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.

Significant Accounting Policies

9 Months Ended

Sep. 30, 2020

Significant Accounting Policies [Abstract]

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.