Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Schedule II - Valuation and Qualifying Accounts

Schedule II – Valuation and Qualifying Accounts

Allowance for Doubtful Accounts for the Years Ended December 31, 2021, 2020, and 2019

($ in millions)	Balance at Beginning of Year	Charged to Costs and Expenses(1)	Deductions(1, 2)	Balance at End of Year
2021	$44	$5	($18)	$31
2020	$22	$44	($22)	$44
2019	$24	$24	($26)	$22

(1)In 2020, PPG recorded an allowance for doubtful accounts of $30 million related to the potential financial impacts of COVID-19. In 2021, PPG released $14 million of the previously established reserve due to improvement in economic conditions in certain countries and a slower pattern of bankruptcies than expected.

(2)Notes and accounts receivable written off as uncollectible, net of recoveries, amounts attributable to divestitures and changes attributable to foreign currency translation.

SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]

Balance at Beginning of Year

$ 167

Balance at End of Year

172

$ 167

Accounts Receivable, Credit Loss Expense (Reversal), CARES Act

(14)

30

$ 0

SEC Schedule, 12-09, Allowance, Credit Loss [Member]

SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]

Balance at Beginning of Year

44

22

24

Charged to Costs and Expenses

5

44

24

Deductions

(18)

(22)

(26)

Balance at End of Year

$ 31

$ 44

$ 22