Condensed Consolidated Statement of Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 3,685	$ 3,826	$ 10,077	$ 11,474
Cost of sales, exclusive of depreciation and amortization	2,026	2,181	5,637	6,542
Selling, general and administrative	836	887	2,507	2,710
Depreciation	96	99	280	276
Amortization	36	34	104	101
Research and development, net	92	107	279	323
Interest expense	34	33	107	99
Interest income	(4)	(10)	(18)	(23)
Business restructuring, net	0	2	172	175
Other charges	21	26	45	69
Other income	(24)	(14)	(53)	(61)
Income before income taxes	572	481	1,017	1,263
Income tax expense	124	109	224	297
Income from continuing operations	448	372	793	966
Income from discontinued operations, net of tax	0	1	3	3
Net income attributable to controlling and noncontrolling interests	448	373	796	969
Net income attributable to noncontrolling interests	6	6	9	18
Net income (attributable to PPG)	442	367	787	951
Income from continuing operations, net of tax	442	366	784	948
Income from discontinued operations, net of tax	$ 0	$ 1	$ 3	$ 3
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.87	$ 1.55	$ 3.32	$ 4.00
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0	0	0.01	0.01
Earnings Per Share, Basic	1.87	1.55	3.33	4.01
Income (Loss) from Continuing Operations, Per Diluted Share	1.86	1.54	3.30	3.98
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0	0	0.01	0.01
Earnings Per Share, Diluted	$ 1.86	$ 1.54	$ 3.31	$ 3.99