Employee Benefit Plans (Employee Savings Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Company-matching contributions are applied to eligible participant compensation		6.00%		6.00%
Company-matching contribution		100.00%		75.00%
Compensation expense related to the ESOP		$ 44	$ 42	$ 36
Deductible dividends on PPG shares held by the ESOP		$ 13	$ 14	$ 15
Minimum
Company-matching contribution	2.00%
Maximum
Company-matching contribution	5.00%			100.00%