Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 1,612	$ 899	$ 1,427
Unrealized foreign currency translation gains/(losses)	248	(476)	(717)
Defined benefit pension and other postretirement benefit adjustments	78	808	113
Unrealized (losses)/gains – derivative financial instruments	(10)	4	5
Other comprehensive income/(loss), net of tax	316	336	(599)
Total comprehensive income	1,928	1,235	828
Less: amounts attributable to noncontrolling interests:
Net income	(21)	(22)	(21)
Unrealized foreign currency translation (losses)/gains	(17)	10	13
Comprehensive income attributable to PPG	$ 1,890	$ 1,223	$ 820