Number of Reportable Business Segments

No definition available.

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- Definition

The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

+ References

+ 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

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

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- Definition

The amount of pension and other (such as medical, dental and life insurance) postretirement benefit costs recognized during the period for (1) defined benefit plans (periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss) on assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments) and for (2) defined contribution plans (to the extent that a plan's defined contributions to an individual's account are to be made for periods in which that individual renders services, the net cost for a period is the contribution called for in that period; if a plan calls for contributions for periods after an individual retires or terminates, the estimated cost is accrued during the employee's service period).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

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- Details

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- Details

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- Details

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Reportable Business Segment Information (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2014 Segment	Dec. 31, 2013 Segment	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2012	Jul. 31, 2014	Mar. 31, 2014
Segment Reporting Information [Line Items]
Environmental Remediation Expense	$ 144us-gaap_EnvironmentalRemediationExpense	$ 108us-gaap_EnvironmentalRemediationExpense	$ 166us-gaap_EnvironmentalRemediationExpense
Number of PPG operating segments	11us-gaap_NumberOfOperatingSegments
Number of PPG reportable business segments, based on economic similarities, the nature of their products, production processes, end-use markets and methods of distribution	3ppg_NumberOfReportableBusinessSegments	5ppg_NumberOfReportableBusinessSegments
PPG percent ownership interest							40.00%
Pittsburgh Glass Works LLC
Segment Reporting Information [Line Items]
PPG percent ownership interest	40.00%	40.00%	40.00%
Costs related to the pension and other postemployment benefit liabilities of the divested business retained by PPG	19	30	35
Legacy Chemical Sites [Member] [Domain]
Segment Reporting Information [Line Items]
Environmental Remediation Expense	138	101	159
Jersey City Manufacturing Plant
Segment Reporting Information [Line Items]
Environmental Remediation Expense	$ 136	$ 89	$ 145	$ 136	$ 89	$ 145
Sunlens Optical Business
Segment Reporting Information [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent								100.00%
Transitions Optical Business
Segment Reporting Information [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent								51.00%