Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2020
Operating activities:
Net income attributable to the controlling and noncontrolling interests	$ 446	$ 433	$ 385	$ 469	$ 818
Loss from discontinued operations, net of tax	(2)	0		(2)	0
Income from continuing operations	448	433		471	818
Adjustments to reconcile net income to cash from operations:
Depreciation and amortization				286	266
Pension income				(13)	(19)
Environmental remediation charges	0	10		0	26
Business restructuring, net	0	(21)		0	(21)
Impairment and other related charges, net	(60)	0		230	0
Stock-based compensation expense	12	18		18	35
Equity affiliate income, net of dividends				10	2
Deferred income taxes				(95)	61
Cash used for restructuring actions				(52)	(48)
Change in certain asset and liability accounts (net of acquisitions):
Receivables				(792)	(480)
Inventories				(437)	(280)
Other current assets				(83)	8
Accounts payable and accrued liabilities				417	392
Taxes and interest payable				33	(60)
Noncurrent assets and liabilities, net				(25)	(53)
Other				(84)	(62)
Cash (used for)/from operating activities				(136)	581
Investing activities:
Capital expenditures				(264)	(142)
Business acquisitions, net of cash balances acquired				(43)	(2,126)
Proceeds from Sales of Assets, Investing Activities				116	0
Other				41	26
Cash used for investing activities				(150)	(2,242)
Financing activities:
Proceeds from Term Loan Credit Agreement, net of fees				0	699
Proceeds from commercial paper and short-term debt, net of payments				(440)	561
Repayment of term loan			(400)	0	(400)	$ (1,100)
Proceeds from the issuance of debt, net of discounts and fees				1,116	692
Repayments of Debt		170		2	172
Repayment of acquired debt				2	86
Purchase of treasury stock				(175)
Issuance of treasury stock				11	44
Dividends paid on PPG common stock				(279)	(256)
Payments related to tax withholding on stock-based compensation awards				(13)	(17)
Other				(3)	(11)
Cash from financing activities				213	1,054
Effect of currency exchange rate changes on cash and cash equivalents				(1)	(24)
Net decrease in cash and cash equivalents				(74)	(631)
Cash and cash equivalents, beginning of period			$ 1,826		1,826
Cash and cash equivalents, end of period	$ 931	$ 1,195		931	1,195	$ 1,826
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Interest paid, net of amount capitalized				69	69
Taxes paid, net of refunds				214	276
Capital expenditures accrued within Accounts payable and accrued liabilities at period-end				51	94
Purchases of treasury stock transacted but not yet settled				$ 15	$ 0