Earnings Per Common Share (Calculations) (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									0	0	0.6
Continuing operations	$ 254	$ 220	$ 341	$ 219	$ 191	$ 288	$ 297	$ (50)	$ 1,034	$ 726	$ 858
Discontinued operations	0	6	0	2,191	36	51	65	63	2,197	215	237
Continuing operations (in dollars per share)	$ 1.80	$ 1.54	$ 2.38	$ 1.50	$ 1.24	$ 1.88	$ 1.94	$ (0.33)	$ 7.21	$ 4.73	$ 5.45
Discontinued operations (in dollars per share)	$ 0.00	$ 0.04	$ 0.00	$ 14.99	$ 0.23	$ 0.33	$ 0.43	$ 0.41	$ 15.32	$ 1.40	$ 1.51
Earnings per common share (attributable to PPG)
Income from continuing operations, net of tax	254	226	341	2,410	227	339	362	13	3,231	941	1,095
Weighted average common shares outstanding									143.4	153.4	157.3
Earnings per common share (attributable to PPG):
Net Income (attributable to PPG) (in dollars per share)	$ 1.80	$ 1.58	$ 2.38	$ 16.49	$ 1.47	$ 2.21	$ 2.37	$ 0.08	$ 22.53	$ 6.13	$ 6.96
Earnings per common share - assuming dilution (attributable to PPG)
Income from continuing operations, net of tax	$ 254	$ 226	$ 341	$ 2,410	$ 227	$ 339	$ 362	$ 13	$ 3,231	$ 941	$ 1,095
Weighted average common shares outstanding									143.4	153.4	157.3
Effect of dilutive securities:
Stock options									0.8	0.8	1.1
Other stock compensation plans									0.9	0.9	0.9
Potentially dilutive common shares									1.7	1.7	2.0
Adjusted weighted average common shares outstanding									145.1	155.1	159.3
Continuing operations (in dollars per share)	$ 1.78	$ 1.52	$ 2.35	$ 1.48	$ 1.23	$ 1.86	$ 1.92	$ (0.32)	$ 7.13	$ 4.69	$ 5.40
Discontinued operations (in dollars per share)	$ 0.00	$ 0.04	$ 0.00	$ 14.83	$ 0.23	$ 0.32	$ 0.42	$ 0.40	$ 15.14	$ 1.37	$ 1.47
Earnings per common share - assuming dilution (attributable to PPG)
Net Income (attributable to PPG) (in dollars per share)	$ 1.78	$ 1.56	$ 2.35	$ 16.31	$ 1.46	$ 2.18	$ 2.34	$ 0.08	$ 22.27	$ 6.06	$ 6.87