Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 342	$ 392	$ 669	$ 1,693
Other comprehensive (loss) income, net of tax:
Defined benefit pension and other postretirement benefits	6	14	74	25
Unrealized foreign currency translation adjustments	(27)	41	(299)	58
Derivative financial instruments, net	(2)	(3)	4	0
Other comprehensive (loss) income, net of tax	(23)	52	(221)	83
Total comprehensive income	319	444	448	1,776
Less: amounts attributable to noncontrolling interests:
Net income	(5)	(6)	(10)	(45)
Unrealized foreign currency translation adjustments	0	(3)	5	(4)
Comprehensive income attributable to PPG	$ 314	$ 435	$ 443	$ 1,727