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	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, 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	818
Other comprehensive loss, net of tax	(68)
Ending balance at Jun. 30, 2021	6,411	969	1,053	20,022	(13,138)	(2,664)	6,242	169
Beginning balance at Mar. 31, 2021	5,969	969	1,029	19,719	(13,148)	(2,730)	5,839	130
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the controlling and noncontrolling interests	433			431			431	2
Other comprehensive loss, net of tax	65					66	66	(1)
Cash dividends	(128)			(128)			(128)
Issuance of treasury stock	27		17		10		27
Stock-based compensation activity	7		7				7
Dividends paid on subsidiary common stock to noncontrolling interests	(4)							(4)
Reductions in noncontrolling interests	(11)							(11)
Ending balance at Jun. 30, 2021	6,411	969	1,053	20,022	(13,138)	(2,664)	6,242	169
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling Interest, Increase from Business Combination	53							53
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
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	469
Other comprehensive loss, net of tax	(181)
Ending balance at Jun. 30, 2022	6,291	969	1,111	20,552	(13,528)	(2,922)	6,182	109
Beginning balance at Mar. 31, 2022	6,333	969	1,093	20,251	(13,381)	(2,714)	6,218	115
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the controlling and noncontrolling interests	446			441			441	5
Other comprehensive loss, net of tax	(214)					(208)	(208)	(6)
Cash dividends	(140)			(140)			(140)
Treasury Stock, Value, Acquired, Cost Method					(150)		(150)
Issuance of treasury stock	9		6		3		9
Stock-based compensation activity	9		9				9
Dividends paid on subsidiary common stock to noncontrolling interests	(6)							(6)
Stockholders' Equity, Other							3	1
Ending balance at Jun. 30, 2022	6,291	$ 969	$ 1,111	$ 20,552	$ (13,528)	$ (2,922)	$ 6,182	$ 109
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling Interest, Increase from Business Combination	$ 4