Note 14 - Reportable Segments - Reconciliation of Reportable Segment Net Income (Loss) to Consolidated Net Income (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net income attributable to Corning Incorporated		$ 563	$ 449	$ 1,144	$ 1,048
Gain on foreign currency hedges related to translated earnings		196	3	325	275
Research, development, and engineering expenses		240	242	488	464
Amortization of intangibles		(30)	(33)	(61)	(65)
Interest expense, net		(72)	(78)	(143)	(155)
Provision for income taxes (Note 3)		(166)	(67)	(346)	(293)
Gain on sale of a business				53	54
Operating Segments [Member]
Net income attributable to Corning Incorporated	[1]	625	595	1,210	1,108
Research, development, and engineering expenses	[2]	203	200	416	387
Provision for income taxes (Note 3)	[3]	170	158	330	294
Operating Segments [Member] | Reportable Segments [Member]
Net income attributable to Corning Incorporated		600	610	1,193	1,147
Operating Segments [Member] | Nonreportable Segments [Member]
Net income attributable to Corning Incorporated		25	(15)	17	(39)
Segment Reconciling Items [Member]
Net income attributable to Corning Incorporated		563	449	1,144	1,048
Impact of foreign currency movements not included in segment net income (loss)		(120)	(20)	(183)	(14)
Gain on foreign currency hedges related to translated earnings		196	3	325	275
Translation gain on Japanese yen-denominated debt		153	5	237	123
Research, development, and engineering expenses		(37)	(42)	(72)	(77)
Amortization of intangibles		(30)	(33)	(61)	(65)
Interest expense, net		(60)	(67)	(121)	(141)
Provision for income taxes (Note 3)		4	91	(16)	1
Gain on sale of a business			40	53	54
Other corporate items		$ (168)	$ (123)	$ (228)	$ (216)

[1] 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 (loss) to consolidated net income.

[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%.