Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2022

Asset Retirement Obligation Disclosure [Abstract]

Summary of Changes in Asset Retirement Obligations

The following table summarizes the changes in asset retirement obligations for the years ended December 31, 2022 and 2021:

Total asset retirement obligations at December 31, 2020	$	165,064
Accretion for the period	26,520
Sites added during the period	2,125
Revisions in estimated cash flows (1)	(12,744)
Expenditures for the period	(16,793)
Total asset retirement obligations at December 31, 2021	$	164,172
Accretion for the period	23,765
Sites added during the period	9,602
Revisions in estimated cash flows	304
Expenditures for the period	(18,832)
Total asset retirement obligations at December 31, 2022	$	179,011
Less current portion (2)	(36,963)
Long-term portion	$	142,048

(1)    The revisions in estimated cash flows resulted primarily from discount rate adjustments and changes in mine plans.

(2)    Included within Accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets. Refer to Note 13.