Commitments and Contingent Liabilities (Additional Information) (Details) $ in Millions	1 Months Ended		3 Months Ended					6 Months Ended		105 Months Ended
	Dec. 31, 2008 USD ($) shares	May. 14, 2002 USD ($) shares	Jun. 30, 2015 USD ($) sites Location LegalMatter	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2000 USD ($)	Jun. 30, 2015 USD ($) sites Location LegalMatter	Jun. 30, 2014 USD ($)	Sep. 30, 2014 LegalMatter	Mar. 31, 2015 Location	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2013 LegalMatter	Dec. 31, 2011 Location	Sep. 30, 2008 Location
Commitments and Contingencies Disclosure [Line Items]
Interest Penalty Asserted by a Foreign Tax Authority			$ 70					$ 70
Reserves for environmental contingencies			$ 267					$ 267				$ 317
Sewer Sites - Responsibility for Remedial Activity is Shared | sites			10					10
Reserves for environmental contingencies classified as current liabilities			$ 122					$ 122				141
Environmental remediation costs			1		$ 3			6	$ 5
Unreserved loss contingencies related to environmental matters, low estimate								75
Unreserved loss contingencies related to environmental matters, high estimate								200
Outstanding letters of credit			148					148
Guarantees			26					26
Payments for Environmental Liabilities			20		48			56	$ 75
Jersey City Manufacturing Plant [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies			$ 160					$ 160				211
Environmental remediation costs				$ 136		$ 89
Administrative Content Order 1990 ACO [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			61					61
Orphan Sites Settlement [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location											6					6
Number of sites | Location			3					3
Judicial Consent Order [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			19					19							20
Other Environmental Contingencies [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies			$ 107					$ 107				$ 106
Environmental remediation costs			$ 1		$ 3
Unfinished Environmental Remediation [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			10					10
Unfinished Environmental Remediation [Member] | Administrative Content Order 1990 ACO [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			14					14
Unfinished Environmental Remediation [Member] | New Jersey Remediation Sites [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			6					6
Finished Environmental Remediation [Member] | Administrative Content Order 1990 ACO [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			47					47
Asbestos Issue [Member]
Commitments and Contingencies Disclosure [Line Items]
Number of pending cases | LegalMatter			114,000					114,000						114,000
Loss Contingency, Claims Settled, Number | LegalMatter										580
Loss Contingency, Number of Plaintiffs | LegalMatter										320
Loss Contingency Claims in the Process of Being Settled | LegalMatter										80
Loss Contingency Number of Claims not in the Process of Being Settled. | LegalMatter										240
Loss Contingency Claims Being Litigated. | LegalMatter			110					110
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					$ 162
Asbestos Issue [Member] | Maximum [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of premises claims currently comprised of the total of asbestos related claims against PPG			2.00%					2.00%
Soil Treatment, Transportation And Disposal Of Excavated Soil [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve			38.00%					38.00%
Construction Services (Related To Soil Excavation, Groundwater Management And Site Security) [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve			35.00%					35.00%
Pittsburgh Corning Corporation [Member]
Commitments and Contingencies Disclosure [Line Items]
PPG percent ownership interest			50.00%					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 [Member] | Asbestos Issue [Member]
Commitments and Contingencies Disclosure [Line Items]
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	1,388,889	1,388,889
Future PPG cash payments to the Trust	$ 825	$ 998
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
Fixed payment schedule, period		21 years
Fixed payment schedule, effective date		June 30, 2003
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%
Period of funding effective date								30 days