BASIS OF PRESENTATION (Policies)	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“GAAP”) for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for future periods. The Consolidated Balance Sheet at December 31, 2018 has been derived from the Audited Consolidated Financial Statements at that date but does not include all disclosures required by GAAP. This Form 10-Q report should be read in conjunction with CONSOL Energy Inc.'s Annual Report on Form 10-K for the year ended December 31, 2018.
Basis of Consolidation	Basis of Consolidation The Consolidated Financial Statements include the accounts of CONSOL Energy Inc. and its wholly-owned and majority-owned and/or controlled subsidiaries. The portion of these entities that is not owned by the Company is presented as non-controlling interest. All significant intercompany transactions and accounts have been eliminated in consolidation.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15 - Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40) to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The amendments in Update 2018-15 align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements of capitalizing implementation costs incurred to develop or obtain internal-use software. These changes will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-14 - Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20) to improve the effectiveness of disclosures in the notes to the financial statements by facilitating clear communication of the information required by GAAP. The amendments modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. These changes will be effective for fiscal years ending after December 15, 2020, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-13 - Fair Value Measurement (Topic 820) to improve the effectiveness of disclosures in the notes to the financial statements by facilitating clear communication of the information required by GAAP. The amendments modify the disclosure requirements on fair value measurements including the consideration of costs and benefits. These changes will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements. In June 2016, the FASB issued ASU 2016-13 - Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this, the amendments in this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The measurement of expected credit losses will be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. In May 2019, the FASB updated Topic 326 by issuing ASU 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief, which provides entities that have certain instruments within the scope of Subtopic 326-20, Financial Instruments-Credit Losses - Measured at Amortized Cost, with an option to irrevocably elect the fair value option in Subtopic 825-10, Financial Instruments-Overall, applied on an instrument-by-instrument basis for eligible instruments, upon adoption of Topic 326. The amendments in these Updates will be applied using a modified-retrospective approach and, for public entities, are effective for fiscal years beginning after December 15, 2019 and interim periods within those annual periods. Management does not expect this update to have a material impact on the Company's financial statements.
Earnings per Share	Earnings per Share Basic earnings per share are computed by dividing net income attributable to CONSOL Energy Inc. shareholders by the weighted average shares outstanding during the reporting period. Dilutive earnings per share are computed similarly to basic earnings per share, except that the weighted average shares outstanding are increased to include additional shares from restricted stock units and performance share units, if dilutive. The number of additional shares is calculated by assuming that outstanding restricted stock units and performance share units were released, and that the proceeds from such activities were used to acquire shares of common stock at the average market price during the reporting period.
Reclassifications	Reclassifications Certain amounts in prior periods have been reclassified to conform with the report classifications of the current period, including the reclassification of restricted cash, previously included in Prepaid Expenses and Other Assets on the Consolidated Balance Sheets, as well as the reclassification of amortization of debt issuance costs and loss on debt extinguishment within the Operating Activities section of the Consolidated Statements of Cash Flows. These reclassifications had no effect on previously reported total assets, net income or stockholders' equity.
Revenue Recognition	CONSOL Energy's coal revenue is recognized when title passes to the customer. The Company has determined that each ton of coal represents a separate and distinct performance obligation. The Company's coal supply contracts and other sales and operating revenue contracts vary in length from short-term to long-term contracts and do not typically have significant financing components. The estimated transaction price from each of the Company's contracts is based on the total amount of consideration to which the Company expects to be entitled under the contract. Included in the transaction price for certain coal supply contracts is the impact of variable consideration, including quality price adjustments, handling services, per ton price fluctuations based on certain coal sales price indices and anticipated payments in lieu of shipments. The estimated transaction price for each contract is allocated to the Company's performance obligations based on relative stand-alone selling prices determined at contract inception. Coal Revenue Revenues are recognized at a point in time, which is generally when title passes to the customers and the price is fixed and determinable. Generally, title passes when coal is loaded at the central preparation facility and, on occasion, at terminal locations or other customer destinations. The Company's coal contract revenue per ton is fixed and determinable and adjusted for nominal quality adjustments. Some coal contracts also contain positive electric power price-related adjustments in addition to a fixed base price per ton. None of the Company’s coal contracts allow for retroactive adjustments to pricing after title to the coal has passed. Some of the Company's contracts span multiple years and have annual pricing modifications, based upon market-driven or inflationary adjustments, where no additional value is exchanged. Also, some of the Company's contracts contain favorable electric power price related adjustments, which represent market-driven price adjustments, wherein there is no additional value being exchanged. Management believes that the invoice price is the most appropriate rate at which to recognize revenue. While CONSOL Energy does, from time to time, experience costs of obtaining coal customer contracts with amortization periods greater than one year, those costs are immaterial to the Company's net income. At June 30, 2019 and December 31, 2018, the Company did not have any capitalized costs to obtain customer contracts on its Consolidated Balance Sheets. As of and for the three and six months ended June 30, 2019 and 2018, the Company has not recognized any amortization of previously existing capitalized costs of obtaining customer contracts. Further, the Company has not recognized any revenue in the current period that is not a result of current period performance. Terminal Revenue Terminal revenues are attributable to the Company's CONSOL Marine Terminal and include revenues earned from providing receipt and unloading of coal from rail cars, transporting coal from the receipt point to temporary storage or stockpile facilities located at the Terminal, stockpiling, blending, weighing, sampling, redelivery, and loading of coal onto vessels. Revenues for these services are generally earned on a rateable basis, and performance obligations are considered fulfilled as the services are performed. CONSOL Marine Terminal does not normally experience material costs of obtaining customer contracts with amortization periods greater than one year. At June 30, 2019 and December 31, 2018, the Company did not have any capitalized costs to obtain customer contracts on its Consolidated Balance Sheets. As of and for the three and six months ended June 30, 2019 and 2018, the Company has not recognized any amortization of previously existing capitalized costs of obtaining Terminal customer contracts. Further, the Company has not recognized any revenue in the current period that is not a result of current period performance. Freight Revenue Some of CONSOL Energy's coal contracts require that the Company sell its coal at locations other than its central preparation plant. The cost to transport the Company's coal to the ultimate sales point is passed through to the Company's customers and CONSOL Energy recognizes the freight revenue equal to the transportation costs when title of the coal passes to the customer.
Leases	The Company determines if an arrangement is an operating or finance lease at inception of the applicable lease. For leases where the Company is the lessee, ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent an obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available on the commencement date in determining the present value of lease payments. The ROU asset also consists of any prepaid lease payments, lease incentives received, and costs which will be incurred in exiting a lease. The lease terms used to calculate the ROU asset and related lease liability include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense while the expense for finance leases is recognized as depreciation expense and interest expense using the interest method of recognition. The Company has operating leases for mining and other equipment used in operations and office space. Many leases include one or more options to renew, some of which include options to extend, the leases, and some leases include options to terminate or buy out the leases within a set period of time. In certain of the Company’s lease agreements, the rental payments are adjusted periodically to reflect actual charges incurred for inflation and/or changes in other indexes. Many of the Company's operating lease payments for mining equipment contain a variable component which is calculated based upon production metrics such as feet of advance or raw tonnage mined. While most of the Company's leases contain clauses regarding the general condition of the equipment upon lease termination, they do not contain residual value guarantees.

BASIS OF PRESENTATION (Policies)

6 Months Ended

Jun. 30, 2019

The accompanying Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“GAAP”) for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for future periods.

The Consolidated Balance Sheet at December 31, 2018 has been derived from the Audited Consolidated Financial Statements at that date but does not include all disclosures required by GAAP. This Form 10-Q report should be read in conjunction with CONSOL Energy Inc.'s Annual Report on Form 10-K for the year ended December 31, 2018.

Basis of Consolidation

The Consolidated Financial Statements include the accounts of CONSOL Energy Inc. and its wholly-owned and majority-owned and/or controlled subsidiaries. The portion of these entities that is not owned by the Company is presented as non-controlling interest. All significant intercompany transactions and accounts have been eliminated in consolidation.

Recent Accounting Pronouncements

In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15 - Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40) to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The amendments in Update 2018-15 align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements of capitalizing implementation costs incurred to develop or obtain internal-use software. These changes will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements.

In August 2018, the FASB issued ASU 2018-14 - Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20) to improve the effectiveness of disclosures in the notes to the financial statements by facilitating clear communication of the information required by GAAP. The amendments modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. These changes will be effective for fiscal years ending after December 15, 2020, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements.

In August 2018, the FASB issued ASU 2018-13 - Fair Value Measurement (Topic 820) to improve the effectiveness of disclosures in the notes to the financial statements by facilitating clear communication of the information required by GAAP. The amendments modify the disclosure requirements on fair value measurements including the consideration of costs and benefits. These changes will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management is currently evaluating the impact this guidance may have on the Company’s financial statements.

In June 2016, the FASB issued ASU 2016-13 - Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this, the amendments in this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The measurement of expected credit losses will be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. In May 2019, the FASB updated Topic 326 by issuing ASU 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief, which provides entities that have certain instruments within the scope of Subtopic 326-20, Financial Instruments-Credit Losses - Measured at Amortized Cost, with an option to irrevocably elect the fair value option in Subtopic 825-10, Financial Instruments-Overall, applied on an instrument-by-instrument basis for eligible instruments, upon adoption of Topic 326. The amendments in these Updates will be applied using a modified-retrospective approach and, for public entities, are effective for fiscal years beginning after December 15, 2019 and interim periods within those annual periods. Management does not expect this update to have a material impact on the Company's financial statements.

Earnings per Share

Basic earnings per share are computed by dividing net income attributable to CONSOL Energy Inc. shareholders by the weighted average shares outstanding during the reporting period. Dilutive earnings per share are computed similarly to basic earnings per share, except that the weighted average shares outstanding are increased to include additional shares from restricted stock units and performance share units, if dilutive. The number of additional shares is calculated by assuming that outstanding restricted stock units and performance share units were released, and that the proceeds from such activities were used to acquire shares of common stock at the average market price during the reporting period.

Reclassifications

Certain amounts in prior periods have been reclassified to conform with the report classifications of the current period, including the reclassification of restricted cash, previously included in Prepaid Expenses and Other Assets on the Consolidated Balance Sheets, as well as the reclassification of amortization of debt issuance costs and loss on debt extinguishment within the Operating Activities section of the Consolidated Statements of Cash Flows. These reclassifications had no effect on previously reported total assets, net income or stockholders' equity.

Revenue Recognition

CONSOL Energy's coal revenue is recognized when title passes to the customer. The Company has determined that each ton of coal represents a separate and distinct performance obligation. The Company's coal supply contracts and other sales and operating revenue contracts vary in length from short-term to long-term contracts and do not typically have significant financing components.

The estimated transaction price from each of the Company's contracts is based on the total amount of consideration to which the Company expects to be entitled under the contract. Included in the transaction price for certain coal supply contracts is the impact of variable consideration, including quality price adjustments, handling services, per ton price fluctuations based on certain coal sales price indices and anticipated payments in lieu of shipments. The estimated transaction price for each contract is allocated to the Company's performance obligations based on relative stand-alone selling prices determined at contract inception.

Coal Revenue

Revenues are recognized at a point in time, which is generally when title passes to the customers and the price is fixed and determinable. Generally, title passes when coal is loaded at the central preparation facility and, on occasion, at terminal locations or other customer destinations. The Company's coal contract revenue per ton is fixed and determinable and adjusted for nominal quality adjustments. Some coal contracts also contain positive electric power price-related adjustments in addition to a fixed base price per ton. None of the Company’s coal contracts allow for retroactive adjustments to pricing after title to the coal has passed.

Some of the Company's contracts span multiple years and have annual pricing modifications, based upon market-driven or inflationary adjustments, where no additional value is exchanged. Also, some of the Company's contracts contain favorable electric power price related adjustments, which represent market-driven price adjustments, wherein there is no additional value being exchanged. Management believes that the invoice price is the most appropriate rate at which to recognize revenue.

While CONSOL Energy does, from time to time, experience costs of obtaining coal customer contracts with amortization periods greater than one year, those costs are immaterial to the Company's net income. At June 30, 2019 and December 31, 2018, the Company did not have any capitalized costs to obtain customer contracts on its Consolidated Balance Sheets. As of and for the three and six months ended June 30, 2019 and 2018, the Company has not recognized any amortization of previously existing capitalized costs of obtaining customer contracts. Further, the Company has not recognized any revenue in the current period that is not a result of current period performance.

Terminal Revenue

Terminal revenues are attributable to the Company's CONSOL Marine Terminal and include revenues earned from providing receipt and unloading of coal from rail cars, transporting coal from the receipt point to temporary storage or stockpile facilities located at the Terminal, stockpiling, blending, weighing, sampling, redelivery, and loading of coal onto vessels. Revenues for these services are generally earned on a rateable basis, and performance obligations are considered fulfilled as the services are performed.

CONSOL Marine Terminal does not normally experience material costs of obtaining customer contracts with amortization periods greater than one year. At June 30, 2019 and December 31, 2018, the Company did not have any capitalized costs to obtain customer contracts on its Consolidated Balance Sheets. As of and for the three and six months ended June 30, 2019 and 2018, the Company has not recognized any amortization of previously existing capitalized costs of obtaining Terminal customer contracts. Further, the Company has not recognized any revenue in the current period that is not a result of current period performance.

Freight Revenue

Some of CONSOL Energy's coal contracts require that the Company sell its coal at locations other than its central preparation plant. The cost to transport the Company's coal to the ultimate sales point is passed through to the Company's customers and CONSOL Energy recognizes the freight revenue equal to the transportation costs when title of the coal passes to the customer.

Leases

The Company determines if an arrangement is an operating or finance lease at inception of the applicable lease. For leases where the Company is the lessee, ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent an obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available on the commencement date in determining the present value of lease payments. The ROU asset also consists of any prepaid lease payments, lease incentives received, and costs which will be incurred in exiting a lease. The lease terms used to calculate the ROU asset and related lease liability include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense while the expense for finance leases is recognized as depreciation expense and interest expense using the interest method of recognition.

The Company has operating leases for mining and other equipment used in operations and office space. Many leases include one or more options to renew, some of which include options to extend, the leases, and some leases include options to terminate or buy out the leases within a set period of time. In certain of the Company’s lease agreements, the rental payments are adjusted periodically to reflect actual charges incurred for inflation and/or changes in other indexes. Many of the Company's operating lease payments for mining equipment contain a variable component which is calculated based upon production metrics such as feet of advance or raw tonnage mined. While most of the Company's leases contain clauses regarding the general condition of the equipment upon lease termination, they do not contain residual value guarantees.