Corning (GLW) 10-Q 29 Oct 20 2020 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 22, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	1-3247
Entity Registrant Name	CORNING INC /NY
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	16-0393470
Entity Address, Address Line One	One Riverfront Plaza
Entity Address, City or Town	Corning
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14831
City Area Code	607
Local Phone Number	974-9000
Title of 12(b) Security	Common Stock
Trading Symbol	GLW
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		764,010,029
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Central Index Key	0000024741
Current Fiscal Year End Date	--12-31

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Consolidated Statements of Income [Abstract]
Net sales	$ 3,001	$ 2,934	$ 7,953	$ 8,686
Cost of sales	2,000	1,917	5,635	5,505
Gross margin	1,001	1,017	2,318	3,181
Operating expenses:
Selling, general and administrative expenses	480	369	1,276	1,184
Research, development and engineering expenses	231	255	922	753
Amortization of purchased intangibles	33	28	87	85
Operating income	257	365	33	1,159
Equity in (losses) earnings of affiliated companies (Note 3)	(76)	23	17	81
Interest income	3	4	12	16
Interest expense	(70)	(55)	(201)	(161)
Translated earnings contract (loss) gain, net (Note 14)	(100)	86	5	163
Transaction-related gain, net (Note 4)	498		498
Other expense, net	(62)	(15)	(71)	(59)
Income before income taxes	450	408	293	1,199
Provision for income taxes (Note 8)	(23)	(71)	(33)	(271)
Net income attributable to Corning Incorporated	$ 427	$ 337	$ 260	$ 928
Earnings per common share attributable to Corning Incorporated:
Basic (Note 10)	$ 0.53	$ 0.40	$ 0.25	$ 1.10
Diluted (Note 10)	$ 0.48	$ 0.38	$ 0.24	$ 1.03

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Consolidated Statements of Comprehensive Income [Abstract]
Net income attributable to Corning Incorporated	$ 427	$ 337	$ 260	$ 928
Foreign currency translation adjustments and other	283	(238)	76	(310)
Net unrealized (losses) gains on investments		(1)		1
Unamortized gains (losses) and prior service credits (costs) for postretirement benefit plans	4	4	(8)	(48)
Net unrealized gains (losses) on designated hedges	11	(22)	(31)	(20)
Other comprehensive income (loss), net of tax (Note 16)	298	(257)	37	(377)
Comprehensive income attributable to Corning Incorporated	$ 725	$ 80	$ 297	$ 551

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 2,514	$ 2,434
Trade accounts receivable, net of doubtful accounts and allowances - $43 and $41	2,099	1,836
Inventories, net of inventory reserves - $252 and $201 (Note 11)	2,581	2,320
Other current assets	864	873
Total current assets	8,058	7,463
Investments	354	334
Property, plant and equipment, net of accumulated depreciation - $13,874 and $12,995	15,449	15,337
Goodwill, net (Note 9)	2,427	1,935
Other intangible assets, net (Note 9)	1,332	1,185
Deferred income taxes (Note 8)	1,173	1,157
Other assets	1,474	1,487
Total Assets	30,267	28,898
Current liabilities:
Current portion of long-term debt and short-term borrowings	256	11
Accounts payable	1,176	1,587
Other accrued liabilities (Note 6 and Note 13)	2,417	1,923
Total current liabilities	3,849	3,521
Long-term debt (Note 12)	7,822	7,729
Postretirement benefits other than pensions	667	671
Other liabilities (Note 6 and Note 13)	5,072	3,980
Total liabilities	17,410	15,901
Commitments, contingencies and guarantees (Note 6)
Shareholders’ equity (Note 16):
Convertible preferred stock, Series A – Par value $100 per share; Shares authorized 3,100; Shares issued: 2,300	2,300	2,300
Common stock – Par value $0.50 per share; Shares authorized 3.8 billion; Shares issued: 1,722 million and 1,718 million	861	859
Additional paid-in capital – common stock	14,494	14,323
Retained earnings	16,065	16,408
Treasury stock, at cost; Shares held: 961 million and 956 million	(19,926)	(19,812)
Accumulated other comprehensive loss	(1,134)	(1,171)
Total Corning Incorporated shareholders’ equity	12,660	12,907
Noncontrolling interests	197	90
Total equity	12,857	12,997
Total Liabilities and Equity	$ 30,267	$ 28,898

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Consolidated Balance Sheets [Abstract]
Doubtful accounts and allowances	$ 43	$ 41
Inventory reserves	252	201
Accumulated depreciation	$ 13,874	$ 12,995
Convertible preferred stock, par value (in dollars per share)	$ 100	$ 100
Convertible preferred stock, shares authorized (in shares)	3,100	3,100
Convertible preferred stock, shares issued (in shares)	2,300	2,300
Common stock, par value (in dollars per share)	$ 0.50	$ 0.50
Common stock, shares authorized (in shares)	3,800,000,000	3,800,000,000
Common stock, shares issued (in shares)	1,722,000,000	1,718,000,000
Treasury stock, shares held (in shares)	961,000,000	956,000,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows from Operating Activities:
Net income	$ 260	$ 928
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,041	1,026
Amortization of purchased intangibles	87	85
Loss on disposal of assets	107	45
Severance charges	141	25
Severence payments	(126)	(7)
Share-based compensation expense	127	43
Equity in earnings of affiliated companies	(17)	(81)
Deferred tax benefit	(96)	(85)
Retirement plan contributions and benefit payments (in excess of) less than expense	(57)	42
Customer deposits and incentives	184	2
Translated earnings contract gain	(5)	(163)
Unrealized translation (gains) losses on transactions	(54)	87
Tax assessment refunds	101
Asset impairment	217
Transaction-related gain, net	(498)
Changes in certain working capital items:
Trade accounts receivable	(281)	(169)
Inventories	240	(338)
Other current assets	(19)	(220)
Accounts payable and other current liabilities	(139)	(88)
Other, net	193	(119)
Net cash provided by operating activities	1,406	1,013
Cash Flows from Investing Activities:
Capital expenditures	(986)	(1,602)
Proceeds from sale or disposal of assets	27
Sale of equipment to related party		62
Realized gains on translated earnings contracts	10	39
Other, net	17	(33)
Net cash used in investing activities	(932)	(1,534)
Cash Flows from Financing Activities:
Proceeds from issuance of long-term debt, net	212	349
Proceeds from exercise of stock options	49	43
Repurchases of common stock for treasury	(105)	(708)
Dividends paid	(587)	(554)
Other, net	16	37
Net cash used in financing activities	(415)	(833)
Effect of exchange rates on cash	21	(30)
Net increase (decrease) in cash and cash equivalents	80	(1,384)
Cash and cash equivalents at beginning of period	2,434	2,355
Cash and cash equivalents at end of period	$ 2,514	$ 971

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions		Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital Common [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Total Corning Incorporated Shareholders' Equity [Member]	Non-controlling Interests [Member]	Total
Balance at Dec. 31, 2018		$ 2,300	$ 857	$ 14,212	$ 16,303	$ (18,870)	$ (1,010)	$ 13,792	$ 94	$ 13,886
Net (loss) income					499			499	6	505
Other comprehensive income (loss)							(156)	(156)		(156)
Purchase of common stock for treasury						(244)		(244)		(244)
Shares issued to benefit plans and for option exercises				31				31		31
Common dividends					(158)			(158)		(158)
Preferred dividends ($10,625 per share)					(24)			(24)		(24)
Other, net	[1]				(131)	(2)		(133)	(1)	(134)
Balance at Mar. 31, 2019		2,300	857	14,243	16,489	(19,116)	(1,166)	13,607	99	13,706
Balance at Dec. 31, 2018		2,300	857	14,212	16,303	(18,870)	(1,010)	13,792	94	13,886
Balance at Sep. 30, 2019		2,300	859	14,295	16,555	(19,588)	(1,387)	13,034	100	13,134
Balance at Mar. 31, 2019		2,300	857	14,243	16,489	(19,116)	(1,166)	13,607	99	13,706
Net (loss) income					92			92	13	105
Other comprehensive income (loss)							36	36		36
Purchase of common stock for treasury						(151)		(151)		(151)
Shares issued to benefit plans and for option exercises			1	34				35		35
Common dividends					(157)			(157)		(157)
Preferred dividends ($10,625 per share)					(25)			(25)		(25)
Other, net						(12)		(12)	(16)	(28)
Balance at Jun. 30, 2019		2,300	858	14,277	16,399	(19,279)	(1,130)	13,425	96	13,521
Net (loss) income					337			337	4	341
Other comprehensive income (loss)							(257)	(257)		(257)
Purchase of common stock for treasury						(308)		(308)		(308)
Shares issued to benefit plans and for option exercises			1	18				19		19
Common dividends					(156)			(156)		(156)
Preferred dividends ($10,625 per share)					(24)			(24)		(24)
Other, net					(1)	(1)		(2)		(2)
Balance at Sep. 30, 2019		2,300	859	14,295	16,555	(19,588)	(1,387)	13,034	100	13,134
Balance at Dec. 31, 2019		2,300	859	14,323	16,408	(19,812)	(1,171)	12,907	90	12,997
Net (loss) income					(96)			(96)		(96)
Other comprehensive income (loss)							(326)	(326)	(1)	(327)
Purchase of common stock for treasury						(105)		(105)		(105)
Shares issued to benefit plans and for option exercises				17				17		17
Common dividends					(168)			(168)		(168)
Preferred dividends ($10,625 per share)					(24)			(24)		(24)
Other, net					(6)	(1)		(7)		(7)
Balance at Mar. 31, 2020		2,300	859	14,340	16,114	(19,918)	(1,497)	12,198	89	12,287
Balance at Dec. 31, 2019		2,300	859	14,323	16,408	(19,812)	(1,171)	12,907	90	12,997
Balance at Sep. 30, 2020		2,300	861	14,494	16,065	(19,926)	(1,134)	12,660	197	12,857
Balance at Mar. 31, 2020		2,300	859	14,340	16,114	(19,918)	(1,497)	12,198	89	12,287
Net (loss) income					(71)			(71)	6	(65)
Other comprehensive income (loss)							65	65		65
Shares issued to benefit plans and for option exercises			1	58				59		59
Common dividends					(171)			(171)		(171)
Preferred dividends ($10,625 per share)					(25)			(25)		(25)
Other, net						(6)		(6)	(11)	(17)
Balance at Jun. 30, 2020		2,300	860	14,398	15,847	(19,924)	(1,432)	12,049	84	12,133
Net (loss) income					427			427	5	432
Other comprehensive income (loss)							298	298	1	299
Shares issued to benefit plans and for option exercises			1	96				97		97
Common dividends					(171)			(171)		(171)
Preferred dividends ($10,625 per share)					(24)			(24)		(24)
Other, net	[2]				(14)	(2)		(16)	107	91
Balance at Sep. 30, 2020		$ 2,300	$ 861	$ 14,494	$ 16,065	$ (19,926)	$ (1,134)	$ 12,660	$ 197	$ 12,857
[1]	Adjustments to beginning retained earnings include the effect of the accounting change were recorded upon adoption of the new standard for reclassification of stranded tax effects in accumulated other comprehensive income in the amount of $ 53 million, and a reduction of $ 186 million, net of tax, effect from an equity affiliate’s adoption of the new revenue standard.
[2]	Non-controlling interests included $ 102 million related to the consolidation of Hemlock Semiconductor Group (“HSG”). Refer to Note 4 (HSG Transactions) to the consolidated financial statements for more information.

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020		Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Common Dividends (Per Share)	$ 0.22		$ 0.22	$ 0.22	$ 0.20	$ 0.20	$ 0.20
Preferred Dividends (Per Share)	$ 10,625		$ 10,625	$ 10,625	$ 10,625	$ 10,625	$ 10,625
Other, net	$ 91	[1]	$ (17)	$ (7)	$ (2)	$ (28)	$ (134)	[2]
Accumulated other comprehensive loss, net of tax	(1,134)
Accounting Standards Update 2014-09 [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Accumulated other comprehensive loss					53
Accumulated other comprehensive loss, net of tax					$ (186)
Non-controlling Interests [Member]
Other, net	107	[1]	$ (11)			$ (16)	$ (1)	[2]
Non-controlling Interests [Member] | HSG [Member]
Other, net	$ 102
[1]	Non-controlling interests included $ 102 million related to the consolidation of Hemlock Semiconductor Group (“HSG”). Refer to Note 4 (HSG Transactions) to the consolidated financial statements for more information.
[2]	Adjustments to beginning retained earnings include the effect of the accounting change were recorded upon adoption of the new standard for reclassification of stranded tax effects in accumulated other comprehensive income in the amount of $ 53 million, and a reduction of $ 186 million, net of tax, effect from an equity affiliate’s adoption of the new revenue standard.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Significant Accounting Policies [Abstract]
Significant Accounting Policies	1. Significant Accounting Policies Basis of Presentation In these notes, the terms “Corning,” “Company,” “we,” “us,” or “our” mean Corning Incorporated and its subsidiary companies. The accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) and in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been omitted or condensed. These interim consolidated financial statements should be read in conjunction with Corning’s consolidated financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2019 (“2019 Form 10-K”). The unaudited consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results of operations, financial position and cash flows for the interim periods presented. All such adjustments are of a normal recurring nature. The results for interim periods are not necessarily indicative of results which may be expected for any other interim period or for the full year. The equity method of accounting is used for investments in affiliated companies that are not controlled by Corning and in which the Company’s interest is generally between 20 % and 50 % and we have significant influence over the entity. On September 9, 2020, Corning obtained a 100 % controlling interest in Hemlock Semiconductor LLC (“HS LLC”) and an 80.5 % controlling interest in Hemlock Semiconductor Operations LLC (“HSO LLC”), which are affiliated entities within the Hemlock Semiconductor Group (“HSG ”). As of that date, Corning began consolidating HSG. Refer to Note 3 (Investments) and Note 4 (HSG Transactions) to the consolidated financial statements for more information. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. The novel coronavirus (“COVID-19”) pandemic and the resulting adverse impacts to global economic conditions, as well as to Corning’s operations, may impact future estimates including, but not limited to, inventory valuations, fair value measurements, goodwill and long-lived asset impairments, the effectiveness of the Company’s hedging instruments, deferred tax valuation allowances, actuarial losses on retirement benefit plans and discount rate assumptions. Certain prior year amounts have been reclassified to conform to the current-year presentation. These reclassifications had no impact on the results of operations, financial position, or changes in shareholders’ equity. New Accounting Standards On January 1, 2020, Corning adopted Accounting Standards Update (“ASU”) No. 2016-13 ASC (Topic 326), Financial Instruments - Credit Losses. The ASU introduces a new accounting model, the Current Expected Credit Losses model (CECL), which requires earlier recognition of credit losses and additional disclosures related to credit risk. The CECL model utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The Company adopted the CECL model to recognize credit losses of financial assets using a modified retrospective method of accounting as of January 1, 2020. The impact of adopting the new standard to the financial statements was a nominal reduction to beginning retained earnings. Other Accounting Standards No other accounting standards newly issued or adopted as of September 30, 2020, had a material impact on Corning’s financial statements or disclosures.

Restructuring, Impairment and O

Restructuring, Impairment and Other Charges and Credits	9 Months Ended
	Sep. 30, 2020
Restructuring, Impairment and Other Charges and Credits [Abstract]
Restructuring, Impairment and Other Charges and Credits	2. Restructuring, Impairment and Other Charges and Credits In the first nine months of 2020, and in response to uncertain global economic conditions, Corning undertook actions to transform the Company’s cost structure and improve operational efficiency. These actions included a corporate-wide workforce reduction program, disposals of certain assets and accelerated depreciation associated with the capacity realignment of certain manufacturing facilities as well as other exit charges and credits. During the three and nine months ended September 30, 2020 and 2019, the following restructuring, impairment and other charges and credits were recorded (in millions): ``` Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Severance $ 6 $ 18 $ 141 $ 25 Asset impairment 22 217 Capacity realignment 96 107 245 168 Other charges and credits 47 23 130 29 Total restructuring, impairment and other charges and credits $ 171 $ 148 $ 733 $ 222 Severance In the second quarter of 2020, the Company implemented a corporate-wide workforce reduction program. Severance charges were primarily incurred to facilitate realignment of capacity in the Asia regions for the Display Technologies segment, optimize the Optical Communications segment and contain corporate costs. For the three months and nine months ended September 30, 2020, severance charges were $ 6 million and $ 141 million, respectively. As of September 30, 2020, and December 31, 2019, the unpaid severance liabilities of $ 60 million and $ 44 million are expected to be substantially completed within the next twelve months. Asset Impairment Corning incurred a long-lived asset impairment loss for an asset group related to the reassessment and reprioritization of research and development programs within “All Other”. Given the current economic environment and market opportunities, Corning has rescoped and significantly reduced its investment in these research and development programs. Corning performed the impairment analysis for the long-lived asset group using discounted cash flow projections and recorded a pre-tax asset impairment loss of $ 195 million in the second quarter of 2020. During the third quarter of 2020, the Company further reduced investments in these research and development programs and reassessed the business plans. As a result, an additional impairment loss of $ 22 million was recorded, inclusive of an insignificant amount of goodwill, to reduce the book value to the fair value of the asset group , which resulted in a total pre-tax asset impairment loss of $ 217 million for the nine months ended September 30, 2020. Capacity Realignment Capacity realignment for the three and nine months ended September 30, 2020, primarily includes accelerated depreciation and asset disposals associated with the exit of certain facilities and other exit activities in the Display Technologies and Specialty Materials business segments. Capacity realignment for the three and nine months ended September 30, 2019, is primarily comprised of accelerated depreciation associated with the exit of certain facilities in the Display Technologies segment. The following tables present the impact and respective location of total restructuring, impairment, and other charges and credits on the consolidated statements of income (in millions): Three months ended Three months ended September 30, 2020 September 30, 2019 Selling, Research, Selling, Research, general development general development and and and and Gross admin. engineering Gross admin. engineering margin (1) expenses expenses Other Total margin (1) expenses expenses Other Total Severance $ 3 $ 3 $ 6 $ 9 $ 6 $ 3 $ 18 Asset impairment 6 $ 16 22 Capacity realignment 95 1 96 94 13 107 Other charges and credits 26 12 1 $ 8 47 14 5 $ 4 23 Total restructuring, impairment and other charges and credits $ 124 $ 21 $ 18 $ 8 $ 171 $ 117 $ 11 $ 16 $ 4 $ 148 (1) Activity reflected in cost of sales. Nine months ended Nine months ended September 30, 2020 September 30, 2019 Selling, Research, Selling, Research, general development general development and and and and Gross admin. engineering Gross admin. engineering margin (1) expenses expenses Other Total margin (1) expenses expenses Other Total Severance $ 79 $ 34 $ 28 $ 141 $ 10 $ 12 $ 3 $ 25 Asset impairment 6 211 217 Capacity realignment 243 2 245 155 13 168 Other charges and credits 61 51 2 $ 16 130 47 5 $ ( 23 ) 29 Total restructuring, impairment and other charges and credits $ 383 $ 91 $ 243 $ 16 $ 733 $ 212 $ 17 $ 16 $ ( 23 ) $ 222 (1) Activity reflected in cost o f sales.

Investments

Investments	9 Months Ended
	Sep. 30, 2020
Investments [Abstract]
Investments	3. Invest ments Investments are comprised of the following (in millions): Ownership September 30, December 31, interest 2020 2019 Affiliated companies accounted for by the equity method (1) 20 % to 50 % $ 285 $ 291 Other investments 69 43 Subtotal investment assets $ 354 $ 334 Affiliated companies accounted for by the equity method HSG (1)(2) 50 % $ — $ 270 Subtotal investment liabilities $ — $ 270 (1) Amounts reflect Corning’s direct ownership interest in the affiliated companies at September 30, 2020 and December 31, 2019. (2) At December 31, 2019, the negative carrying value of Corning’s investment in HSG was $ 270 million and recorded in other liabilities. Hemlock Semiconductor Group (“HSG”) In 2016, Corning realigned its ownership interest in Dow Corning Corporation, exchanging its 50 % interest in the joint venture between Corning and Dow Chemical Company for a newly formed company that holds a 49.9 % interest in HS LLC and a 40.25 % interest in HSO LLC which were recorded as equity method investments of Corning and were affiliated companies of HSG. DuPont de Nemours, Inc. (“DuPont”) subsequently undertook Dow Chemical Company’s ownership interest in HSG. HSG manufactures polysilicon products for the semiconductor and solar industries, and it is one of the world’s leading providers of ultra-pure polycrystalline silicon to the semiconductor industry. On September 9, 2020, HSG entered into a series of agreements with DuPont. HSG acquired DuPont’s Trichlorosilane (“TCS”) manufacturing assets, which was determined to be a business and recorded as a business combination. The fair value of the purchase price was $ 255 million. In conjunction with this acquisition, HSG settled its pre-existing contract dispute related to a long-term supply agreement with DuPont (“TCS Settlement”) for a contractual amount of $ 175 million, which was determined to have a fair value of $ 200 million. See Note 4 (HSG Transactions) to the consolidated financial statements for more information. Immediately following these transactions, HSG redeemed DuPont’s entire ownership interest in HSG with a fair value of $ 250 million (“Redemption”). Upon completion of the Redemption, Corning obtained a controlling interest of 100 % in Hemlock Semiconductor LLC and 80.5 % in Hemlock Semiconductor Operations LLC and began consolidating HSG as of September 9, 2020. HSG’s net income for the period ended September 8, 2020, included a pre-tax gain recorded in the second quarter of 2020, related to the settlement of a long-term supply agreement of approximately $ 165 million, partially offset by an inventory provision of approximately $ 44 million associated with the settlement of the agreement. Prior to the Redemption, in the third quarter of 2020, HSG recorded a pre-tax loss of $ 200 million resulting from the TCS Settlement as disclosed above. Corning’s share of the pre-tax loss was $81 million and recorded in equity in (losses) earnings of affiliated companies in the consolidated statements of income. Accordingly, Corning’s share of the net impact was an equity loss of $ 19 million. HSG’s results of operations prior to the Redemption were as follows (in millions): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Statements of Operations (1) : Net sales $ 78 $ 200 $ 423 $ 566 Gross profit $ 21 $ 61 $ 87 $ 205 Net (loss) income $ ( 192 ) $ 46 $ 11 $ 185 Net (loss) income attributable to HSG $ ( 154 ) $ 42 $ 44 $ 165 Corning's equity in (losses) earnings of affiliated companies $ ( 77 ) $ 21 $ 22 $ 81 Related party transactions: Intercompany sales within HSG (included in net sales) $ 12 $ 31 $ 55 $ 85 (1) The three and nine months ended September 30, 2020, only include HSG’s results of operations through September 8, 2020. Immediately following the Redemption, Corning began consolidating HSG on September 9, 2020 .

HSG Transactions

HSG Transactions	9 Months Ended
	Sep. 30, 2020
HSG Transactions [Abstract]
HSG Transactions	4. HSG Transactions In 2016, Corning realigned its ownership interest in Dow Corning Corporation, exchanging its 50 % interest in the joint venture between Corning and Dow Chemical Company for a newly formed company that holds interests in HS LLC and HSO LLC, which were recorded as equity method investments of Corning and were affiliated companies of HSG. On September 9, 2020, HSG acquired DuPont’s TCS manufacturing assets, which was determined to be a business and recorded as a business combination. The fair value of the purchase price was $ 255 million. In conjunction with this acquisition, HSG settled a dispute with DuPont for a contractual amount of $ 175 million, related to a pre-existing long-term supply agreement with a fair value of $ 200 million. HSG will pay for the TCS Settlement over three years with equal annual payments of approximately $ 58 million, which was a non-cash financing activity in the current reporting period. The TCS Settlement was recorded as a pre-tax loss of $ 200 million, which was its fair value estimate based on the income approach. Corning’s share of the TCS Settlement was a pre-tax loss of $ 81 million, which was recorded in equity in (losses) earnings of affiliated companies in Corning’s consolidated statements of income for the three and nine months ended September 30, 2020. Subsequent to the closing of the TCS purchase and execution of the TCS Settlement, HSG redeemed DuPont’s entire ownership interest in HSG for $ 250 million. The Redemption was funded with HSG’s existing cash on-hand of $ 75 million and its newly obtained third-party debt of $ 175 million, maturing on September 8, 2021. The third-party debt was a non-cash financing activity in the current reporting period. Upon completion of the Redemption, Corning obtained controlling interests of 100 % in HS LLC and 80.5 % in HSO LLC. Corning accounted for the Redemption under the acquisition method of accounting in accordance with business combinations without the transfer of net cash consideration. The Redemption price of $ 250 million approximated the fair value of Corning’s equity interest in HSG immediately preceding the Redemption. The fair value of Corning’s equity interest in HSG was estimated by applying the income approach, which was based on significant inputs such as revenue and profitability as well as key assumptions including a discount rate of 16.5 % and terminal growth rate of zero . As no net-cash consideration was transferred, the fair value of Corning’s previously held equity interest in HSG was used to measure the goodwill of the Redemption. Corning had a pre-tax gain of $ 498 million on its previously held equity investment in HSG following the Redemption. The gain was calculated based on the fair value of the investment immediately preceding the Redemption and included in the transaction-related gain, net in Corning’s consolidated statements of income for the three and nine months ended September 30, 2020. The net gain on previously owned equity was calculated as follows (in millions): Fair value of previously held equity investment $ 250 Equity investment liability balance as of acquisition date ( 248 ) Corning's gain on previously held equity investment $ 498 The following table summarizes the amounts of recorded assets acquired and liabilities assumed as of September 9, 2020, which includes the TCS assets and liabilities acquired by HSG immediately prior to the Redemption and the consolidation by Corning. Recognized amounts of identified assets and liabilities recorded at fair value (in millions): Inventory $ 503 Property, plant and equipment 657 Intangible assets 285 Other current and non-current assets (1) 166 Short-term borrowings ( 178 ) Trade payables and other accrued liabilities ( 322 ) Other liabilities ( 1,254 ) Total identified net liabilities ( 143 ) Non-controlling interests (2) ( 102 ) Total fair value of Corning's previously held equity investment (2) ( 250 ) Goodwill (3) $ 495 (1) The other current and non-current assets included a contingent consideration asset of $ 20 million at fair value for a cost adjustment contract related to the TCS Transaction. Refer to Note 3 (Investments), Note 4 (HSG Transactions) and Note 15 (Fair Value Measurements) to the consolidated financial statements for additional information. (2) The purchase price being used to measure the goodwill of the Redemption is $ 352 million, including the fair value of Corning’s previously held equity interest and non-controlling interest, in the amount of $ 250 million and $ 102 million, respectively. (3) The goodwill recognized is not deductible for U.S. income tax purposes . The goodwill was allocated to “All Other” within segment reporting as disclosed in Note 18 (Reportable Segments) to the consolidated financial statements for more information. Upon completion of the Redemption and resulting consolidation , Corning recorded a customer deposit liability of $ 264 million at the fair value of refundable payments that HSG received from a customer under a long-term supply agreement. The discount rates being used to calculate the present value of the customer deposit range from 2.54 % to 3.23 %. The deposits will be repaid from 2029 to 2034 provided that all purchase obligations of this customer under the supply agreement have been satisfied. In addition, Corning recorded deferred revenues of $ 1,070 million at fair value related to the performance obligations of non-refundable consideration previously received by HSG from its customers under long term supply agreements. The fair values of deferred revenue were estimated by applying a bottom-up cost buildup method of the cost approach based on significant inputs such as the cost to fulfill the obligations as well as key assumptions including a normal profit margin as of September 9, 2020. The goodwill is primarily related to other intangibles and synergies of the acquired business which do not qualify for separate recognition. Intangible assets consist primarily of $ 215 million of developed technologies and know-how, and $ 70 million of other intangibles that are amortized over the weighted average useful life of approximately 20 and 15 years, respectively. Acquisition-related costs of $ 11 million for the nine-months ended September 30, 2020, included costs for legal and other professional services and were included in selling, general and administrative expense in the consolidated statements of income. The fair value of the non-controlling interest in HSG was estimated to be $ 102 million by applying the income approach, which used the same key assumptions as the estimate of fair value for Corning’s equity interest in HSG. The amounts of revenue and net income of HSG since September 9, 2020, have been consolidated in “All Other” and are not material to Corning’s consolidated statements of income for the three and nine months ended September 30, 2020. Supplemental pro forma financial information was not provided because the purchased business is not material to Corning’s consolidated financial statements.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2020
Revenue [Abstract]
Revenue	5. Revenue Revenue Disaggregation Table The following table shows revenues by major product categories, similar to the Company’s reportable segment disclosure. Within each product category, contract terms, conditions and economic factors affecting the nature, amount, timing and uncertainty of revenue recognition and cash flows are substantially similar. The commercial markets and selling channels are also similar. Except for an inconsequential amount of revenue for Telecommunications products, product category revenues are recognized at point in time when control transfers to the customer. Revenues by product category are as follows (in millions): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Display products $ 834 $ 780 $ 2,211 $ 2,395 Telecommunication products 909 1,008 2,587 3,162 Specialty glass products 570 463 1,339 1,141 Environmental substrate and filter products 369 380 891 1,084 Life science products 220 250 707 744 All Other 99 53 218 160 Total revenue $ 3,001 $ 2,934 $ 7,953 $ 8,686 Impact of foreign currency movements (1) 6 35 66 119 Cumulative adjustment related to customer contract 105 Net sales of reportable segments and All Other $ 3,007 $ 2,969 $ 8,124 $ 8,805 (1) This amount primarily represents the impact of foreign currency adjustments in the Display Technologies, Environmental Technologies and Life Sciences segments. At the end of 2015, Corning entered into an agreement with a customer pursuant to which Corning exchanged contingent consideration, for the incremental fair value associated with several commercial agreements, including the amendment of the customer’s long-term supply agreement. The net present fair value ($ 212 million) of the commercial benefit asset related to the long-term supply agreement was reclassified to the other asset line of the consolidated balance sheets and amortized over the term of agreement as a reduction in revenue. During March 2020, this customer announced its decision to exit its production of LCD panels by the end of 2020. Based on this announcement, Corning recorded a cumulative adjustment of $ 105 million during the first quarter of 2020 as a reduction to revenue and will reflect the remaining balance as a reduction to revenue over the remainder of the current year. Due to the one-time nature of this cumulative adjustment, we have excluded it from segment results. However, it is included in the reconciliation from segment net income (loss) to consolidated net income. Refer to Note 18 (Reportable Segments) to the consolidated financial statements for additional information. Contract Assets and Liabilities Contract assets, such as incremental costs to obtain or fulfill contracts, are an insignificant component of Corning’s revenue recognition process. Most of Corning’s cost of fulfillment as a manufacturer of products is classified as inventory, fixed assets and intangible assets, which are accounted for under the respective guidance for those asset types. Other costs of contract fulfillment are immaterial due to the nature of Corning’s products and their respective manufacturing processes. Contract liabilities include deferred revenue, other advanced payments and customer deposits. Other advanced payments are not significant to Corning’s operations and are classified as part of other accrued liabilities in the financial statements. Customer deposits are predominately related to Display products and deferred revenue is predominately related to obtaining a controlling interest in HSG. Both are classified as other accrued liabilities and other liabilities, as appropriate, and are disclosed below. Refer to Note 4 (HSG Transactions ) to the consolidated financial statements for additional information. Shipping and handling fees are treated as a fulfillment cost and not as a separate performance obligation under the terms of the Company’s revenue contracts due to the perfunctory nature of the shipping and handling obligations. Corning Customer Deposits As of September 30, 2020, and December 31, 2019, Corning had customer deposits of approximately $ 1.3 billion and $ 1.0 billion, respectively. The majority of the customer deposits were non-refundable cash deposits for customers to secure rights to an amount of glass produced by Corning under long-term supply agreements. The duration of these long-term supply agreements ranges up to 10 years. As glass is shipped to customers, Corning will recognize revenue and reduce the amount of the customer deposit liability. HSG Customer Deposits During the third quarter of 2020, Corning obtained a controlling interest in HSG and recorded a customer deposit liability of $ 264 million , at the fair value , of refundable payments that HSG received from a customer under a long-term supply agreement. The discount rates being used to calculate the present value of the customer deposit range from 2.54 % to 3.23 %. The deposits will be repaid from 2029 to 2034 provided that all purchase obligations of this customer under the supply agreement have been satisfied. In the nine months ended September 30, 2020 and 2019, credits issued for customer deposits were $ 107 million and $ 37 million, respectively. As of September 30, 2020, and December 31, 2019, $ 1,153 million and $ 927 million were recorded as other long-term liabilities, respectively. The remaining $ 181 million and $ 104 million, respectively, were classified as other current liabilities. HSG Deferred Revenue During the third quarter of 2020, Corning obtained a controlling interest in HSG and recorded deferred revenue of $ 1,070 million at fair value related to the performance obligations of non-refundable consideration previously received by HSG from its customers under long term supply agreements. The fair values of deferred revenue were estimated by applying a bottom-up cost buildup method of the cost approach based on significant inputs such as the cost to fulfill the obligations as well as key assumptions including a normal profit margin as of September 9, 2020. The deferred revenue recorded from customer deposits is tracked on a per customer contract unit basis. As customers take delivery of the committed volumes under the terms of the contracts, a per unit amount of deferred revenue is recognized when control of promised goods is transferred to the customer based upon the units shipped as compared to the remaining contractual units. As of September 30, 2020, $ 931 million was classified as a long-term liability and $ 132 million remaining was classified as a current liability. These balances reflect deferred revenue reductions since September 9, 2020.

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2020
Commitments, Contingencies and Guarantees [Abstract]
Commitments, Contingencies and Guarantees	6. Commitments, Contingencies and Guarantees Corning is a defendant in various lawsuits and is subject to various claims that arise in the normal course of business, the most significant of which are summarized below. In the opinion of management, the likelihood that the ultimate disposition of these matters will have a material adverse effect on Corning’s consolidated financial position, liquidity, or results of operations, is remote. Asbestos Claims Corning and PPG Industries, Inc. each owned 50 % of the capital stock of Pittsburgh Corning Corporation (“PCC”). PCC filed for Chapter 11 reorganization in 2000, and the Modified Third Amended Plan of Reorganization for PCC (the “Plan”) became effective in April 2016. At December 31, 2016, the Company’s liability under the Plan was $ 290 million, which is required to be paid through a series of fixed payments that began in the second quarter of 2017. Payments of $ 35 million and $ 50 million were made in June 2020 and June 2019, respectively. The total amount of remaining payments due in years 2021 through 2022 is $ 100 million, of which $ 50 million will be paid in the second quarter of 2021 and is classified as a current liability. The remaining $ 50 million is classified as a non-current liability. Non-PCC Asbestos Claims Corning is a defendant in certain cases alleging injuries from asbestos unrelated to PCC (the “non-PCC asbestos claims”) which had been stayed pending the confirmation of the Plan. The stay was lifted on August 25, 2016. At September 30, 2020 and December 31, 2019, the amount of the reserve for these non-PCC asbestos claims was estimated to be $ 97 million and $ 98 million, respectively. The reserve balance as of September 30, 2020 represents the undiscounted projection of claims and related legal fees for the estimated life of the litigation. Dow Corning Chapter 11 Related Matters Until June 1, 2016, Corning and The Dow Chemical Company (“Dow”) each owned 50 % of the common stock of Dow Corning Corporation (“Dow Corning”). On May 31, 2016, Corning and Dow realigned their ownership interest in Dow Corning. Following the realignment, Corning no longer owned any interest in Dow Corning. With the realignment, Corning agreed to indemnify Dow Corning for 50 % of Dow Corning’s non-ordinary course, pre-closing liabilities to the extent such liabilities exceed the amounts reserved for them by Dow Corning as of May 31, 2016, subject to certain conditions and limits. Dow Corning Breast Implant Litigation In May 1995, Dow Corning filed for bankruptcy protection to address pending and claimed liabilities arising from many thousands of breast implant product lawsuits. On June 1, 2004, Dow Corning emerged from Chapter 11 with a Plan of Reorganization (the “Plan”) which provided for the settlement or other resolution of implant claims. The Plan also includes releases for Corning and Dow as shareholders in exchange for contributions to the Plan. Under the terms of the Plan, Dow Corning has established and funded a Settlement Trust and a Litigation Facility, referred to above, to provide a means for tort claimants to settle or litigate their claims. Inclusive of insurance, Dow Corning has paid approximately $ 1.8 billion to the Settlement Trust. As of May 31, 2016, Dow Corning had recorded a reserve for breast implant litigation of $ 290 million. In the event Dow Corning’s total liability for these claims exceeds such amount, Corning may be required to indemnify Dow Corning for up to 50 % of the excess liability, subject to certain conditions and limits. As of September 30, 2020, Dow Corning had recorded a reserve for breast implant litigation of $ 160 million. As a result, Corning does not believe its indemnity obligation for Dow Corning’s breast implant litigation liability, if any, will be material. Dow Corning Bankruptcy Pendency Interest Claims As a separate matter arising from the bankruptcy proceedings, Dow Corning has been defending claims asserted by commercial creditors who claimed additional compounded interest at default and state statutory judgment rates as well as attorneys’ fees and other enforcement costs, during the period from May 1995 through June 2004. As of May 31, 2016, Dow Corning had recorded a reserve for these claims of $ 107 million. Dow Corning settled those claims as of September 30, 2019 and received approval of the settlement from the bankruptcy court. Corning does not believe its indemnity obligation, if any, for Dow Corning’s liability to be material. Dow Corning Environmental Claims In September 2019, Dow Corning formally notified Corning of certain environmental matters for which Dow Corning asserts that it has, or will, experience losses arising from remediation and response at a number of sites. In the event Dow Corning incurs a liability for these claims, Corning may be required to indemnify Dow Corning for up to 50 % of that liability, subject to certain conditions and limits. As of September 30, 2020, Corning has determined a potential liability for certain of these environmental matters to be probable, and the amount recorded was not material. For the remainder of the environmental matters, the Company cannot reasonably estimate the indemnification liability owed to Dow Corning. Environmental Litigation Corning has been named by the Environmental Protection Agency (“the Agency”) under the Superfund Act, or by state governments under similar state laws, as a potentially responsible party for 15 active hazardous waste sites. Under the Superfund Act, all parties who may have contributed any waste to a hazardous waste site, identified by the Agency, are jointly and severally liable for the cost of cleanup unless the Agency agrees otherwise. It is Corning’s policy to accrue for its estimated liability related to Superfund sites and other environmental liabilities related to property owned by Corning based on expert analysis and continual monitoring by both internal and external consultants. At September 30, 2020 and December 31, 2019, Corning had accrued approximately $ 78 million and $ 41 million, respectively, for the undiscounted estimated liability for environmental cleanup and related litigation. Based upon the information developed to date, management believes that the accrued reserve is a reasonable estimate of the Company’s liability and that the risk of an additional loss in an amount materially higher than that accrued is remote.

Employee Retirement Plans

Employee Retirement Plans	9 Months Ended
	Sep. 30, 2020
Employee Retirement Plans [Abstract]
Employee Retirement Plans	7. Employee Retirement Plans Corning has defined benefit pension plans covering certain domestic and international employees. The Company’s funding policy is to contribute, over time, an amount exceeding the minimum requirements to achieve the Company’s long-term funding targets. Corning contributed $ 60 million and $ 80 million in cash to the U.S. pension plans for the three and nine months ended September 30, 2020, respectively, and plans to contribute $ 45 million in cash to the international plans during the fourth quarter of 2020. The following table summarizes the components of net periodic benefit cost for Corning’s defined benefit pension and postretirement health care and life insurance plans (in millions): Pension benefits Postretirement benefits Three months ended Nine months ended Three months ended Nine months ended September 30, September 30, September 30, September 30, 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 29 $ 25 $ 87 $ 76 $ 2 $ 3 $ 7 $ 7 Interest cost 32 37 94 111 5 7 15 21 Expected return on plan assets ( 49 ) ( 42 ) ( 147 ) ( 128 ) Amortization of actuarial net gain 1 ( 1 ) 1 ( 1 ) Amortization of prior service cost (credit) 1 2 4 5 ( 2 ) ( 2 ) ( 5 ) ( 6 ) Recognition of actuarial (gain) loss ( 2 ) 23 Total pension and postretirement benefit expense $ 13 $ 22 $ 36 $ 87 $ 6 $ 7 $ 18 $ 21 The components of net periodic benefit cost other than the service cost component are included in the line item other expense, net, in the consolidated statements of income .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Taxes [Abstract]
Income Taxes	8. Income Taxes The provision for income taxes and the related effective income tax rates are as follows (in millions): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Provision for income taxes $ ( 23 ) $ ( 71 ) $ ( 33 ) $ ( 271 ) Effective tax rate 5.1 % 17.4 % 11.3 % 22.6 % For the three months ended September 30, 2020, the effective income tax rate differed from the United States (“U.S.”) statutory rate of 21 %, primarily due to an estimate of income tax benefits generated by a current year net operating loss that will be carried-back to prior years as allowed under the CARES Act and changes of estimates based on the final U.S. tax return which were partially offset by additional income tax reserves. For the nine months ended September 30, 2020, the effective income tax rate differed from the U.S. statutory rate of 21 % primarily due to an estimate of income tax benefits generated by a current year net operating loss that will be carried-back to prior years as allowed under the CARES Act and changes of estimates based on the final U.S. tax return which were partially offset by income tax reserves, an adjustment to the permanently reinvested foreign income position and foreign valuation allowances on deferred tax assets. Prior to the HSG Transactions, Corning had a deferred tax asset resulting from its equity method investment in HSG. As a result of the HSG Transactions, Corning adjusted its deferred taxes by approximately $ 117 million to reflect the impacts of the HSG Transactions, specifically the pre-tax gain of $ 498 million on its previously held equity investment. The resulting net deferred tax liability is approximately $ 9 million at September 30, 2020. For the three months ended September 30, 2019, the effective income tax rate differed from the United States (“U.S.”) statutory rate of 21 % primarily due to an increase in the estimated impact of base erosion and anti-abuse tax (“BEAT”) offset by changes of estimates based on the U.S. Federal 2018 tax return filed in October 2019, primarily due to tax reform. For the nine months ended September 30, 2019, the effective income tax rate differed from the U.S. statutory rate of 21 % primarily due to an increase in the estimated impact of BEAT offset by changes of estimates based on the U.S. Federal 2018 tax return filed in October 2019, primarily due to tax reform, additional net tax expense of $ 86 million driven by changes to tax reserves and the release of foreign valuation allowances on deferred tax assets. Corning Precision Materials is currently appealing certain tax assessments and tax refund claims for tax years 2010 through 2018. The Company is required to deposit the disputed tax amounts with the South Korean government as a condition of its appeal of any tax assessments. Corning believes that it is more likely than not we will prevail in the appeal process. During the first nine months of 2020, we received refunds of $ 101 million related to these claims . As of September 30, 2020, a non-current receivable of $ 348 million related to the appeals was recorded. As of December 31, 2019, a current and non-current receivable of $ 33 million and $ 415 million, respectively , had been recorded.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets	9. Goodwill and Other Intangible Assets The carrying amount of goodwill by segment as of September 30, 2020 and December 31, 2019 is as follows (in millions): Display Optical Specialty Life All Technologies Communications Materials Sciences Other Total Balance at December 31, 2019 $ 129 $ 931 $ 150 $ 616 $ 109 $ 1,935 Acquired goodwill (1) 495 495 Foreign currency translation adjustment and other ( 2 ) 1 1 ( 3 ) ( 3 ) Balance at September 30, 2020 $ 127 $ 932 $ 150 $ 617 $ 601 $ 2,427 (1) The Company obtained a controlling interest in HSG during the third quarter of 2020. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information on this transaction. Corning’s gross goodwill balances as of September 30, 2020 and December 31, 2019 were $ 8.9 billion and $ 8.4 billion, respectively. Accumulated impairment losses were $ 6.5 billion as of September 30, 2020 and December 31, 2019, and were generated primarily through goodwill impairments related to the Optical Communications segment. Other intangible assets are as follows (in millions): September 30, 2020 December 31, 2019 Accumulated Accumulated Gross amortization Net Gross amortization Net Amortized intangible assets: Patents, trademarks, and trade names $ 499 $ 248 $ 251 $ 469 $ 228 $ 241 Customer lists and other 1,505 424 1,081 1,301 357 944 Total $ 2,004 $ 672 $ 1,332 $ 1,770 $ 585 $ 1,185 Corning’s amortizable intangible assets are primarily related to the Optical Communications and Life Sciences segments and “All Other”. The net carrying amount of intangible assets increased during the first nine months of 2020, primarily driven by the consolidation of HSG, foreign currency translation and other adjustments of $ 4 million partially offset by amortization of $ 87 million and an impairment of $ 55 million. Intangible assets obtained from HSG consist primarily of $ 215 million of developed technologies and know-how, and $ 70 million of other intangibles that are amortized over the weighted average useful life of approximately 20 and 15 years, respectively. Annual amortization expense related to intangible assets is estimated to be $ 133 million for 2021, $ 131 million 20 22, $ 130 million for 2023, $ 128 million for 2024 , and $ 126 million for 2025. Refer to Note 4 (HSG Transactions ) to the consolidated financial statements for additional information.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Common Share [Abstract]
Earnings Per Common Share	10. Earnings per Common Share The following table sets forth the computation of basic and diluted earnings per common share (in millions, except per share amounts): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net income attributable to Corning Incorporated $ 427 $ 337 $ 260 $ 928 Less: Series A convertible preferred stock dividend 24 24 73 73 Net income available to common stockholders – basic 403 313 187 855 Plus: Series A convertible preferred stock dividend 24 24 73 Net income available to common stockholders – diluted $ 427 $ 337 $ 187 $ 928 Weighted-average common shares outstanding – basic 760 775 760 780 Effect of dilutive securities: Employee stock options and other dilutive securities 14 7 8 8 Series A convertible preferred stock (1) 115 115 115 Weighted-average common shares outstanding – diluted 889 897 768 903 Basic earnings per common share $ 0.53 $ 0.40 $ 0.25 $ 1.10 Diluted earnings per common share $ 0.48 $ 0.38 $ 0.24 $ 1.03 Anti-dilutive potential shares excluded from diluted earnings per common share: Series A convertible preferred stock (1) 115 Employee stock options and awards 3 2 7 2 Total 3 2 122 2 (1) For the nine months ended September 30, 2020, the Series A preferred stock was anti-dilutive; therefore, it was excluded from the calculation of diluted earnings per share.

Inventories, Net of Inventory R

Inventories, Net of Inventory Reserves	9 Months Ended
	Sep. 30, 2020
Inventories, Net of Inventory Reserves [Abstract]
Inventories, Net of Inventory Reserves	11. Inventories, Net of Inventory Reserves Inventories, net of inventory reserves comprise the following (in millions): September 30, December 31, 2020 2019 Finished goods $ 1,322 $ 973 Work in process 370 421 Raw materials and accessories 412 481 Supplies and packing materials 477 445 Total inventories, net of inventory reserves $ 2,581 $ 2,320 Corning obtained a controlling interest in HSG as of September 9, 2020. Consolidated inventory balances as of September 30, 2020, included $ 503 million of inventory from HSG. Refer to Note 4 (HSG Transactions ) to the consolidated financial statements for additional information.

Debt

Debt	9 Months Ended
	Sep. 30, 2020
Debt [Abstract]
Debt	12 . Debt Based on borrowing rates currently available to us for loans with similar terms and maturities, the fair value of long-term debt was $ 9.2 billion and $ 8.5 billion at September 30, 2020 and December 31, 2019, respectively, compared to recorded book values of $ 7.8 billion and $ 7.7 billion at September 30, 2020 and December 31, 2019, respectively. The Company measures the fair value of its long-term debt using Level 2 inputs based primarily on current market yields for its existing debt traded in the secondary market. In conjunction with the change in control of HSG on September 9, 2020, a variable interest rate loan of $ 175 million U.S. dollars (“USD”), maturing on September 8, 2021, was made to DC HSC Holdings, LLC, now a consolidated subsidiary of Corning and is reflected in Current portion of long term debt and short-term borrowings in Corning’s consolidated balance sheets. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information. Corning had no outstanding commercial paper at September 30, 2020 and December 31, 2019. Debt Issuances 2020 During the second quarter of 2020, Corning established an incremental liquidity facility for 25 billion Japanese yen, equivalent to $ 232 million USD, with a maturity of three years . As of September 30, 2020, the facility has not been drawn upon. In the first quarter of 2020, Corning established two unsecured variable rate loan facilities for 1,050 million Chinese yuan, equivalent to $ 150 million USD, and 749 million Chinese yuan, equivalent to $ 105 million USD, each with a maturity of five year s . Borrowings under these loan facilities through the end of the third quarter totaled 1,491 million Chinese yuan, or approximately $ 212 million USD. These Chinese yuan-denominated proceeds will not be converted into USD and will be used for capital projects. Payments of principal and interest on the Notes will be in Chinese yuan, or should yuan be unavailable due to circumstances beyond Corning’s control, a USD equivalent. 2019 In the third quarter of 2019, Corning issued two Japanese yen-denominated debt securities (the “Notes”), as follows:  ¥ 31.3 billion 1.153 % senior unsecured notes with a maturity of 12 years; and  ¥ 5.9 billion 1.513 % senior unsecured notes with a maturity of 20 years. The proceeds from the Notes were received in Japanese yen and converted to USD on the date of issuance. The net proceeds received in USD, after deducting offering expenses, were approximately $ 349 million and will be used for general corporate purposes. Payments of principal and interest on the Notes will be in Japanese yen, or should yen be unavailable due to circumstances beyond Corning’s control, a USD equivalent. On a quarterly basis, Corning will recognize the foreign currency translation gains and losses resulting from changes in exchange rates within accumulated other comprehensive income (loss) in shareholders’ equity. Cash proceeds from loans and debt issuances are disclosed as financing activities, and cash payments for interest will be disclosed as operating activities, in the consolidated statements of cash flows.

Other Liabilities

Other Liabilities	9 Months Ended
	Sep. 30, 2020
Other Liabilities [Abstract]
Other Liabilities	13. Other Liabilities Other liabilities follow (in millions): September 30, December 31, 2020 2019 Current liabilities: Wages and employee benefits $ 501 $ 565 Income taxes 194 182 Derivative instruments (Note 15) 143 100 Asbestos and other litigation (Note 6) 63 57 Deferred revenue (Note 5) 132 Settlement liability (Note 4) 58 Customer deposits (Note 5) 181 104 Short-term leases 89 62 Other current liabilities 1,056 853 Other accrued liabilities $ 2,417 $ 1,923 Non-current liabilities: Defined benefit pension plan liabilities $ 927 $ 980 Derivative instruments (Note 15) 131 165 Asbestos and other litigation (Note 6) 144 196 Deferred revenue (Note 5) 931 Settlement liability (Note 4) 117 Investment in HSG (1) 270 Customer deposits (Note 5) 1,153 927 Deferred tax liabilities 247 325 Long-term leases 606 450 Other non-current liabilities 816 667 Other liabilities $ 5,072 $ 3,980 (1) The negative carrying value resulted from a one-time charge to this entity as of December 31, 2019 for the impairment of certain assets .

Hedging Activities

Hedging Activities	9 Months Ended
	Sep. 30, 2020
Hedging Activities [Abstract]
Hedging Activities	14. Hedging Activities Cash Flow Hedges Corning’s cash flow hedging activities utilize over-the-counter (“OTC”) foreign exchange forward contracts to reduce the risk that movements in exchange rates will adversely affect the net cash flows resulting from the sale of products to customers and purchases from suppliers. The total gross notional values for foreign currency cash flow hedges are $ 0.8 billion and $ 2.1 billion at September 30, 2020 and December 31, 2019, respectively, with maturities spanning the years 2020 through 2023. Corning defers gains and losses related to the cash flow hedges into accumulated other comprehensive loss on the consolidated balance sheets until the hedged item impacts earnings. At September 30, 2020, the amount expected to be reclassified into earnings within the next 12 months is a pre-tax gain of $ 11 million. As of March 31, 2020, a loss of $ 14 million was reclassified from accumulated other comprehensive loss into other expense, net, due to the de-designation of certain cash flow hedges related to Japanese yen-denominated sales. The effect of cash flow hedges on Corning’s consolidated statements of income and comprehensive income is not material for the three and nine months ended September 30, 2020 and 2019. Undesignated Hedges Corning also uses OTC foreign exchange forward and option contracts that are not designated as hedging instruments for accounting purposes. The undesignated hedges limit exposure to foreign functional currency fluctuations related to certain subsidiaries’ monetary assets, monetary liabilities and net earnings in foreign currencies. The table below includes a total gross notional value for translated earnings contracts of $ 8.9 billion and $ 12.2 billion at September 30, 2020 and December 31, 2019, respectively. These include gross notional value for average rate forward contracts of $ 6.6 billion and $ 9.7 billion, zero-cost collars and purchased put or call options of $ 2.3 billion and $ 2.5 billion at September 30, 2020 and December 31, 2019, respectively. The majority of the average rate forward contracts hedge a significant portion of the Company’s exposure to the Japanese yen with maturities spanning the years 2020-2023 and with gross notional values of $ 5.4 billion and $ 7.7 billion at September 30, 2020 and December 31, 2019, respectively. The average rate forward contracts also partially hedge the impacts of the South Korean won, Chinese yuan, euro, new Taiwan dollar and British pound translation on the Company’s projected net income. With respect to the zero-cost collars, the gross notional amount includes the value of both the put and call options. However, due to the nature of the zero-cost collars, only the put or the call option can be exercised at maturity. The following table summarizes the notional amounts and respective fair values of Corning’s derivative financial instruments on a gross basis for September 30, 2020 and December 31, 2019 (in millions): Asset derivatives Liability derivatives Notional amount Balance Fair value Balance Fair value Sept. 30, Dec. 31, sheet Sept. 30, Dec. 31, sheet Sept. 30, Dec. 31, 2020 2019 location 2020 2019 location 2020 2019 Derivatives designated as hedging instruments Foreign exchange contracts $ 826 $ 2,123 Other current assets $ 18 $ 38 Other accrued liabilities $ ( 7 ) $ ( 7 ) Other assets 14 37 Other liabilities ( 1 ) ( 4 ) Derivatives not designated as hedging instruments Foreign exchange and other contracts 6,816 1,815 Other current assets 28 5 Other accrued liabilities ( 61 ) ( 19 ) Other assets 32 21 Other liabilities ( 58 ) Translated earnings contracts 8,906 12,166 Other current assets 58 114 Other accrued liabilities ( 75 ) ( 74 ) Other assets 33 34 Other liabilities ( 72 ) ( 161 ) Total derivatives $ 16,548 $ 16,104 $ 183 $ 249 $ ( 274 ) $ ( 265 ) The following tables summarize the effect on the consolidated financial statements relating to Corning’s derivative financial instruments (in millions): Effect of derivative instruments on the consolidated financial statements for the three months ended September 30, Derivatives in hedging Gain (loss) recognized in other Location of gain (loss) reclassified from Gain (loss) reclassified from relationships for comprehensive income (OCI) accumulated OCI into income accumulated OCI into income cash flow hedges 2020 2019 effective (ineffective) 2020 2019 Net sales $ ( 2 ) Foreign exchange contracts $ 16 $ ( 26 ) Cost of sales 3 $ 2 Total cash flow hedges $ 16 $ ( 26 ) $ 1 $ 2 Effect of derivative instruments on the consolidated financial statements for the nine months ended September 30, Derivatives in hedging Gain (loss) recognized in other Location of gain (loss) reclassified from Gain (loss) reclassified from relationships for comprehensive income (OCI) accumulated OCI into income accumulated OCI into income cash flow hedges 2020 2019 effective (ineffective) 2020 2019 Net sales $ ( 4 ) Cost of sales 7 $ 7 Foreign exchange contracts $ ( 51 ) $ ( 19 ) Other expense, net (1) ( 14 ) Total cash flow hedges $ ( 51 ) $ ( 19 ) $ ( 11 ) $ 7 Gains recognized in income Three months ended Nine months ended Location of gains September 30, September 30, Undesignated derivatives recognized in income 2020 2019 2020 2019 Foreign exchange and other contracts – balance sheet, loans and other Other (expense) income, net (1) $ ( 48 ) $ 19 $ ( 62 ) $ 38 Translated earnings contracts Translated earnings contract (loss) gain, net ( 100 ) 86 5 163 Total undesignated $ ( 148 ) $ 105 $ ( 57 ) $ 201 (1) A loss of $ 14 million was reclassified from accumulated other comprehensive loss into other expense, net, resulting from the de-designation of certain cash flow hedges .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Measurements [Abstract]
Fair Value Measurements	15. Fair Value Measurements Fair value standards under GAAP define fair value, establish a framework for measuring fair value in applying generally accepted accounting principles, and require disclosures about fair value measurements. The standards also identify two kinds of inputs that are used to determine the fair value of assets and liabilities: observable and unobservable. Observable inputs are based on market data or independent sources, while unobservable inputs are based on the Company’s own market assumptions. Once inputs have been characterized, the inputs are prioritized into one of three broad levels (provided in the table below) used to measure fair value. Fair value standards apply whenever an entity is measuring fair value under other accounting pronouncements that require or permit fair value measurement and require the use of observable market data when available. The following tables provide fair value measurement information for the Company’s major categories of financial assets and liabilities measured on a recurring basis (in millions): Fair value measurements at reporting date using Quoted prices in Significant other Significant active markets for observable unobservable September 30, identical assets inputs inputs 2020 (Level 1) (Level 2) (Level 3) Current assets: Other current assets (1)(2) $ 132 $ 104 $ 28 Non-current assets: Investments (3) $ 13 $ 13 Other assets (1)(2) $ 95 $ 79 $ 16 Current liabilities: Other accrued liabilities (1) $ 143 $ 143 Non-current liabilities: Other liabilities (1) $ 131 $ 131 (1) Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities. (2) Included in other current assets and other assets are auction rate securities of $ 24 million and a contingent consideration asset for a cost adjustment contract of $ 20 million, resulting from the HSG Transactions as of September 9, 2020, that were measured using unobservable (Level 3) inputs. (3) Included in the investments were equity securities with readily available fair values that were measured using Level 1 inputs. Fair value measurements at reporting date using Quoted prices in Significant other Significant active markets for observable unobservable December 31, identical assets inputs inputs 2019 (Level 1) (Level 2) (Level 3) Current assets: Other current assets (1) $ 157 $ 157 Non-current assets: Other assets (1)(2) $ 92 $ 71 $ 21 Current liabilities: Other accrued liabilities (1) $ 100 $ 100 Non-current liabilities: Other liabilities (1) $ 165 $ 165 (1) Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities. (2) Other assets include one of the Company’s renewable energy derivative contracts that was measured using unobservable (Level 3) inputs, in the amount of $ 21 million. For the nine months ended September 30, 2020, assets and liabilities that were measured using unobservable (Level 3) inputs resulted in a loss recognized in earnings of $ 21 million for a renewable energy derivative contract. For the year ended December 31, 2019, assets and liabilities that were measured using unobservable (Level 3) inputs resulted in unrealized gains recognized in earnings of $ 21 million for a renewable energy derivative contract and the reversal of a liability for contingent consideration of $ 20 million. Assets and Liabilities Measured on a Non-Recurring Basis During the second quarter of 2020, Corning performed an impairment analysis for the long-lived asset group in “All Other” using discounted cash flow projections and recorded a pre-tax asset impairment loss of $ 195 million. During the third quarter of 2020, the Company further reduced investments in these research and development programs and reassessed the business plans. As a result, an additional impairment loss of $ 22 million was recorded, inclusive of an insignificant amount of goodwill, to reduce the book value to the fair value of the asset group, which resulted in a total pre-tax asset impairment loss of $ 217 million for the nine months ended September 30, 2020. The fair value of the asset group was measured using unobservable (Level 3) inputs. Refer to Note 2 (Restructuring, Impairment and Other Charges and Credits) to the consolidated financial statements for additional information on restructuring activities and impairment. On December 31, 2019, HSG, one of the Company’s equity method affiliates, wrote down its long-lived assets to fair value on a nonrecurring basis. HSG engaged a third-party appraiser to assist in determining the fair value of its long-lived assets using unobservable (Level 3) inputs based on the highest and best use of the asset group. As a result, HSG recognized pre-tax asset impairment losses of $ 916 million for the year ended December 31, 2019. Corning’s share of the pre-tax impairment loss was $ 369 million. For the nine months ended September 30, 2020, no material asset impairment losses were recognized on a nonrecurring basis by HSG. Fair value measurements (Level 3) related to the Redemption are disclosed in Note 4 (HSG Transactions) to the consolidated financial statements. There were no other significant financial assets and liabilities measured on a nonrecurring basis as of September 30, 2020 and December 31, 2019.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2020
Shareholders' Equity [Abstract]
Shareholders' Equity	16. Shareholders’ Equity Fixed Rate Cumulative Convertible Preferred Stock, Series A Corning has 2,300 outstanding shares of Fixed Rate Cumulative Convertible Preferred Stock, Series A. The Preferred Stock is convertible at the option of the holder and the Company upon certain events, at a conversion rate of 50,000 shares of Corning’s common stock per one share of Preferred Stock, subject to certain anti-dilution provisions. As of September 30, 2020, the Preferred Stock has not been converted, and none of the anti-dilution provisions have been triggered. Share Repurchases On April 26, 2018, Corning’s Board of Directors approved a $ 2 billion share repurchase program with no expiration date (the “2018 Repurchase Program”). On July 17, 2019, Corning’s Board of Directors authorized $ 5 billion in share repurchases with no expiration date (the “2019 Repurchase Program”). The Company suspended share buybacks during the first quarter of 2020 and made no share repurchases for the three months ended September 30, 2020. For the nine months ended September 30, 2020, the Company repurchased 4.1 million shares of common stock on the open market for approximately $ 105 million, as part of its 2018 Repurchase Program. In the three and nine months ended September 30, 2019, the Company repurchased 10.8 million and 23.4 million shares of common stock on the open market for approximately $ 308 million and $ 703 million, respectively, as part of its 2018 Repurchase Program. Accumulated Other Comprehensive Loss In the three and nine months ended September 30, 2020 and 2019, the change in accumulated other comprehensive loss was primarily related to the foreign currency translation adjustment and the net unrealized gains (losses) on designated hedges components. A summary of changes in the foreign currency translation adjustment component of accumulated other comprehensive loss is as follows (in millions) (1) : Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Beginning balance $ ( 1,064 ) $ ( 786 ) $ ( 857 ) $ ( 714 ) Other comprehensive income (loss) (2) 274 ( 235 ) 75 ( 293 ) Equity method affiliates (3) 9 ( 3 ) 1 ( 17 ) Net current-period other comprehensive income (loss) 283 ( 238 ) 76 ( 310 ) Ending balance $ ( 781 ) $ ( 1,024 ) $ ( 781 ) $ ( 1,024 ) (1) All amounts are after tax. Amounts in parentheses indicate debits to accumulated other comprehensive loss. (2) For the three and nine months ended September 30, 2020, amounts are net of tax expense of $ 21 million and $ 10 million, respectively. For the three and nine months ended September 30, 2019, amounts are net of tax benefit of $ 16 million and $ 39 million, respectively. (3) Tax effects are not significant. A summary of changes in the net unrealized gains (losses) on designated hedges component of accumulated other comprehensive loss is as follows (in millions) (1) : Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Beginning balance $ 9 $ 8 $ 51 $ 6 Other comprehensive income (loss) before reclassifications (2) 11 ( 21 ) ( 40 ) ( 16 ) Amounts reclassified from accumulated other comprehensive (loss) income (3) ( 1 ) 9 ( 4 ) Net current-period other comprehensive income (loss) 11 ( 22 ) ( 31 ) ( 20 ) Ending balance $ 20 $ ( 14 ) $ 20 $ ( 14 ) (1) All amounts are after tax. Amounts in parentheses indicate debits to accumulated other comprehensive loss. (2) For the three and nine months ended September 30, 2020, amounts are net of tax expense of $ 5 million and tax benefit of $ 11 million, respectively. For the three and nine months ended September 30, 2019, tax effects are not significant. (3) Tax effects are not significant .

Share-based Compensation

Share-based Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Compensation [Abstract]
Share-based Compensation	17. Share-Based Compensation Corning maintains long-term incentive plans (the “Plans”) for key employees and non-employee members of its Board of Directors. The Plans allow us to grant equity-based compensation awards, including stock options, stock appreciation rights, performance share units, restricted stock units, restricted stock awards or a combination of awards (collectively, share-based awards). At September 30, 2020, there were approximately 36 million unissued common shares available for future grants authorized under the Plans. Beginning in 2020, Corning increased the equity component in its Long-Term Incentive (“LTI”) Plan from 40 % to 75 % of an executive’s annual targeted compensation opportunity. On May 20, 2020, the Company announced temporary compensation actions in response to the impact of the global COVID-19 pandemic on the Company. Effective June 1, 2020, the base salary of the Company’s CEO was reduced by 40 % and each of the other named executive officers’ salaries were reduced by 30 %. Each non-employee director’s cash compensation was reduced by 40 %. Additionally, the Company reduced salaries, from 5 % to 30 %, for all other salaried employees in the United States from June 1, 2020 through December 31, 2020. The Company took similar actions outside the United States based on local regulations and mutual consent requirements. The Company took these and other actions to preserve cash in 2020, and has issued equity to each employee, including the named executive officers, in the form of restricted stock units and stock options, in an amount equivalent to the employee’s salary reduction on the grant date, which vest over a period of three year s . Similarly, each non-employee director received restricted stock units in an amount equivalent to the director’s fee reduction. Share-based compensation expense is allocated to the selling, general and administrative, research, development and engineering, and cost of sales expenses lines in the consolidated statements of income. Stock Compensation Plans The Company measures and recognizes compensation cost for all share-based payment awards made to employees and directors based on estimated fair values. Total share-based compensation expense was approximately $ 62 million and $ 13 million, respectively, and $ 127 million and $ 43 million, respectively, for the three and nine months ended September 30, 2020 and 2019. The incremental change in expense was $ 49 million and $ 84 million for the three and nine months ended September 30, 2020, respectively. The increase was primarily driven by a larger equity component for Director and Executive compensation and issuance of employee share-based compensation awards. The income tax benefit realized from share-based compensation was not significant for the three and nine months ended September 30, 2020 and 2019. Refer to Note 8 (Income Taxes) to the consolidated financial statements for additional information. Stock Options Corning’s stock option plans provide non-qualified and incentive stock options to purchase authorized but unissued common shares, or treasury shares, at the market price on the grant date and generally become exercisable in installments from one year to five years from the grant date. The maximum term of non-qualified and incentive stock options is 10 years from the grant date. An award is considered vested when the employee’s retention of the award is no longer contingent on providing subsequent service (the “non-substantive vesting period approach”). The following table summarizes information concerning stock options outstanding, including the related transactions under the stock option plans for the nine months ended September 30, 2020: Weighted- average Weighted- remaining Aggregate Number average contractual intrinsic of shares exercise term in value (in thousands) price years (in thousands) Options Outstanding as of December 31, 2019 13,172 $ 21.94 Granted 10,653 19.65 Exercised ( 2,560 ) 18.88 Forfeited and Expired ( 166 ) 20.04 Options Outstanding as of September 30, 2020 21,099 21.17 7.24 $ 239,564 Options Expected to Vest as of September 30, 2020 20,703 21.19 7.19 234,719 Options Exercisable as of September 30, 2020 7,400 19.38 3.56 96,460 Corning uses a multiple-point Black-Scholes valuation model to estimate the fair value of stock option grants. Corning utilizes a blended approach for calculating the volatility assumption used in the multiple-point Black-Scholes valuation model defined as the weighted average of the short-term implied volatility, the most recent volatility for the period equal to the expected term, and the most recent 15-year historical volatility. The expected term is the period the options are expected to be outstanding and is calculated using a combination of historical exercise experience adjusted to reflect the current vesting period of options being valued, and partial life cycles of outstanding options. The risk-free rates used in the multiple-point Black-Scholes valuation model are the implied rates for a zero-coupon U.S. Treasury bond with a term equal to the option’s expected term. The ranges given below reflect results from separate groups of employees exhibiting different exercise behavior. The following inputs were used for the valuation of option grants under the stock option plans (1) : Three months ended Nine months ended September 30, September 30, 2019 2020 2019 Expected volatility 29.5 % 32.9 - 32.9 % 29.5 - 29.9 % Weighted-average volatility 29.5 % 32.9 - 32.9 % 29.5 - 29.9 % Expected dividends 2.95 % 4.48 - 4.48 % 2.36 - 2.95 % Risk-free rate 1.5 % 0.5 - 0.5 % 1.5 - 2.4 % Average risk-free rate 1.5 % 0.5 - 0.5 % 1.5 - 2.4 % Expected term (in years) 7.4 7.4 - 7.4 7.4 - 7.4 Pre-vesting executive departure rate 0.6 % 0.6 - 0.6 % 0.6 - 0.6 % Pre-vesting non-executive departure rate 2.5 - 2.5 % (1) Stock options were granted during the three months ended June 30, 2020, and three months ended June 30 and September 30, 2019. There were no stock options granted during the three months ended March 31 and September 30, 2020, and the three months ended March 31, 2019 . Incentive Stock Plans The Corning Incentive Stock Plan permits restricted stock and restricted stock unit grants, either determined by specific performance goals or issued directly, in most instances, subject to the possibility of forfeiture and without cash consideration. Restricted stock and restricted stock units under the Incentive Stock Plan are granted at the closing market price on the grant date, contingently vest over a period of generally one year to ten years , and generally have contractual lives of one year to ten years . The fair value of each restricted stock grant or restricted stock unit awarded under the Incentive Stock Plan is based on the grant date closing price of the Company’s stock. The following table represents a summary of the status of the Company’s non-vested time-based restricted stock and restricted stock units as of December 31, 2019 and changes which occurred during the nine months ended September 30, 2020: Weighted Number average of shares grant-date (in thousands) fair value Non-vested shares and share units at December 31, 2019 5,189 $ 27.58 Granted 9,272 20.69 Vested ( 1,176 ) 27.50 Forfeited ( 192 ) 24.42 Non-vested shares and share units at September 30, 2020 13,093 $ 22.76

Reportable Segments

Reportable Segments	9 Months Ended
	Sep. 30, 2020
Reportable Segments [Abstract]
Reportable Segments	18. Reportable Segments The Company’s reportable segments are as follows:  Display Technologies – manufactures glass substrates for flat panel liquid crystal displays and other high-performance display panels.  Optical Communications – manufactures carrier network and enterprise network components for the telecommunications industry.  Specialty Materials – manufactures products that provide more than 150 material formulations for glass, glass ceramics and fluoride crystals to meet demand for unique customer needs.  Environmental Technologies – manufactures ceramic substrates and filters for automotive and diesel applications.  Life Sciences – manufactures glass and plastic labware, equipment, media, serum and reagents enabling workflow solutions for drug discovery and bioproduction. All other businesses that do not meet the quantitative threshold for separate reporting have been grouped as “All Other.” This group is primarily comprised of the results of the pharmaceutical technologies, auto glass and new product lines and development projects, as well as certain corporate investments. The Company obtained a controlling interest in HSG during the third quarter of 2020 and has consolidated results in “All Other” as of September 9, 2020. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information on this transaction. The financial results for the reportable segments are prepared on a basis consistent with the internal disaggregation of financial information to assist the chief operating decision maker (“CODM”) in making internal operating decisions. The impact of changes in the Japanese yen, South Korean won, Chinese yuan and new Taiwan dollar are excluded from segment sales and segment net income for the Display Technologies and Specialty Materials segments. The impact of changes in the euro, Chinese yuan and Japanese yen are excluded from segment sales and segment net income for the Environmental Technologies and Life Sciences segments. Certain income and expenses are included in the unallocated amounts in the reconciliation of reportable segment net income (loss) to consolidated net income. These include items that are not used by the CODM in evaluating the results of or in allocating resources to the segments and include the following items: the impact of translated earnings contracts; acquisition-related costs; discrete tax items and other tax-related adjustments; certain litigation, regulatory and other legal matters; restructuring, impairment losses and other charges and credits; adjustments relating to acquisitions; and other non-recurring non-operational items. Although these amounts have been excluded from segment results, they are included in reported consolidated results. The earnings of equity affiliates that are closely associated with the reportable segments are included in the respective segment’s net income (loss). Certain common expenses among reportable segments have been allocated differently than they would be for stand-alone financial information. Segment net income (loss) may not be consistent with measures used by other companies. Reportable Segments (in millions ) : Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Three months ended September 30, 2020 Segment net sales $ 827 $ 909 $ 570 $ 379 $ 223 $ 99 $ 3,007 Depreciation (1) $ 134 $ 59 $ 40 $ 32 $ 12 $ 16 $ 293 Research, development and engineering expenses (2) $ 22 $ 50 $ 39 $ 24 $ 7 $ 35 $ 177 Income tax (provision) benefit (3) $ ( 52 ) $ ( 32 ) $ ( 38 ) $ ( 18 ) $ ( 8 ) $ 12 $ ( 136 ) Segment net income (loss) (4) $ 196 $ 115 $ 146 $ 69 $ 28 $ ( 50 ) $ 504 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Three months ended September 30, 2019 Segment net sales $ 793 $ 1,007 $ 463 $ 397 $ 256 $ 53 $ 2,969 Depreciation (1) $ 144 $ 59 $ 35 $ 32 $ 12 $ 13 $ 295 Research, development and engineering expenses (2) $ 30 $ 53 $ 37 $ 29 $ 5 $ 52 $ 206 Income tax (provision) benefit (3) $ ( 49 ) $ ( 35 ) $ ( 25 ) $ ( 21 ) $ ( 11 ) $ 19 $ ( 122 ) Segment net income (loss) (4) $ 185 $ 127 $ 92 $ 79 $ 41 $ ( 70 ) $ 454 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Nine months ended September 30, 2020 Segment net sales $ 2,331 $ 2,587 $ 1,339 $ 925 $ 724 $ 218 $ 8,124 Depreciation (1) $ 400 $ 183 $ 120 $ 99 $ 37 $ 43 $ 882 Research, development and engineering expenses (2) $ 77 $ 157 $ 113 $ 74 $ 20 $ 126 $ 567 Income tax (provision) benefit (3) $ ( 133 ) $ ( 63 ) $ ( 76 ) $ ( 27 ) $ ( 26 ) $ 50 $ ( 275 ) Segment net income (loss) (4) $ 500 $ 225 $ 287 $ 104 $ 97 $ ( 185 ) $ 1,028 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Nine months ended September 30, 2019 Segment net sales $ 2,459 $ 3,161 $ 1,141 $ 1,125 $ 759 $ 160 $ 8,805 Depreciation (1) $ 445 $ 178 $ 107 $ 95 $ 37 $ 36 $ 898 Research, development and engineering expenses (2) $ 85 $ 163 $ 119 $ 87 $ 15 $ 164 $ 633 Income tax (provision) benefit (3) $ ( 159 ) $ ( 117 ) $ ( 56 ) $ ( 53 ) $ ( 30 ) $ 56 $ ( 359 ) Segment net income (loss) (4) $ 606 $ 427 $ 208 $ 199 $ 112 $ ( 210 ) $ 1,342 (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) Income tax (provision) benefit reflects a tax rate of 21 %. (4) 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 . Expenses that are not allocated to the segments are included in the reconciliation of reportable segment net income (loss) to consolidated net income. A reconciliation of reportable segment and All Other net sales to consolidated net sales follows (in millions): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net sales of reportable segments and All Other $ 3,007 $ 2,969 $ 8,124 $ 8,805 Impact of foreign currency movements (1) ( 6 ) ( 35 ) ( 66 ) ( 119 ) Cumulative adjustment related to customer contract (2) ( 105 ) Consolidated net sales $ 3,001 $ 2,934 $ 7,953 $ 8,686 (1) This amount primarily represents the impact of foreign currency adjustments in the Display Technologies, Environmental Technologies and Life Sciences segments. (2) Amount represents the negative impact of a cumulative adjustment to reduce revenue in the amount of $ 105 million recorded during the first quarter of 2020. The adjustment was associated with a previously recorded commercial benefit asset, reflected as a prepayment, to a customer with a long-term supply agreement that is exiting its production of LCD panels. Refer to Note 5 (Revenue) to the consolidated financial statements for additional information. A reconciliation of reportable segment net income (loss) to consolidated net income follows (in millions): Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net income of reportable segments $ 554 $ 524 $ 1,213 $ 1,552 Net loss of All Other (1) ( 50 ) ( 70 ) ( 185 ) ( 210 ) Unallocated amounts: Impact of foreign currency movements not included in segment net income (loss) ( 20 ) ( 25 ) ( 93 ) (Loss) gain on foreign currency hedges related to translated earnings ( 99 ) 84 ( 6 ) 161 Translation (loss) gain on Japanese yen-denominated debt ( 39 ) 11 ( 50 ) ( 10 ) Litigation, regulatory and other legal matters ( 83 ) 24 ( 108 ) 24 Research, development, and engineering expenses ( 35 ) ( 33 ) ( 111 ) ( 104 ) Transaction-related gain, net (2) 498 498 Equity in (losses) earnings of affiliated companies (3) ( 79 ) 20 20 80 Amortization of intangibles ( 33 ) ( 28 ) ( 87 ) ( 85 ) Interest expense, net ( 67 ) ( 51 ) ( 189 ) ( 145 ) Income tax benefit 113 51 242 88 Cumulative adjustment related to customer contract (4) ( 105 ) Severance charges (5) ( 6 ) ( 18 ) ( 141 ) ( 25 ) Asset impairment (5) ( 22 ) ( 217 ) Capacity realignment and other charges and credits (5) ( 143 ) ( 130 ) ( 375 ) ( 197 ) Other corporate items ( 82 ) ( 27 ) ( 114 ) ( 108 ) Net income $ 427 $ 337 $ 260 $ 928 (1) The Company obtained a controlling interest in HSG during the third quarter of 2020 and has consolidated results in “All Other” as of September 9, 2020. (2) Amount represents the pre-tax gain recorded on Corning’s previously held equity investment in HSG. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information on this transaction. (3) Primarily represents the equity earnings of HSG prior to September 9, 2020. Refer to Note 3 (Investments) and Note 4 ( HSG Transactions ) to the consolidated financial statements for more information. (4) Amount represents the negative impact of a cumulative adjustment to reduce revenue in the amount of $ 105 million recorded during the first quarter of 2020. The adjustment was associated with a previously recorded commercial benefit asset, reflected as a prepayment, to a customer with a long-term supply agreement that is exiting its production of LCD panels. Refer to Note 5 (Revenue) to the consolidated financial statements for additional information. (5) Refer to Note 2 (Restructuring, Impairment and Other Charges and Credits) to the consolidated financial statements for additional information on restructuring activities and impairment .

Significant Accounting Polici_2

Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2020
Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation In these notes, the terms “Corning,” “Company,” “we,” “us,” or “our” mean Corning Incorporated and its subsidiary companies. The accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) and in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been omitted or condensed. These interim consolidated financial statements should be read in conjunction with Corning’s consolidated financial statements and notes thereto included in its Annual Report on Form 10-K for the year ended December 31, 2019 (“2019 Form 10-K”). The unaudited consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results of operations, financial position and cash flows for the interim periods presented. All such adjustments are of a normal recurring nature. The results for interim periods are not necessarily indicative of results which may be expected for any other interim period or for the full year. The equity method of accounting is used for investments in affiliated companies that are not controlled by Corning and in which the Company’s interest is generally between 20 % and 50 % and we have significant influence over the entity. On September 9, 2020, Corning obtained a 100 % controlling interest in Hemlock Semiconductor LLC (“HS LLC”) and an 80.5 % controlling interest in Hemlock Semiconductor Operations LLC (“HSO LLC”), which are affiliated entities within the Hemlock Semiconductor Group (“HSG ”). As of that date, Corning began consolidating HSG. Refer to Note 3 (Investments) and Note 4 (HSG Transactions) to the consolidated financial statements for more information. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. The novel coronavirus (“COVID-19”) pandemic and the resulting adverse impacts to global economic conditions, as well as to Corning’s operations, may impact future estimates including, but not limited to, inventory valuations, fair value measurements, goodwill and long-lived asset impairments, the effectiveness of the Company’s hedging instruments, deferred tax valuation allowances, actuarial losses on retirement benefit plans and discount rate assumptions. Certain prior year amounts have been reclassified to conform to the current-year presentation. These reclassifications had no impact on the results of operations, financial position, or changes in shareholders’ equity.
New and Other Accounting Standards	New Accounting Standards On January 1, 2020, Corning adopted Accounting Standards Update (“ASU”) No. 2016-13 ASC (Topic 326), Financial Instruments - Credit Losses. The ASU introduces a new accounting model, the Current Expected Credit Losses model (CECL), which requires earlier recognition of credit losses and additional disclosures related to credit risk. The CECL model utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The Company adopted the CECL model to recognize credit losses of financial assets using a modified retrospective method of accounting as of January 1, 2020. The impact of adopting the new standard to the financial statements was a nominal reduction to beginning retained earnings. Other Accounting Standards No other accounting standards newly issued or adopted as of September 30, 2020, had a material impact on Corning’s financial statements or disclosures.

Restructuring, Impairment and_2

Restructuring, Impairment and Other Charges (Tables)	9 Months Ended
	Sep. 30, 2020
Restructuring, Impairment and Other Charges and Credits [Abstract]
Restructuring, Impairment, and Other Charges and Credits	During the three and nine months ended September 30, 2020 and 2019, the following restructuring, impairment and other charges and credits were recorded (in millions): ``` Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Severance $ 6 $ 18 $ 141 $ 25 Asset impairment 22 217 Capacity realignment 96 107 245 168 Other charges and credits 47 23 130 29 Total restructuring, impairment and other charges and credits $ 171 $ 148 $ 733 $ 222 Severance In the second quarter of 2020, the Company implemented a corporate-wide workforce reduction program. Severance charges were primarily incurred to facilitate realignment of capacity in the Asia regions for the Display Technologies segment, optimize the Optical Communications segment and contain corporate costs. For the three months and nine months ended September 30, 2020, severance charges were $ 6 million and $ 141 million, respectively. As of September 30, 2020, and December 31, 2019, the unpaid severance liabilities of $ 60 million and $ 44 million are expected to be substantially completed within the next twelve months. Asset Impairment Corning incurred a long-lived asset impairment loss for an asset group related to the reassessment and reprioritization of research and development programs within “All Other”. Given the current economic environment and market opportunities, Corning has rescoped and significantly reduced its investment in these research and development programs. Corning performed the impairment analysis for the long-lived asset group using discounted cash flow projections and recorded a pre-tax asset impairment loss of $ 195 million in the second quarter of 2020. During the third quarter of 2020, the Company further reduced investments in these research and development programs and reassessed the business plans. As a result, an additional impairment loss of $ 22 million was recorded, inclusive of an insignificant amount of goodwill, to reduce the book value to the fair value of the asset group , which resulted in a total pre-tax asset impairment loss of $ 217 million for the nine months ended September 30, 2020. Capacity Realignment Capacity realignment for the three and nine months ended September 30, 2020, primarily includes accelerated depreciation and asset disposals associated with the exit of certain facilities and other exit activities in the Display Technologies and Specialty Materials business segments. Capacity realignment for the three and nine months ended September 30, 2019, is primarily comprised of accelerated depreciation associated with the exit of certain facilities in the Display Technologies segment. The following tables present the impact and respective location of total restructuring, impairment, and other charges and credits on the consolidated statements of income (in millions): Three months ended Three months ended September 30, 2020 September 30, 2019 Selling, Research, Selling, Research, general development general development and and and and Gross admin. engineering Gross admin. engineering margin (1) expenses expenses Other Total margin (1) expenses expenses Other Total Severance $ 3 $ 3 $ 6 $ 9 $ 6 $ 3 $ 18 Asset impairment 6 $ 16 22 Capacity realignment 95 1 96 94 13 107 Other charges and credits 26 12 1 $ 8 47 14 5 $ 4 23 Total restructuring, impairment and other charges and credits $ 124 $ 21 $ 18 $ 8 $ 171 $ 117 $ 11 $ 16 $ 4 $ 148 (1) Activity reflected in cost of sales. Nine months ended Nine months ended September 30, 2020 September 30, 2019 Selling, Research, Selling, Research, general development general development and and and and Gross admin. engineering Gross admin. engineering margin (1) expenses expenses Other Total margin (1) expenses expenses Other Total Severance $ 79 $ 34 $ 28 $ 141 $ 10 $ 12 $ 3 $ 25 Asset impairment 6 211 217 Capacity realignment 243 2 245 155 13 168 Other charges and credits 61 51 2 $ 16 130 47 5 $ ( 23 ) 29 Total restructuring, impairment and other charges and credits $ 383 $ 91 $ 243 $ 16 $ 733 $ 212 $ 17 $ 16 $ ( 23 ) $ 222 (1) Activity reflected in cost o f sales.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Investments [Abstract]
Investments	Ownership September 30, December 31, interest 2020 2019 Affiliated companies accounted for by the equity method (1) 20 % to 50 % $ 285 $ 291 Other investments 69 43 Subtotal investment assets $ 354 $ 334 Affiliated companies accounted for by the equity method HSG (1)(2) 50 % $ — $ 270 Subtotal investment liabilities $ — $ 270 (1) Amounts reflect Corning’s direct ownership interest in the affiliated companies at September 30, 2020 and December 31, 2019. (2) At December 31, 2019, the negative carrying value of Corning’s investment in HSG was $ 270 million and recorded in other liabilities.
Results From Operations	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Statements of Operations (1) : Net sales $ 78 $ 200 $ 423 $ 566 Gross profit $ 21 $ 61 $ 87 $ 205 Net (loss) income $ ( 192 ) $ 46 $ 11 $ 185 Net (loss) income attributable to HSG $ ( 154 ) $ 42 $ 44 $ 165 Corning's equity in (losses) earnings of affiliated companies $ ( 77 ) $ 21 $ 22 $ 81 Related party transactions: Intercompany sales within HSG (included in net sales) $ 12 $ 31 $ 55 $ 85 (1) The three and nine months ended September 30, 2020, only include HSG’s results of operations through September 8, 2020. Immediately following the Redemption, Corning began consolidating HSG on September 9, 2020

HSG Transactions (Tables)

HSG Transactions (Tables)	9 Months Ended
	Sep. 30, 2020
Notes Tables
Net Gain on Previously Owned Equity	Fair value of previously held equity investment $ 250 Equity investment liability balance as of acquisition date ( 248 ) Corning's gain on previously held equity investment $ 498
Recognized Amounts of Identified Assets Acquired and Liabilities Assumed	Inventory $ 503 Property, plant and equipment 657 Intangible assets 285 Other current and non-current assets (1) 166 Short-term borrowings ( 178 ) Trade payables and other accrued liabilities ( 322 ) Other liabilities ( 1,254 ) Total identified net liabilities ( 143 ) Non-controlling interests (2) ( 102 ) Total fair value of Corning's previously held equity investment (2) ( 250 ) Goodwill (3) $ 495 (1) The other current and non-current assets included a contingent consideration asset of $ 20 million at fair value for a cost adjustment contract related to the TCS Transaction. Refer to Note 3 (Investments), Note 4 (HSG Transactions) and Note 15 (Fair Value Measurements) to the consolidated financial statements for additional information. (2) The purchase price being used to measure the goodwill of the Redemption is $ 352 million, including the fair value of Corning’s previously held equity interest and non-controlling interest, in the amount of $ 250 million and $ 102 million, respectively. (3) The goodwill recognized is not deductible for U.S. income tax purposes . The goodwill was allocated to “All Other” within segment reporting as disclosed in Note 18 (Reportable Segments) to the consolidated financial statements for more information.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue [Abstract]
Disaggregation of Revenue	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Display products $ 834 $ 780 $ 2,211 $ 2,395 Telecommunication products 909 1,008 2,587 3,162 Specialty glass products 570 463 1,339 1,141 Environmental substrate and filter products 369 380 891 1,084 Life science products 220 250 707 744 All Other 99 53 218 160 Total revenue $ 3,001 $ 2,934 $ 7,953 $ 8,686 Impact of foreign currency movements (1) 6 35 66 119 Cumulative adjustment related to customer contract 105 Net sales of reportable segments and All Other $ 3,007 $ 2,969 $ 8,124 $ 8,805 (1) This amount primarily represents the impact of foreign currency adjustments in the Display Technologies, Environmental Technologies and Life Sciences segments.

Employee Retirement Plans (Tabl

Employee Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2020
Employee Retirement Plans [Abstract]
Net Periodic Benefit Expense	Pension benefits Postretirement benefits Three months ended Nine months ended Three months ended Nine months ended September 30, September 30, September 30, September 30, 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 29 $ 25 $ 87 $ 76 $ 2 $ 3 $ 7 $ 7 Interest cost 32 37 94 111 5 7 15 21 Expected return on plan assets ( 49 ) ( 42 ) ( 147 ) ( 128 ) Amortization of actuarial net gain 1 ( 1 ) 1 ( 1 ) Amortization of prior service cost (credit) 1 2 4 5 ( 2 ) ( 2 ) ( 5 ) ( 6 ) Recognition of actuarial (gain) loss ( 2 ) 23 Total pension and postretirement benefit expense $ 13 $ 22 $ 36 $ 87 $ 6 $ 7 $ 18 $ 21

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2020
Income Taxes [Abstract]
Provision for Income Taxes	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Provision for income taxes $ ( 23 ) $ ( 71 ) $ ( 33 ) $ ( 271 ) Effective tax rate 5.1 % 17.4 % 11.3 % 22.6 %

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Other Intangible Assets [Abstract]
Carrying Amount of Goodwill by Segment	Display Optical Specialty Life All Technologies Communications Materials Sciences Other Total Balance at December 31, 2019 $ 129 $ 931 $ 150 $ 616 $ 109 $ 1,935 Acquired goodwill (1) 495 495 Foreign currency translation adjustment and other ( 2 ) 1 1 ( 3 ) ( 3 ) Balance at September 30, 2020 $ 127 $ 932 $ 150 $ 617 $ 601 $ 2,427 (1) The Company obtained a controlling interest in HSG during the third quarter of 2020. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information on this transaction.
Other Intangible Assets	September 30, 2020 December 31, 2019 Accumulated Accumulated Gross amortization Net Gross amortization Net Amortized intangible assets: Patents, trademarks, and trade names $ 499 $ 248 $ 251 $ 469 $ 228 $ 241 Customer lists and other 1,505 424 1,081 1,301 357 944 Total $ 2,004 $ 672 $ 1,332 $ 1,770 $ 585 $ 1,185

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Common Share [Abstract]
Computation of Basic and Diluted Earnings (Loss) per Common Share	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net income attributable to Corning Incorporated $ 427 $ 337 $ 260 $ 928 Less: Series A convertible preferred stock dividend 24 24 73 73 Net income available to common stockholders – basic 403 313 187 855 Plus: Series A convertible preferred stock dividend 24 24 73 Net income available to common stockholders – diluted $ 427 $ 337 $ 187 $ 928 Weighted-average common shares outstanding – basic 760 775 760 780 Effect of dilutive securities: Employee stock options and other dilutive securities 14 7 8 8 Series A convertible preferred stock (1) 115 115 115 Weighted-average common shares outstanding – diluted 889 897 768 903 Basic earnings per common share $ 0.53 $ 0.40 $ 0.25 $ 1.10 Diluted earnings per common share $ 0.48 $ 0.38 $ 0.24 $ 1.03 Anti-dilutive potential shares excluded from diluted earnings per common share: Series A convertible preferred stock (1) 115 Employee stock options and awards 3 2 7 2 Total 3 2 122 2 (1) For the nine months ended September 30, 2020, the Series A preferred stock was anti-dilutive; therefore, it was excluded from the calculation of diluted earnings per share.

Inventories, Net of Inventory_2

Inventories, Net of Inventory Reserves (Tables)	9 Months Ended
	Sep. 30, 2020
Inventories, Net of Inventory Reserves [Abstract]
Inventories, Net	September 30, December 31, 2020 2019 Finished goods $ 1,322 $ 973 Work in process 370 421 Raw materials and accessories 412 481 Supplies and packing materials 477 445 Total inventories, net of inventory reserves $ 2,581 $ 2,320

Other Liabilities (Tables)

Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Other Liabilities [Abstract]
Other Liabilities	September 30, December 31, 2020 2019 Current liabilities: Wages and employee benefits $ 501 $ 565 Income taxes 194 182 Derivative instruments (Note 15) 143 100 Asbestos and other litigation (Note 6) 63 57 Deferred revenue (Note 5) 132 Settlement liability (Note 4) 58 Customer deposits (Note 5) 181 104 Short-term leases 89 62 Other current liabilities 1,056 853 Other accrued liabilities $ 2,417 $ 1,923 Non-current liabilities: Defined benefit pension plan liabilities $ 927 $ 980 Derivative instruments (Note 15) 131 165 Asbestos and other litigation (Note 6) 144 196 Deferred revenue (Note 5) 931 Settlement liability (Note 4) 117 Investment in HSG (1) 270 Customer deposits (Note 5) 1,153 927 Deferred tax liabilities 247 325 Long-term leases 606 450 Other non-current liabilities 816 667 Other liabilities $ 5,072 $ 3,980 (1) The negative carrying value resulted from a one-time charge to this entity as of December 31, 2019 for the impairment of certain assets

Hedging Activities (Tables)

Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2020
Summary of Notional Amounts and Respective Fair Values of Derivative Financial Instruments	Asset derivatives Liability derivatives Notional amount Balance Fair value Balance Fair value Sept. 30, Dec. 31, sheet Sept. 30, Dec. 31, sheet Sept. 30, Dec. 31, 2020 2019 location 2020 2019 location 2020 2019 Derivatives designated as hedging instruments Foreign exchange contracts $ 826 $ 2,123 Other current assets $ 18 $ 38 Other accrued liabilities $ ( 7 ) $ ( 7 ) Other assets 14 37 Other liabilities ( 1 ) ( 4 ) Derivatives not designated as hedging instruments Foreign exchange and other contracts 6,816 1,815 Other current assets 28 5 Other accrued liabilities ( 61 ) ( 19 ) Other assets 32 21 Other liabilities ( 58 ) Translated earnings contracts 8,906 12,166 Other current assets 58 114 Other accrued liabilities ( 75 ) ( 74 ) Other assets 33 34 Other liabilities ( 72 ) ( 161 ) Total derivatives $ 16,548 $ 16,104 $ 183 $ 249 $ ( 274 ) $ ( 265 )
Designated as Hedging Instrument [Member]
Effect on Consolidated Financial Statements	Effect of derivative instruments on the consolidated financial statements for the three months ended September 30, Derivatives in hedging Gain (loss) recognized in other Location of gain (loss) reclassified from Gain (loss) reclassified from relationships for comprehensive income (OCI) accumulated OCI into income accumulated OCI into income cash flow hedges 2020 2019 effective (ineffective) 2020 2019 Net sales $ ( 2 ) Foreign exchange contracts $ 16 $ ( 26 ) Cost of sales 3 $ 2 Total cash flow hedges $ 16 $ ( 26 ) $ 1 $ 2 Effect of derivative instruments on the consolidated financial statements for the nine months ended September 30, Derivatives in hedging Gain (loss) recognized in other Location of gain (loss) reclassified from Gain (loss) reclassified from relationships for comprehensive income (OCI) accumulated OCI into income accumulated OCI into income cash flow hedges 2020 2019 effective (ineffective) 2020 2019 Net sales $ ( 4 ) Cost of sales 7 $ 7 Foreign exchange contracts $ ( 51 ) $ ( 19 ) Other expense, net (1) ( 14 ) Total cash flow hedges $ ( 51 ) $ ( 19 ) $ ( 11 ) $ 7
Not Designated as Hedging Instrument [Member]
Effect on Consolidated Financial Statements	Gains recognized in income Three months ended Nine months ended Location of gains September 30, September 30, Undesignated derivatives recognized in income 2020 2019 2020 2019 Foreign exchange and other contracts – balance sheet, loans and other Other (expense) income, net (1) $ ( 48 ) $ 19 $ ( 62 ) $ 38 Translated earnings contracts Translated earnings contract (loss) gain, net ( 100 ) 86 5 163 Total undesignated $ ( 148 ) $ 105 $ ( 57 ) $ 201 (1) A loss of $ 14 million was reclassified from accumulated other comprehensive loss into other expense, net, resulting from the de-designation of certain cash flow hedges

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Measurements [Abstract]
Major Categories of Financial Assets and Liabilities Measured on a Recurring Basis	Fair value measurements at reporting date using Quoted prices in Significant other Significant active markets for observable unobservable September 30, identical assets inputs inputs 2020 (Level 1) (Level 2) (Level 3) Current assets: Other current assets (1)(2) $ 132 $ 104 $ 28 Non-current assets: Investments (3) $ 13 $ 13 Other assets (1)(2) $ 95 $ 79 $ 16 Current liabilities: Other accrued liabilities (1) $ 143 $ 143 Non-current liabilities: Other liabilities (1) $ 131 $ 131 (1) Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities. (2) Included in other current assets and other assets are auction rate securities of $ 24 million and a contingent consideration asset for a cost adjustment contract of $ 20 million, resulting from the HSG Transactions as of September 9, 2020, that were measured using unobservable (Level 3) inputs. (3) Included in the investments were equity securities with readily available fair values that were measured using Level 1 inputs. Fair value measurements at reporting date using Quoted prices in Significant other Significant active markets for observable unobservable December 31, identical assets inputs inputs 2019 (Level 1) (Level 2) (Level 3) Current assets: Other current assets (1) $ 157 $ 157 Non-current assets: Other assets (1)(2) $ 92 $ 71 $ 21 Current liabilities: Other accrued liabilities (1) $ 100 $ 100 Non-current liabilities: Other liabilities (1) $ 165 $ 165 (1) Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities. (2) Other assets include one of the Company’s renewable energy derivative contracts that was measured using unobservable (Level 3) inputs, in the amount of $ 21 million.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss)	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Beginning balance $ ( 1,064 ) $ ( 786 ) $ ( 857 ) $ ( 714 ) Other comprehensive income (loss) (2) 274 ( 235 ) 75 ( 293 ) Equity method affiliates (3) 9 ( 3 ) 1 ( 17 ) Net current-period other comprehensive income (loss) 283 ( 238 ) 76 ( 310 ) Ending balance $ ( 781 ) $ ( 1,024 ) $ ( 781 ) $ ( 1,024 ) (1) All amounts are after tax. Amounts in parentheses indicate debits to accumulated other comprehensive loss. (2) For the three and nine months ended September 30, 2020, amounts are net of tax expense of $ 21 million and $ 10 million, respectively. For the three and nine months ended September 30, 2019, amounts are net of tax benefit of $ 16 million and $ 39 million, respectively. (3) Tax effects are not significant.
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss)	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Beginning balance $ 9 $ 8 $ 51 $ 6 Other comprehensive income (loss) before reclassifications (2) 11 ( 21 ) ( 40 ) ( 16 ) Amounts reclassified from accumulated other comprehensive (loss) income (3) ( 1 ) 9 ( 4 ) Net current-period other comprehensive income (loss) 11 ( 22 ) ( 31 ) ( 20 ) Ending balance $ 20 $ ( 14 ) $ 20 $ ( 14 ) (1) All amounts are after tax. Amounts in parentheses indicate debits to accumulated other comprehensive loss. (2) For the three and nine months ended September 30, 2020, amounts are net of tax expense of $ 5 million and tax benefit of $ 11 million, respectively. For the three and nine months ended September 30, 2019, tax effects are not significant. (3) Tax effects are not significant

Share-based Compensation (Table

Share-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Compensation [Abstract]
Summary of Information Concerning Stock Options Outstanding Including the Related Transactions under the Stock Option Plans	Weighted- average Weighted- remaining Aggregate Number average contractual intrinsic of shares exercise term in value (in thousands) price years (in thousands) Options Outstanding as of December 31, 2019 13,172 $ 21.94 Granted 10,653 19.65 Exercised ( 2,560 ) 18.88 Forfeited and Expired ( 166 ) 20.04 Options Outstanding as of September 30, 2020 21,099 21.17 7.24 $ 239,564 Options Expected to Vest as of September 30, 2020 20,703 21.19 7.19 234,719 Options Exercisable as of September 30, 2020 7,400 19.38 3.56 96,460
Valuation of Option Grants under Stock Option Plans	Three months ended Nine months ended September 30, September 30, 2019 2020 2019 Expected volatility 29.5 % 32.9 - 32.9 % 29.5 - 29.9 % Weighted-average volatility 29.5 % 32.9 - 32.9 % 29.5 - 29.9 % Expected dividends 2.95 % 4.48 - 4.48 % 2.36 - 2.95 % Risk-free rate 1.5 % 0.5 - 0.5 % 1.5 - 2.4 % Average risk-free rate 1.5 % 0.5 - 0.5 % 1.5 - 2.4 % Expected term (in years) 7.4 7.4 - 7.4 7.4 - 7.4 Pre-vesting executive departure rate 0.6 % 0.6 - 0.6 % 0.6 - 0.6 % Pre-vesting non-executive departure rate 2.5 - 2.5 % (1) Stock options were granted during the three months ended June 30, 2020, and three months ended June 30 and September 30, 2019. There were no stock options granted during the three months ended March 31 and September 30, 2020, and the three months ended March 31, 2019 .
Summary of the Status of Non-vested Time-based Restricted Stock and Restricted Stock Units	Weighted Number average of shares grant-date (in thousands) fair value Non-vested shares and share units at December 31, 2019 5,189 $ 27.58 Granted 9,272 20.69 Vested ( 1,176 ) 27.50 Forfeited ( 192 ) 24.42 Non-vested shares and share units at September 30, 2020 13,093 $ 22.76

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Sep. 30, 2020
Reportable Segments [Abstract]
Reportable Segments	: Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Three months ended September 30, 2020 Segment net sales $ 827 $ 909 $ 570 $ 379 $ 223 $ 99 $ 3,007 Depreciation (1) $ 134 $ 59 $ 40 $ 32 $ 12 $ 16 $ 293 Research, development and engineering expenses (2) $ 22 $ 50 $ 39 $ 24 $ 7 $ 35 $ 177 Income tax (provision) benefit (3) $ ( 52 ) $ ( 32 ) $ ( 38 ) $ ( 18 ) $ ( 8 ) $ 12 $ ( 136 ) Segment net income (loss) (4) $ 196 $ 115 $ 146 $ 69 $ 28 $ ( 50 ) $ 504 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Three months ended September 30, 2019 Segment net sales $ 793 $ 1,007 $ 463 $ 397 $ 256 $ 53 $ 2,969 Depreciation (1) $ 144 $ 59 $ 35 $ 32 $ 12 $ 13 $ 295 Research, development and engineering expenses (2) $ 30 $ 53 $ 37 $ 29 $ 5 $ 52 $ 206 Income tax (provision) benefit (3) $ ( 49 ) $ ( 35 ) $ ( 25 ) $ ( 21 ) $ ( 11 ) $ 19 $ ( 122 ) Segment net income (loss) (4) $ 185 $ 127 $ 92 $ 79 $ 41 $ ( 70 ) $ 454 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Nine months ended September 30, 2020 Segment net sales $ 2,331 $ 2,587 $ 1,339 $ 925 $ 724 $ 218 $ 8,124 Depreciation (1) $ 400 $ 183 $ 120 $ 99 $ 37 $ 43 $ 882 Research, development and engineering expenses (2) $ 77 $ 157 $ 113 $ 74 $ 20 $ 126 $ 567 Income tax (provision) benefit (3) $ ( 133 ) $ ( 63 ) $ ( 76 ) $ ( 27 ) $ ( 26 ) $ 50 $ ( 275 ) Segment net income (loss) (4) $ 500 $ 225 $ 287 $ 104 $ 97 $ ( 185 ) $ 1,028 Display Optical Specialty Environmental Life All Technologies Communications Materials Technologies Sciences Other Total Nine months ended September 30, 2019 Segment net sales $ 2,459 $ 3,161 $ 1,141 $ 1,125 $ 759 $ 160 $ 8,805 Depreciation (1) $ 445 $ 178 $ 107 $ 95 $ 37 $ 36 $ 898 Research, development and engineering expenses (2) $ 85 $ 163 $ 119 $ 87 $ 15 $ 164 $ 633 Income tax (provision) benefit (3) $ ( 159 ) $ ( 117 ) $ ( 56 ) $ ( 53 ) $ ( 30 ) $ 56 $ ( 359 ) Segment net income (loss) (4) $ 606 $ 427 $ 208 $ 199 $ 112 $ ( 210 ) $ 1,342 (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) Income tax (provision) benefit reflects a tax rate of 21 %. (4) 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 . Expenses that are not allocated to the segments are included in the reconciliation of reportable segment net income (loss) to consolidated net income.
Reconciliation of Reportable Segment and All Other Net Sales to Consolidated Net Sales	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net sales of reportable segments and All Other $ 3,007 $ 2,969 $ 8,124 $ 8,805 Impact of foreign currency movements (1) ( 6 ) ( 35 ) ( 66 ) ( 119 ) Cumulative adjustment related to customer contract (2) ( 105 ) Consolidated net sales $ 3,001 $ 2,934 $ 7,953 $ 8,686 (1) This amount primarily represents the impact of foreign currency adjustments in the Display Technologies, Environmental Technologies and Life Sciences segments. (2) Amount represents the negative impact of a cumulative adjustment to reduce revenue in the amount of $ 105 million recorded during the first quarter of 2020. The adjustment was associated with a previously recorded commercial benefit asset, reflected as a prepayment, to a customer with a long-term supply agreement that is exiting its production of LCD panels. Refer to Note 5 (Revenue) to the consolidated financial statements for additional information.
Reconciliation of Reportable Segment Net Income to Consolidated Net Income (Loss)	Three months ended Nine months ended September 30, September 30, 2020 2019 2020 2019 Net income of reportable segments $ 554 $ 524 $ 1,213 $ 1,552 Net loss of All Other (1) ( 50 ) ( 70 ) ( 185 ) ( 210 ) Unallocated amounts: Impact of foreign currency movements not included in segment net income (loss) ( 20 ) ( 25 ) ( 93 ) (Loss) gain on foreign currency hedges related to translated earnings ( 99 ) 84 ( 6 ) 161 Translation (loss) gain on Japanese yen-denominated debt ( 39 ) 11 ( 50 ) ( 10 ) Litigation, regulatory and other legal matters ( 83 ) 24 ( 108 ) 24 Research, development, and engineering expenses ( 35 ) ( 33 ) ( 111 ) ( 104 ) Transaction-related gain, net (2) 498 498 Equity in (losses) earnings of affiliated companies (3) ( 79 ) 20 20 80 Amortization of intangibles ( 33 ) ( 28 ) ( 87 ) ( 85 ) Interest expense, net ( 67 ) ( 51 ) ( 189 ) ( 145 ) Income tax benefit 113 51 242 88 Cumulative adjustment related to customer contract (4) ( 105 ) Severance charges (5) ( 6 ) ( 18 ) ( 141 ) ( 25 ) Asset impairment (5) ( 22 ) ( 217 ) Capacity realignment and other charges and credits (5) ( 143 ) ( 130 ) ( 375 ) ( 197 ) Other corporate items ( 82 ) ( 27 ) ( 114 ) ( 108 ) Net income $ 427 $ 337 $ 260 $ 928 (1) The Company obtained a controlling interest in HSG during the third quarter of 2020 and has consolidated results in “All Other” as of September 9, 2020. (2) Amount represents the pre-tax gain recorded on Corning’s previously held equity investment in HSG. Refer to Note 4 (HSG Transactions) to the consolidated financial statements for additional information on this transaction. (3) Primarily represents the equity earnings of HSG prior to September 9, 2020. Refer to Note 3 (Investments) and Note 4 ( HSG Transactions ) to the consolidated financial statements for more information. (4) Amount represents the negative impact of a cumulative adjustment to reduce revenue in the amount of $ 105 million recorded during the first quarter of 2020. The adjustment was associated with a previously recorded commercial benefit asset, reflected as a prepayment, to a customer with a long-term supply agreement that is exiting its production of LCD panels. Refer to Note 5 (Revenue) to the consolidated financial statements for additional information. (5) Refer to Note 2 (Restructuring, Impairment and Other Charges and Credits) to the consolidated financial statements for additional information on restructuring activities and impairment

Summary of Significant Accounti

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 09, 2020	Dec. 31, 2019
Equity Method Investments	$ 285		$ 291
Hemlock Semiconductor LLC [Member]
Business combination ownership interest acquired		100.00%
Hemlock Semiconductor Operations LLC [Member]
Equity Method Investments		$ (250)
Business combination ownership interest acquired		80.50%
Minimum [Member]
Equity Method Investment, Ownership Percentage	20.00%
Maximum [Member]
Equity Method Investment, Ownership Percentage	50.00%

Restructuring, Impairment and_3

Restructuring, Impairment and Other Charges and Credits (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Restructuring, Impairment and Other Charges and Credits [Abstract]
Severance payments	$ 6		$ 18	$ 141	$ 25
Unpaid severance	60			60		$ 44
Asset Impairment Charges	$ 22	$ 195		$ 217		$ 369

Restructuring, Impairment and_4

Restructuring, Impairment and Other Charges and Credits (Restructuring, Impairment, and Other Charges and Credits) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Severance charges	$ 6		$ 18	$ 141	$ 25
Asset impairment	22	$ 195		217		$ 369
Capacity realignment	96		107	245	168
Other charges and credits	47		23	130	29
Total restructuring, impairment and other charges and credits	171		148	733	222
Gross Margin [Member]
Restructuring Cost and Reserve [Line Items]
Severance charges	3		9	79	10
Capacity realignment	95		94	243	155
Other charges and credits	26		14	61	47
Total restructuring, impairment and other charges and credits	124		117	383	212
Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Severance charges	3		6	34	12
Asset impairment	6			6
Other charges and credits	12		5	51	5
Total restructuring, impairment and other charges and credits	21		11	91	17
Research, Development And Engineering Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Severance charges			3	28	3
Asset impairment	16			211
Capacity realignment	1		13	2	13
Other charges and credits	1			2
Total restructuring, impairment and other charges and credits	18		16	243	16
Other [Member]
Restructuring Cost and Reserve [Line Items]
Other charges and credits	8		4	16	(23)
Total restructuring, impairment and other charges and credits	$ 8		$ 4	$ 16	$ (23)

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	Sep. 09, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2016	May 31, 2016
Loss from settlement		$ (83)	$ 24	$ (108)	$ 24
TCS Settlement [Member]
Loss from settlement		(81)		(81)
Equity loss from settlement		$ 19		$ 19
Dow Corning Corporation [Member]
Equity Method Investment, Ownership Percentage						50.00%	50.00%
Pittsburgh Corning Corporation PCC [Member] | Asbestos Litigation [Member]
Equity Method Investment, Ownership Percentage						50.00%
HSG [Member]
Equity Method Investment, Ownership Percentage		50.00%		50.00%
Hemlock Semiconductor LLC [Member]
Equity Method Investment, Ownership Percentage						49.90%
HSG [Member]
Loss from settlement				$ 165
Inventory Write-down				$ 44
HSG [Member] | TCS Settlement [Member]
Loss from settlement		$ (200)
Hemlock Semiconductor LLC [Member]
Business combination ownership interest acquired	100.00%
HSG [Member]
Purchase price	$ 250
HSG [Member] | HSG [Member]
Purchase price	250
Dupont’s Trichlorosilane [Member] | HSG [Member]
Purchase price	255
Pre-existing contract disputes	175
Pre-existing contract disputes, fair value	$ 200

Investments (Investments) (Deta

Investments (Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2016	May 31, 2016
Investment in affiliated companies, at equity	$ 285	$ 291
Other investments	69	43
Investment assets	$ 354	334
Investment liabilities		270
Other Liabilities [Member]
Investment liabilities		270
Dow Corning Corporation [Member]
Ownership interest			50.00%	50.00%
HSG [Member]
Ownership interest	50.00%
Investment liabilities		$ 270
Hemlock Semiconductor LLC [Member]
Ownership interest			49.90%
Hemlock Semiconductor Operations LLC [Member]
Ownership interest			40.25%
Minimum [Member]
Ownership interest	20.00%
Maximum [Member]
Ownership interest	50.00%

Investments (Results From Opera

Investments (Results From Operations) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Net sales	$ 3,001			$ 2,934			$ 7,953	$ 8,686
Gross profit	1,001			1,017			2,318	3,181
Net (loss) income	432	$ (65)	$ (96)	341	$ 105	$ 505
Corning’s equity in earnings of affiliated companies	(76)			23			17	81
Affiliated Companies [Member]
Net sales	78			200			423	566
Gross profit	21			61			87	205
Net (loss) income	(192)			46			11	185
Corning’s equity in earnings of affiliated companies	(77)			21			22	81
HSG [Member]
Net (loss) income	(154)			42			44	165
HSG [Member] | Intersegment Eliminations [Member]
Intercompany sales within HSG	$ 12			$ 31			$ 55	$ 85

HSG Transactions (Narrative) (D

HSG Transactions (Narrative) (Details)	Sep. 09, 2020USD ($)item	Sep. 30, 2020USD ($)item	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)item	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2016	May 31, 2016
Pre-existing contract disputes, loss on settlement		$ 83,000,000	$ (24,000,000)	$ 108,000,000	$ (24,000,000)
Cash and cash equivalents		2,514,000,000	$ 971,000,000	2,514,000,000	$ 971,000,000	$ 2,434,000,000	$ 2,355,000,000
Customer deposits/ deferred revenue		1,300,000,000		1,300,000,000		1,000,000,000
Deferred revenue	$ 1,070,000,000
Noncontrolling interests		197,000,000		197,000,000		$ 90,000,000
HSG [Member]
Pre-tax gain				$ 498,000,000
Customer deposits/ deferred revenue	264,000,000
HSG [Member] | Developed Technologies [Member]
Intangible asset estimated useful lives				20 years
Intangible assets		215,000,000		$ 215,000,000
HSG [Member] | Other Intangible Assets [Member]
Intangible asset estimated useful lives				15 years
Intangible assets		$ 70,000,000		$ 70,000,000
HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item		0.165		0.165
HSG [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]
Measurement input | item		0		0
HSG [Member]
Pre-existing contract disputes, loss on settlement				$ (165,000,000)
Cash and cash equivalents	75,000,000
Customer deposits/ deferred revenue		$ 264,000,000		264,000,000
Deferred revenue		1,070,000,000		1,070,000,000
Noncontrolling interests		102,000,000		$ 102,000,000
HSG [Member] | HSG Debt [Member]
Debt Instrument, Face Amount	175,000,000
Dow Corning Corporation [Member]
Ownership interest								50.00%	50.00%
Dupont’s Trichlorosilane [Member]
Settlement term				3 years
Annual payment amount	58,000,000
Dupont’s Trichlorosilane [Member] | HSG [Member]
Purchase consideration	255,000,000
Pre-existing contract disputes	175,000,000
Pre-existing contract disputes, fair value	200,000,000
HSG [Member]
Purchase consideration	250,000,000
Pre-tax gain	498,000,000
Acquisition-related costs		11,000,000		$ 11,000,000
HSG [Member] | Developed Technologies [Member]
Intangible asset estimated useful lives				20 years
Intangible assets		215,000,000		$ 215,000,000
HSG [Member] | Other Intangible Assets [Member]
Intangible asset estimated useful lives				15 years
Intangible assets		$ 70,000,000		$ 70,000,000
HSG [Member] | HSG [Member]
Redemption price	250,000,000
HSG [Member] | HSG [Member]
Purchase consideration	$ 250,000,000
Hemlock Semiconductor LLC [Member]
Business combination ownership interest acquired	100.00%
Previously Held Interest In HSG [Member]
Purchase consideration	$ 0
Minimum [Member]
Ownership interest		20.00%		20.00%
Minimum [Member] | HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item	0.0254
Minimum [Member] | HSG [Member]
Year		2029		2029
Minimum [Member] | HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item		0.0254		0.0254
Maximum [Member]
Ownership interest		50.00%		50.00%
Maximum [Member] | HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item	0.0323
Maximum [Member] | HSG [Member]
Year		2034		2034
Maximum [Member] | HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item		0.0323		0.0323
TCS Settlement [Member]
Pre-existing contract disputes, loss on settlement		$ 81,000,000		$ 81,000,000
TCS Settlement [Member] | HSG [Member]
Pre-existing contract disputes, loss on settlement		$ 200,000,000

HSG Transactions (Net Gain on P

HSG Transactions (Net Gain on Previously Owned Equity) (Details) - HSG [Member] $ in Millions	Sep. 09, 2020USD ($)
Fair value of previously held equity investment	$ 250
Equity investment liability balance as of acquisition date	(248)
Corning's gain on previously held equity investment	$ 498

HSG Transactions (Recognized Am

HSG Transactions (Recognized Amounts of Identified Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions	Sep. 09, 2020	Sep. 30, 2020	Dec. 31, 2019
Total fair value of Corning's previously held equity investment		$ 285	$ 291
Goodwill		2,427	1,935
Optical Communications [Member]
Goodwill		932	931
Display Technologies [Member]
Goodwill		$ 127	$ 129
Hemlock Semiconductor Operations LLC [Member]
Inventory	$ 503
Property, plant and equipment	657
Intangible assets	285
Other current and non-current assets	166
Short-term borrowings	(178)
Trade payables and other accrued liabilities	(322)
Other liabilities	(1,254)
Total identified net liabilities	(143)
Non-controlling interests	(102)
Total fair value of Corning's previously held equity investment	(250)
Goodwill	495
Contingent consideration	20
Purchase price	$ 352

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020USD ($)item	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)item	Sep. 30, 2019USD ($)	Sep. 09, 2020USD ($)item	Dec. 31, 2019USD ($)
Customer deposits/ deferred revenue	$ 1,300			$ 1,300			$ 1,000
Deferred revenue current	181			181			104
Deferred revenue non-current	1,153			1,153			927
Increase (decrease) in customer deposits				$ (107)	$ (37)
Long-term supply commitment				10 years
Revenue	3,001		$ 2,934	$ 7,953	$ 8,686
Other assets	1,474			1,474			1,487
Deferred revenue						$ 1,070
Cumulative adjustment related to customer contract		$ 105		(105)
Other Noncurrent Liabilities [Member]
Customer deposits/ deferred revenue	1,153			1,153			927
Other Current Liabilities [Member]
Customer deposits/ deferred revenue	181			181			104
Accounting Standards Update 2014-09 [Member]
Other assets							$ 212
HSG [Member]
Customer deposits/ deferred revenue	264			264
Deferred revenue current	132			132
Deferred revenue non-current	931			931
Deferred revenue	$ 1,070			$ 1,070
HSG [Member] | Minimum [Member]
Year	2029			2029
HSG [Member] | Maximum [Member]
Year	2034			2034
Revenue Adjustments [Member]
Cumulative adjustment related to customer contract				$ 105
Measurement Input, Discount Rate [Member] | HSG [Member] | Minimum [Member]
Measurement input | item	0.0254			0.0254
Measurement Input, Discount Rate [Member] | HSG [Member] | Maximum [Member]
Measurement input | item	0.0323			0.0323
HSG [Member]
Customer deposits/ deferred revenue						$ 264
HSG [Member] | Measurement Input, Discount Rate [Member]
Measurement input | item	0.165			0.165
HSG [Member] | Measurement Input, Discount Rate [Member] | Minimum [Member]
Measurement input | item						0.0254
HSG [Member] | Measurement Input, Discount Rate [Member] | Maximum [Member]
Measurement input | item						0.0323
HSG [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]
Measurement input | item	0			0

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 3,001		$ 2,934	$ 7,953	$ 8,686
Cumulative adjustment related to customer contract		$ 105		(105)
Net sales of reportable segments and All Other	3,007		2,969	8,124	8,805
Foreign Currency Gain (Loss) [Member]
Impact of foreign currency movements	6		35	66	119
Revenue Adjustments [Member]
Cumulative adjustment related to customer contract				105
Display Products [Member]
Revenue	834		780	2,211	2,395
Telecommunication Products [Member]
Revenue	909		1,008	2,587	3,162
Specialty Glass Products [Member]
Revenue	570		463	1,339	1,141
Environmental Substrate and Filter Products [Member]
Revenue	369		380	891	1,084
Life Science Products [Member]
Revenue	220		250	707	744
All Other [Member]
Revenue	$ 99		$ 53	$ 218	$ 160

Commitments, Contingencies an_2

Commitments, Contingencies and Guarantees (Details) $ in Millions	May 31, 2016USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018	Sep. 30, 2020USD ($)item	Dec. 31, 2019USD ($)	Dec. 31, 2016USD ($)
Loss Contingency, Accrual, Current					$ 63	$ 57
Loss Contingency, Accrual, Noncurrent					144	196
Investment in affiliated companies, at equity					285	291
Asbestos Litigation [Member]
Loss Contingency, Accrual					97	98
Dow Corning Breast Implant Litigation [Member]
Payment					1,800
Loss Contingency, Accrual	$ 290				160
Indemnification of excess liability				50.00%
Dow Corning Bankruptcy Pendency Interest Claims [Member]
Loss Contingency, Accrual	$ 107
Dow Corning Environmental Claims [Member]
Indemnification of excess liability				50.00%
Amended Pittsburgh Corning Corporation Plan [Member] | Asbestos Litigation [Member]
Loss Contingency, Accrual					100
Loss Contingency, Accrual, Current					50
Loss Contingency, Accrual, Noncurrent					$ 50
Pittsburgh Corning Corporation PCC [Member] | Asbestos Litigation [Member]
Equity Method Investment, Ownership Percentage							50.00%
Payment		$ 35	$ 50
Loss Contingency, Accrual							$ 290
Dow Corning Corporation [Member]
Equity Method Investment, Ownership Percentage	50.00%						50.00%
Indemnification of excess liability	50.00%
Environmental Cleanup and Related Litigation [Member]
Number of Hazardous Waste Sites | item					15
Accrual for Environmental Loss Contingencies					$ 78	$ 41
Minimum [Member]
Equity Method Investment, Ownership Percentage					20.00%
Maximum [Member]
Equity Method Investment, Ownership Percentage					50.00%

Employee Retirement Plans (Narr

Employee Retirement Plans (Narrative) (Details) - Pension Benefits [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 60	$ 80
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 45	$ 45

Employee Retirement Plans (Net

Employee Retirement Plans (Net Periodic Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 29	$ 25	$ 87	$ 76
Interest cost	32	37	94	111
Expected return on plan assets	(49)	(42)	(147)	(128)
Amortization of prior service cost (credit)	1	2	4	5
Recognition of actuarial (gain) loss			(2)	23
Total pension and postretirement benefit expense	13	22	36	87
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	7	7
Interest cost	5	7	15	21
Amortization of actuarial net gain	1	(1)	1	(1)
Amortization of prior service cost (credit)	(2)	(2)	(5)	(6)
Total pension and postretirement benefit expense	$ 6	$ 7	$ 18	$ 21

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Sep. 09, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Taxes [Line Items]
Additional income tax as result of agreement with IRS					$ 86
Statutory U.S. income tax rate		21.00%	21.00%	21.00%	21.00%
Tax Year 2010 - 2018 [Member]
Income Taxes [Line Items]
Tax assessment refunds		$ 101		$ 101
Current receivable						$ 33
Non-current receivable		348		348		$ 415
Hemlock Semiconductor LLC [Member]
Income Taxes [Line Items]
Business combination ownership interest acquired	100.00%
Hemlock Semiconductor Operations LLC [Member]
Income Taxes [Line Items]
Business combination ownership interest acquired	80.50%
HSG [Member]
Income Taxes [Line Items]
Increase (decrease) in tax liability	$ 117
Pre-tax gain on previously hed equity investment	$ 498
Net deferred tax liability		$ 9		$ 9

Income Taxes (Provision for Inc

Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Taxes [Abstract]
Provision for income taxes	$ (23)	$ (71)	$ (33)	$ (271)
Effective tax rate	5.10%	17.40%	11.30%	22.60%

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Goodwill, Gross	$ 8,900		$ 8,900		$ 8,400
Goodwill, Impaired, Accumulated Impairment Loss	6,500		6,500		$ 6,500
Amortization of intangibles	33	$ 28	87	$ 85
Finite-Lived Intangible Assets, Amortization Expense, 2021	133		133
Finite-Lived Intangible Assets, Amortization Expense, 2022	131		131
Finite-Lived Intangible Assets, Amortization Expense, 2023	130		130
Finite-Lived Intangible Assets, Amortization Expense, 2024	128		128
Finite-Lived Intangible Assets, Amortization Expense, 2025	126		126
HSG [Member]
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)			4
Amortization of intangibles			87
Impairment			55
Developed Technologies [Member] | HSG [Member]
Intangible assets	215		$ 215
Intangible asset estimated useful lives			20 years
Other Intangible Assets [Member] | HSG [Member]
Intangible assets	$ 70		$ 70
Intangible asset estimated useful lives			15 years

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Carrying Amount of Goodwill by Segment) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Balance	$ 1,935
Acquired goodwill	495
Foreign currency translation adjustment and other	(3)
Balance	2,427
Display Technologies [Member]
Balance	129
Foreign currency translation adjustment and other	(2)
Balance	127
Optical Communications [Member]
Balance	931
Foreign currency translation adjustment and other	1
Balance	932
Specialty Materials [Member]
Balance	150
Balance	150
Life Sciences [Member]
Balance	616
Foreign currency translation adjustment and other	1
Balance	617
All Other [Member]
Balance	109
Acquired goodwill	495
Foreign currency translation adjustment and other	(3)
Balance	$ 601

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Amortized intangible assets:
Other intangible assets, gross	$ 2,004	$ 1,770
Other intangible assets, accumulated amortization	672	585
Other intangible assets, net	1,332	1,185
Patents, Trademarks, and Trade Names [Member]
Amortized intangible assets:
Other intangible assets, gross	499	469
Other intangible assets, accumulated amortization	248	228
Other intangible assets, net	251	241
Customer Lists and Other [Member]
Amortized intangible assets:
Other intangible assets, gross	1,505	1,301
Other intangible assets, accumulated amortization	424	357
Other intangible assets, net	$ 1,081	$ 944

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income attributable to Corning Incorporated	$ 427	$ 337	$ 260	$ 928
Less: Series A convertible preferred stock dividend	24	24	73	73
Net income available to common stockholders – basic	403	313	187	855
Plus: Series A convertible preferred stock dividend	24	24		73
Net income available to common stockholders – diluted	$ 427	$ 337	$ 187	$ 928
Weighted-average common shares outstanding - basic (in shares)	760	775	760	780
Effect of dilutive securities:
Weighted-average common shares outstanding - diluted (in shares)	889	897	768	903
Basic earnings per common share (in dollars per share)	$ 0.53	$ 0.40	$ 0.25	$ 1.10
Diluted earnings per common share (in dollars per share)	$ 0.48	$ 0.38	$ 0.24	$ 1.03
Antidilutive potential shares excluded from diluted earnings per common share:
Total	3	2	122	2
Stock Compensation Plan [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	14	7	8	8
Antidilutive potential shares excluded from diluted earnings per common share:
Total	3	2	7	2
Series A Convertible Preferred Stock [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	115	115		115
Antidilutive potential shares excluded from diluted earnings per common share:
Total			115

Inventories, Net of Inventory_3

Inventories, Net of Inventory Reserves (Narrative) (Details) $ in Millions	Sep. 09, 2020USD ($)
HSG [Member]
Inventory [Line Items]
Inventory	$ 503

Inventories, Net of Inventory_4

Inventories, Net of Inventory Reserves (Inventories, Net) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Inventories, Net of Inventory Reserves [Abstract]
Finished goods	$ 1,322	$ 973
Work in process	370	421
Raw materials and accessories	412	481
Supplies and packing materials	477	445
Total inventories, net of inventory reserves	$ 2,581	$ 2,320

Debt (Details)

Debt (Details) ¥ in Millions, ¥ in Billions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020CNY (¥)	Sep. 30, 2020JPY (¥)	Sep. 30, 2020CNY (¥)	Sep. 09, 2020USD ($)	Dec. 31, 2019USD ($)
Proceeds from loan facilities		$ 349,000,000
Long-term debt	$ 7,822,000,000		$ 7,822,000,000					$ 7,729,000,000
Yen-denominated Debentures, 1.153%, due 2031 [Member] | Unsecured Debt [Member]
Debt Instrument, Face Amount | ¥					¥ 31.3
Debt Instrument, Interest Rate, Stated Percentage	1.153%		1.153%		1.153%	1.153%
Debt Instrument, Term			12 years	12 years
Yen-denominated Debentures, 1.513%, due 2039 [Member] | Unsecured Debt [Member]
Debt Instrument, Face Amount | ¥					¥ 5.9
Debt Instrument, Interest Rate, Stated Percentage	1.513%		1.513%		1.513%	1.513%
Debt Instrument, Term			20 years	20 years
Variable Rate Loan Facility [Member] | Unsecured Debt [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150,000,000		$ 150,000,000			¥ 1,050
Debt Instrument, Term			5 years	5 years
Variable Rate Loan Facility B [Member] | Unsecured Debt [Member]
Line of Credit Facility, Maximum Borrowing Capacity	105,000,000		$ 105,000,000			¥ 749
Debt Instrument, Term			5 years	5 years
Incremental Liquidity Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 232,000,000		$ 232,000,000		¥ 25
Debt Instrument, Term	3 years
Revolving Credit Facility [Member]
Proceeds from loan facilities			212,000,000	¥ 1,491
Commercial Paper [Member]
Commercial paper	$ 0		0					0
Significant Other Observable Inputs (Level 2) [Member]
Fair value of long-term debt	$ 9,200,000,000		$ 9,200,000,000					$ 8,500,000
HSG [Member]
Debt consolidated							$ 175,000,000

Other Liabilities (Details)

Other Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Other Liabilities [Abstract]
Wages and employee benefits	$ 501	$ 565
Income taxes	194	182
Derivative instruments (Note 15)	143	100
Asbestos and other litigation (Note 6)	63	57
Deferred revenue (Note 5)	132
Settlement liability (4)	58
Customer deposits (Note 5)	181	104
Short-term leases	89	62
Other current liabilities	1,056	853
Other accrued liabilities	2,417	1,923
Defined benefit pension plan liabilities	927	980
Derivative instruments (Note 15)	131	165
Asbestos and other litigation (Note 6)	144	196
Deferred revenue (Note 5)	931
Settlement liability (Note 4)	117
Investment in HSG (1)		270
Customer deposits (Note 5)	1,153	927
Deferred tax liabilities	247	325
Long-term leases	606	450
Other non-current liabilities	816	667
Other liabilities	$ 5,072	$ 3,980

Hedging Activities (Narrative)

Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Amount expected to be reclassified into earnings within the next 12 months		$ 11
Derivative Asset, Notional Amount		16,548	$ 16,104
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount		5,400	7,700
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount		800	2,100
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Not Designated as Hedging Instrument [Member]
Amount reclassified	$ 14
Gross Notional Value, Translated Earnings Contracts [Member]
Derivative Asset, Notional Amount		8,900	12,200
Gross Notional Value, Collar Options [Member]
Derivative Asset, Notional Amount		2,300	2,500
Gross Notional Value, Foreign Exchange Forward [Member]
Derivative Asset, Notional Amount		$ 6,600	$ 9,700

Hedging Activities (Summary of

Hedging Activities (Summary of Notional Amounts and Respective Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Notional amount	$ 16,548	$ 16,104
Asset derivatives, fair value	183	249
Liability derivatives, fair value	(274)	(265)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member]
Notional amount	826	2,123
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	18	38
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	14	37
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(7)	(7)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	(1)	(4)
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	6,816	1,815
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	28	5
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	32	21
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(61)	(19)
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	(58)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	8,906	12,166
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	58	114
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	33	34
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(75)	(74)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	$ (72)	$ (161)

Hedging Activities (Effect on C

Hedging Activities (Effect on Consolidated Financial Statements) (Details) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Sales [Member]
Gain (loss) reclassified from accumulated OCI into income	$ (2)		$ (4)
Cost of Sales [Member]
Gain (loss) reclassified from accumulated OCI into income	3	$ 2	7	$ 7
Other Expense [Member]
Gain (loss) reclassified from accumulated OCI into income			(14)
Cash Flow Hedging [Member]
Gain (loss) recognized in other comprehensive income (OCI)	16	(26)	(51)	(19)
Gain (loss) reclassified from accumulated OCI into income	1	2	(11)	7
Foreign Exchange Contracts [Member]
Gain (loss) recognized in other comprehensive income (OCI)	$ 16	$ (26)	$ (51)	$ (19)

Hedging Activities (Effect on_2

Hedging Activities (Effect on Consolidated Financial Statements) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Gain (loss) recognized in income	$ (148)	$ 105	$ (57)	$ 201
Foreign Exchange And Other Contracts - Balance Sheet, Loans And Other [Member] | Other Income (Expense), Net [Member]
Gain (loss) recognized in income	(48)	19	(62)	38
Foreign Currency Hedges Related To Translated Earnings [Member] | Translated Earnings Contract (Loss) Gain, Net [Member]
Gain (loss) recognized in income	$ (100)	$ 86	$ 5	$ 163

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Asset Impairment Charges	$ 22,000,000	$ 195,000,000	$ 217,000,000	$ 369,000,000
Fair Value, Nonrecurring [Member]
Assets, Fair Value Disclosure	0		0	0
Liabilities, Fair Value Disclosure	$ 0		0	0
Renewable Energy [Member]
Decrease in liability				20,000,000
Gain (loss) recognized			(21,000,000)	21,000,000
HSG [Member]
Asset Impairment Charges			$ 0	$ 916,000,000

Fair Value Measurements (Major

Fair Value Measurements (Major Categories of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 09, 2020	Dec. 31, 2019
Other Current Assets [Member]
Other assets	$ 132		$ 157
Contingent consideration		$ 24
Other Current Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other assets	104		157
Other Current Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Other assets	28
Other Assets [Member]
Contingent consideration		$ 20
Other Noncurrent Assets [Member]
Investments	13
Other assets	95		92
Other Noncurrent Assets [Member] | Quoted Market Prices in Active Markets for Identical Assets (Level 1) [Member]
Investments	13
Other Noncurrent Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other assets	79		71
Other Noncurrent Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Other assets	16		21
Other Accrued Liabilities [Member]
Other accrued liabilities	143		100
Other Accrued Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other accrued liabilities	143		100
Other Liabilities [Member]
Other liabilities	131		165
Other Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other liabilities	$ 131		165
Renewable Energy [Member] | Other Noncurrent Assets [Member]
Other assets			$ 21

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Jul. 17, 2019	Apr. 26, 2018
Treasury Stock, Value, Acquired	$ 105	$ 308	$ 151	$ 244
The 2018 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount								$ 2,000
Treasury Stock, Shares, Acquired		10,800,000			4,100,000	23,400,000
Treasury Stock, Value, Acquired		$ 308			$ 105	$ 703
2019 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount							$ 5,000
Common Stock [Member]
Convertible Preferred Stock, Shares Issued upon Conversion					50,000
Series A Convertible Preferred Stock [Member]
Convertible Preferred Stock, Shares Issued upon Conversion					2,300

Shareholders' Equity (Accumulat

Shareholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance	$ 12,133	$ 13,521	$ 12,997	$ 13,886
Net current-period other comprehensive income (loss)	298	(257)	37	(377)
Balance	12,857	13,134	12,857	13,134
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(1,064)	(786)	(857)	(714)
Other comprehensive income (loss)	274	(235)	75	(293)
Equity method affiliates	9	(3)	1	(17)
Net current-period other comprehensive income (loss)	283	(238)	76	(310)
Balance	(781)	(1,024)	(781)	(1,024)
Other Comprehensive Income, Tax	21	(16)	10	(39)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	9	8	51	6
Other comprehensive income (loss)	11	(21)	(40)	(16)
Amounts reclassified from accumulated other comprehensive income (loss)		(1)	9	(4)
Net current-period other comprehensive income (loss)	11	(22)	(31)	(20)
Balance	20	$ (14)	20	$ (14)
Other Comprehensive Income, Tax	$ 5		$ 11

Share-based Compensation (Narra

Share-based Compensation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 01, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	36,000,000		36,000,000
Allocated Share-based Compensation Expense	$ 62	$ 13	$ 127	$ 43
Granted, number of shares (in shares)			10,653,000
Chief Executive Officer [Member]
Decrease In Salary						40.00%
Other Executive Officers [Member]
Decrease In Salary						30.00%
Director [Member]
Decrease In Salary						40.00%
Executive Officer [Member]
Allocated Share-based Compensation Expense	$ 49		$ 84
Long-Term Incentive Plan			75.00%		40.00%
Employee Stock Option [Member]
Share-based compensation award expiration period			10 years
Granted, number of shares (in shares)	0	0	0	0
Employee Stock Option [Member] | Executive Officer [Member]
Vesting period			3 years
Restricted Stock Units (RSUs) [Member] | Executive Officer [Member]
Vesting period			3 years
Minimum [Member] | Salaried Employees [Member]
Decrease In Salary						5.00%
Minimum [Member] | Employee Stock Option [Member]
Stock Options Exercisable Period from Date of Grant			1 year
Minimum [Member] | Restricted Stock and Restricted Stock Units [Member]
Stock Options Exercisable Period from Date of Grant			1 year
Share-based compensation award expiration period			1 year
Maximum [Member] | Salaried Employees [Member]
Decrease In Salary						30.00%
Maximum [Member] | Employee Stock Option [Member]
Stock Options Exercisable Period from Date of Grant			5 years
Maximum [Member] | Restricted Stock and Restricted Stock Units [Member]
Stock Options Exercisable Period from Date of Grant			10 years
Share-based compensation award expiration period			10 years

Share-based Compensation (Summa

Share-based Compensation (Summary of Information Concerning Stock Options Outstanding Including the Related Transactions under the Stock Option Plans) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2020
Share-based Compensation [Abstract]
Balance, number of shares (in shares)	13,172
Granted, number of shares (in shares)	10,653
Exercised, number of shares (in shares)	(2,560)
Forfeited and expired, number of shares (in shares)	(166)
Balance, number of shares (in shares)	21,099
Options Expected to Vest, number of shares (in shares)	20,703
Options Exercisable, number of shares (in shares)	7,400
Balance, weighted-average exercise price (in dollars per share)	$ 21.94
Granted, weighted-average exercise price (in dollars per share)	19.65
Exercised, weighted-average exercise price (in dollars per share)	18.88
Forfeited and expired, weighted-average exercise price (in dollars per share)	20.04
Balance, weighted-average exercise price (in dollars per share)	21.17
Options Expected to Vest, weighted-average exercise price (in dollars per share)	21.19
Options Exercisable, weighted-average exercise price (in dollars per share)	$ 19.38
Options Outstanding, weighted-average remaining contractual term in years (Year)	7 years 2 months 26 days
Options Expected to Vest, weighted-average remaining contractual term in years (Year)	7 years 2 months 8 days
Options Exercisable, weighted-average remaining contractual term in years (Year)	3 years 6 months 21 days
Options Outstanding, aggregate intrinsic value	$ 239,564
Options Expected to Vest, aggregate intrinsic value	234,719
Options Exercisable, aggregate intrinsic value	$ 96,460

Share-based Compensation (Input

Share-based Compensation (Inputs Used for Valuation of Option Grants under Stock Option Plans) (Details) - shares shares in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Expected volatility	29.50%
Weighted-average volatility	29.50%
Expected dividends	2.95%
Risk-free rate	1.50%
Average risk-free rate	1.50%
Expected term (in years)	7 years 4 months 24 days
Pre-vesting executive departure rate	0.60%
Granted, number of shares (in shares)		10,653
Minimum [Member]
Expected volatility		32.90%	29.50%
Weighted-average volatility		32.90%	29.50%
Expected dividends		4.48%	2.36%
Risk-free rate		0.50%	1.50%
Average risk-free rate		0.50%	1.50%
Expected term (in years)		7 years 4 months 24 days	7 years 4 months 24 days
Pre-vesting executive departure rate		0.60%	0.60%
Pre-vesting non-executive departure rate		2.50%
Maximum [Member]
Expected volatility		32.90%	29.90%
Weighted-average volatility		32.90%	29.90%
Expected dividends		4.48%	2.95%
Risk-free rate		0.50%	2.40%
Average risk-free rate		0.50%	2.40%
Expected term (in years)		7 years 4 months 24 days	7 years 4 months 24 days
Pre-vesting executive departure rate		0.60%	0.60%
Pre-vesting non-executive departure rate		2.50%

Share-based Compensation (Sum_2

Share-based Compensation (Summary of the Status of Non-vested Time-based Restricted Stock and Restricted Stock Units) (Details) - Time-Based Restricted Stock and Restricted Stock Units [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Balance, Number of shares (in shares) | shares	5,189
Granted, Number of shares (in shares) | shares	9,272
Vested, Number of shares (in shares) | shares	(1,176)
Forfeited, Number of shares (in shares) | shares	(192)
Balance, Number of shares (in shares) | shares	13,093
Balance, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 27.58
Granted, weighted average grant-date fair value (in dollars per share) | $ / shares	20.69
Vested, weighted average grant-date fair value (in dollars per share) | $ / shares	27.50
Forfeited, weighted average grant-date fair value (in dollars per share) | $ / shares	24.42
Balance, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 22.76

Reportable Segments (Narrative)

Reportable Segments (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)item	Sep. 30, 2019USD ($)
Loss on assets | $	$ 107	$ 45
Minimum [Member]
Number of Material Formulations | item	150

Reportable Segments (Reportable

Reportable Segments (Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment net sales	$ 3,007	$ 2,969	$ 8,124	$ 8,805
Depreciation			1,041	1,026
Research, development and engineering expenses	231	255	922	753
Income tax (provision) benefit	(23)	(71)	(33)	(271)
Net income (loss) attributable to Corning Incorporated	$ 427	$ 337	$ 260	$ 928
Statutory U.S. income tax rate	21.00%	21.00%	21.00%	21.00%
Operating Segments [Member]
Segment net sales	$ 3,007	$ 2,969	$ 8,124	$ 8,805
Depreciation	293	295	882	898
Research, development and engineering expenses	177	206	567	633
Income tax (provision) benefit	(136)	(122)	(275)	(359)
Net income (loss) attributable to Corning Incorporated	504	454	1,028	1,342
Display Technologies [Member] | Operating Segments [Member]
Segment net sales	827	793	2,331	2,459
Depreciation	134	144	400	445
Research, development and engineering expenses	22	30	77	85
Income tax (provision) benefit	(52)	(49)	(133)	(159)
Net income (loss) attributable to Corning Incorporated	196	185	500	606
Optical Communications [Member] | Operating Segments [Member]
Segment net sales	909	1,007	2,587	3,161
Depreciation	59	59	183	178
Research, development and engineering expenses	50	53	157	163
Income tax (provision) benefit	(32)	(35)	(63)	(117)
Net income (loss) attributable to Corning Incorporated	115	127	225	427
Specialty Materials [Member] | Operating Segments [Member]
Segment net sales	570	463	1,339	1,141
Depreciation	40	35	120	107
Research, development and engineering expenses	39	37	113	119
Income tax (provision) benefit	(38)	(25)	(76)	(56)
Net income (loss) attributable to Corning Incorporated	146	92	287	208
Environmental Technologies [Member] | Operating Segments [Member]
Segment net sales	379	397	925	1,125
Depreciation	32	32	99	95
Research, development and engineering expenses	24	29	74	87
Income tax (provision) benefit	(18)	(21)	(27)	(53)
Net income (loss) attributable to Corning Incorporated	69	79	104	199
Life Sciences [Member] | Operating Segments [Member]
Segment net sales	223	256	724	759
Depreciation	12	12	37	37
Research, development and engineering expenses	7	5	20	15
Income tax (provision) benefit	(8)	(11)	(26)	(30)
Net income (loss) attributable to Corning Incorporated	28	41	97	112
All Other [Member] | Operating Segments [Member]
Segment net sales	99	53	218	160
Depreciation	16	13	43	36
Research, development and engineering expenses	35	52	126	164
Income tax (provision) benefit	12	19	50	56
Net income (loss) attributable to Corning Incorporated	$ (50)	$ (70)	$ (185)	$ (210)

Reportable Segments (Reconcilia

Reportable Segments (Reconciliation of Reportable Segment and All Other Net Sales to Consolidated Net Sales) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reportable Segments [Abstract]
Net sales of reportable segments and All Other	$ 3,007		$ 2,969	$ 8,124	$ 8,805
Impact of foreign currency movements	(6)		(35)	(66)	(119)
Cumulative adjustment related to customer contract		$ 105		(105)
Net sales	$ 3,001		$ 2,934	$ 7,953	$ 8,686

Reportable Segments (Reconcil_2

Reportable Segments (Reconciliation of Reportable Segment Net Income to Consolidated Net Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Litigation, regulatory and other legal matters	$ (83)			$ 24	$ (108)	$ 24
Research, development, and engineering expenses	(231)			(255)	(922)	(753)
Transaction-related gain, net	498				498
Equity in (losses) earnings of affiliated companies	(76)			23	17	81
Amortization of intangibles	(33)			(28)	(87)	(85)
Interest expense, net	(70)			(55)	(201)	(161)
Income tax (provision) benefit	(23)			(71)	(33)	(271)
Cumulative adjustment related to customer contract			$ 105		(105)
Accelerated depreciation					(1,041)	(1,026)
Severance charges	(6)			(18)	(141)	(25)
Asset impairment	(22)	$ (195)			(217)		$ (369)
Net income attributable to Corning Incorporated	427			337	260	928
Operating Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Research, development, and engineering expenses	(177)			(206)	(567)	(633)
Income tax (provision) benefit	(136)			(122)	(275)	(359)
Accelerated depreciation	(293)			(295)	(882)	(898)
Net income attributable to Corning Incorporated	504			454	1,028	1,342
Operating Segments [Member] | Reportable Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net income attributable to Corning Incorporated	554			524	1,213	1,552
Operating Segments [Member] | Non Reportable Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net income attributable to Corning Incorporated	(50)			(70)	(185)	(210)
Segment Reconciling Items [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Impact of foreign currency movements not included in segment net income (loss)				(20)	(25)	(93)
(Loss) gain on foreign currency hedges related to translated earnings	(99)			84	(6)	161
Translation (loss) gain on Japanese yen-denominated debt	(39)			11	(50)	(10)
Research, development, and engineering expenses	(35)			(33)	(111)	(104)
Equity in (losses) earnings of affiliated companies	(79)			20	20	80
Amortization of intangibles	(33)			(28)	(87)	(85)
Interest expense, net	(67)			(51)	(189)	(145)
Income tax (provision) benefit	113			51	242	88
Cumulative adjustment related to customer contract					(105)
Severance charges	(6)			(18)	(141)	(25)
Asset impairment	(22)				(217)
Capacity realignment and other charges and credits	(143)			(130)	(375)	(197)
Other corporate items	(82)			(27)	(114)	(108)
Net income attributable to Corning Incorporated	$ 427			$ 337	$ 260	$ 928