Earnings Per Common Share (Additional Detail) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings per common share (attributable to PPG)
Income from continuing operations, net of tax	$ 1,344	$ 1,223	$ 1,007
(Loss)/income from discontinued operations, net of tax	(228)	47	19
Net income (attributable to PPG)	$ 1,116	$ 1,270	$ 1,026
Weighted average common shares outstanding	233.8	236.0	236.1
Effect of dilutive securities:
Stock options	0.4	0.5	0.5
Other stock compensation plans	0.7	0.7	0.7
Potentially dilutive common shares	1.1	1.2	1.2
Adjusted weighted average common shares outstanding	234.9	237.2	237.3
Earnings per common share (attributable to PPG)
Continuing operations (in dollars per share)	$ 5.75	$ 5.18	$ 4.26
Discontinued operations (in dollars per share)	(0.98)	0.20	0.08
Net Income (attributable to PPG) (in dollars per share)	4.77	5.38	4.34
Earnings per common share - assuming dilution (attributable to PPG)
Continuing operations (in dollars per share)	5.72	5.16	4.24
Discontinued operations (in dollars per share)	(0.97)	0.19	0.08
Earnings per common share - assuming dilution (in dollars per share)	$ 4.75	$ 5.35	$ 4.32
Outstanding stock options excluded from the computation of diluted earnings per share due to their antidilutive effect	1.3	0.9	0.9