Reportable Segments (Reportable Segments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment net sales		$ 11,656	$ 11,398	$ 10,258
Depreciation		1,390	1,199	1,083
Research, development and engineering expenses		1,031	993	864
Income tax (provision) benefit		(256)	(437)	(2,154)
Net income (loss) attributable to Corning Incorporated		960	1,066	(497)
Operating Segments [Member]
Segment net sales	[1]	11,656	11,398	10,258
Depreciation	[2]	1,192	1,146	1,077
Research, development and engineering expenses	[3]	867	850	760
Income tax (provision) benefit		(451)	(477)	(442)
Net income (loss) attributable to Corning Incorporated	[4]	1,701	1,784	1,659
Investment in affiliated companies, at equity		154	312	279
Segment assets	[5]	17,889	17,248	16,180
Capital expenditures		1,899	2,071	1,878
Display Technologies [Member] | Operating Segments [Member]
Segment net sales		3,254	3,276	3,137
Depreciation	[2]	583	585	534
Research, development and engineering expenses	[3]	119	106	88
Income tax (provision) benefit		(206)	(221)	(234)
Net income (loss) attributable to Corning Incorporated	[4]	786	835	888
Investment in affiliated companies, at equity		145	131	134
Segment assets	[5]	9,022	8,794	8,662
Capital expenditures		872	755	795
Optical Communications [Member] | Operating Segments [Member]
Segment net sales		4,064	4,192	3,545
Depreciation	[2]	237	218	193
Research, development and engineering expenses	[3]	218	212	174
Income tax (provision) benefit		(134)	(163)	(129)
Net income (loss) attributable to Corning Incorporated	[4]	489	592	469
Investment in affiliated companies, at equity		3	3	2
Segment assets	[5]	3,004	3,042	2,599
Capital expenditures		329	417	505
Specialty Materials [Member] | Operating Segments [Member]
Segment net sales		1,594	1,479	1,403
Depreciation	[2]	145	136	129
Research, development and engineering expenses	[3]	154	163	152
Income tax (provision) benefit		(81)	(83)	(79)
Net income (loss) attributable to Corning Incorporated	[4]	302	313	301
Investment in affiliated companies, at equity		3	6	3
Segment assets	[5]	2,433	2,176	2,155
Capital expenditures		176	242	223
Environmental Technologies [Member] | Operating Segments [Member]
Segment net sales		1,499	1,289	1,106
Depreciation	[2]	128	119	124
Research, development and engineering expenses	[3]	118	118	113
Income tax (provision) benefit		(70)	(55)	(44)
Net income (loss) attributable to Corning Incorporated	[4]	263	208	165
Segment assets	[5]	1,912	1,633	1,402
Capital expenditures		287	273	157
Life Sciences [Member] | Operating Segments [Member]
Segment net sales		1,015	946	879
Depreciation	[2]	49	50	52
Research, development and engineering expenses	[3]	21	20	22
Income tax (provision) benefit		(40)	(31)	(25)
Net income (loss) attributable to Corning Incorporated	[4]	150	117	95
Investment in affiliated companies, at equity		3	1
Segment assets	[5]	627	585	538
Capital expenditures		80	55	42
All Other [Member]
Segment net sales		230	216	188
Depreciation	[2]	50	38	45
Research, development and engineering expenses	[3]	237	231	211
Income tax (provision) benefit		80	76	69
Net income (loss) attributable to Corning Incorporated	[4]	(289)	(281)	(259)
Investment in affiliated companies, at equity			171	140
Segment assets	[5]	891	1,018	824
Capital expenditures		155	329	156
All Other [Member] | Operating Segments [Member]
Segment net sales		$ (153)	$ (108)	$ (142)

[1] Net sales are attributed to countries based on location of customer.

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

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

[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.

[5] Segment assets include inventory, accounts receivable, property, plant and equipment, net of accumulated depreciation, and associated equity companies and cost investments.