Consolidated Statement of Cash Flows - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income attributable to the controlling and noncontrolling interests	$ 1,269	$ 1,358	$ 1,615
Income from discontinued operations, net of tax	0	18	225
Income from continuing operations	1,269	1,340	1,390
Adjustments to reconcile net income to cash from operations:
Depreciation and amortization	511	497	460
Pension expense	54	43	65
Pension settlement charge	0	0	60
Business restructuring, net	176	66	0
Environmental remediation charges and other costs, net	61	77	0
Stock-based compensation expense	39	37	35
Gain on sale of land	0	(26)	0
Net gain, from sale of businesses	0	0	(25)
Equity affiliate loss/(income), net of dividends	4	(1)	(4)
Deferred income taxes	(5)	45	38
Cash contributions to pension plans	(13)	(99)	(87)
Restructuring cash expenditures	(58)	(66)	(49)
Change in certain asset and liability accounts (net of acquisitions):
Receivables	121	(69)	(76)
Inventories	145	(109)	(116)
Other current assets	(95)	5	(43)
Accounts payable and accrued liabilities	(63)	(76)	188
Noncurrent assets and liabilities, net	(13)	(207)	(170)
Taxes and interest payable	(32)	50	(129)
Other	(17)	(20)	14
Cash from operating activities - continuing operations	2,084	1,487	1,551
Cash (used for)/from operating activities - discontinued operations	(4)	(20)	17
Cash from operating activities	2,080	1,467	1,568
Investing activities
Additions to property and investments	(413)	(411)	(360)
Business acquisitions, net of cash balances acquired (See Note 2)	(643)	(378)	(225)
Payments for acquisition of equity investment	0	0	(100)
Net proceeds from the sale of businesses	0	0	593
Proceeds from sale of land	0	27	0
Payments for the settlement of cross currency swap contracts	(8)	(28)	(34)
Proceeds from the settlement of cross currency swap contracts	28	23	37
Other	27	3	26
Cash used for investing activities - continuing operations	(1,009)	(764)	(63)
Cash used for investing activities - discontinued operations	0	0	(4)
Cash used for investing activities	(1,009)	(764)	(67)
Financing activities
Net change in borrowings with maturities of three months or less	6	(1)	(7)
Net proceeds/(payments) on commercial paper and short-term debt	100	(2)	(93)
Proceeds from long term debt (net of discount and issuance costs) (See Note 8)	595	992	0
Repayment of long-term debt (See Note 8)	(637)	(6)	(588)
Repayments of acquired debt	(23)	0	0
Payments related to tax withholding on stock-based compensation awards	(20)	(15)	(28)
Purchase of treasury stock	(325)	(1,721)	(813)
Issuance of treasury stock	61	15	52
Dividends paid on PPG common stock	(468)	(453)	(434)
Payments to noncontrolling interests	(39)	0	0
Other	(8)	(14)	(43)
Cash used for financing activities	(758)	(1,205)	(1,954)
Effect of currency exchange rate changes on cash and cash equivalents	1	(32)	69
Net increase/(decrease) in cash and cash equivalents	314	(534)	(384)
Cash and cash equivalents, beginning of year	902	1,436	1,820
Cash and cash equivalents, end of year	1,216	902	1,436
Supplemental disclosures of cash flow information:
Interest paid, net of amount capitalized	127	108	100
Taxes paid, net of refunds	$ 348	$ 380	$ 648
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued	164	0	0