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, 2023	$ 8,023	$ 969	$ 1,202	$ 21,500	$ (13,600)	$ (2,239)	$ 7,832	$ 191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	409			400			400	9
Other comprehensive income/(loss), net of tax	(14)					(12)	(12)	(2)
Cash dividends	(153)			(153)			(153)
Purchase of treasury stock	(152)				(152)		(152)
Issuance of treasury stock	37		31		6		37
Stock-based compensation activity	(11)		(11)				(11)
Dividends paid on subsidiary common stock to noncontrolling interests	(2)							(2)
Reductions in noncontrolling interests	(11)							(11)
Ending balance at Mar. 31, 2024	8,126	969	1,222	21,747	(13,746)	(2,251)	7,941	185
Beginning balance at Dec. 31, 2023	8,023	969	1,202	21,500	(13,600)	(2,239)	7,832	191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	1,420
Other comprehensive income/(loss), net of tax	(544)
Ending balance at Sep. 30, 2024	7,972	969	1,258	22,432	(14,091)	(2,780)	7,788	184
Beginning balance at Mar. 31, 2024	8,126	969	1,222	21,747	(13,746)	(2,251)	7,941	185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	537			528			528	9
Other comprehensive income/(loss), net of tax	(414)					(412)	(412)	(2)
Cash dividends	(152)			(152)			(152)
Purchase of treasury stock	(152)				(152)		(152)
Issuance of treasury stock	4		3		1		4
Stock-based compensation activity	10		10				10
Dividends paid on subsidiary common stock to noncontrolling interests	(13)							(13)
Other	1							1
Ending balance at Jun. 30, 2024	7,945	969	1,235	22,123	(13,897)	(2,663)	7,767	178
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	474			468			468	6
Other comprehensive income/(loss), net of tax	(116)					(117)	(117)	1
Cash dividends	(159)			(159)			(159)
Purchase of treasury stock	(202)				(202)		(202)
Issuance of treasury stock	19		11		8		19
Stock-based compensation activity	12		12				12
Dividends paid on subsidiary common stock to noncontrolling interests	(1)							(1)
Ending balance at Sep. 30, 2024	7,972	969	1,258	22,432	(14,091)	(2,780)	7,788	184
Beginning balance at Dec. 31, 2024	6,962	969	1,272	21,994	(14,342)	(3,108)	6,785	177
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	378			373			373	5
Other comprehensive income/(loss), net of tax	276					275	275	1
Cash dividends	(154)			(154)			(154)
Purchase of treasury stock	(385)				(385)		(385)
Issuance of treasury stock	37		29		8		37
Stock-based compensation activity	(4)		(4)				(4)
Dividends paid on subsidiary common stock to noncontrolling interests	(3)							(3)
Reductions in noncontrolling interests	(15)							(15)
Ending balance at Mar. 31, 2025	7,092	969	1,297	22,213	(14,719)	(2,833)	6,927	165
Beginning balance at Dec. 31, 2024	6,962	969	1,272	21,994	(14,342)	(3,108)	6,785	177
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	1,283
Other comprehensive income/(loss), net of tax	846
Ending balance at Sep. 30, 2025	7,956	969	1,312	22,802	(15,019)	(2,264)	7,800	156
Beginning balance at Mar. 31, 2025	7,092	969	1,297	22,213	(14,719)	(2,833)	6,927	165
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	458			450			450	8
Other comprehensive income/(loss), net of tax	496					491	491	5
Cash dividends	(154)			(154)			(154)
Purchase of treasury stock	(151)				(151)		(151)
Issuance of treasury stock	5		4		1		5
Stock-based compensation activity	9		9				9
Dividends paid on subsidiary common stock to noncontrolling interests	(11)							(11)
Ending balance at Jun. 30, 2025	7,744	969	1,310	22,509	(14,869)	(2,342)	7,577	167
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss) attributable to the controlling and noncontrolling interests	447			453			453	(6)
Other comprehensive income/(loss), net of tax	74					78	78	(4)
Cash dividends	(160)			(160)			(160)
Purchase of treasury stock	(152)				(152)		(152)
Issuance of treasury stock	5		3		2		5
Stock-based compensation activity	(1)		(1)				(1)
Dividends paid on subsidiary common stock to noncontrolling interests	(1)							(1)
Ending balance at Sep. 30, 2025	$ 7,956	$ 969	$ 1,312	$ 22,802	$ (15,019)	$ (2,264)	$ 7,800	$ 156