Document And Entity Information Document Information [Table] Class of Stock [Axis] Class of Stock [Domain] Common Class A [Member] Class A Common Stock Common Class B [Member] Class B Common Stock Debt Instrument [Axis] Debt Instrument, Name [Domain] Refers to Senior Notes Due 2029. Senior Notes Due 2029 [Member] Senior Notes due 2029 8.375% Senior Notes due 2029 Represents the information pertaining to 8.25% Senior Unsecured Notes due 2030. Senior Notes, Due 2030 [Member] Senior Notes due 2030 8.250% Senior Notes due 2030 Document Information [Line Items] Document And Entity Information Document Type Document Quarterly Report Document Period End Date Document Transition Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line Two Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag Condensed Consolidated Balance Sheets Statement [Table] Statement Assets, Current [Abstract] Current assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Total cash & cash equivalents Accounts Receivable, after Allowance for Credit Loss, Current Accounts receivable Inventory, Net Inventories Total inventories Prepaid Expense, Current Prepaid expenses and other Assets, Current Total current assets Property, Plant and Equipment, Net Total property, plant, and equipment, net Property, plant, and equipment, net Finance Lease, Right-of-Use Asset, after Accumulated Amortization Financing lease right-of-use assets, net Advance Royalties, Noncurrent Advanced coal royalties Other Assets, Noncurrent Other Assets Total Assets Liabilities [Abstract] Liabilities Liabilities, Current [Abstract] Current liabilities Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued liabilities Total accrued liabilities Asset Retirement Obligation, Current Current portion of asset retirement obligations Long-Term Debt, Current Maturities Current portion of long-term debt Current portion of long-term debt Finance Lease, Liability, Current Current portion of financing lease obligations The amount outstanding on insurance financing liability. Insurance Financing Liability Insurance financing liability Liabilities, Current Total current liabilities Asset Retirement Obligations, Noncurrent Long-term asset retirement obligations Finance Lease, Liability, Noncurrent Long-term financing lease obligations Senior Notes Long-term debt, net Deferred Income Tax Liabilities, Net Deferred tax liability, net Other Liabilities, Noncurrent Other long-term liabilities Liabilities Total liabilities Commitments and Contingencies. Commitments and contingencies EQUITY Stockholders' Equity Preferred Stock, Value, Issued Preferred stock, $0.01 par value, 50,000,000 shares authorized, none issued or outstanding Common Stock, Value, Issued Common stock Additional Paid in Capital, Common Stock Additional paid-in capital Treasury Stock, Common, Value Treasury stock, at cost: 1,032,202 shares at March 31, 2026 and zero at December 31, 2025 Retained Earnings (Accumulated Deficit) Retained earnings (accumulated deficit) Equity, Attributable to Parent Balance Balance Total stockholders' equity Liabilities and Equity Total Liabilities and Stockholders' Equity Preferred Stock, Par or Stated Value Per Share Preferred stock, par value (in dollars per share) Preferred Stock, Shares Authorized Preferred stock, shares authorized (in shares) Preferred Stock, Shares Issued Preferred stock, shares issued (in shares) Preferred Stock, Shares Outstanding Preferred stock, shares outstanding (in shares) Common Stock, Par or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares Authorized Common stock, shares authorized (in shares) Common Stock, Shares, Issued Common stock, shares issued (in shares) Common Stock, Shares, Outstanding Common stock, shares outstanding (in shares) Treasury Stock, Common, Shares Treasury stock, common, shares (in shares) Condensed Consolidated Statements of Operations Revenue from Contract with Customer, Including Assessed Tax Revenue Total revenue Cost of Goods and Services Sold [Abstract] Costs and expenses Cost of Goods and Services Sold Cost of sales (exclusive of items shown separately below) Asset retirement obligations accretion Asset retirement obligations accretion Accretion of asset retirement obligations Asset retirement obligations accretion Depreciation, Depletion and Amortization Depreciation, depletion, and amortization Depreciation, depletion, and amortization Total depreciation, depletion, and amortization Selling, General and Administrative Expense Selling, general, and administrative Selling, general, and administrative Costs and Expenses Total costs and expenses Operating Income (Loss) Operating income (loss) Other Nonoperating Income (Expense) Other income (expense), net Other segment items Interest Income (Expense), Nonoperating Interest expense, net Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (loss) before tax Income Tax Expense (Benefit) Income tax benefit (expense) Income tax expense (benefit) Net income (loss) Net income (loss) EARNINGS (LOSS) PER SHARE Earnings (loss) per common share Earnings Per Share, Basic Basic (in dollars per share) Earnings Per Share, Diluted Diluted (in dollars per share) Condensed Consolidated Statements of Stockholders' Equity Equity Components [Axis] Equity Component [Domain] Common Stock [Member] Common Stock Additional Paid-in Capital [Member] Additional Paid-in Capital Treasury Stock, Common [Member] Treasury Stock Retained Earnings [Member] Retained Earnings Retained Earnings APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Stock-based compensation Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Shares surrendered for withholding taxes payable Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense) Stock options exercised Dividends, Common Stock, Cash Cash dividends and dividend equivalents declared Value of non-cash dividend declared and distributed . Adjustment To Additional Paid In Capital, Non Cash Dividends Declared and Distributed Non-cash dividends declared and distributed Dividends, Common Stock, Paid-in-kind Non-cash dividends declared but not distributed Amount of increase in additional paid in capital (APIC) resulting from cash dividend equivalent units. Adjustments To Additional Paid In Capital, Cash Dividend Equivalent Units Cash dividend equivalent units Treasury Stock, Value, Acquired, Cost Method Common stock repurchases Condensed Consolidated Statements of Cash Flows Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash from operating activities: Amortization of Debt Issuance Costs Amortization of debt issuance costs Share-Based Payment Arrangement, Noncash Expense Stock-based compensation Stock-based compensation Gain (Loss) on Disposition of Property Plant Equipment (Gain)/loss on disposal of assets Deferred Income Tax Expense (Benefit) Deferred income taxes Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts and Notes Receivable Accounts receivable Increase (Decrease) in Prepaid Expense Prepaid expenses and other current assets Increase (Decrease) in Inventories Inventories Increase (Decrease) in Other Operating Assets and Liabilities, Net Other assets and liabilities Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accrued Liabilities Accrued liabilities Net Cash Provided by (Used in) Operating Activities Net cash from (used in) operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from (used in) investing activities: Payments for Capital Improvements Capital expenditures Interest Paid, Capitalized, Investing Activities Capitalized interest The cash inflow associated with other. Other Other Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from (used in) financing activities: Proceeds from Issuance of Debt Proceeds from borrowings Repayments of Debt Repayment of borrowings Payments for Repurchase of Common Stock Purchase of treasury shares Payments of Dividends Payment of dividends The repayments of financing insurance payable. Repayments Of Financed Insurance Payable Repayments of insurance financing Refers to repayments of financing lease equipment. Repayments of financing leased equipment Repayments of equipment finance leases Payments of Debt Issuance Costs Payment of debt issuance costs Payment, Tax Withholding, Share-Based Payment Arrangement Shares surrendered for withholding taxes payable Net Cash Provided by (Used in) Financing Activities Net cash from (used in) financing activities Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Net change in cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Cash and cash equivalents and restricted cash, end of period Cash and cash equivalents and restricted cash, beginning of period Cash Equivalents, at Carrying Value Cash and cash equivalents Restricted Cash, Current Restricted cash Restricted Cash and Cash Equivalents, Current Total cash, cash equivalents and restricted cash Supplemental Cash Flow Information [Abstract] Supplemental cash flow information: Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid for interest (net of amounts capitalized) Noncash Investing and Financing Items [Abstract] Non-cash investing and financing activities: Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Leased assets under financing leases Capital Expenditures Incurred but Not yet Paid Capital expenditures included in accounts payable and accrued liabilities Accrued purchase of treasury shares. Accrued Purchase of Treasury Shares Accrued purchase of treasury shares Accrued dividends and dividend equivalents payable in non-cash transactions. Accrued Dividends And Dividend Equivalents Payable Accrued dividends and dividend equivalents payable BUSINESS AND BASIS OF PRESENTATION Business Description and Basis of Presentation [Text Block] BUSINESS AND BASIS OF PRESENTATION CASH & CASH EQUIVALENTS. CASH & CASH EQUIVALENTS INVENTORIES Inventory Disclosure [Text Block] INVENTORIES PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment Disclosure [Text Block] PROPERTY, PLANT AND EQUIPMENT DEBT Debt Disclosure [Text Block] DEBT ACCRUED LIABILITIES AND OTHER LONG-TERM LIABILITIES Accounts Payable and Accrued Liabilities Disclosure [Text Block] ACCRUED LIABILITIES AND OTHER LONG-TERM LIABILITIES Equity [Text Block] EQUITY COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] COMMITMENTS AND CONTINGENCIES. REVENUE Revenue from Contract with Customer [Text Block]. REVENUES INCOME TAXES Income Tax Disclosure [Text Block] INCOME TAXES Earnings Per Share [Text Block] EARNINGS (LOSS) PER SHARE SEGMENT REPORTING Segment Reporting Disclosure [Text Block] SEGMENT REPORTING RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS SUBSEQUENT EVENTS Subsequent Events [Text Block] SUBSEQUENT EVENTS Basis of Accounting, Policy [Policy Text Block] Basis of Presentation New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Pronouncements Schedule of Cash and Cash Equivalents [Table Text Block] Schedule of cash and cash equivalents Schedule of Inventory, Current [Table Text Block] Schedule of inventories Property, Plant and Equipment [Table Text Block] Schedule of property, plant, and equipment, net Tabular disclosure of depreciation and amortization. Depreciation And Amortization [Text Block} Schedule of Depreciation, depletion, and amortization Schedule of Long-Term Debt Instruments [Table Text Block] Schedule of outstanding debt Schedule of Accrued Liabilities [Table Text Block] Schedule of accrued liabilities Disaggregation of Revenue [Table Text Block] Schedule of disaggregation of revenue Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule computation of basic and diluted EPS Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of antidilutive shares excluded from the dilutive EPS calculation Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of the Company's reportable segment information Number of Reportable Segments Number of reportable segments Cash Cash Asset, Held-in-Trust U.S. Treasury securities Inventory, Current [Table] Inventory [Line Items] Inventory, Net [Abstract] Inventories Refers to the amount of raw coal. Raw Coal Raw coal Refers to the amount of saleable coal. Saleable Coal Saleable coal Refers to the amount of coal supplies. Coal Supplies Supplies Property, Plant and Equipment [Table] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Domain] Refers to information regarding plant and equipment at cost. Plant and Equipment Plant and equipment Mining Properties and Mineral Rights [Member] Mining property and mineral rights Construction in Progress [Member] Construction in process Mine Development [Member] Capitalized mine development costs Property, Plant and Equipment [Line Items] PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment, Gross Property, plant and equipment, gross Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less: accumulated depreciation, depletion, and amortization Depreciation Depreciation of plant and equipment Depreciation, Lessor Asset under Operating Lease Amortization of right of use assets (finance leases) Amortization Amortization and depletion of capitalized mine development costs and mineral rights Schedule of Long-Term Debt Instruments [Table] Long-Term Debt, Type [Axis] Long-Term Debt, Type [Domain] NA Equipment loans Equipment loans Unsecured Debt [Member] Senior Notes, net Unsecured notes Convertible Senior Notes, net Convertible Senior Notes, net Debt Instrument [Line Items] DEBT Long-Term Debt, Gross Total debt Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt, classified as noncurrent. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Debt Instrument Carrying Amount Noncurrent Total long-term debt Line of Credit Facility [Table] Represents information pertaining to 9.00% senior unsecured notes due 2026. Senior Unsecured Notes Due 2026 [Member] Senior Unsecured Notes Due 2026 Represents information pertaining to 8.375% senior unsecured notes due 2029. Senior Unsecured Notes Due 2029 [Member] Senior Unsecured Notes Due 2029 Represents information pertaining to 8.25% senior unsecured notes due 2030. Senior Unsecured Notes Due 2030 [Member] Senior Unsecured Notes Due 2030 Represents information pertaining to 0.0% convertible senior notes due 2031. Convertible Senior Notes Due 2031 [Member] Convertible Senior Notes Due 2031 Statistical Measurement [Axis] Statistical Measurement [Domain] Minimum [Member] Minimum Maximum [Member] Maximum Line of Credit Facility [Line Items] DEBT Debt Instrument, Face Amount Aggregate principal amount Amount of permitted additional unsecured debt Debt Instrument, Interest Rate, Stated Percentage Interest rate Debt Instrument, Redemption Price, Percentage Redemption price percentage Debt Issuance Costs, Net Amount of unamortized discounts and issuance costs Long-Term Debt Long-term Debt, Total Debt Instrument, Interest Rate, Effective Percentage Effective interest rate Debt Instrument, Maturity Date Debt instrument, maturity date Short-Term Debt, Percentage Bearing Fixed Interest Rate Short-term debt, percentage bearing fixed interest rate Debt Instrument, Convertible, Conversion Ratio Debt instrument, convertible Debt Instrument, Convertible, Conversion Price Debt instrument, convertible, conversion price The number of shares issuable to the holder of debt instrument if the debt was converted to equity. Debt Instrument, Convertible, Number Of Shares Issuable Debt Instrument, Convertible, Number Of Shares Issuable Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger Debt instrument, convertible, threshold percentage Debt Instrument, Convertible, Threshold Trading Days Debt instrument, convertible, threshold trading days Debt Instrument, Convertible, Threshold Consecutive Trading Days consecutive trading days Credit Facility [Axis] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility Variable Rate [Axis] Variable Rate [Domain] Secured Overnight Financing Rate (SOFR) [Member] Secured Overnight Financing Rate (SOFR) Base Rate [Member] Base Rate Line of Credit Facility, Maximum Borrowing Capacity Initial aggregate revolving commitment Maximum borrowing capacity under the credit facility, accordion feature without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Line of Credit Facility, Accordion Feature, Maximum Borrowing Capacity Additional revolving commitment (Accordion feature) Short-Term Debt, Percentage Bearing Variable Interest Rate Short-Term Debt, Percentage Bearing Variable Interest Rate Amount of borrowings base of initial aggregate revolving commitment under line of credit facility. Line of Credit Facility, Initial Aggregate Revolving Commitment, Borrowings Base Initial aggregate revolving commitment The percentage of excess availability on the maximum borrowing amount to be maintained for fixed charge coverage ratio. Debt Instrument, Excess Availability, Percentage Debt instrument, excess availability Fixed charge coverage ratio . Fixed Charge Coverage Ratio Fixed charge coverage ratio Amount of average daily cash balance to be maintained. Average Daily Cash Balance to be Maintained Average daily cash balance Amount of average additional daily cash balance to be maintained. Average Additional Daily Cash Balance To Be Maintained Additional amount to be maintained in a separate dedicated account Minimum excess availability of maximum borrowing capacity considered for distributions and dividend under debt instrument. Debt Instrument, Restrictions On Dividends And Distribution, Excess Availability, Minimum Percentage Of Maximum Borrowing Capacity Excess availability Threshold number of consecutive days during which excess availability must exceed the required threshold under dividend and distribution restrictions in a debt agreement. Debt Instrument, Restrictions On Dividends And Distribution, Excess Availability, Threshold Number Of Days Distribution restrictions Notes Payable, Fair Value Disclosure Senior notes fair value Accrued Liabilities Accrued payables Accrued Employee Benefits, Current Accrued compensation Accrued Income Taxes, Current Accrued sales-related taxes Dividends Payable, Current Accrued dividends Other Accrued Liabilities, Current Other accrued Disclosure of information about accrued liabilities and other long-term liabilities. Schedule of Accrued Liabilities and Other Long-Term Liabilities [Table] Statement of Financial Position Location, Balance [Axis] Statement of Financial Position Location, Balance [Domain] Other Noncurrent Liabilities [Member] Other long-term liabilities Line items represent accrued liabilities and other long-term liabilities. Accrued Liabilities and Other Long-Term Liabilities [Line Items] ACCRUED LIABILITIES AND OTHER LONG-TERM LIABILITIES The amount of uninsured claims. Uninsured claims Estimated aggregate liability Restricted Cash Restricted cash Stock, Class of Stock [Table] Class of Stock [Line Items] EQUITY Number of reclassified common stock issuable upon distribution for each share of common stock. Common Stock, Reclassification, Distribution Ratio Distribution ratio The number of votes per common share. Common Stock, Number of Votes Per Share Number of votes per common share The percent of royalty fee income. Royalty Fee Income, Percent Percent of royalty fee income The price per ton of infrastructure fee income from coal processed at preparation plants. Infrastructure Fees Income, Coal, Preparation Plant, Price Per Ton Price per ton of coal processed at preparation plants The price per ton of infrastructure fee income from coal loaded at rail load out facilities. Infrastructure Fees Income, Coal, Rail Load Out, Price Per Ton Price per ton of loaded coal at rail load-out facilities The percent of dividend on tracking stock from financial performance of carbon ore rare earth assets. Tracking Stock, Dividend from Financial Performance of Carbon Ore-Rare Earth Assets, Percent Percentage dividend from financial performance of carbon The threshold trading days volume weighted average price considered for exchange ratio calculation for exchange to common stock. Common Stock, Class Exchange, Ratio Calculation, Threshold Trading Days Volume Weighted Average Price Threshold trading days volume weighted average price Share Price Share price Share Repurchase Program [Table] Share Repurchase Program [Line Items] EQUITY Share Repurchase Program, Authorized, Amount Amount of repurchased shares authorized Share Repurchase Program, Period in Force Over a period Treasury Stock, Shares, Acquired Common stock repurchase Shares Acquired, Average Cost Per Share Average price per share including commissions Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Restricted Stock [Member] Restricted Stock Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] EQUITY Share-Based Payment Arrangement, Expense Compensation costs Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Granted (in shares) Grantee Status [Axis] Grantee Status [Domain] Recipient, of award granted under share-based payment arrangement, over whom grantor exercises or has right to exercise sufficient control to establish employer-employee relationship based on law of pertinent jurisdiction. Includes, but is not limited to, nonemployee director treated as employee when acting as member of board of directors, if elected by grantor's shareholders or appointed to board position to be filled by shareholder election when existing term expires. Executives and Employees Executives and Employees Recipient, of award granted under share-based payment arrangement, over whom grantor exercises or has right to exercise sufficient control to establish employer-employee relationship based on law of pertinent jurisdiction. Includes, but is not limited to, nonemployee director treated as employee when acting as member of board of directors, if elected by grantor's shareholders or appointed to board position to be filled by shareholder election when existing term expires. Directors Directors Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Granted, Weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Fair value of awards Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Vesting period Restricted Stock Units (RSUs) [Member] Restricted Stock Units RSUs Represent number of voting rights Number of Voting Rights Number of voting rights Represent number of dividend rights. Number of Dividend Rights Number of dividend rights The number of shares converted from each common unit. Sale Of Stock Conversion Of Each Common Unit Shares delivered per unit awarded Refers to Performance Stock Units. Performance Stock Units Performance Stock Units PSUs Percentage of potential earnings of award under share-based payment arrangement. Share-Based Compensation Arrangement by Share-Based Payment Award, Award Potential Earnings, Percentage Potential earnings (as a percentage) Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Option exercise price (per share) Number of executives. Number of Executives Number of executives Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Options exercised, intrinsic value Number of options surrendered. Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Surrendered Number of options surrendered Dividends [Axis] Dividends [Domain] Represents information pertaining to quarterly dividend declared during first quarter of 2026. O 2026 Q1 Dividends [Member] Q1 2026 dividends Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event [Member] SUBSEQUENT EVENTS Dividends Payable, Amount Per Share Dividend payable per share Common Stock, Dividends, Per Share, Declared Dividend declared Number of common shares issued by the company as dividend. Dividends, Common Stock, Paid in Share Number of Class B common stock received as dividend from each Class B common stock Purchase Commitment, Excluding Long-Term Purchase Commitment [Table] Purchase Commitment, Excluding Long-Term Commitment [Axis] Purchase Commitment, Excluding Long-Term Commitment [Domain] Represents information about take-or-pay purchase commitments. Take-or-pay Purchase Commitments Take-or-pay Purchase Commitments Environmental Restoration Costs [Member] Environmental Restoration Costs Environmental Issue [Member] Environmental Issue Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Surety Bond [Member] Surety Bond Purchase Commitment, Excluding Long-Term Commitment [Line Items] COMMITMENTS AND CONTINGENCIES Accrual for Environmental Loss Contingencies Environmental liabilities Asset Retirement Obligation Asset retirement obligation Royalty Expense Royalty expense Long-Term Purchase Commitment, Amount Total commitment Purchase Commitment, Remaining Minimum Amount Committed Commitment Loss Contingency Accrual Accrued amount Regulatory Liability Regulatory liability Payments to Acquire Property, Plant, and Equipment Payments to acquire property, plant, and equipment The number of raw coal storage silos that experienced partial structure failure. Partial Structure Failure, Number of Raw Coal Storage Silos Number of raw coal storage silos, failure The number of raw coal storage silos. Number of Raw Coal Storage Silos Number of raw coal storage silos The percent of plant capacity restored after partial structural failure. Percent of Plant Capacity Restored after Partial Structural Failure Percentage of structural failure Loss Contingency, Damages Awarded, Value Compensatory damages Litigation Settlement, Amount Awarded from Other Party Award to cover inconvenience and aggravation Loss Contingency, Receivable, Additions Additional loss recovery asset Loss Contingency, Receivable Total loss recovery asset The amount of expenses relating to loss contingency receivable, during the period. Loss Contingency, Receivable, Expense, Included in Prepaid Expenses Corresponding reduction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Product and Service [Axis] Product and Service [Domain] Represents information about fixed priced contracts. Fixed Priced Contracts Fixed Priced Contracts Represents information about contracts with indexed based pricing mechanisms. Contracts with Indexed Based Pricing Mechanisms Contracts with indexed based pricing mechanisms Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] REVENUES Refers to the term of sales contract. Revenue, Contract Term Term of domestic sales contracts Contract with Customer, Performance Obligation Satisfied in Previous Period Increase to revenue Mass of product allocated to performance obligation. Revenue Remaining Performance Obligation Mass Outstanding performance obligation, mass Refers to the average fixed sales price per ton. Contracts With Fixed Sales Prices Average Average per ton Represents the percentage of committed tons. Percentage Of Committed Tons Percentage of committed tons Disaggregation of Revenue [Table] Represents information about domestic coal revenues. Domestic Coal Revenues North American revenue Represents information about export coal revenues. Export Revenues Export revenue, excluding Canada Disaggregation of Revenue [Line Items] REVENUES Concentration Risk [Table] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Customer Concentration Risk [Member] Customer Concentration Risk Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Revenue Benchmark [Member] Revenue Benchmark Accounts Receivable [Member] Accounts Receivable Customer [Axis] Customer [Domain] Information pertaining to top customers as a group. Top Customers [Member] Top Customers Information pertaining to largest customer. Customer A Customer A Information pertaining to second largest customer. Customer B Customer B Information pertaining to third largest customer. Customer C Customer C Information pertaining to fourth largest customer. Customer D Customer D Concentration Risk [Line Items] Concentrations Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc. Number Of Major Customers Number of major customers Concentration Risk, Percentage Concentration risk percentage Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to discrete items. Effective Income Tax Rate Reconciliation, Discrete Expense Benefit, Percent Percentage of discrete benefit The percentage of refundable tax credit calculated on production costs. Refundable Tax Credit Rate, Percentage Refundable tax credit rate, percentage Amount of refundable tax credit. Refundable Tax Credit Refundable tax credit Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] EARNINGS (LOSS) PER SHARE Earnings Per Share Reconciliation [Abstract] EARNINGS (LOSS) PER SHARE Net Income (Loss) Available to Common Stockholders, Basic Net earnings (loss) for basic and diluted earnings per common share The amount of forfeitable dividends declared on unvested stock based awards. Forfeitable Dividends Declared on Unvested Stock Based Awards monetary Forfeitable dividends declared on unvested stock-based awards Dilutive Securities, Effect on Basic Earnings Per Share Add: Class B net diluted earnings per diluted share Net Income (Loss) Available to Common Stockholders, Diluted Net diluted earnings (loss) per diluted share Weighted Average Number of Shares Outstanding, Basic Weighted average shares used to compute basic earnings per share (in shares) Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of conversion of Class B common stock to Class A common stock. Incremental Common Shares Attributable to Dilutive Effect of Conversion of Class B Common Stock to Class A Common Stock Dilutive effect of conversion of Class B common stock to Class A common stock Weighted Average Number of Shares Outstanding, Diluted Weighted average shares used to compute diluted earnings per share (in shares) The share of dividends for unvested restricted stock awards with common shares. Share of Dividends for Unvested Restricted Stock Awards with Common Shares Share in dividends for unvested restricted stock awards with common shares Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Convertible Debt Securities [Member] Convertible senior notes Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] EARNINGS (LOSS) PER SHARE Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive shares Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Domain] Represents the information related to REE critical minerals. REE Critical Minerals [Member] REE & Critical Minerals Segment Reporting Information [Line Items] SEGMENT REPORTING Number of Operating Segments Number of Operating Segments Revenues Revenue Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description CODM of segment description Represents the information related to metallurgical coal. Metallurgical Coal [Member] Metallurgical Coal Consolidation Items [Axis] Consolidation Items [Domain] Operating Segments [Member] Operating Segments Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Corporate Non segment NA Significant Segment Expenses [Abstract] Significant segment expenses: Cost of Revenue Cost of sales (exclusive of transportation costs) Oil and Gas, Result of Operation, Transportation Cost Transportation costs Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Segment Adjusted EBITDA Other Expenses Corporate expenses Nonoperating Income (Expense) Other expense Interest Expense, Nonoperating Interest expense, net Capital Expenditure, Discontinued Operations Segment capital expenditures The cash outflow for acquisition of or capital improvements to properties held for investment (operating, managed, leased) or for use. Capital Expenditures, Including Accrued Capital Expenditures And Capitalized Interest Total capital expenditures (including accrued capital expenditures and capitalized interest) Subsequent Event [Table] Subsequent Event [Line Items] SUBSEQUENT EVENTS Dividends Payable, Date Declared Date dividends declared Dividends Payable, Date to be Paid Date of dividend paid Dividends Payable, Date of Record Date of dividend record