Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 4,913	$ 5,069
Net income	$ 615	$ (179)	1,460	551
Other comprehensive income, net of tax	(2)	209	308	160
Cash dividends			(321)	(309)
Issuance of treasury stock			75	51
Purchase of treasury stock			(413)	(400)
Stock-based compensation activity			(2)	12
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders			5	4
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			(5)	(9)
Ending balance	6,010	5,121	6,010	5,121
Total PPG Shareholders' Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			4,826	4,983
Net income			1,444	533
Other comprehensive income, net of tax			293	161
Cash dividends			(321)	(309)
Issuance of treasury stock			75	51
Purchase of treasury stock			(413)	(400)
Stock-based compensation activity			(2)	12
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders			0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			0	0
Ending balance	5,902	5,031	5,902	5,031
Non-controlling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			87	86
Net income			16	18
Other comprehensive income, net of tax			15	(1)
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 Distributions to Noncontrolling Interest Holders			5	4
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			(5)	(9)
Ending balance	$ 108	$ 90	$ 108	$ 90