Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2024

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Reconciliation of Beginning and Ending Aggregate Carrying Amount of Asset Retirement Obligations

A reconciliation of the beginning and ending aggregate carrying amount of the ARO for the three-month periods ended March 31, 2024 and 2023 is shown in the following table.

(Thousands of dollars)	March 31, 2024		March 31, 2023
Balance at beginning of year	$	914,763	$	911,653
Accretion	12,774		11,157
Liabilities incurred	8,960		3,605
Revisions of previous estimates	1,995		(822)
Liabilities settled	(737)		(4,855)
Changes due to translation of foreign currencies	(3,143)		394
Balance at end of period	934,612		921,132
Current portion of liability 1	(17,797)		(90,774)
Noncurrent portion of liability	$	916,815	$	830,358

1 Included in “Other accrued liabilities” on the Consolidated Balance Sheets.