Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income attributable to controlling and noncontrolling interests	$ 248	$ 317
Other comprehensive (loss)/income, net of tax:
Defined benefit pension and other postretirement benefits	1	(6)
Unrealized foreign currency translation adjustments	(706)	81
Derivative financial instruments	3	0
Other comprehensive (loss)/income, net of tax	(702)	75
Total comprehensive (loss)/income	(454)	392
Less: amounts attributable to noncontrolling interests:
Net income	(5)	(5)
Unrealized foreign currency translation adjustments	10	1
Comprehensive (loss)/income attributable to PPG	$ (449)	$ 388