Note 7 - Investments - Results From Operations (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity in earnings of affiliated companies		$ 165,000	$ 19,000	$ 41,000	$ 59,000	$ 104,000	$ 39,000	$ 62,000	$ 94,000	$ 284,000	$ 299,000	$ 266,000
Proceeds from Equity Method Investment, Dividends or Distributions										85,000	143,000	1,704,000
Affiliated Companies [Member]
Net sales										4,024,000	6,461,000	7,124,000
Gross profit										1,006,000	1,606,000	1,701,000
Net income										565,000	586,000	647,000
Equity in earnings of affiliated companies										284,000	299,000	266,000
Corning sales to affiliated companies										95,000	75,000	53,000
Corning purchases from affiliated companies										19,000	19,000	25,000
Corning transfers of assets, at cost, to affiliated companies										42,000
Proceeds from Equity Method Investment, Dividends or Distributions										85,000	143,000	130,000
Royalty income from affiliated companies												2,000
Current assets		1,522,000				5,228,000				1,522,000	5,228,000
Noncurrent assets		2,112,000				6,453,000				2,112,000	6,453,000
Short-term borrowings, including current portion of long-term debt		3,000				6,000				3,000	6,000
Other current liabilities		715,000				1,461,000				715,000	1,461,000
Long-term debt		23,000				800,000				23,000	800,000
Other long-term liabilities		2,523,000				4,557,000				2,523,000	4,557,000
Non-controlling interest		267,000				631,000				267,000	631,000
Balances due from affiliated companies		27,000				11,000				27,000	11,000
Balances due to affiliated companies						1,000					1,000
Dow Corning Corporation [Member]
Net sales										2,215,000	5,649,000	6,221,000
Gross profit	[1]									588,000	1,472,000	1,543,000
Net income										163,000	563,000	513,000
Equity in earnings of affiliated companies										82,000	281,000	252,000
Corning purchases from affiliated companies										7,000	15,000	15,000
Proceeds from Equity Method Investment, Dividends or Distributions										$ 20,000	143,000	$ 125,000
Current assets						4,511,000					4,511,000
Noncurrent assets						6,064,000					6,064,000
Short-term borrowings, including current portion of long-term debt						6,000					6,000
Other current liabilities						1,305,000					1,305,000
Long-term debt						785,000					785,000
Other long-term liabilities						4,539,000					4,539,000
Non-controlling interest						$ 631,000					$ 631,000

[1] Gross profit for the five months ended May 31, 2016 includes R&D cost of $100 million (2015: $233 million and 2014: $273 million).