Stock-Based Compensation (Additional Information) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended	3 Months Ended				12 Months Ended		3 Months Ended	12 Months Ended				3 Months Ended	12 Months Ended			3 Months Ended		12 Months Ended		3 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended				3 Months Ended
	Mar. 31, 2013 OptionPlan	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Stock Options [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member]	Mar. 31, 2012 Restricted Stock Units (RSUs) [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member] Minimum [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] Minimum [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] Minimum [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member] Maximum [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] Maximum [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] Maximum [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] 2010-2013 Performance Period [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] 2010-2013 Performance Period [Member] Performance Targets Met [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member] Performance Period 2011 to 2013 [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] Performance Period 2011 to 2013 [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] Performance Period 2011 to 2013 [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] Performance Period 2011 to 2013 [Member] Performance Targets Met [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member] Performance Period Twenty Thirteen To Twenty Fifteen [Member] [Domain]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member] 2012-2014 Performance Period [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member] 2012-2014 Performance Period [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] 2012-2014 Performance Period [Member]	Mar. 31, 2013 Executive Officer Incentive Plan [Member]	Dec. 31, 2012 Executive Officer Incentive Plan [Member]	Dec. 31, 2011 Executive Officer Incentive Plan [Member]	Mar. 31, 2013 Executive Officer Incentive Plan [Member] Minimum [Member]	Dec. 31, 2012 Executive Officer Incentive Plan [Member] Minimum [Member]	Dec. 31, 2011 Executive Officer Incentive Plan [Member] Minimum [Member]	Mar. 31, 2013 Executive Officer Incentive Plan [Member] Maximum [Member]	Dec. 31, 2012 Executive Officer Incentive Plan [Member] Maximum [Member]	Dec. 31, 2011 Executive Officer Incentive Plan [Member] Maximum [Member]	Dec. 31, 2011 Executive Officer Incentive Plan [Member] 2010-2013 Performance Period [Member]	Dec. 31, 2012 Executive Officer Incentive Plan [Member] Performance Period 2011 to 2013 [Member]	Mar. 31, 2013 Executive Officer Incentive Plan [Member] 2012-2014 Performance Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants under the PPG Omnibus Plan	7,600,000
Total stock-based compensation cost	$ 15	$ 14
Total income tax benefit recognized related to the stock-based compensation	$ 5	$ 5
Description of the terms of the outstanding stock options for the PPG Omnibus Plan and the PPG Stock Plan for certain employees	The options are generally exercisable beginning from six to 48 months after being granted and have a maximum term of 10 years.
Maximum term of the outstanding stock options for the PPG Omnibus Plan and the PPG Stock Plan for certain employees	10 years
Number of stock option plans	2
Options exercisable period, minimum	6 months
Options exercisable period, maximum	48 months
Stock options granted from the PPG Omnibus Plan	497,711	779,498
Stock options granted from the PPG Omnibus Plan, weighted average exercise price per share	$ 131.51	$ 89.94
Stock options granted from the PPG Omnibus Plan, weighted average fair value per share	$ 27.37	$ 17.90
Award vest period (in years)				3 years	3 years																		3 years	3 years	3 years
Percentage of the target award that is paid based on performance							0.00%	0.00%	0.00%	180.00%	180.00%	180.00%														0.00%	0.00%	0.00%	220.00%	220.00%	220.00%
Percentage of the target award that is assumed to vest for the purposes of expense recognition													180.00%		150.00%	100.00%	100.00%		100.00%	100.00%	100.00%	100.00%
Number of performance targets			4,000,000										4	4		2		2
RSUs granted					152,875	245,997
RSUs granted, weighted average fair value per share					$ 124.80	$ 83.27
Earned payout if the target performance is achieved																							100.00%
Performance share payout description																																Dividend equivalents for the award period, which will be paid to participants with the award payout at the end of the period based on the actual number of contingent shares that are earned.	Dividend equivalents for the award period, which will be paid to participants with the award payout at the end of the period based on the actual number of contingent shares that are earned.	Dividend equivalents for the award period, which will be paid to participants with the award payout at the end of the period based on the actual number of contingent shares that are earned.