Shareholders' Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 4,322	$ 5,198	$ 4,322
Net income	377	255		2,070	3,071
Other comprehensive income, net of tax	(272)	173		(189)	189
Cash dividends				(269)	(259)
Issuance of treasury stock				64	74
Purchase of treasury stock			(1,561)	(450)	(320)
Stock-based compensation activity				40	40
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				(211)	(17)
Dividends paid on subsidiary common stock to noncontrolling interests				(48)	(58)
Ending balance	6,205	5,481		6,205	5,481
Total PPG Shareholders' Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			4,063	4,932	4,063
Net income				2,019	2,977
Other comprehensive income, net of tax				(187)	197
Cash dividends				(269)	(259)
Issuance of treasury stock				64	74
Purchase of treasury stock			(1,561)	(450)	(320)
Stock-based compensation activity				40	40
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				(28)	0
Dividends paid on subsidiary common stock to noncontrolling interests				0	0
Ending balance	6,121	5,211		6,121	5,211
Non-controlling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			259	266	259
Net income				51	94
Other comprehensive income, net of tax				(2)	(8)
Cash dividends				0	0
Issuance of treasury stock				0	0
Purchase of treasury stock			0	0	0
Stock-based compensation activity				0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				(183)	(17)
Dividends paid on subsidiary common stock to noncontrolling interests				(48)	(58)
Ending balance	$ 84	$ 270		$ 84	$ 270