Commitments and Contingent Liabilities (Additional Information) (Details) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	May 14, 2002 shares	Sep. 30, 2016 USD ($) Location	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Location	Sep. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2011 Location	Dec. 31, 2008 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Interest Penalty Asserted by a Foreign Tax Authority			$ 70.0		$ 70.0
Reserves for environmental contingencies		$ 209.0		$ 209.0			$ 233.0
Accrual for Environmental Loss Contingencies, Component Amount		3.6		3.6
Reserves for environmental contingencies classified as current liabilities		57.0		57.0			51.0
Outstanding letters of credit		175.0		175.0
Guarantees		21.0		21.0
Payments for Environmental Liabilities		12.0	18.0	35.0	84.0
Prepayment of future pre-tax cash payments to the trust						$ 764.0
Minimum [Member]
Commitments and Contingencies Disclosure [Line Items]
Unreserved loss contingencies related to environmental matters				75.0
Maximum [Member]
Commitments and Contingencies Disclosure [Line Items]
Unreserved loss contingencies related to environmental matters				200.0
Jersey City Manufacturing Plant [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies		$ 112.0		$ 112.0			133.0
Orphan Sites Settlement [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location		6		6
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		$ 97.0		$ 97.0			$ 100.0
Environmental remediation charge		$ 3.0	$ 3.0	$ 11.0	$ 9.0
Asbestos Issue [Member]
Commitments and Contingencies Disclosure [Line Items]
PPG's reserve for asbestos-related claims that will not be channeled to the Trust						$ 162.0		$ 162.0
Soil Treatment, Transportation And Disposal Of Excavated Soil [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve		33.00%		33.00%
Construction Services (Related To Soil Excavation, Groundwater Management And Site Security) [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve		39.00%		39.00%
Pittsburgh Corning Corporation [Member] | Asbestos Issue [Member]
Commitments and Contingencies Disclosure [Line Items]
Settlement Payables Shares | shares	2,777,778
Settlement Prepayment Discount Rate	5.50%
Insurance Settlements Receivable										$ 1,700.0