Note 14 - Reportable Segments - Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
Depreciation (1)			$ 932		$ 1,014
Research, development and engineering expenses (2)	$ 270	$ 278	787		766
Income tax provision (3)	35	34	178		380
Net income of reportable segments	164	208	621		1,352
Operating Segments [Member]
Net sales of reportable segments	3,459	3,666	10,308		11,172
Depreciation (1)	308	301	922		982
Research, development and engineering expenses (2)	222	235	640		651
Income tax provision (3)	(140)	(153)	(412)		(483)
Net income of reportable segments	509	561	1,499		1,771
Optical Communications [Member] | Operating Segments [Member]
Net sales of reportable segments	918	1,317	3,109		3,828
Depreciation (1)	65	58	195		185
Research, development and engineering expenses (2)	60	60	176		173
Income tax provision (3)	(24)	(50)	(105)	[1]	(146)
Net income of reportable segments	91	183	390		531
Display Products [Member] | Operating Segments [Member]
Net sales of reportable segments	972	686	2,663		2,523
Depreciation (1)	119	124	362		426
Research, development and engineering expenses (2)	26	31	73		92
Income tax provision (3)	(64)	(35)	(161)		(157)
Net income of reportable segments	242	134	610		598
Specialty Materials [Member] | Operating Segments [Member]
Net sales of reportable segments	563	519	1,392		1,497
Depreciation (1)	37	36	111		118
Research, development and engineering expenses (2)	62	66	172	[2]	163
Income tax provision (3)	(19)	(26)	(38)		(70)
Net income of reportable segments	72	96	144		262
Environmental Technologies [Member] | Operating Segments [Member]
Net sales of reportable segments	449	425	1,337		1,190
Depreciation (1)	32	31	97	[3]	98
Research, development and engineering expenses (2)	26	25	73		74
Income tax provision (3)	(27)	(23)	(77)		(59)
Net income of reportable segments	99	87	288		223
Life Science Products [Member] | Operating Segments [Member]
Net sales of reportable segments	230	312	717		934
Depreciation (1)	18	14	52		44
Research, development and engineering expenses (2)	7	10	25		28
Income tax provision (3)	(4)	(11)	(9)		(32)
Net income of reportable segments	13	43	33		122
Hemlock and Emerging Growth Businesses [Member]
Net sales of reportable segments	327	407	1,090		1,200
Depreciation (1)	37	38	105		111
Research, development and engineering expenses (2)	41	43	121		121
Income tax provision (3)	(2)	(8)	(22)		(19)
Net income of reportable segments	$ (8)	$ 18	$ 34		$ 35

[1] Income tax provision reflects a tax rate of 21%.

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

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