Commitments and Contingent Liabilities (Additional Information) (Details) (USD $)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended		3 Months Ended		9 Months Ended		9 Months Ended			1 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended										9 Months Ended	3 Months Ended		9 Months Ended						6 Months Ended									3 Months Ended		1 Months Ended			9 Months Ended
	Jan. 31, 2000 Plaintiff	Dec. 31, 1999 cases	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2010 LegalMatter	Dec. 31, 2011	Mar. 31, 2012 Jersey City Manufacturing Plant [Member]	Sep. 30, 2006 Jersey City Manufacturing Plant [Member]	Sep. 30, 2012 Jersey City Manufacturing Plant [Member]	Dec. 31, 2011 Jersey City Manufacturing Plant [Member]	Sep. 30, 2012 Jersey City Manufacturing Plant [Member] Maximum [Member]	Sep. 30, 2012 Jersey City Manufacturing Plant [Member] Minimum [Member]	Sep. 30, 2012 Administrative Content Order 1990 ACO [Member] Location	Oct. 31, 2006 Calcasieu River [Member]	Aug. 06, 2012 Calcasieu River [Member] Entity	Oct. 31, 2011 Calcasieu River [Member] Entity	Jun. 30, 2011 Calcasieu River [Member] Entity	Sep. 30, 2012 Calcasieu River [Member] Maximum [Member] acre	Sep. 30, 2012 Calcasieu River [Member] Minimum [Member] acre	Sep. 30, 2012 Calcasieu River And Three Chemicals Plants [Member]	Dec. 31, 2011 Calcasieu River And Three Chemicals Plants [Member]	Sep. 30, 2008 Orphan Sites Settlement [Member] Location	Sep. 30, 2012 Orphan Sites Settlement [Member] Location	Sep. 30, 2012 Judicial Consent Order [Member] Location	Sep. 30, 2012 Other Environmental Contingencies [Member]	Dec. 31, 2011 Other Environmental Contingencies [Member]	Sep. 30, 2012 New Jersey Remediation Sites [Member] ton	Sep. 30, 2011 New Jersey Remediation Sites [Member] ton	Sep. 30, 2012 Unfinished Environmental Remediation [Member] Administrative Content Order 1990 ACO [Member] Location	Sep. 30, 2012 Unfinished Environmental Remediation [Member] Orphan Sites Settlement [Member] Location	Sep. 30, 2008 Unfinished Environmental Remediation [Member] Orphan Sites Settlement [Member] Location	Sep. 30, 2008 Partially Liable Environmental Remediation [Member] Orphan Sites Settlement [Member] Location	Sep. 30, 2012 Finished Environmental Remediation [Member] Administrative Content Order 1990 ACO [Member] Location	Sep. 30, 2012 Future Period [Member]	Sep. 30, 2012 Other Charges [Member]	Sep. 30, 2011 Other Charges [Member]	Sep. 30, 2012 Other Charges [Member]	Sep. 30, 2011 Other Charges [Member]	Sep. 30, 2012 Asbestos Issue [Member] LegalMatter	Dec. 31, 2011 Asbestos Issue [Member]	Dec. 31, 2008 Asbestos Issue [Member]	Sep. 30, 2012 Asbestos Issue [Member] Maximum [Member]	Jun. 30, 2006 Phase 1 [Member] Location	Sep. 30, 2012 Phase 1 [Member] Settlement Of Litigation [Member]	Sep. 24, 2012 Phase 1 [Member] Settlement Of Litigation [Member]	Jun. 30, 2009 Phase 2 [Member]	Dec. 31, 2008 Phase 2 [Member] Location	Jun. 30, 2009 Phase 2 [Member] Potential Liability [Member]	Dec. 31, 2008 Phase 2 [Member] Potential Liability [Member] Location	Sep. 30, 2012 Soil Treatment, Transportation And Disposal Of Excavated Soil [Member] New Jersey Remediation Sites [Member]	Sep. 30, 2012 Construction Services (Related To Soil Excavation, Groundwater Management And Site Security) [Member] New Jersey Remediation Sites [Member]	Mar. 31, 2000 Pittsburgh Corning Corporation [Member]	Sep. 30, 2012 Pittsburgh Corning Corporation [Member]	Jan. 31, 2009 Pittsburgh Corning Corporation [Member] Asbestos Issue [Member]	May 14, 2002 Pittsburgh Corning Corporation [Member] Asbestos Issue [Member]	Jul. 17, 2012 Pittsburgh Corning Corporation [Member] Asbestos Issue [Member] Third Amendment [Member]	Sep. 30, 2012 Pittsburgh Corning Corporation [Member] Asbestos Issue [Member] Third Amendment [Member]
Commitments and Contingencies Disclosure [Line Items]
Private putative class cases filed							30
PPG percent ownership interest																																																							50.00%
Number of pending cases																																									114,000
After-tax charge, write-off of investment in PC, related to PC filing for chapter 11 bankruptcy																																																						$ 35,000,000
Number of days after effective date of a confirmed reorganization plan																																																						30 days
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																																																								1,388,889	1,388,889
Future PPG cash payments to the Trust																																																								825,000,000	998,000,000
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																																																									30,000,000
Fixed payment schedule, period																																																									21 years
Fixed payment schedule, effective date																																																									2003-06-30
Future cash payments to the Trust by PPG's participating historical insurance carriers																																																								1,700,000,000	1,700,000,000
Future cash payments to the Trust by PPG's participating historical insurance carriers, prepayment discount rate																																																								5.50%	5.50%
Third amendment plan last filing date																																																										August 20, 2012
Hearing date for the plan																																																										Oct. 10, 2012
Period of funding effective date																																																											30 days
Percentage of premises claims currently comprised of the total of asbestos related claims against PPG																																												2.00%
Claims alleging personal injury caused by asbestos on PPG premises, approximate number of claims settled																																									500
Claims alleging personal injury caused by asbestos on PPG premises, approximate number of claims being considered for potential settlement																																									375
Reduction in cash obligation to the Trust, corresponding increase in reserve for PPG claims responsibility																																											162,000,000
PPG's reserve for asbestos-related claims that will not be channeled to the Trust																																									162,000,000	162,000,000
PC-related claims at trial that PPG was found not responsible		2
Number of plaintiffs one jury found PPG, for the first time, partly responsible for injuries	5
Reserves for environmental contingencies			350,000,000		350,000,000			226,000,000			239,000,000	129,000,000										62,000,000	50,000,000				49,000,000	47,000,000	256,000,000
Percentage of the total remaining reserve																																																				55.00%	30.00%
Reserves for environmental contingencies classified as current liabilities			94,000,000		94,000,000			59,000,000
Environmental remediation costs					159,000,000	0			145,000,000	165,000,000	159,000,000																										1,000,000	3,000,000	165,000,000	15,000,000
Cash outlays related to environmental remediation			20,000,000	9,000,000	45,000,000	43,000,000
Increase in liability for environmental remediation, impact of foreign currency					1,000,000	(2,000,000)
Increase in liability for environment contingencies					3,000,000
Expected cash payments for environmental remediation costs for remaining fiscal year			40,000,000		40,000,000
Expectations of cash outlays for environmental remediation costs through 2014																																				100,000,000
Expectations of cash outlays for environmental remediation costs, low estimate annually 2015 and 2016																																				10,000,000
Expectations of cash outlays for environmental remediation costs, high estimate annually 2015 and 2016																																				30,000,000
Total number of sites to be remediated															61									53		20					14	6	6	10	47
PPG agrees to reimburse the NJDEP for a portion of past costs																								5,000,000
Judicial Consent Order combining ACO and Orphan Sites Settlement, reparation claim payable to the City of Jersey City																										1,500,000
Payment time period																										5 years
Soil that may be potentially impacted for all remaining sites (in tons)																													1,000,000	70,000
Time Period for Final Resolution of New Jersey Chrome Site Legal Matters													3 years	2 years
Number of Acres or Adjacent Marshes																				200	150
PPG's exposure regarding the Calcasieu Estuary																Lower few miles of Bayou d’Inde, a small tributary to the Calcasieu Estuary near PPG’s Lake Charles facility, and about 150 to 200 acres of adjacent marshes.
Number of potentially responsible parties																		3
Number of remaining parties who submitted revised cooperative agreements																	2
Proposed new cooperative agreement with the companies																			4
Number of potentially responsible parties no longer responsible																		1
Unreserved loss contingencies related to environmental matters, low estimate					100,000,000
Unreserved loss contingencies related to environmental matters, high estimate					275,000,000
Portion of unreserved loss related to environmental matters					0.33
Number of sites																									3																				4				18		1
Litigation where PPG is a defendant, damages sought																																													The jury returned a verdict in the amount of $3.1 million against PPG, The Dow Chemical Company, Vulcan, Oxy, and R.R. Street. The verdict was not apportioned.
Estimate of possible loss from contingency																																													3,100,000	3,100,000	300,000			27,000,000
Litigation where PPG is a defendant, jury verdict																																																18,000,000
Reserve for product warranties			11,000,000		11,000,000			11,000,000
Outstanding letters of credit			121,000,000		121,000,000
Guarantees			$ 87,000,000		$ 87,000,000