INVENTORIES

12 Months Ended

Dec. 31, 2020

INVENTORIES [Abstract]

INVENTORIES

NOTE 3: INVENTORIES

Inventories at December 31 are as follows:

in thousands	2020	2019
Inventories
Finished products 1	$      378,389	$     391,666
Raw materials	33,780	31,318
Products in process	4,555	5,604
Operating supplies and other	31,861	29,720
Total	$      448,585	$     458,308

¹ Includes inventories encumbered by volumetric production payments (see Note 2), as follows: December 31, 2020 — $2,416 thousand and December 31, 2019 — $2,861 thousand.

In addition to the inventory balances presented above, as of December 31, 2020 and December 31, 2019, we have $10,978,000 and $7,557,000, respectively, of inventory classified as long-term assets (other noncurrent assets) as we do not expect to sell the inventory within one year of their respective balance sheet dates.

We use the LIFO method of valuation for most of our inventories as it results in a better matching of costs with revenues. Inventories valued under the LIFO method total $307,656,000 at December 31, 2020 and $309,429,000 at December 31, 2019. During 2020, 2019 and 2018, inventory reductions resulted in liquidations of LIFO inventory layers carried at costs prevailing in prior years as compared to current-year costs. The effect of the LIFO liquidation on 2020 results was to decrease cost of revenues by $867,000 and increase net earnings by $646,000. The effect of the LIFO liquidation on 2019 results was to decrease cost of revenues by $1,147,000 and increase net earnings by $854,000. The effect of the LIFO liquidation on 2018 results was to increase cost of revenues by $132,000 and decrease net earnings by $99,000.

Estimated current cost exceeded LIFO cost at December 31, 2020 and 2019 by $192,974,000 and $183,181,000, respectively. In periods of increasing costs, LIFO generally results in higher cost of revenues than under FIFO. In periods of decreasing costs, the results are generally the opposite. We provide supplemental income disclosures to facilitate comparisons with companies not on LIFO. The supplemental income calculation is derived by tax-affecting the change in the LIFO reserve for the periods presented. If all inventories valued at LIFO cost had been valued under first-in, first-out (FIFO) method, the approximate effect on net earnings would have been an increase of $7,292,000 in 2020, an increase of $5,462,000 in 2019 and an increase of $5,223,000 in 2018.