Note 8 - Acquisitions - Net Gain on Previously Owned Equity (Details) - USD ($) $ in Thousands			12 Months Ended
		Jan. 15, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
December 2013 Investment Balance			$ 1,905,000
Dividend (1)			(85,000)	$ (143,000)	$ (1,704,000)
Net investment book balance at 1/15/2014			$ 269,000	1,905,000
Samsung Corning Precision Materials Co., Ltd. [Member]
December 2013 Investment Balance		$ 3,709,000		$ 2,117,000	3,709,000
Dividend (1)		(1,600,000)			(1,574,000)
Other					(18,000)
Net investment book balance at 1/15/2014					2,117,000
Fair value Samsung Corning Precision Materials		4,000,000			4,038,000
57.5% of Samsung Corning Precision Materials (2)		$ 2,300,000			2,323,000	[1]
Working capital adjustment and other					52,000
57.5% of the pre-acquisition fair value of assets					2,375,000
Gain on previously held equity investment (2)	[1]				258,000
Translation gain					136,000
Net gain					$ 394,000

[1] As Corning was a 57.5% shareholder at the date of acquisition, immediately preceding the acquisition of Samsung Corning Precision Materials, Corning recognized an asset and respective gain as part of the calculation of its previously held equity investment which included approximately $184 million attributed to its economic interest in the royalty contract.