Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to controlling and noncontrolling interests	$ 317	$ 340
Other comprehensive (loss) income, net of tax:
Defined benefit pension and other postretirement benefits	(6)	17
Unrealized foreign currency translation adjustments	81	146
Derivative financial instruments	0	(2)
Other comprehensive income, net of tax	75	161
Total comprehensive income	392	501
Less: amounts attributable to noncontrolling interests:
Net income	(5)	(6)
Unrealized foreign currency translation adjustments	1	(2)
Comprehensive income attributable to PPG	$ 388	$ 493