Inventories	3 Months Ended
Mar. 31, 2021
Inventories [Abstract]
Inventories	Note 2—Inventories Inventories consisted of the following: Millions of Dollars March 31 December 31 2021 2020 Crude oil and natural gas $ 541 461 Materials and supplies 557 541 $ 1,098 1,002 Inventories valued on the LIFO basis totaled $ 352 million and $ 282 million at March 31, 2021 and December 31, 2020, respectively.

The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-URI http://asc.fasb.org/topic&trid=2126998

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