Consolidated Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 2,159us-gaap_ProfitLoss	$ 3,353us-gaap_ProfitLoss	$ 1,064us-gaap_ProfitLoss
Other comprehensive income / (loss), net of tax
Unrealized foreign currency translation adjustment	(596)	(51)	146
Defined benefit pension and other postretirement benefit adjustments	(335)	440
Net change – derivative financial instruments	69	10	(7)
Other comprehensive (loss) / income, net of tax	(862)	399	139
Total comprehensive income	1,297	3,752	1,203
Less: amounts attributable to noncontrolling interests:
Net income	(57)	(122)	(123)
Unrealized foreign currency translation adjustment	6	7	(5)
Comprehensive income attributable to PPG	$ 1,246us-gaap_ComprehensiveIncomeNetOfTax	$ 3,637us-gaap_ComprehensiveIncomeNetOfTax	$ 1,075us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to noncontrolling interests.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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