Restatement of Previously Reported Condensed Consolidated Quarterly Financial Statements - Consolidated Statement of Income (unaudited) - Summary of Restatement (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net sales	$ 3,781	$ 3,486	$ 3,486
Selling, general and administrative	906	875	875
Other charges	41	25	25
Income before income taxes from continuing operations	421	446	446
Income tax expense	87	110	110
Income from continuing operations	334	336	336
Income from discontinued operations, net of tax	6	6	6
Net income attributable to the controlling and noncontrolling interests	340	342	342
Net income (loss) attributable to noncontrolling interest	6	5	(5)
Net income (attributable to PPG)	334	337	337
Income from continuing operations, net of tax	328	331	331
Income from discontinued operations, net of tax	$ 6	$ 6	$ 6
Income from continuing operations, net of tax (in usd per share)	$ 1.32	$ 1.29	$ 1.29
Income from discontinued operations, net of tax (in usd per share)	0.02	0.02	0.02
Net income (attributable to PPG) (in usd per share)	1.34	1.31	1.31
Income from continuing operations, net of tax (in usd per share)	1.31	1.28	1.28
Income from discontinued operations, net of tax (in usd per share)	0.02	0.02	0.02
Net income (attributable to PPG) (in usd per share)	$ 1.33	$ 1.30	1.30
Common stock, dividends, per share, declared			$ 0.40
Scenario, Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net sales			$ 3,486
Selling, general and administrative			881
Other charges			25
Income before income taxes from continuing operations			440
Income tax expense			107
Income from continuing operations			333
Income from discontinued operations, net of tax			6
Net income attributable to the controlling and noncontrolling interests			339
Net income (loss) attributable to noncontrolling interest			(5)
Net income (attributable to PPG)			334
Income from continuing operations, net of tax			328
Income from discontinued operations, net of tax			$ 6
Income from continuing operations, net of tax (in usd per share)			$ 1.28
Income from discontinued operations, net of tax (in usd per share)			0.02
Net income (attributable to PPG) (in usd per share)			1.30
Income from continuing operations, net of tax (in usd per share)			1.27
Income from discontinued operations, net of tax (in usd per share)			0.02
Net income (attributable to PPG) (in usd per share)			1.29
Common stock, dividends, per share, declared			$ 0.40
Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net sales			$ 0
Selling, general and administrative			(6)
Other charges			0
Income before income taxes from continuing operations			6
Income tax expense			3
Income from continuing operations			3
Income from discontinued operations, net of tax			0
Net income attributable to the controlling and noncontrolling interests			3
Net income (loss) attributable to noncontrolling interest			0
Net income (attributable to PPG)			3
Income from continuing operations, net of tax		$ (3)	3
Income from discontinued operations, net of tax			$ 0
Income from continuing operations, net of tax (in usd per share)			$ 0.01
Income from discontinued operations, net of tax (in usd per share)			0.00
Net income (attributable to PPG) (in usd per share)			0.01
Income from continuing operations, net of tax (in usd per share)		$ (0.01)	0.01
Income from discontinued operations, net of tax (in usd per share)			0.00
Net income (attributable to PPG) (in usd per share)			0.01
Common stock, dividends, per share, declared			$ 0.00