Quarterly Financial Information - Quarterly Condensed Consolidated Balance Sheets (unaudited) (As Restated) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents	$ 1,436	$ 2,287	$ 1,569	$ 1,349	$ 1,820	$ 1,311	$ 686
Short-term investments	55	41	48	40	43
Receivables	2,903	3,155	3,191	3,013	2,654
Inventories	1,730	1,805	1,766	1,699	1,514
Assets held for sale	0	0	177	223	223
Other	353	350	390	439	320
Total current assets	6,477	7,638	7,141	6,763	6,574
Property, plant and equipment, net	2,824	2,730	2,710	2,659	2,608	2,608
Goodwill	3,942	3,881	3,845	3,720	3,572	3,625
Identifiable intangible assets, net	2,045	2,099	2,118	2,080	1,983
Deferred income taxes	305	422	321	170	186
Investments	268	261	256	175	179
Other assets	677	585	582	587	669
Assets	16,538	17,616	16,973	16,154	15,771
Accounts payable and accrued liabilities	3,781	3,900	3,656	3,517	3,460
Restructuring reserves	102	107	115	95	100
Short-term debt and current portion of long-term debt	12	616	619	604	629
Liabilities held for sale	0	0	54	69	64
Total current liabilities	3,895	4,623	4,444	4,285	4,253
Long-term debt	4,134	4,089	3,998	3,817	3,787
Accrued pensions	729	759	748	712	740
Other postretirement benefits	699	767	755	720	724
Deferred income taxes	145	445	390	400	231
Deferred income taxes	442				417
Deferred Tax Liabilities, Gross	948				1,341
Other liabilities	967	928	910	934	935
Liabilities	10,866	11,611	11,245	10,868	10,856
Commitments and contingent liabilities (See Note 14)
Common stock	969	969	969	969	969
Additional paid-in capital	756	745	723	711	707
Retained earnings	17,140	17,101	16,606	16,214	15,980
Treasury stock, value	(11,251)	(10,855)	(10,616)	(10,626)	(10,472)
Accumulated other comprehensive loss	(2,057)	(2,063)	(2,059)	(2,076)	(2,356)
Total PPG shareholders’ equity	5,557	5,897	5,623	5,192	4,828
Noncontrolling interests	115	108	105	94	87
Stockholders' equity, including portion attributable to noncontrolling interest	5,672	6,005	5,728	5,286	4,915	$ 5,069	$ 5,265
Liabilities and Equity	16,538	17,616	16,973	$ 16,154	15,771
Restatement Adjustment
Other			(4)
Total current assets			(4)
Assets		1	(4)		2
Accounts payable and accrued liabilities	1	5	3
Total current liabilities	1	5	3
Accrued pensions		1
Other liabilities		0	0
Liabilities	1	6	3
Additional paid-in capital					6
Retained earnings	(1)	(5)	(7)		(4)
Total PPG shareholders’ equity	(1)	(5)	(7)		2
Noncontrolling interests	0
Stockholders' equity, including portion attributable to noncontrolling interest	(1)	(5)	(7)
Liabilities and Equity	0	1	(4)		2
As Previously Reported
Other			394
Total current assets			7,145
Assets		17,615	16,977		15,769
Accounts payable and accrued liabilities	3,780	3,895	3,653
Total current liabilities	3,894	4,618	4,441
Accrued pensions		758
Other liabilities		928	910
Liabilities	10,865	11,605	11,242
Additional paid-in capital					701
Retained earnings	17,141	17,106	16,613		15,984
Total PPG shareholders’ equity	5,558	5,902	5,630		4,826
Noncontrolling interests	115	108	105		87
Stockholders' equity, including portion attributable to noncontrolling interest	5,673	6,010	5,735		4,913
Liabilities and Equity	$ 16,538	$ 17,615	$ 16,977		$ 15,769