Employee Benefit Plans (Other Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined contribution plan contribution rates as percentage of employee earnings	6.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Compensation expense related to the ESOP	$ 56	$ 52	$ 50
Deductible dividends on PPG shares held by the ESOP	11	10	11
Recognized expense for defined contribution pension plans	92	88	64
Expense (income) of the deferred compensation plan	23	20	25
Increase (Decrease) in fair value of investments	24	18	$ 24
Obligations under the deferred compensation plan	105	139
Investments in marketable securities by the deferred compensation plan	$ 70	$ 104