Commitments and Contingent Liabilities (Additional Information) (Detail) $ in Millions	1 Months Ended			3 Months Ended			9 Months Ended	12 Months Ended				48 Months Ended
	Dec. 31, 2009 LegalMatter	Dec. 31, 2008 USD ($) shares	May. 14, 2002 USD ($) shares	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2000 USD ($)	Sep. 30, 2012	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Location LegalMatter	Dec. 31, 2014 USD ($) LegalMatter	Dec. 31, 2013 USD ($)	Dec. 31, 2020 USD ($)	Jul. 31, 2014	Dec. 31, 2011 Location	Sep. 30, 2008 Location	Jan. 31, 2000 Plaintiff
Commitments and Contingencies Disclosure [Line Items]
Interest Penalty Asserted by a Foreign Tax Authority									$ 70
Asbestos [Abstract]
PPG percent ownership interest													40.00%
Obligation reported as a current liability									796	$ 821
Obligation reported as a non-current liability									252	259
PC-related claims at trial that PPG was found not responsible | LegalMatter	2
Number of plaintiffs one jury found PPG, for the first time, partly responsible for injuries | Plaintiff																5
Environmental Matters [Abstract]
Reserves for environmental contingencies									233	317
Reserves for environmental contingencies classified as current liabilities									51	141
Cash outlays related to environmental remediation									109	165	$ 111
Pretax charges for environmental remediation costs									9	$ 144	108
Historical low end of range of annual environmental remediation expense over the past 15 years									8
Historical high end of range of annual environmental remediation expense over the past 15 years									$ 30
Remediation Period									10 years
Unreserved loss contingencies related to environmental matters, low estimate									$ 75
Unreserved loss contingencies related to environmental matters, high estimate									$ 200
Unfinished Environmental Remediation [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location									7
Asbestos Issue
Asbestos [Abstract]
Number of pending cases | LegalMatter									114,000	114,000
Reduction in cash obligation to the Trust, corresponding increase in reserve for PPG claims responsibility		$ 162
PPG's reserve for asbestos-related claims that will not be channeled to the Trust									$ 162	$ 162
Pittsburgh Corning Corporation
Asbestos [Abstract]
PPG percent ownership interest									50.00%
After-tax charge, write-off of investment in PC, related to PC filing for Chapter 11 Bankruptcy						$ 35
Number of days after effective date of a confirmed reorganization plan						30 days
Pittsburgh Corning Corporation | Asbestos Issue
Asbestos [Abstract]
Number of days after second amended reorganization plan			30 days
Agreement to convey assets to the PC asbestos settlement trust (the "Trust"), shares of PPG common stock | shares		2,777,778	2,777,778
Future PPG cash payments to the Trust		$ 825	$ 998
Fixed payment schedule, period			21 years
Fixed payment schedule, effective date			Jun. 30, 2003
Future PPG cash payments to the Trust, prepayment discount rate		5.50%	5.50%
Future PPG legal fees and expenses on behalf of the Trust			$ 30
Future cash payments to the Trust by PPG's participating historical insurance carriers		$ 1,700	$ 1,700
Future cash payments to the Trust by PPG's participating historical insurance carriers, prepayment discount rate		5.50%	5.50%
Total obligation									$ 1,048	1,080
Obligation reported as a current liability									796	821
Obligation reported as a non-current liability									252	259
Accretion of asbestos liability									$ 67
Scenario, Forecast | Maximum
Environmental Matters [Abstract]
Cash For Environmental Loss Contingencies High Estimate								$ 60				$ 45
Scenario, Forecast | Minimum
Environmental Matters [Abstract]
Cash For Environmental Loss Contingencies Low Estimate								$ 40				$ 25
Third Amendment | Pittsburgh Corning Corporation | Asbestos Issue
Asbestos [Abstract]
Period of funding effective period							30 days
Construction Services [Member]
Environmental Matters [Abstract]
Percentage of the total remaining reserve									34.00%
Administrative Content Order Nineteen Ninety Aco [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location									61
Administrative Content Order Nineteen Ninety Aco [Member] | Finished Environmental Remediation [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location									47
Administrative Content Order Nineteen Ninety Aco [Member] | Unfinished Environmental Remediation [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location									14
Jersey City Manufacturing Plant
Environmental Matters [Abstract]
Reserves for environmental contingencies									$ 133	211
Pretax charges for environmental remediation costs				$ 136	$ 89				$ 0	136	89
Orphan Sites Settlement
Environmental Matters [Abstract]
Number of sites | Location									4
Other Contingency Matters [Abstract]
Number of sites | Location									4
Orphan Sites Settlement | Unfinished Environmental Remediation [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location															6
Other Environmental Contingencies [Member]
Environmental Matters [Abstract]
Reserves for environmental contingencies									$ 100	106
Pretax charges for environmental remediation costs									$ 9	$ 8	$ 19
Judicial Consent Order [Member]
Environmental Matters [Abstract]
Number Of Sites Involved For Environmental Remediation | Location														20
Soil Treatment Transportation And Disposal Of Excavated Soil [Member]
Environmental Matters [Abstract]
Percentage of the total remaining reserve									36.00%