Reportable Segments (Reportable Segments) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment net sales		$ 2,934	$ 3,008	$ 8,686	$ 8,255
Depreciation				1,026	895
Research, development and engineering expenses		255	244	753	728
Income tax (provision) benefit		(71)	(133)	(271)	(383)
Net income (loss) attributable to Corning Incorporated		$ 337	$ 625	$ 928	$ 774
Statutory U.S. income tax rate		21.00%	21.00%	21.00%	21.00%
Operating Segments [Member]
Segment net sales		$ 2,969	$ 3,045	$ 8,805	$ 8,317
Depreciation	[1]	295	287	898	857
Research, development and engineering expenses	[2]	206	213	633	627
Income tax (provision) benefit	[3]	(122)	(139)	(359)	(341)
Net income (loss) attributable to Corning Incorporated	[4]	454	520	1,342	1,278
Display Technologies [Member] | Operating Segments [Member]
Segment net sales		793	852	2,459	2,377
Depreciation	[1]	144	146	445	436
Research, development and engineering expenses	[2]	30	26	85	76
Income tax (provision) benefit	[3]	(49)	(57)	(159)	(157)
Net income (loss) attributable to Corning Incorporated	[4]	185	218	606	595
Optical Communications [Member] | Operating Segments [Member]
Segment net sales		1,007	1,117	3,161	3,026
Depreciation	[1]	59	55	178	160
Research, development and engineering expenses	[2]	53	53	163	153
Income tax (provision) benefit	[3]	(35)	(46)	(117)	(117)
Net income (loss) attributable to Corning Incorporated	[4]	127	168	427	427
Specialty Materials [Member] | Operating Segments [Member]
Segment net sales		463	459	1,141	1,080
Depreciation	[1]	35	34	107	102
Research, development and engineering expenses	[2]	37	43	119	123
Income tax (provision) benefit	[3]	(25)	(31)	(56)	(60)
Net income (loss) attributable to Corning Incorporated	[4]	92	116	208	226
Environmental Technologies [Member] | Operating Segments [Member]
Segment net sales		397	331	1,125	970
Depreciation	[1]	32	30	95	89
Research, development and engineering expenses	[2]	29	28	87	86
Income tax (provision) benefit	[3]	(21)	(16)	(53)	(44)
Net income (loss) attributable to Corning Incorporated	[4]	79	60	199	166
Life Sciences [Member] | Operating Segments [Member]
Segment net sales		256	231	759	708
Depreciation	[1]	12	12	37	39
Research, development and engineering expenses	[2]	5	5	15	15
Income tax (provision) benefit	[3]	(11)	(8)	(30)	(23)
Net income (loss) attributable to Corning Incorporated	[4]	41	30	112	88
All Other [Member] | Operating Segments [Member]
Segment net sales		53	55	160	156
Depreciation	[1]	13	10	36	31
Research, development and engineering expenses	[2]	52	58	164	174
Income tax (provision) benefit	[3]	19	19	56	60
Net income (loss) attributable to Corning Incorporated	[4]	$ (70)	$ (72)	$ (210)	$ (224)

[1] Depreciation expense for Corning’s reportable segments includes an allocation of depreciation of corporate property not specifically identifiable to a segment.

[2] Research, development and engineering expenses include direct project spending that is identifiable to a segment.

[3] Income tax (provision) benefit reflects a tax rate of 21%.

[4] Many of Corning’s administrative and staff functions are performed on a centralized basis. Where practicable, Corning charges these expenses to segments based upon the extent to which each business uses a centralized function. Other staff functions, such as corporate finance, human resources and legal, are allocated to segments, primarily as a percentage of sales. Expenses that are not allocated to the segments are included in the reconciliation of reportable segment net income to consolidated net income below.