Asset Retirement Obligations

12 Months Ended

Dec. 31, 2025

Asset Retirement Obligation Disclosure [Abstract]

NOTE 8—ASSET RETIREMENT OBLIGATIONS:

The reconciliation of changes in the Company’s asset retirement obligations is as follows:


	December 31,
	2025		2024
Balance at Beginning of Period	$	247,732	$	241,192
Accretion Expense	42,297		19,727
Payments	(36,205)		(30,089)
Revisions in Estimated Cash Flows	26,442		16,902
Obligations Assumed in Merger	254,474		—

Balance at End of Period (a)	$	534,740	$	247,732

(a) Includes current portion of $38,738 and $35,554 at December 31, 2025 and 2024, respectively.

Through December 31, 2025, the Company has contributed $131,585 to a fund that will serve to defease the long-term asset retirement obligation for its Powder River Basin thermal asset base; this amount is included in Funds for Asset Retirement Obligations on the Consolidated Balance Sheets.

On October 2, 2024, three Company subsidiaries voluntarily entered into a Post-Mining Discharge Treatment Trust Consent Order and Agreement (“CO&A”) with the Pennsylvania Department of Environmental Protection (“PADEP”). The CO&A serves as an approved alternative financial assurance mechanism associated with the Company’s perpetual water treatment obligations located in Pennsylvania and establishes a Global Water Treatment Trust Fund (“WTTF”). The WTTF is a long-term funding mechanism for 22 legacy mine water treatment systems (“treatment systems”) in Pennsylvania. The Company intends to make minimum annual contributions of $2,000 until the cash balance of the fund equals 100% of the present value of future operation, maintenance and recapitalization costs for the treatment systems, currently estimated to be $74,795. As the cash balance of the fund grows, surety bonds associated with the treatment systems will be adjusted or released by the PADEP, thereby reducing the Company’s exposure to surety bonds and related collateral requirements. Through December 31, 2025, the Company has contributed $14,066 to the fund, and the PADEP has approved bond reductions totaling $66,294.

During the years ended December 31, 2025 and 2024, the Company’s contributions into the WTTF were managed and invested, at the direction of the trustee in accordance with the trust agreement, into various debt and equity securities. These investments are held in the custody of the WTTF trustee. These investments are classified as available-for-sale securities.

The Company’s investments in available-for-sale securities are as follows:


	Amortized Cost		Allowance for Credit Losses		Gross Unrealized
Funds for Asset Retirement Obligations					Gains		Losses		Fair Value
December 31, 2025	$	15,546	$	—	$	2,403	$	(660)	$	17,289
December 31, 2024	$	12,112	$	—	$	87	$	(145)	$	12,054

Available-for-sale investments are reported at fair value in the accompanying Consolidated Balance Sheets, and any unrealized gains or losses are recognized in Other Comprehensive Income (Loss), net of tax. Any unrealized gains or losses in the Company’s portfolio are a result of normal market fluctuations. Interest, dividends and realized gains or losses are included in net income when earned.