Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 340	$ 342
Other comprehensive income, net of tax:
Defined benefit pension and other postretirement benefits	(67)	21
Unrealized foreign currency translation adjustments	123	279
Derivative financial instruments	(2)	(13)
Other comprehensive income, net of tax	54	287
Total comprehensive income	394	629
Less: amounts attributable to noncontrolling interests:
Net income	(6)	(5)
Unrealized foreign currency translation adjustments	(2)	(7)
Comprehensive income attributable to PPG	$ 386	$ 617