High estimate of anticipated cash outlays for environmental remediation costs.

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Low estimate of anticipated cash outlays for environmental remediation costs.

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Environmental Matters [Abstract]

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Historical Environmental Remediation Expense, Lower Limit

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Historical Environmental Remediation Expense, Upper Limit

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Total number of PPG sites to be remediated under the 1990 administrative consent order.

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Percentage Of Total Remaining Reserve

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Remediation Period

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

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Estimate of reasonably possible loss exposure in excess of amount accrued for remediation, site restoration, postclosure, monitoring commitments, or other exit costs associated with the sale, disposal or abandonment of a particular property resulting from unanticipated contamination of the assets.

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The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

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Cash outflows made during the period for environmental remediation activities.

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Commitments and Contingent Liabilities (Additional Information) (Detail) $ in Millions	12 Months Ended				48 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) Location	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2009 Location
Environmental Matters [Abstract]
Reserves for environmental contingencies		$ 291	$ 258
Reserves for environmental contingencies classified as current liabilities		105	73
Pretax charges for environmental remediation costs		78	10	$ 94
Cash outlays related to environmental remediation		64	44	47
Historical low end of range of annual environmental remediation expense over the past 15 years		5
Historical high end of range of annual environmental remediation expense over the past 15 years		$ 35
Remediation Period		10 years
Maximum
Environmental Matters [Abstract]
Unreserved loss contingencies related to environmental matters, high estimate		$ 200
Minimum
Environmental Matters [Abstract]
Unreserved loss contingencies related to environmental matters, high estimate		$ 100
Scenario, Forecast \| Maximum
Environmental Matters [Abstract]
Cash For Environmental Loss Contingencies High Estimate	$ 100				$ 50
Scenario, Forecast \| Minimum
Environmental Matters [Abstract]
Cash For Environmental Loss Contingencies Low Estimate	$ 80				$ 20
Soil Treatment Transportation And Disposal Of Excavated Soil
Environmental Matters [Abstract]
Percentage of the total remaining reserve		19.00%
Construction Services
Environmental Matters [Abstract]
Percentage of the total remaining reserve		28.00%
Jersey City Manufacturing Plant
Environmental Matters [Abstract]
Reserves for environmental contingencies		$ 151	136
Pretax charges for environmental remediation costs		62	4	60
Legacy Glass and Chemical Sites
Environmental Matters [Abstract]
Reserves for environmental contingencies		90	71
Other Environmental Contingencies
Environmental Matters [Abstract]
Reserves for environmental contingencies		50	51
Pretax charges for environmental remediation costs		$ 16	$ 6	$ 34
Judicial Consent Order
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation \| Location		19				20
Excavation of Soil
Environmental Matters [Abstract]
Percentage of the total remaining reserve		22.00%