Note 18 - Reportable Segments (Details) - Reportable Segments - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net sales		$ 2,343	$ 2,482	$ 4,608	$ 4,771
Depreciation				562	583
Amortization of purchased intangibles		16	8	28	16
Research, development and engineering expenses		191	208	380	406
Restructuring, impairment & other charges			34		51
Equity in earnings of affiliated companies		62	62	156	148
Income tax (provision) benefit		(110)	(172)	(196)	(352)
NetIncomeLoss		496	169	903	470
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		2,343	2,482	4,608	4,771
Depreciation	[1]	280	290	553	576
Amortization of purchased intangibles		16	8	27	16
Research, development and engineering expenses	[2]	163	183	324	352
Restructuring, impairment & other charges		3	34	2	51
Equity in earnings of affiliated companies		3	4	3	(2)
Income tax (provision) benefit		(205)	(181)	(395)	(427)
NetIncomeLoss	[3]	443	388	848	675
Display Technologies [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		789	987	1,597	1,916
Depreciation	[1]	152	171	308	344
Research, development and engineering expenses	[2]	26	41	50	86
Restructuring, impairment & other charges			24		29
Equity in earnings of affiliated companies		(3)	(4)	(5)	(13)
Income tax (provision) benefit		(136)	(119)	(268)	(317)
NetIncomeLoss	[3]	303	282	597	491
Optical Communications [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		800	686	1,497	1,279
Depreciation	[1]	43	37	81	73
Amortization of purchased intangibles		11	2	17	4
Research, development and engineering expenses	[2]	35	34	68	71
Restructuring, impairment & other charges				(1)	12
Income tax (provision) benefit		(37)	(31)	(66)	(50)
NetIncomeLoss	[3]	77	61	134	88
Environmental Technologies [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		260	285	542	560
Depreciation	[1]	32	30	61	60
Research, development and engineering expenses	[2]	23	21	46	42
Equity in earnings of affiliated companies			1		2
Income tax (provision) benefit		(22)	(23)	(45)	(44)
NetIncomeLoss	[3]	46	47	94	90
Specialty Materials [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		272	298	544	559
Depreciation	[1]	27	29	53	56
Research, development and engineering expenses	[2]	29	34	60	67
Restructuring, impairment & other charges		3		3
Income tax (provision) benefit		(22)	(21)	(43)	(37)
NetIncomeLoss	[3]	44	39	82	70
Life Sciences [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		211	223	408	433
Depreciation	[1]	15	16	30	31
Amortization of purchased intangibles		5	6	10	12
Research, development and engineering expenses	[2]	6	5	11	10
Income tax (provision) benefit		(9)	(9)	(17)	(17)
NetIncomeLoss	[3]	18	18	34	35
Other Segments [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		11	3	20	24
Depreciation	[1]	11	7	20	12
Research, development and engineering expenses	[2]	44	48	89	76
Restructuring, impairment & other charges			10		10
Equity in earnings of affiliated companies		6	7	8	9
Income tax (provision) benefit		21	22	44	38
NetIncomeLoss	[3]	$ (45)	$ (59)	$ (93)	$ (99)

[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] 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.