Condensed Consolidated Statement of Shareholders' Equity (Unaudited) Statement - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive (Loss)/Income	Total PPG	Non-controlling Interests
Beginning balance at Dec. 31, 2020	$ 5,815	$ 969	$ 1,008	$ 19,469	$ (13,158)	$ (2,599)	$ 5,689	$ 126
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the controlling and noncontrolling interests	385			378			378	7
Other comprehensive loss, net of tax	(133)					(131)	(131)	(2)
Cash dividends	(128)			(128)			(128)
Issuance of treasury stock	35		25		10		35
Stock-based compensation activity	(4)		(4)				(4)
Reductions in noncontrolling interests	(1)							(1)
Ending balance at Mar. 31, 2021	5,969	969	1,029	19,719	(13,148)	(2,730)	5,839	130
Beginning balance at Dec. 31, 2021	6,411	969	1,081	20,372	(13,386)	(2,750)	6,286	125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the controlling and noncontrolling interests	23			18			18	5
Other comprehensive loss, net of tax	33					36	36	(3)
Cash dividends	(139)			(139)			(139)
Issuance of treasury stock	29		24		5		29
Stock-based compensation activity	(12)		(12)				(12)
Dividends paid on subsidiary common stock to noncontrolling interests	(1)							(1)
Reductions in noncontrolling interests	(11)							(11)
Ending balance at Mar. 31, 2022	$ 6,333	$ 969	$ 1,093	$ 20,251	$ (13,381)	$ (2,714)	$ 6,218	$ 115