Consolidated Statement of Cash Flows - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income attributable to the controlling and noncontrolling interests	$ 1,460	$ 1,074	$ 1,269
Income from discontinued operations, net of tax	19	3	0
Income from continuing operations	1,441	1,071	1,269
Adjustments to reconcile net income to cash from operations:
Depreciation and amortization	561	509	511
Pension (income)/expense	(36)	43	54
Pension settlement charge and pension curtailment charge	50	13	0
Asbestos-related claims reserve adjustment	(133)	0	12
Business restructuring, net	31	174	176
Impairment charges	21	93	0
Environmental remediation charges and other costs, net	35	26	61
Stock-based compensation expense	57	44	39
Gain from sale of production facility	(34)	0	0
Deferred income taxes	35	(47)	(5)
Cash contributions to pension plans	(10)	(17)	(13)
Cash used for restructuring actions	(77)	(126)	(58)
Change in certain asset and liability accounts (net of acquisitions):
Receivables	(63)	187	121
Inventories	(279)	111	145
Other current assets	32	49	(95)
Accounts payable and accrued liabilities	295	127	(63)
Noncurrent assets and liabilities, net	(109)	(25)	(25)
Taxes and interest payable	(64)	(108)	(32)
Other	(191)	5	(13)
Cash from operating activities - continuing operations	1,562	2,129	2,084
Cash from/(used for) operating activities - discontinued operations	0	1	(4)
Cash from operating activities	1,562	2,130	2,080
Investing activities
Capital expenditures	(371)	(304)	(413)
Business acquisitions, net of cash balances acquired	(2,137)	(1,169)	(643)
Proceeds from sale of production facility	47	0	0
Other	57	26	47
Cash used for investing activities	(2,404)	(1,447)	(1,009)
Financing activities
Proceeds from Term Loan Credit Agreement, net of fees	1,399	0	0
Proceeds on commercial paper and short-term debt, net of payments	190	1,647	100
Repayment of Term Loan	(400)	(1,100)	0
Proceeds from revolving credit facility	0	800	0
Repayment of revolving credit facility	0	(800)	0
Proceeds from the issuance of debt, net of discounts and fees	692	415	595
Repayment of long-term debt	(850)	(504)	(637)
Repayment of acquired debt	(207)	(13)	(23)
Payments related to tax withholding on stock-based compensation awards	(19)	(17)	(20)
Purchase of treasury stock	(210)	0	(325)
Issuance of treasury stock	47	54	61
Dividends paid on PPG common stock	(536)	(496)	(468)
Purchase of noncontrolling interest	0	0	(39)
Other	(13)	(45)	(2)
Cash from/(used for) financing activities	93	(59)	(758)
Effect of currency exchange rate changes on cash and cash equivalents	(72)	6	1
Cash reclassified to assets held for sale	0	(20)	0
Net (decrease)/increase in cash and cash equivalents	(821)	610	314
Cash and cash equivalents, beginning of year	1,826	1,216	902
Cash and cash equivalents, end of year	1,005	1,826	1,216
Supplemental disclosures of cash flow information:
Interest paid, net of amount capitalized	140	153	127
Taxes paid, net of refunds	491	367	348
Capital expenditures accrued within Accounts payable and accrued liabilities at year-end	163	37	53
Purchases of treasury stock transacted but not yet settled	$ 40	$ 0	$ 0
Reissuance of common stock for business acquisition	0	0	164