Earnings Per Common Share (Calculations) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0
Income from continuing operations, net of tax	$ 277	$ 191
Net income from discontinued operations (attributable to PPG)	985	2,219
Earnings per common share (attributable to PPG)
Net income (attributable to PPG)	1,262	2,410
Weighted average common shares outstanding	139,100,000	146,100,000
Earnings per common share (attributable to PPG)	$ 9.07	$ 16.49
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.99	$ 1.31
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$ 7.08	$ 15.18
Earnings per common share - assuming dilution (attributable to PPG)
Net income (attributable to PPG)	$ 1,262	$ 2,410
Weighted average common shares outstanding	139,100,000	146,100,000
Effect of dilutive securities:
Stock options	800,000	900,000
Other stock compensation plans	800,000	700,000
Potentially dilutive common shares	1,600,000	1,600,000
Adjusted weighted average common shares outstanding	140,700,000	147,700,000
Income from continuing operations, net of tax	$ 1.97	$ 1.29
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share	$ 7.00	$ 15.02
Earnings per common share - assuming dilution (attributable to PPG)	$ 8.97	$ 16.31