Receivables (Tables)

12 Months Ended

Dec. 31, 2020

Financing Receivable, Allowance for Credit Loss [Line Items]

Rollforward of Allowance for Bad Debts

The table below presents a rollforward of our global allowance for credit losses for 2018, 2019 and 2020.

Millions of dollars	Balance at Beginning of Period		Provision (a)		Other (b)		Balance at End of Period (c)
Year ended December 31, 2018	$	725	$	57	$	(44)	$	738
Year ended December 31, 2019	738		50		(12)		776
Year ended December 31, 2020	776		58		(10)		824

(a) Represents increases to allowance for credit losses charged to costs and expenses, net of recoveries.

(b) Includes write-offs, balance sheet reclassifications, and other activity.

(c) The allowance for credit losses in all years is primarily comprised of a full reserve against accounts receivable with our primary customer in Venezuela.