Quarterly Financial Information - Quarterly Financial Information (unaudited) (As Restated) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Net sales	$ 3,682	$ 3,776	$ 3,804	$ 3,486	$ 3,417	$ 3,660	$ 3,782	$ 3,411	$ 7,290	$ 11,066	$ 14,748	$ 14,270	$ 14,241
Cost of sales, exclusive of depreciation and amortization	2,119	2,101	2,082	1,905	1,910	1,978	1,988	1,817	3,987	6,088	8,207	7,693	7,786
Continuing operations	148	393	497	331	87	(211)	339	328	828	1,221	1,369	543	1,311
Discontinued operations	3	217	(1)	6	253	27	31	19	5	222	225	330	95
Net income (loss) attributable to parent	$ 151	$ 610	$ 496	$ 337	$ 340	$ (184)	$ 370	$ 347	$ 833	$ 1,443	$ 1,594	$ 873	$ 1,406
Continuing operations (in dollars per share)	$ 0.59	$ 1.53	$ 1.93	$ 1.29	$ 0.34	$ (0.79)	$ 1.26	$ 1.23	$ 3.22	$ 4.75	$ 5.34	$ 2.05	$ 4.83
Discontinued operations (in dollars per share)	0.01	0.85	0.00	0.02	0.96	0.10	0.12	0.07	0.02	0.86	0.88	1.24	0.35
Net Income (attributable to PPG) (in dollars per share)	0.60	2.38	1.93	1.31	1.30	(0.69)	1.38	1.30	3.24	5.61	6.22	3.29	5.18
Continuing operations (in dollars per share)	0.58	1.52	1.92	1.28	0.33	(0.79)	1.25	1.22	3.19	4.72	5.31	2.04	4.79
Discontinued operations (in dollars per share)	0.01	0.84	0.00	0.02	0.96	0.10	0.12	0.07	0.02	0.86	0.87	1.23	0.35
Earnings per common share - assuming dilution (in dollars per share)	$ 0.59	$ 2.36	$ 1.92	$ 1.30	$ 1.29	$ (0.69)	$ 1.37	$ 1.29	$ 3.21	$ 5.58	$ 6.18	$ 3.27	$ 5.14