Discontinued Operations (Net sales and earnings from discontinued operations) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from operations					$ 0
Net gain from separation and merger of commodity chemicals business		1,468
Income from discontinued operations, net of tax	(6)		48	1,005	2,343
Less: Net income attributable to non-controlling interests, discontinued operations	6		29	51	94
Net income from discontinued operations (attributable to PPG)	(6)		22	972	2,264
Commodity Chemicals Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales					108
Net gain from separation and merger of commodity chemicals business					2,192
Income tax expense					5
Income from discontinued operations, net of tax					2,197
Less: Net income attributable to non-controlling interests, discontinued operations					0
Net income from discontinued operations (attributable to PPG)					2,197
Transitions Optical Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	0		206	247	649
Income from operations	0		62	104	206
Net gain from separation and merger of commodity chemicals business	0		0	1,468	0
Income tax expense	(6)		(20)	(567)	(60)
Income from discontinued operations, net of tax	(6)		42	1,005	146
Less: Net income attributable to non-controlling interests, discontinued operations	0		(26)	(33)	(79)
Net income from discontinued operations (attributable to PPG)	$ (6)		$ 16	$ 972	$ 67