Note 8 - Investments (Details) - Results of Operations (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Statement of Operations:
Corning’s equity in earnings of Dow Corning	$ 94		$ 86
Dow Corning Corporation [Member]
Statement of Operations:
Net sales	1,364		1,524
Gross profit (1)	358	[1]	483	[1]
Net income attributable to Dow Corning	185		191
Corning’s equity in earnings of Dow Corning	$ 92		$ 92

[1] Gross profit for the three months ended March 31, 2015 includes research and development costs of $62 million (2014: $67 million).