Commitments and Contingent Liabilities (Impact of PPG Settlement Arrangement Including Change in Fair Value of Stock to be Transferred) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Change in fair value:
PPG stock	$ (8)	$ 5
Equity forward instrument	7	(6)
Accretion of asbestos liability	4us-gaap_AccretionExpense	4us-gaap_AccretionExpense
Asbestos settlement - net expense	$ 3ppg_LitigationExpense	$ 3ppg_LitigationExpense

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Fair value of the PPG stock to be contributed to the Asbestos Trust.

+ References

No definition available.

+ Details

Name:	ppg_CompanyStockToBeContributedToAsbestosTrust
Namespace Prefix:	ppg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Forward Contract Indexed to Issuers Equity, Change In Fair Value Of Contract

+ References

No definition available.

+ Details

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Namespace Prefix:	ppg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

This element represents the expenses incurred by the entity which are directly related to litigation reserves or settlements.

+ References

No definition available.

+ Details

Name:	ppg_LitigationExpense
Namespace Prefix:	ppg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6394232&loc=d3e17558-110866

+ Details

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Balance Type:	debit
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