Reportable Segment Net Sales and Segment Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended					6 Months Ended
	Jun. 30, 2012		Mar. 31, 2012	Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 3,955	[1]		$ 3,986	[1]	$ 7,707	[1]	$ 7,519	[1]
Segment income (loss)	635			594		1,178		1,074
Legacy items	(15)	[2]		(11)	[2]	(190)	[2]	(37)	[2]
Business restructuring			(208)			(208)	[3]
Acquisition-related (costs) gain, net				9	[4]	(6)	[4]	9	[4]
Transaction expenses related to Separation and merger transaction	(4)	[5]				(4)	[5]
Interest expense, net of interest income	(41)			(44)		(82)		(87)
Other unallocated corporate expense - net	(48)			(48)		(110)		(108)
Income before income taxes	527			500		578		851
Performance Coatings Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,241			1,230		2,391		2,282
Segment income (loss)	204			204		364		343
Business restructuring						(65)
Industrial Coatings Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,099			1,075		2,175		2,100
Segment income (loss)	143			115		293		231
Business restructuring						(46)
Architectural Coatings - EMEA
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	601			611		1,118		1,082
Segment income (loss)	64			50		80		62
Business restructuring						(63)
Optical and Specialty Materials Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	314			326		648		634
Segment income (loss)	95			90		204		180
Business restructuring						(32)
Commodity Chemicals Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	427			470		846		889
Segment income (loss)	106			106		206		203
Business restructuring						(1)
Glass Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	273			274		529		532
Segment income (loss)	$ 23			$ 29		$ 31		$ 55

[1] Intersegment net sales for the three and six months ended June 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 six months ended June 30, 2012 includes a 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 six months ended June 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 six months ended June 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 six months ended June 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