabilities for Remediation Activities (Detail) $ in Millions |
9 Months Ended |
---|---|
Sep. 30, 2018
USD ($)
| |
Change in Accrued Liabilities for Remediation Activities [Roll Forward] | |
Beginning of period | $ 179 |
Accruals for environmental remediation deemed probable and reasonably estimable | 2 |
Obligations settled | (4) |
End of period | $ 177 |