Earnings Per Common Share (Calculations) (Detail) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares	Sep. 30, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Earnings per common share (attributable to PPG)
Continuing operations | $	$ 77	$ (201)	$ 351	$ 337	$ 295	$ 415	$ 319	$ 309	$ 564	$ 1,338	$ 1,085
Discontinued operations | $	267	17	19	10	19	18	18	13	313	68	1,017
Net income (attributable to PPG) | $	$ 344	$ (184)	$ 370	$ 347	$ 314	$ 433	$ 337	$ 322	$ 877	$ 1,406	$ 2,102
Weighted average common shares outstanding | shares									265,600,000	271,400,000	276,600,000
Effect of dilutive securities:
Stock options | shares									800,000	1,000,000	1,400,000
Other stock compensation plans | shares									1,000,000	1,200,000	1,600,000
Potentially dilutive common shares | shares									1,800,000	2,200,000	3,000,000
Adjusted weighted average common shares outstanding | shares									267,400,000	273,600,000	279,600,000
Earnings per common share (attributable to PPG):
Continuing operations (in dollars per share) | $ / shares	$ 0.29	$ (0.75)	$ 1.31	$ 1.26	$ 1.10	$ 1.53	$ 1.17	$ 1.13	$ 2.12	$ 4.93	$ 3.92
Discontinued operations (in dollars per share) | $ / shares	1.02	0.06	0.07	0.04	0.07	0.07	0.07	0.05	1.18	0.25	3.68
Net Income (attributable to PPG) (in dollars per share) | $ / shares	1.31	(0.69)	1.38	1.30	1.17	1.60	1.24	1.18	3.30	5.18	7.60
Earnings per common share - assuming dilution (attributable to PPG)
Continuing operations (in dollars per share) | $ / shares	0.29	(0.75)	1.30	1.25	1.09	1.52	1.16	1.12	2.11	4.89	3.88
Discontinued operations (in dollars per share) | $ / shares	1.01	0.06	0.07	0.04	0.07	0.07	0.07	0.05	1.17	0.25	3.64
Net Income (attributable to PPG) (in dollars per share) | $ / shares	$ 1.30	$ (0.69)	$ 1.37	$ 1.29	$ 1.16	$ 1.59	$ 1.23	$ 1.17	$ 3.28	$ 5.14	$ 7.52
Outstanding stock options excluded from the computation of diluted earnings per share due to their antidilutive effect | shares									600,000.0	600,000.0	0
Stockholders' Equity Note, Stock Split, Conversion Ratio									2