Commitments and Contingent Liabilities (Additional Information) (Details) $ in Millions	1 Months Ended		3 Months Ended				9 Months Ended		105 Months Ended
	Dec. 31, 2008 USD ($) shares	May. 14, 2002 USD ($) shares	Sep. 30, 2015 USD ($) sites Location LegalMatter	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2000 USD ($)	Sep. 30, 2015 USD ($) sites Location LegalMatter	Sep. 30, 2014 USD ($)	Sep. 30, 2014 USD ($) LegalMatter	Mar. 31, 2015 Location	Dec. 31, 2014 USD ($)	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	$ 70
Reserves for environmental contingencies			$ 252				$ 252				$ 317
Sewer Sites - Responsibility for Remedial Activity is Shared | sites			10				10
Reserves for environmental contingencies classified as current liabilities			$ 76				$ 76				141
Environmental remediation charge			3	138			9	143
Unreserved loss contingencies related to environmental matters, low estimate							75
Unreserved loss contingencies related to environmental matters, high estimate							200
Outstanding letters of credit			166				166
Guarantees			23				23
Payments for Environmental Liabilities			18	31			84	$ 106
Jersey City Manufacturing Plant [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies			$ 148				$ 148				211
Environmental remediation charge				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			4				4
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			$ 104				$ 104				$ 106
Environmental remediation charge			$ 3	$ 138
Unfinished Environmental Remediation [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			7				7
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			8				8
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									290
Loss Contingency Claims in the Process of Being Settled | LegalMatter									80
Loss Contingency Number of Claims not in the Process of Being Settled. | LegalMatter									210
Loss Contingency Claims Being Litigated. | LegalMatter			115				115
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			32.00%				32.00%
Construction Services (Related To Soil Excavation, Groundwater Management And Site Security) [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve			30.00%				30.00%
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