Consolidated Statement of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales	$ 16,802	$ 13,834	$ 15,146
Cost of sales, exclusive of depreciation and amortization	10,286	7,777	8,653
Selling, general and administrative	3,780	3,389	3,604
Depreciation	389	371	375
Amortization	172	138	136
Research and development, net	439	379	432
Interest expense	121	138	132
Interest income	(26)	(23)	(32)
Pension settlement charge	50	0	0
Asbestos-related claims reserve adjustment	(133)	0	12
Impairment charges	21	93	0
Business restructuring, net	31	174	176
Other charges	29	104	86
Other income	(172)	(68)	(89)
Income before income taxes	1,815	1,362	1,661
Income tax expense	374	291	392
Income from continuing operations	1,441	1,071	1,269
Income from discontinued operations, net of tax	19	3	0
Net income attributable to the controlling and noncontrolling interests	1,460	1,074	1,269
Less: Net income attributable to noncontrolling interests	21	15	26
Net income (attributable to PPG)	1,439	1,059	1,243
Income from continuing operations, net of tax	1,420	1,056	1,243
Income from discontinued operations, net of tax	$ 19	$ 3	$ 0
Earnings per common share
Continuing operations (in dollars per share)	$ 5.98	$ 4.46	$ 5.25
Discontinued operations (in dollars per share)	0.08	0.01	0
Net Income (attributable to PPG) (in dollars per share)	6.06	4.47	5.25
Earnings per common share - assuming dilution
Continuing operations (in dollars per share)	5.93	4.44	5.22
Discontinued operations (in dollars per share)	0.08	0.01	0
Net Income (attributable to PPG) (in dollars per share)	$ 6.01	$ 4.45	$ 5.22