Commitments and Contingent Liabilities (Additional Information) (Details) $ in Millions	1 Months Ended		3 Months Ended			105 Months Ended
	Dec. 31, 2008 USD ($) shares	May. 14, 2002 USD ($) shares	Mar. 31, 2016 USD ($) Location LegalMatter	Mar. 31, 2015 USD ($)	Mar. 31, 2000 USD ($)	Sep. 30, 2014 LegalMatter	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2013 LegalMatter	Dec. 31, 2011 Location
Commitments and Contingencies Disclosure [Line Items]
Interest Penalty Asserted by a Foreign Tax Authority				$ 70.0
Reserves for environmental contingencies			$ 227.0				$ 233.0
Accrual for Environmental Loss Contingencies, Component Amount			3.6
Reserves for environmental contingencies classified as current liabilities			57.0				51.0
Unreserved loss contingencies related to environmental matters, low estimate			75.0
Unreserved loss contingencies related to environmental matters, high estimate			200.0
Outstanding letters of credit			175.0
Guarantees			25.0
Payments for Environmental Liabilities			14.0	36.0
Jersey City Manufacturing Plant [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies			$ 126.0				133.0
Orphan Sites Settlement [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			6
Judicial Consent Order [Member]
Commitments and Contingencies Disclosure [Line Items]
Total number of sites to be remediated | Location			19							20
Other Environmental Contingencies [Member]
Commitments and Contingencies Disclosure [Line Items]
Reserves for environmental contingencies			$ 101.0				$ 100.0
Environmental remediation charge			$ 5.0	$ 4.0
Asbestos Issue [Member]
Commitments and Contingencies Disclosure [Line Items]
Number of pending cases | LegalMatter			114,000						114,000
Loss Contingency, Claims Settled, Number | LegalMatter						580
Loss Contingency, Number of Plaintiffs | LegalMatter						255
Loss Contingency Claims in the Process of Being Settled | LegalMatter						45
Loss Contingency Number of Claims not in the Process of Being Settled. | LegalMatter						210
Loss Contingency Claims Being Litigated. | LegalMatter			115
Reduction in cash obligation to the Trust, corresponding increase in reserve for PPG claims responsibility	$ 162.0
PPG's reserve for asbestos-related claims that will not be channeled to the Trust			$ 162.0					$ 162.0
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%
Soil Treatment, Transportation And Disposal Of Excavated Soil [Member]
Commitments and Contingencies Disclosure [Line Items]
Percentage of the total remaining reserve			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			34.00%
Pittsburgh Corning Corporation [Member]
Commitments and Contingencies Disclosure [Line Items]
PPG percent ownership interest			50.00%
After-tax charge, write-off of investment in PC, related to PC filing for chapter 11 bankruptcy					$ 35.0
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	2,777,778	2,777,778
Future PPG cash payments to the Trust	$ 825.0	$ 998.0
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		$ 30.0
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	$ 1,700.0	$ 1,700.0
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