Borrowings (Details) € in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2015 EUR (€)	Jun. 30, 2015 USD ($)	Jun. 30, 2015 EUR (€)	Jun. 30, 2014 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2015 EUR (€)
Schedule of Held-to-maturity Securities [Line Items]
Euro-denominated borrowings hedging a portion of PPG's net investment in European operations | €	€ 300		€ 300
Repayments of Debt		$ 338		$ 4
Debt Instrument, Face Amount					$ 1,260	€ 1,200
Proceeds from Notes Payable		1,240
Seven-year Fixed Rate Euro Bank Loan Due 2022 [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Instrument, Face Amount | €						€ 600
Stated interest rate					0.875%	0.875%
Twelve-year Fixed Rate Euro Bank Loan Due 2027 [Member] [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Instrument, Face Amount | €						€ 600
Stated interest rate					1.40%	1.40%
Notes 2.3 Percent Due 2019 [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Redemption Price Percent Of Principal Amount					101.00%	101.00%
Net Investment Hedging [Member]
Schedule of Held-to-maturity Securities [Line Items]
Repayments of Debt		$ 336