Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 5,265	$ 5,198
Net income	$ 342	$ 392	669	1,693
Other comprehensive income, net of tax	(23)	52	(221)	83
Cash dividends			(189)	(177)
Issuance of treasury stock			65	52
Purchase of treasury stock			(351)	(300)
Stock-based compensation activity			23	24
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			(5)	(206)
Dividends paid on subsidiary common stock to noncontrolling interests				(46)
Ending balance	5,256	6,321	5,256	6,321
Total PPG Shareholders' Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			5,180	4,932
Net income			659	1,648
Other comprehensive income, net of tax			(216)	79
Cash dividends			(189)	(177)
Issuance of treasury stock			65	52
Purchase of treasury stock			(351)	(300)
Stock-based compensation activity			23	24
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			0	(26)
Dividends paid on subsidiary common stock to noncontrolling interests				0
Ending balance	5,171	6,232	5,171	6,232
Non-controlling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			85	266
Net income			10	45
Other comprehensive income, net of tax			(5)	4
Cash dividends			0	0
Issuance of treasury stock			0	0
Purchase of treasury stock			0	0
Stock-based compensation activity			0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			(5)	(180)
Dividends paid on subsidiary common stock to noncontrolling interests				(46)
Ending balance	$ 85	$ 89	$ 85	$ 89