Inventory	12 Months Ended
Dec. 31, 2020
Inventory [Abstract]
Inventory	5. INVENTORY Our inventory, comprised entirely of finished goods, is stated at the lower of cost (generally determined using the LIFO cost method) or market. Inventories valued using the LIFO method comprised 89% and 90% of the total inventories at December 31, 2020 and 2019, respectively. Had the first-in, first-out (“FIFO”) method been used, merchandise inventory would have been $227.2 million and $186.5 million greater than reported under the LIFO method at December 31, 2020 and 2019, respectively. In 2020, we liquidated portions of previously created LIFO layers, resulting in decreases in cost of merchandise sold of $4.1 million. We did not liquidate any portion of previously-created LIFO layers in 2019 and 2018. Reserves for excess and obsolete inventories were $8.6 million and $9.2 million at December 31, 2020 and 2019, respectively. The change in the reserve for excess and obsolete inventories, included in cost of merchandise sold, was $(0.6) million, $1.4 million, and $(1.4) million for the years ended December 31, 2020, 2019, and 2018, respectively.

Inventory

12 Months Ended

Dec. 31, 2020

5. INVENTORY

Our inventory, comprised entirely of finished goods, is stated at the lower of cost (generally determined using the LIFO cost method) or market. Inventories valued using the LIFO method comprised 89% and 90% of the total inventories at December 31, 2020 and 2019, respectively. Had the first-in, first-out (“FIFO”) method been used, merchandise inventory would have been $227.2 million and $186.5 million greater than reported under the LIFO method at December 31, 2020 and 2019, respectively. In 2020, we liquidated portions of previously created LIFO layers, resulting in decreases in cost of merchandise sold of $4.1 million. We did not liquidate any portion of previously-created LIFO layers in 2019 and 2018.

Reserves for excess and obsolete inventories were $8.6 million and $9.2 million at December 31, 2020 and 2019, respectively. The change in the reserve for excess and obsolete inventories, included in cost of merchandise sold, was $(0.6) million, $1.4 million, and $(1.4) million for the years ended December 31, 2020, 2019, and 2018, respectively.