Consolidated Statement of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 15,146	$ 15,374	$ 14,748
Cost of sales, exclusive of depreciation and amortization	8,653	9,001	8,209
Selling, general and administrative	3,604	3,573	3,554
Depreciation	375	354	331
Amortization	136	143	129
Research and development, net	432	441	451
Interest expense	132	118	105
Interest income	(32)	(23)	(20)
Business restructuring, net	176	66	0
Pension settlement charges	0	0	60
Other charges	98	122	74
Other income	(89)	(114)	(150)
Income before income taxes	1,661	1,693	2,005
Income tax expense	392	353	615
Income from continuing operations	1,269	1,340	1,390
Income from discontinued operations, net of tax	0	18	225
Net income attributable to the controlling and noncontrolling interests	1,269	1,358	1,615
Less: Net income attributable to noncontrolling interests	26	17	21
Net income (attributable to PPG)	1,243	1,341	1,594
Income from continuing operations, net of tax	1,243	1,323	1,369
Income from discontinued operations, net of tax	$ 0	$ 18	$ 225
Earnings per common share
Continuing operations (in dollars per share)	$ 5.25	$ 5.43	$ 5.34
Discontinued operations (in dollars per share)	0	0.07	0.88
Net Income (attributable to PPG) (in dollars per share)	5.25	5.50	6.22
Earnings per common share - assuming dilution
Continuing operations (in dollars per share)	5.22	5.40	5.31
Discontinued operations (in dollars per share)	0	0.07	0.87
Net Income (attributable to PPG) (in dollars per share)	$ 5.22	$ 5.47	$ 6.18