PPG's share of undistributed net earnings of equity affiliates.

No definition available.

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

Percentage Of Ownership Interests

+ References

No definition available.

+ Details

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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- Definition

Amount of principal loans outstanding to affiliates for management investment companies.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611322-123010

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column B

-Article 12

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Dividends received on equity and other investments during the current period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

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- Details

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- Details

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- Details

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- Details

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Investments (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 31, 2014
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Equity Method Investment, Ownership Percentage				40.00%
Equity In Undistributed Earnings Losses Of Subsidiaries	$ 171	$ 98
Proceeds from Dividends Received	5us-gaap_ProceedsFromDividendsReceived	9us-gaap_ProceedsFromDividendsReceived	12us-gaap_ProceedsFromDividendsReceived
Investments In Other Operating Joint Ventures [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Percentage Of Ownership Interests	50.00%
Pittsburgh Glass Works LLC
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Equity Method Investment, Ownership Percentage	40.00%
Investments in and Advances to Affiliates, Balance, Principal Amount	$ 94	$ 30
R S Cogen L L C [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Percentage Of Ownership Interests			50.00%