Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 1,269	$ 1,358	$ 1,615
Defined benefit pension and other postretirement benefit adjustments	(156)	9	78
Unrealized foreign currency translation adjustments	106	(155)	248
Derivative financial instruments	(1)	(1)	(10)
Other comprehensive (loss)/income, net of tax	(51)	(147)	316
Total comprehensive income	1,218	1,211	1,931
Less: amounts attributable to noncontrolling interests:
Net income	(26)	(17)	(21)
Unrealized foreign currency translation adjustments	1	11	(17)
Comprehensive income attributable to PPG	$ 1,193	$ 1,205	$ 1,893