Reportable Segment Information (Segment Net Sales and Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended					9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2012		Mar. 31, 2012	Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012 Performance Coatings Segment [Member]	Sep. 30, 2011 Performance Coatings Segment [Member]	Sep. 30, 2012 Performance Coatings Segment [Member]	Sep. 30, 2011 Performance Coatings Segment [Member]	Sep. 30, 2012 Industrial Coatings Segment [Member]	Sep. 30, 2011 Industrial Coatings Segment [Member]	Sep. 30, 2012 Industrial Coatings Segment [Member]	Sep. 30, 2011 Industrial Coatings Segment [Member]	Sep. 30, 2012 Architectural Coatings - EMEA [Member]	Sep. 30, 2011 Architectural Coatings - EMEA [Member]	Sep. 30, 2012 Architectural Coatings - EMEA [Member]	Sep. 30, 2011 Architectural Coatings - EMEA [Member]	Sep. 30, 2012 Optical and Specialty Materials Segment [Member]	Sep. 30, 2011 Optical and Specialty Materials Segment [Member]	Sep. 30, 2012 Optical and Specialty Materials Segment [Member]	Sep. 30, 2011 Optical and Specialty Materials Segment [Member]	Sep. 30, 2012 Commodity Chemicals Segment [Member]	Sep. 30, 2011 Commodity Chemicals Segment [Member]	Sep. 30, 2012 Commodity Chemicals Segment [Member]	Sep. 30, 2011 Commodity Chemicals Segment [Member]	Jul. 19, 2012 Commodity Chemicals Segment [Member]	Sep. 30, 2012 Glass Segment [Member]	Sep. 30, 2011 Glass Segment [Member]	Sep. 30, 2012 Glass Segment [Member]	Sep. 30, 2011 Glass Segment [Member]	Sep. 30, 2012 Segment, Discontinued Operations [Member]	Sep. 30, 2012 Corporate [Member]	Mar. 31, 2012 Jersey City Manufacturing Plant [Member]	Sep. 30, 2006 Jersey City Manufacturing Plant [Member]	Sep. 30, 2012 Jersey City Manufacturing Plant [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 3,845	[1]		$ 3,849	[1]	$ 11,552	[1]	$ 11,368	[1]	$ 1,210	$ 1,208	$ 3,601	$ 3,490	$ 1,090	$ 1,039	$ 3,265	$ 3,139	$ 564	$ 573	$ 1,682	$ 1,655	$ 282	$ 311	$ 930	$ 945	$ 437	$ 445	$ 1,283	$ 1,334		$ 262	$ 273	$ 791	$ 805
Segment income (loss)	606			564		1,784		1,638		203	190	567	533	153	101	446	332	56	53	136	115	76	93	280	273	94	104	300	307		24	23	55	78
Legacy items	(14)	[2]		(15)	[2]	(204)	[2]	(52)	[2]
Business restructuring	0		(208)	0		(208)	[3]	0				(65)				(46)				(63)				(32)				(1)								(1)
Acquisition-related (costs) gain, net				0	[4]	(6)	[4]	9	[4]
Transaction expenses related to Separation and merger transaction	(9)	[5]				(13)	[5]																			(9)		(13)
Interest expense, net of interest income	(44)			(40)		(126)		(127)
Other unallocated corporate expense - net	(53)			(47)		(163)		(155)
Income before income taxes	486			462		1,064		1,313
PPG percent ownership interest																														50.50%					40.00%
Environmental remediation costs						$ 159		$ 0																													$ 145	$ 165	$ 159

[1] Intersegment net sales for the three and nine months ended September 30, 2012 and 2011 were not material.

[2] Legacy items include current costs related to former operations of the Company, including pension and other postretirement benefit costs, certain charges for legal matters and environmental remediation costs, and certain charges which are considered to be unusual or non-recurring including the earnings impact of the proposed asbestos settlement. Legacy items also include equity earnings from PPG’s approximate 40 percent investment in the former automotive glass and services business. The expense for the nine months ended September 30, 2012 includes a nonrecurring environmental remediation pretax charge of $159 million. The charge relates to continued environmental remediation activities at legacy chemicals sites, primarily at PPG’s former Jersey City, N.J. chromium manufacturing plant and associated sites.

[3] The charge for business restructuring costs in the nine months ended September 30, 2012, includes charges of $65 million related to the Performance Coatings segment, $46 million related to the Industrial Coatings segment, $63 million related to the Architectural Coatings - EMEA segment, $32 million related to the Optical and Specialty Materials segment $1 million related to the Commodity Chemicals segment and $1 million related to Corporate. These costs are considered to be unusual and non-recurring and do not reduce the segment earnings used to evaluate the performance of the operating segments.

[4] For the nine months ended September 30, 2012, the expense represents the flow-through cost of sales of the step up to fair value of inventory acquired from Dyrup and Colpisa. These costs are considered to be unusual and non-recurring and do not reduce the segment earnings used to evaluate the performance of the operating segments. For the three and nine months ended September 30, 2011, represents a net benefit stemming primarily from a bargain purchase gain reflecting the excess of the fair value of the net assets acquired over the price paid for the business, net of the flow-through cost of sales of the step up to fair value of acquired inventory.

[5] Represents costs incurred in connection with the announced separation and merger of the commodity chemicals business.