Performance Share Payout

No definition available.

Name:	ppg_PerformanceSharePayout
Namespace Prefix:	ppg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share Based Compensation Arrangement by Share Based Payment Award, Target Award

+ References

No definition available.

+ Details

Name:	ppg_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetAward
Namespace Prefix:	ppg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share Based Compensation Arrangement by Share based Payment Award, Vesting Percentage

+ References

No definition available.

+ Details

Name:	ppg_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentage
Namespace Prefix:	ppg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of deferred tax expense from write-off of the deferred tax asset related to deductible stock options at exercise.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredTaxExpenseFromStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of noncash expense for share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

+ Details

Name:	us-gaap_ShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of modification of award under share-based payment arrangement. Includes, but is not limited to, terms for expiration date, vesting rights and exercise price.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDescriptionAndTerms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_StockCompensationPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation (Additional Information) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Description and Terms	The options are generally exercisable 36 months after being granted and have a maximum term of 10 years.
Shares available for future grants under the PPG Omnibus Plan	5.0
Stock-based compensation expense	$ 57	$ 44	$ 39
Total income tax benefit recognized related to the stock-based compensation	$ 12	$ 10	$ 9
Maximum term of the outstanding stock options for the PPG Omnibus Plan and the PPG Stock Plan for certain employees	10 years
Weighted average fair value of options granted (in dollars per share)	$ 29.27	$ 21.93	$ 22.50
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	36 months
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost that have not yet vested	$ 8
Cost not yet recognized, period for recognition	1 year 6 months
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost that have not yet vested	$ 24
Award vesting period	3 years
Cost not yet recognized, period for recognition	1 year 6 months
Restricted Stock Units (RSUs) \| Share-based Payment Arrangement, 2019-2021 Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is assumed to vest for the purposes of expense recognition	150.00%
Restricted Stock Units (RSUs) \| Share-based Payment Arrangement, 2020-2022 Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is assumed to vest for the purposes of expense recognition	133.00%
Restricted Stock Units (RSUs) \| Share-based Payment Arrangement, 2021-2023 Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is assumed to vest for the purposes of expense recognition	100.00%
Restricted Stock Units (RSUs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is paid based on performance	0.00%	0.00%	0.00%
Restricted Stock Units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is paid based on performance	200.00%	200.00%	180.00%
Contingent Share Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost that have not yet vested	$ 7
Award vesting period	3 years
Earned payout if the target performance is achieved	100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	92.80%
Cost not yet recognized, period for recognition	1 year 4 months 24 days
Contingent Share Grants \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is paid based on performance	0.00%	0.00%	0.00%
Contingent Share Grants \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the target award that is paid based on performance	200.00%	200.00%	220.00%