Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income attributable to controlling and noncontrolling interests	$ 100	$ 279	$ 348	$ 596
Other comprehensive income/(loss), net of tax:
Defined benefit pension and other postretirement benefits	5	12	6	6
Unrealized foreign currency translation adjustments	117	(15)	(589)	66
Derivative financial instruments	(3)	(1)	0	(1)
Other comprehensive income/(loss), net of tax	119	(4)	(583)	71
Total comprehensive income/(loss)	219	275	(235)	667
Less: amounts attributable to noncontrolling interests:
Net loss/(income)	2	(7)	(3)	(12)
Unrealized foreign currency translation adjustments	(2)	(2)	8	(1)
Comprehensive income/(loss) attributable to PPG	$ 219	$ 266	$ (230)	$ 654