Revenue

On January 1, 2018, we adopted ASC 606, “Revenue from Contracts with Customers” and the related amendments (“ASC 606”) to contracts not completed as of the adoption date using the modified retrospective method. Accordingly, the comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The cumulative effect of initially applying this standard was zero. The adoption of ASC 606 did not result in a change to the amount or timing of our revenue recognition.

We disaggregate our revenue by geographical region as follows:



	Year ended December 31,
Net Sales	2018		2017		2016
United States	$	1,138.6	$	938.4	$	808.9
Iceland	754.6		650.7		510.2
Total	$	1,893.2	$	1,589.1	$	1,319.1

We enter into contracts to sell primary aluminum to our customers. Revenue is recognized when our performance obligations with our customer are satisfied. Our obligations under the contracts are satisfied when we transfer control of our primary aluminum to our customer which is generally upon shipment or delivery to customer directed locations. The amount of consideration we receive, thus the revenue we recognize, is a function of volume delivered, market price of primary aluminum, as determined on the LME, plus regional premiums and any value-added product premiums.

The payment terms and conditions in our contracts vary and are not significant to our revenue. We complete an appropriate credit evaluation for each customer at contract inception. Customer payments are due in arrears and are recognized as accounts receivable - net and due from affiliates in our consolidated balance sheets. Accounts receivable - net increased $39.4 million from December 31, 2017 to December 31, 2018, driven primarily by the increase in direct sales to end users with longer payment terms than our related party customer.

In connection with our sales agreement with Glencore, we invoice Glencore prior to physical shipment of goods for substantially all production generated from each of our U.S. domestic smelters. For those sales, revenue is recognized only when Glencore has specifically requested such treatment and has made a commitment to purchase the product. The goods must be complete, ready for shipment and separated from other inventory with control over the goods passing to Glencore. We must retain no further performance obligations.