Condensed Consolidated Statement of Comprehensive Income/(Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income attributable to controlling and noncontrolling interests	$ 433	$ 100	$ 818	$ 348
Other comprehensive income/(loss), net of tax:
Defined benefit pension and other postretirement benefits	(2)	5	(7)	6
Unrealized foreign currency translation adjustments	67	117	(61)	(589)
Derivative financial instruments	0	(3)	0	0
Other comprehensive income/(loss), net of tax	65	119	(68)	(583)
Total comprehensive income/(loss)	498	219	750	(235)
Less: amounts attributable to noncontrolling interests:
Net income	(2)	2	(9)	(3)
Unrealized foreign currency translation adjustments	1	(2)	3	8
Comprehensive income/(loss) attributable to PPG	$ 497	$ 219	$ 744	$ (230)