Condensed Consolidated Statement of Comprehensive Income/(Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Statement of Comprehensive Income [Abstract]
Net income/(loss) attributable to the controlling and noncontrolling interests	$ 447	$ 474	$ 1,283	$ 1,420
Other comprehensive income/(loss), net of tax:
Defined benefit pension and other postretirement benefits	2	(3)	(5)	17
Unrealized foreign currency translation adjustments	72	(113)	851	(561)
Other comprehensive income/(loss), net of tax	74	(116)	846	(544)
Total comprehensive income	521	358	2,129	876
Less: amounts attributable to noncontrolling interests:
Net loss/(income)	6	(6)	(7)	(24)
Unrealized foreign currency translation adjustments	4	(1)	(2)	3
Comprehensive income attributable to PPG	$ 531	$ 351	$ 2,120	$ 855