Quarterly Financial Information - Quarterly Condensed Consolidated Statement of Cash Flows (unaudited) (As Restated) (Details) - USD ($) $ in Millions	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Cash Flows [Abstract]
Net income attributable to the controlling and noncontrolling interests	$ 156	$ 616	$ 501	$ 342	$ 344	$ (179)	$ 376	$ 354	$ 843		$ 1,459		$ 1,615	$ 895	$ 1,427
Income from discontinued operations, net of tax	3	217	(1)	6	253	27	31	19	5		222		225	330	95
Income from continuing operations	153	399	502	336	91	(206)	345	335	838		1,237		1,390	565	1,332
Depreciation and amortization				110					223		340		460	440	446
Defined benefit pension expense				18					34		52		65	85	88
Pension settlement charges	38	0	0	22	0	$ 968	0	0	22	$ 0	22	$ 968	60	968	0
Stock-based compensation expense			8	9			16	$ 10	17	26	26		35	45	54
Net gain, from sale of businesses		0	0	0			$ (20)		(25)	$ (20)	(25)	$ (20)	(25)	(39)	0
Equity affiliate (income)/loss, net of dividends				(1)					3		0		(4)	(6)	66
Deferred income taxes				6					(40)		(53)		38	171	0
Cash contributions to pension plans				(34)					(37)		(43)		(87)	(188)	(263)
Restructuring cash expenditures				(10)					(20)		(31)		(49)	(76)	(47)
Receivables				(296)					(406)		(350)		(76)	(68)	(125)
Inventories				(157)					(185)		(200)		(116)	56	37
Other current assets				(47)					(49)		(40)		(43)	21	(81)
Accounts payable and accrued liabilities				62					147		229		188	169	152
Noncurrent assets and liabilities, net				39					(14)		(102)		(170)	(53)	79
Taxes and interest payable				(82)					(128)		(115)		(129)	(268)	(96)
Other				24					52		71		14	(64)	(19)
Cash from operating activities - continuing operations				(1)					432		1,018		1,551	1,218	1,759
Cash from operating activities - discontinued operations				10					14		14		17	133	136
Cash from operating activities				9					446		1,032		1,568	1,351	1,895
Additions to property and investments				(63)					(135)		(207)		(360)	(380)	(430)
Business acquisitions, net of cash balances acquired (See Note 2)				(61)					(62)		(69)		(225)	(349)	(320)
Payments for acquisition of equity investment				0					(100)		(100)		(100)	0	0
Net proceeds from the sale of businesses				0					52		593		593	1,094	47
Proceeds from maturity of short-term investments													0	92	402
Purchase of short-term investments				0					0		0		(1)	0	(97)
Payments for the settlement of cross currency swap contracts				(34)					(34)		(34)		(34)	(36)	(34)
Proceeds from the settlement of cross currency swap contracts				19					19		37		37	37	37
(Payments on) / Proceeds from net investment hedges													0	(13)	19
Other				2					2		0		27	27	27
Cash (used for)/from investing activities - continuing operations				(137)					(258)		220		(63)	472	(349)
Cash used for investing activities - discontinued operations				(1)					(3)		(4)		(4)	(36)	(46)
Cash (used for)/from investing activities				(138)					(261)		216		(67)	436	(395)
Net change in borrowings with maturities of three months or less				(7)					(3)		(6)		(7)	(15)	(32)
Net payments on commercial paper and short-term debt				(32)					(61)		(81)		(93)	(361)	(528)
Proceeds from long term debt (net of discount and issuance costs) (See Note 8)													0	988	1,242
Repayments of debt				(7)					(8)		(9)		(588)	(379)	(340)
Payments related to tax withholding on stock-based compensation awards				(16)					(20)		(25)		(28)	(26)	(58)
Purchase of treasury stock				(163)					(163)		(413)		(813)	(1,050)	(751)
Issuance of treasury stock				9					20		45		52	31	53
Dividends paid on PPG common stock				(103)					(205)		(321)		(434)	(414)	(383)
Other				(53)					(50)		(41)		(43)	16	(15)
Cash used for financing activities				(372)					(490)		(851)		(1,954)	(1,210)	(812)
Effect of currency exchange rate changes on cash and cash equivalents				30					54		70		69	(68)	(63)
Net (decrease) increase in cash and cash equivalents				(471)					(251)		467		(384)	509	625
Cash and cash equivalents	$ 1,436	$ 2,287	$ 1,569	1,349	$ 1,820				1,569		2,287		1,436	1,820	1,311	$ 686
Interest paid, net of amount capitalized				23					52		60		100	118	115
Taxes paid, net of refunds				$ 90					$ 326		$ 481		$ 648	$ 349	$ 383