Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-K/A
Amendment Flag	true
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	PPG
Entity Registrant Name	PPG INDUSTRIES INC
Entity Central Index Key	0000079879
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		249,880,613
Entity Public Float			$ 28,173
Amendment Description	PPG is filing this Amendment No. 1 (this “Form 10-K/A”) to amend our Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission (the “SEC”) on February 15, 2018 (the “Original Filing”) to restate our audited consolidated financial statements for the years ended December 31, 2017 and 2016 and to amend related disclosures, including those regarding our disclosure controls and procedures. We have also restated certain unaudited quarterly results related to the quarters ended December 31, 2016, March 31, 2017, June 30, 2017, September 30, 2017 and December 31, 2017. This Form 10-K/A also amends certain other items in the Original Filing, as listed in “Items Amended in this Filing” in the Explanatory Note.