Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2020
Operating activities:
Net income attributable to the controlling and noncontrolling interests	$ 339	$ 345	$ 385	$ 808	$ 1,163
Loss from discontinued operations, net of tax	0	0		(2)	0
Income from continuing operations	339	345		810	1,163
Adjustments to reconcile net income to cash from operations:
Depreciation and amortization				421	412
Pension income				(19)	(27)
Environmental remediation charges	0	0		0	26
Business restructuring, net	36	0		36	(21)
Impairment and other related charges, net	0	21		230	21
Stock-based compensation expense	9	4		27	39
Gain from sale of production facility		(34)		0	(34)
Equity affiliate income, net of dividends				15	6
Deferred income taxes				(129)	58
Cash used for restructuring actions				(63)	(60)
Change in certain asset and liability accounts (net of acquisitions):
Receivables				(644)	(376)
Inventories				(458)	(334)
Other current assets				(68)	24
Accounts payable and accrued liabilities				340	423
Taxes and interest payable				67	(52)
Noncurrent assets and liabilities, net				(41)	(74)
Other				(118)	(76)
Cash from operating activities				376	1,106
Investing activities:
Capital expenditures				(368)	(220)
Business acquisitions, net of cash balances acquired				(43)	(2,137)
Proceeds from asset sales				116	0
Proceeds from sale of production facility				0	47
Other				49	34
Cash used for investing activities				(246)	(2,276)
Financing activities:
Proceeds from commercial paper and short-term debt, net of payments				(439)	375
Proceeds from Term Loan Credit Agreement, net of fees				0	699
Repayment of Term Loan Credit Agreement				(100)	0
Repayment of term loan			(400)	0	(400)	$ (1,100)
Proceeds from the issuance of debt, net of discounts and fees				1,116	692
Repayment of long-term debt		170		3	173
Repayment of acquired debt				2	207
Purchase of treasury stock				(190)
Issuance of treasury stock				11	46
Dividends paid on PPG common stock				(424)	(396)
Payments related to tax withholding on stock-based compensation awards				(14)	(18)
Other				(11)	(12)
Cash (used for)/from financing activities				(56)	606
Effect of currency exchange rate changes on cash and cash equivalents				(50)	(46)
Net increase/(decrease) in cash and cash equivalents				24	(610)
Cash and cash equivalents, beginning of period			$ 1,826		1,826
Cash and cash equivalents, end of period	$ 1,029	$ 1,216		1,029	1,216	$ 1,826
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Interest paid, net of amount capitalized				119	110
Taxes paid, net of refunds				343	376
Capital expenditures accrued within Accounts payable and accrued liabilities at period-end				$ 76	$ 76