Consolidated Statement of Income - 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
Income Statement [Abstract]
Net sales	$ 3,682	$ 3,776	$ 3,804	$ 3,486	$ 3,417	$ 3,660	$ 3,782	$ 3,411	$ 7,290		$ 11,066		$ 14,748	$ 14,270	$ 14,241
Cost of sales, exclusive of depreciation and amortization	2,119	2,101	2,082	1,905	1,910	1,978	1,988	1,817	3,987		6,088		8,207	7,693	7,786
Selling, general and administrative	908	902	872	882	868	893	930	897	1,754		2,656		3,564	3,588	3,584
Depreciation	86	85	81	79	79	82	79	79	160		245		331	319	314
Amortization	34	32	32	31	30	31	30	30	63		95		129	121	132
Research and development, net	116	114	113	110	115	115	115	114	223		337		453	459	466
Interest expense	27	27	26	25	29	34	31	31	51		78		105	125	125
Interest income	(7)	(5)	(4)	(4)	(6)	(6)	(7)	(7)	(8)		(13)		(20)	(26)	(39)
Asbestos settlement, net					0	0	2	3					0	5	12
Business restructuring					191	0	0	0					0	191	136
Pension settlement charges	38	0	0	22	0	968	0	0	22	$ 0	22	$ 968	60	968	0
Other charges	25	13	12	14	117	12	29	17	26		39		64	175	90
Other income	(41)	(16)	(69)	(24)	(47)	(21)	(45)	(14)	(93)		(109)		(150)	(127)	(110)
Income before income taxes	377	523	659	446	131	(426)	630	444	1,105	$ 1,074	1,628	$ 648	2,005	779	1,745
Income tax expense	224	124	157	110	40	(220)	285	109	267		391		615	214	413
Income from continuing operations	153	399	502	336	91	(206)	345	335	838		1,237		1,390	565	1,332
Income from discontinued operations, net of tax	3	217	(1)	6	253	27	31	19	5		222		225	330	95
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
Less: net income attributable to noncontrolling interests	5	6	5	5	4	5	6	7	10		16		21	22	21
Net income (attributable to PPG)	151	610	496	337	340	(184)	370	347	833		1,443		1,594	873	1,406
Continuing operations	148	393	497	331	87	(211)	339	328	828		1,221		1,369	543	1,311
Discontinued operations	$ 3	$ 217	$ (1)	$ 6	$ 253	$ 27	$ 31	$ 19	$ 5		$ 222		$ 225	$ 330	$ 95
Earnings per common share
Continuing operations (in dollars per share)	$ 0.59	$ 1.53	$ 1.93	$ 1.29	$ 0.34	$ (0.79)	$ 1.26	$ 1.23	$ 3.22		$ 4.75		$ 5.34	$ 2.05	$ 4.83
Discontinued operations (in dollars per share)	0.01	0.85	0.00	0.02	0.96	0.10	0.12	0.07	0.02		0.86		0.88	1.24	0.35
Net Income (attributable to PPG) (in dollars per share)	0.60	2.38	1.93	1.31	1.30	(0.69)	1.38	1.30	3.24		5.61		6.22	3.29	5.18
Earnings per common share - assuming dilution
Continuing operations (in dollars per share)	0.58	1.52	1.92	1.28	0.33	(0.79)	1.25	1.22	3.19		4.72		5.31	2.04	4.79
Discontinued operations (in dollars per share)	0.01	0.84	0.00	0.02	0.96	0.10	0.12	0.07	0.02		0.86		0.87	1.23	0.35
Net Income (attributable to PPG) (in dollars per share)	$ 0.59	$ 2.36	$ 1.92	$ 1.30	$ 1.29	$ (0.69)	$ 1.37	$ 1.29	$ 3.21		$ 5.58		$ 6.18	$ 3.27	$ 5.14