| Cover | Oct. 19, 2020 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 19, 2020 |
| Entity Registrant Name | PPG INDUSTRIES, INC. |
| Entity Incorporation, State or Country Code | PA |
| Entity File Number | 001-1687 |
| Entity Tax Identification Number | 25-0730780 |
| Entity Address, Address Line One | One PPG Place |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15272 |
| City Area Code | 412 |
| Local Phone Number | 434-3131 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000079879 |
| Amendment Flag | false |
| Common Stock | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $1.66 2/3 |
| Trading Symbol | PPG |
| Security Exchange Name | NYSE |
| 0.875% Notes due 2022 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 0.875% Notes due 2022 |
| Trading Symbol | PPG 22 |
| Security Exchange Name | NYSE |
| 0.875% Notes due 2025 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 0.875% Notes due 2025 |
| Trading Symbol | PPG 25 |
| Security Exchange Name | NYSE |
| 1.400% Notes due 2027 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 1.400% Notes due 2027 |
| Trading Symbol | PPG 27 |
| Security Exchange Name | NYSE |
