Note 8 - Investments (Details) - Results of Operations - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2015	Jun. 30, 2014
Statement of Operations:
Corning’s equity in earnings of Dow Corning	$ 62		$ 62		$ 156	$ 148
Dow Corning Corporation [Member]
Statement of Operations:
Net sales	1,424		1,501		2,788	3,025
Gross profit (1)	364	[1]	349	[1]	722	720
Net income attributable to Dow Corning	113		109		298	300
Corning’s equity in earnings of Dow Corning	$ 57		$ 54		$ 149	$ 146

[1] Gross profit for the three and six months ended June 30, 2015 includes research and development costs of $63 million and $125 million (2014: $70 million and $137 million).