Employee Benefit Plans (Other Plans) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined contribution plan contribution rates as percentage of employee earnings	6.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Compensation expense related to the ESOP	$ 52	$ 49	$ 44
Deductible dividends on PPG shares held by the ESOP	11
Recognized expense for defined contribution pension plans	97	83	85
Expense (income) of the deferred compensation plan	25	23	23
Increase (Decrease) in fair value of investments	23	21	$ 24
Obligations under the deferred compensation plan	125	113
Investments in marketable securities by the deferred compensation plan	$ 94	$ 83
Minimum
Defined contribution plan contribution rates as percentage of employee earnings	2.00%
Maximum
Defined contribution plan contribution rates as percentage of employee earnings	5.00%

Deferred Compensation Arrangement with Individual, Compensation Expense (Income)

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- Definition

Deferred Compensation Arrangement with Individual, Increase (Decrease) in Fair Value of Investments

+ References

No definition available.

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- Definition

Deferred compensation plan - marketable securities

+ References

No definition available.

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- Definition

Company matching contribution percentage for Defined Contribution Plan.

+ References

No definition available.

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- Definition

The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 710
-SubTopic 10
-Name Accounting Standards Codification
-Section 30
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483043/710-10-30-1

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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

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- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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- Definition

The amount of plan compensation cost recognized during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480489/718-40-50-1

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- Definition

Dividends paid on stock held by an employee stock ownership plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480489/718-40-50-1

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