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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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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Description of significant changes to reserve quantities during the period including, but not limited to, changes in the following: revisions of previous estimates, revisions of estimates from application of improved recovery techniques, purchases of minerals in place, extensions and discoveries made, production, and sales of minerals in place.

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Commitments and Contingent Liabilities (Additional Information) (Detail) $ in Millions	12 Months Ended			60 Months Ended
	Dec. 31, 2017 USD ($) Location	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2011 Location
Environmental Matters [Abstract]
Reserves for environmental contingencies	$ 258	$ 285
Reserves for environmental contingencies classified as current liabilities	73	76
Pretax charges for environmental remediation costs	$ 10	94	$ 9
Significant Changes in Reserves	27
Cash outlays related to environmental remediation	$ 44	47	109
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				$ 75
Scenario, Forecast \| Minimum
Environmental Matters [Abstract]
Cash For Environmental Loss Contingencies Low Estimate				$ 25
Soil Treatment Transportation And Disposal Of Excavated Soil [Member]
Environmental Matters [Abstract]
Percentage of the total remaining reserve	27.00%
Construction Services [Member]
Environmental Matters [Abstract]
Percentage of the total remaining reserve	23.00%
Jersey City Manufacturing Plant
Environmental Matters [Abstract]
Reserves for environmental contingencies	$ 136	163
Pretax charges for environmental remediation costs	4	60	0
Legacy Glass and Chemical Sites [Member]
Environmental Matters [Abstract]
Reserves for environmental contingencies	71	70
Other Environmental Contingencies [Member]
Environmental Matters [Abstract]
Reserves for environmental contingencies	51	52
Pretax charges for environmental remediation costs	$ 6	$ 34	$ 9
Judicial Consent Order [Member]
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	29.00%