Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to controlling and noncontrolling interests	$ 279	$ 375	$ 596	$ 715
Other comprehensive (loss) income, net of tax:
Defined benefit pension and other postretirement benefits	12	15	6	32
Unrealized foreign currency translation adjustments	(15)	(297)	66	(151)
Derivative financial instruments	(1)	2	(1)	0
Other comprehensive (loss) income, net of tax	(4)	(280)	71	(119)
Total comprehensive income	275	95	667	596
Less: amounts attributable to noncontrolling interests:
Net income	(7)	(4)	(12)	(10)
Unrealized foreign currency translation adjustments	(2)	10	(1)	8
Comprehensive income attributable to PPG	$ 266	$ 101	$ 654	$ 594