2. Revenue

On January 1, 2018, we adopted ASC Topic 606 “Revenue from Contracts with Customer”, and all related amendments, using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under ASC Topic 605 “Revenue Recognition”.

We have determined that the impact of transition to the new standard is immaterial to our revenue recognition model since the vast majority of our recognition is based on point in time transfer of control. Accordingly, we have not made any adjustment to opening retained earnings.

Product Revenue (Point in Time)

The majority of our revenues are generated by delivery of products to our customers and recognized at a point in time based on our evaluation of when the customer obtains control of the products. Revenue is recognized when all performance obligations under the terms of a contract with our customer are satisfied, and control of the product has been transferred to the customer. If customer acceptance clauses are present and it cannot be objectively determined that control has been transferred, revenue is only recorded when customer acceptance is received and all performance obligations have been satisfied. Sales of goods typically do not include multiple product and/or service elements.

Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services. Sales tax, value-added tax, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. Incidental contract costs that are not material in the context of the delivery of goods and services are recognized as expense.

At the time revenue is recognized, allowances are recorded, with the related reduction to revenue, for estimated product returns, allowances and price discounts based upon historical experience and related terms of customer arrangements. Where we have offered product warranties, we also establish liabilities for estimated warranty costs based upon historical experience and specific warranty provisions. Warranty liabilities are adjusted when experience indicates the expected outcome will differ from initial estimates of the liability. Product warranty liabilities are not material at March 31, 2018 and December 31, 2017.

Other Revenue (Over Time)

Corning’s over time revenues are mainly related to Telecommunications products, and are comprised of design, install, training and software maintenance services. The performance obligations under these contracts generally require services to be performed over time, resulting in either a straight-line amortization method or an input method using incurred and forecasted expense to predict revenue recognition patterns which follows satisfaction of the performance obligation. Corning’s other revenue is inconsequential to our results.

Revenue Disaggregation Table

The following table shows revenues by major product categories, similar to our reportable segment disclosure. Within each product category, contract terms, conditions and economic factors affecting the nature, amount, timing and uncertainty around revenue recognition and cash flows are substantially similar. The commercial markets and selling channels are also similar. With the exception of an inconsequential amount of Telecommunications products, our product category revenues are recognized at point in time when control transfers to the customer. Prior year amounts are presented under the ASC 605 basis of revenue recognition.



	Three Months Ended
	March 31,
Revenues by Product Category	2018		2017
Display products	$	732	$	736

Telecommunication products		886		818

Specialty glass products		278		300

Environmental substrate and filter products		322		275

Life science products		232		210

All Other		50		36
	$	2,500	$	2,375

Contract Assets and Liabilities

Contract assets, such as costs to obtain or fulfill contracts, are an insignificant component of Corning’s revenue recognition process. The majority 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 our products and their respective manufacturing processes.

Contract liabilities include deferred revenues, other advanced payments and customer deposits. Deferred revenue and other advanced payments are not significant to our operations and are classified as part of other current liabilities in our financial statements. Customer deposits are predominately related to Display products and are classified as part of other current liabilities and other long term liabilities as appropriate, and are disclosed below.

Customer Deposits

As of March 31, 2018, Corning has customer deposits of $682 million, of which $276 million was received in the first quarter of 2018. These represent 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 range up to ten years. As glass is shipped to customers, Corning will recognize revenue and issue credit memoranda to reduce the amount of the customer deposit liability, which are applied against customer receivables resulting from the sale of glass. In 2018, 2017 and 2016, no credit memoranda were issued.

Practical Expedients and Exemptions

We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed.

We treat shipping and handling fees as a fulfillment cost and not as a separate performance obligation under the terms of our revenue contracts due to the perfunctory nature of the shipping and handling obligations.