Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net income attributable to the controlling and noncontrolling interests	$ 342	$ 843	$ 1,459	$ 1,615	$ 895	$ 1,427
Income from discontinued operations, net of tax	6	5	222	225	330	95
Income from continuing operations	336	838	1,237	1,390	565	1,332
Adjustments to reconcile to cash from operations:
Depreciation and amortization	110	223	340	460	440	446
Defined benefit pension expense	18	34	52	65	85	88
Pension settlement charge	22	22	22	60	968	0
Business restructuring				0	191	136
Environmental remediation charge				0	82	0
Stock-based compensation expense	9	17	26	35	45	54
Net gain, from sale of businesses	0	(25)	(25)	(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)
Funding of asbestos settlement trust				0	(813)	0
Change in certain asset and liability accounts (net of acquisitions):
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
Investing activities
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)
Financing activities
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
Repayment of long-term debt (See Note 8)	(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, beginning of year	1,820	1,820	1,820	1,820	1,311	686
Cash and cash equivalents, end of year	1,349	1,569	2,287	1,436	1,820	1,311
Supplemental disclosures of cash flow information:
Interest paid, net of amount capitalized	23	52	60	100	118	115
Taxes paid, net of refunds	$ 90	$ 326	$ 481	$ 648	$ 349	$ 383