Foresight Energy (FELPQ) 10-K 11 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Feb. 27, 2015
Document And Entity Information [Line Items]
Entity Registrant Name	Foresight Energy LP
Entity Central Index Key	1540729
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2014
Trading Symbol	FELP
Document Fiscal Period Focus	FY
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float		$353,991,400
Common Units
Document And Entity Information [Line Items]
Entity Units Outstanding			65,059,477
Subordinated Units
Document And Entity Information [Line Items]
Entity Units Outstanding			64,954,691

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$25,406	$23,284
Accounts receivable	80,763	58,987
Due from affiliates	574	368
Inventories	92,402	71,290
Prepaid expenses	2,134	3,028
Prepaid royalties	8,380	6,330
Deferred longwall costs	23,224	14,265
Coal derivative assets	36,080	1,976
Other current assets	6,302	6,568
Total current assets	275,265	186,096
Property, plant, equipment and development, net	1,473,063	1,414,074
Prepaid royalties	59,967	73,242
Coal derivative assets	24,957	912
Other assets	31,970	35,847
Total assets	1,865,222	1,710,171
Current liabilities:
Current portion of long-term debt and capital lease obligations	44,143	70,034
Accrued interest	25,136	27,645
Accounts payable	59,937	50,155
Accrued expenses and other current liabilities	37,602	37,515
Due to affiliates	15,878	9,572
Total current liabilities	182,696	194,921
Long-term debt and capital lease obligations	1,316,528	1,449,179
Sale-leaseback financing arrangements	193,434	193,434
Asset retirement obligations	31,373	20,416
Other long-term liabilities	5,508	337
Total liabilities	1,729,539	1,858,287
Limited partners' capital (deficit):
Total limited partners' capital	127,756
Total partners' capital (deficit)	135,683	-148,116
Noncontrolling interests	7,927	9,240
Total liabilities and partners' capital (deficit)	1,865,222	1,710,171
Common Units
Limited partners' capital (deficit):
Total limited partners' capital	238,925
Subordinated Units
Limited partners' capital (deficit):
Total limited partners' capital	-111,169
Predecessor
Limited partners' capital (deficit):
Total partners' capital (deficit)		($157,356)

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2014
In Thousands, unless otherwise specified
Common Units
Capital units, Outstanding	64,831
Subordinated Units
Capital units, Outstanding	64,739

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Coal sales	$1,109,404	$957,412	$845,886
Costs and expenses:
Cost of coal produced (excluding depreciation, depletion and amortization)	449,905	360,861	303,638
Cost of coal purchased	18,232	2,163	6,163
Transportation	226,029	197,839	171,679
Depreciation, depletion and amortization	167,039	161,216	124,552
Accretion on asset retirement obligations	1,621	1,527	1,368
Impairment of prepaid royalties	34,700
Selling, general and administrative	33,679	32,291	41,528
Gain on coal derivatives	-76,330	-2,392	-534
Other operating income, net	-2,527	-280	-10,759
Operating income	257,056	204,187	208,251
Other expenses:
Loss on early extinguishment of debt	4,979	77,773
Interest expense, net	113,030	115,897	82,580
Net income	139,047	10,517	125,671
Less: net income (loss) attributable to noncontrolling interests	3,847	2,236	-160
Net income attributable to controlling interests	135,200	8,281	125,831
Less: predecessor net income attributable to controlling interests prior to initial public offering	65,008
Net income subsequent to initial public offering available to limited partner units (June 23, 2014 through December 31, 2014) - basic and diluted:
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through December 31, 2014)	70,192
Weighted average limited partner units outstanding - basic and diluted:
Distribution declared per limited partner unit	$0.38
Subordinated Units
Net income subsequent to initial public offering available to limited partner units (June 23, 2014 through December 31, 2014) - basic and diluted:
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through December 31, 2014)	35,038
Net income subsequent to initial public offering per limited partner unit - basic and diluted	$0.54
Weighted average limited partner units outstanding - basic and diluted:
Weighted average limited partner units outstanding - basic and diluted	64,739
Common Units
Net income subsequent to initial public offering available to limited partner units (June 23, 2014 through December 31, 2014) - basic and diluted:
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through December 31, 2014)	$35,154
Net income subsequent to initial public offering per limited partner unit - basic and diluted	$0.54
Weighted average limited partner units outstanding - basic and diluted:
Weighted average limited partner units outstanding - basic and diluted	64,790

Consolidated_Statement_of_Part

Consolidated Statement of Partners Capital Deficit (USD $)	Total	Noncontrolling Interests	Predecessor Equity	Limited Partners	Limited Partners	Limited Partners	Limited Partners
	USD ($)	USD ($)	USD ($)	Common Unitholders' Capital	Common Units	Subordinated Unitholders' Capital	Number of Subordinated Units
				USD ($)		USD ($)
Beginning Balance at Dec. 31, 2011	$394,205,000	($919,000)	$395,124,000
Net income (loss)	125,671,000	-160,000	125,831,000
Non-cash member contribution	4,632,000		4,632,000
Cash distributions	-244,405,000	-171,000	-244,234,000
Ending Balance at Dec. 31, 2012	280,103,000	-1,250,000	281,353,000
Net income (loss)	10,517,000	2,236,000	8,281,000
Consolidation of variable interest entities	10,120,000	10,120,000
Non-cash distributions	-61,990,000		-61,990,000
Cash distributions	-386,866,000	-1,866,000	-385,000,000
Ending Balance at Dec. 31, 2013	-148,116,000	9,240,000	-157,356,000
Net income (loss)	139,047,000
Consolidation of variable interest entities	0
Net income prior to initial public offering	66,789,000	1,781,000	65,008,000
Non-cash distributions	-12,187,000		-12,187,000
Contribution of net assets to Foresight Energy LP			104,878,000	-51,354,000		-53,524,000
Issuance of common units, net of offering costs	322,813,000			322,813,000
Issuance of common units, net of offering costs (in units)					64,738,895		64,738,895
Cash distributions	-169,723,000	-5,160,000	-343,000	-71,537,000		-92,683,000
Net income subsequent to initial public offering	72,258,000	2,066,000		35,154,000		35,038,000
Equity-based compensation	5,024,000			5,024,000
Issuance of equity-based awards					92,417
Distribution equivalent rights on LTIP awards	-231,000			-231,000
Net settlement of withholding taxes on issued LTIP awards	-944,000			-944,000
Ending Balance at Dec. 31, 2014	$135,683,000	$7,927,000		$238,925,000		($111,169,000)
Ending Balance (in units) at Dec. 31, 2014					64,831,312		64,738,895

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net income (loss)	$139,047	$10,517	$125,671
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	167,039	161,216	124,552
Amortization of debt issuance costs and debt premium/discount	7,022	7,574	8,235
Equity-based compensation	4,749		4,632
Unrealized gain on coal derivatives	-57,126	-2,453	-534
Impairment of prepaid royalties	34,700
Non-cash loss on early extinguishment of debt	4,681	5,625
Other	-5,248	-490	5,934
Changes in operating assets and liabilities:
Accounts receivable	-21,776	9,533	-36,463
Due from/to affiliates, net	6,117	-1,190	-7,593
Inventories	-13,893	12,095	-19,397
Prepaid expenses and other current assets	-7,799	-6,323	3,808
Prepaid royalties	-23,475	-17,064	-29,646
Coal derivative assets and liabilities	-1,891	-499
Accounts payable	9,628	1,449	2,057
Accrued interest	-2,509	-2,695	12,149
Accrued expenses and other current liabilities	1,166	4,847	17,233
Other	-4,392	-2,616	-947
Net cash provided by operating activities	236,040	179,526	209,691
Cash flows from investing activities
Investment in property, plant, equipment and development	-229,251	-210,726	-209,937
Acquisition of an affiliate	-3,822
Proceeds from sale of equipment	1,619	465	2,898
Settlement of certain coal derivatives	7,345	986
Net cash used in investing activities	-224,109	-209,275	-207,039
Cash flows from financing activities
Net increase (decrease) in borrowings under revolving credit facility	60,500	23,000	-88,000
Proceeds from other long-term debt and capital lease obligations	85,620	1,072,772	264,007
Payments on other long-term debt and capital lease obligations	-307,607	-634,863	-19,663
Payments on short-term debt			-6,627
Proceeds from sale-leaseback financing arrangement			49,950
Distributions paid	-169,723	-411,891	-219,405
Proceeds from issuance of common units (net of underwriters' discount)	329,875
Initial public offering costs paid (other than underwriters' discount)	-7,206	-144	-3,079
Debt issuance costs paid	-297	-23,729	-3,708
Other	-971
Net cash (used in) provided by financing activities	-9,809	25,145	-26,525
Net increase (decrease) in cash and cash equivalents	2,122	-4,604	-23,873
Cash and cash equivalents, beginning of period	23,284	27,888	51,761
Cash and cash equivalents, end of period	$25,406	$23,284	$27,888

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation
	As used in this report, the terms “Foresight Energy LP,” “FELP,” the “Partnership,” “we,” “us” or like terms, refer to the combined results (as described below) of Foresight Energy LP and Foresight Energy LLC and its consolidated subsidiaries and affiliates, unless the context otherwise requires or where otherwise indicated. The information presented in this Annual Report on Form 10-K contains, for all periods presented, the audited combined financial results of Foresight Energy LP and Foresight Energy LLC (“FELLC”), our predecessor for accounting purposes (the “Predecessor”), and variable interest entities (“VIEs”) for which FELLC or its subsidiaries are the primary beneficiary. Prior to June 23, 2014, FELP had no operating or cash flow activity and no recorded net assets.
	FELLC, a limited liability company, was formed in September 2006 for the development, mining, transportation and sale of coal. Prior to June 23, 2014, Foresight Reserves, L.P. (“Foresight Reserves”) owned 99.333% of FELLC and a member of management owned 0.667%. In January 2012, Foresight Energy LP (formerly named Foresight Energy Partners LP), a Delaware limited partnership, and Foresight Energy GP LLC (“general partner” or “FEGP”), a Delaware limited liability company, were formed. FELP was formed to own FELLC and FEGP was formed to be the general partner of FELP.
	On June 23, 2014, in connection with the initial public offering of FELP, Foresight Reserves and a member of management contributed their ownership interests in FELLC to FELP for which they were issued common and subordinated units in FELP. Because this transaction was between entities under common control, the contributed assets and liabilities of FELLC were recorded in the consolidated financial statements at FELLC’s historical cost. See Note 3 for information regarding our initial public offering.  Subsequent to the initial public offering, FELP is managed by FEGP.
	The Partnership operates in a single reportable segment and currently operates four underground mining complexes in the Illinois Basin: Williamson Energy, LLC (“Williamson”); Sugar Camp Energy, LLC (“Sugar Camp”); Hillsboro Energy, LLC (“Hillsboro”); and Macoupin Energy, LLC (“Macoupin”). Our coal is sold to a diverse customer base, including electric utility and industrial companies primarily in the eastern United States, as well as overseas markets.
	Intercompany transactions, including those between consolidated VIEs, FELP and its consolidated subsidiaries, are eliminated in consolidation.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies
	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and loss during the reporting period. Actual results could differ from those estimates.
	Revenue Recognition
	Once mines are in production, coal sales include sales to customers of coal produced and, from time to time, the re-sale of coal purchased from third parties. The Partnership recognizes sales at the time legal title and risk of loss pass to the customer at contracted amounts that are fixed or determinable. For domestic coal sales, this generally occurs when coal is loaded onto railcars at the mine or onto barges at terminals. For coal sales to international markets, this generally occurs when coal is loaded onto an ocean vessel. Quality and weight adjustments are recorded as necessary based on contract specifications as a reduction or increase to coal sales and accounts receivable.
	Transportation Expenses
	Costs related to the handling and transporting of coal to the point of sale are included in coal inventory in the consolidated balance sheets. Upon the recognition of the sale, these costs are included in transportation expenses in the consolidated statements of operations.
	Cash and Cash Equivalents
	The Partnership considers cash deposits with original maturities of less than three months to be cash and cash equivalents. Cash and cash equivalents are stated at cost, which approximates fair value.
	Allowance for Doubtful Accounts
	The Partnership evaluates the need for an allowance for uncollectible receivables based on a review of account balances that are likely to be uncollectible, as determined by such variables as customer creditworthiness, the age of the receivables and disputed amounts. Historically, credit losses have been insignificant. At December 31, 2014 and 2013, no allowance was recorded for uncollectible accounts receivable as all amounts were deemed collectible.
	Inventories
	Inventories are valued at the lower of average cost or market. Parts and supplies inventory consists of spare parts for equipment and supplies used in the mining process. Raw coal represents coal stockpiles that require processing through a preparation plant prior to shipment to a customer. Clean coal represents coal stockpiles that will be sold in their current condition. Coal inventory costs include labor, equipment costs, supplies, transportation costs incurred prior to the transfer of title to customers, depreciation, depletion, amortization and direct mine operating overhead.
	Deferred Longwall Costs
	The Partnership defers the direct costs associated with longwall moves, including longwall set-up costs, supplies and refurbishment costs of longwall equipment. These deferred costs are expensed on a units-of-production basis into cost of coal produced (excluding depreciation, amortization and depreciation) over the panel benefited by these costs, which has historically approximated one year.
	Prepaid Royalties
	Prepaid royalties consist of recoupable minimum royalty payments due under various lease agreements entered into by the Partnership. Prepaid royalties expected to be recouped within one year are classified as current assets in the Partnership’s consolidated balance sheets. The Partnership continually evaluates its ability to recoup prepaid royalty balances, which includes, among other factors, assessing mine production plans, sales commitments, future coal market conditions and remaining years available for recoupment. The contractual recoupment periods on the prepaid royalty balances generally range from five to ten years from the date the minimum royalty was paid.
	Property, Plant, Equipment and Development, Net
	Property, plant and equipment are recorded at cost. Costs that extend the useful lives or increase the productivity of the assets are capitalized, while normal repairs and maintenance that do not extend the useful life or increase the productivity of the asset are expensed as incurred. Asset retirement obligations for the various assets have been recorded as components of the specific assets to which they relate. Interest costs applicable to major additions are capitalized during the construction period. Interest costs capitalized into property, plant, equipment and development, net for the years ended December 31, 2014, 2013, and 2012, were $5.2 million, $3.6 million, and $19.0 million, respectively. Property, plant and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Machinery and equipment under capital lease agreements are amortized using the straight-line method over the useful lives of the assets given that, in each case, ownership transfers at the end of the lease terms. The cost of acquiring land (subsidence) rights and mineral rights is amortized using the units-of-production method over the mineral reserves benefited by the costs. The estimated useful lives of machinery and equipment, buildings and structures and other categories are as follows:
	Machinery and equipment	3–20 years
	Buildings and structures	3–40 years
	Other	3–20 years
	Costs of developing new mines or significantly expanding the capacity of existing mines are capitalized and amortized using the units-of-production method over the mineral reserves benefited by the development. Costs related to locating coal deposits and evaluating the economic viability of such deposits are expensed as incurred. During the development phase, the Partnership establishes access to the mineral reserves and makes other preparations for commercial production. Development costs principally include clearing land, building roads, sinking shafts, driving slopes and developing refuse areas, ventilation and transportation passageways at the mines. Development costs also include the build-out of the Partnership’s transportation infrastructure. Costs incurred during the development phase are capitalized and proceeds from the incidental sale of coal during development are recorded as a reduction of the related mine development costs. For reporting in the statements of cash flows, cash expended in the investment in mining rights, equipment and development during the development phase is reported net of capitalized coal sales. Mines in development included the first and second longwalls at Sugar Camp through March 1, 2012 and June 1, 2014, respectively, and the first longwall at Hillsboro through September 1, 2012.
	Impairment of Depreciable Assets
	The Partnership records impairment losses on depreciable assets used in operations when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than their carrying amounts. Impairment losses are measured by comparing the estimated fair value of the impaired asset to its carrying amount. There were no impairment losses recorded during the years ended December 31, 2014, 2013 or 2012.
	Debt Issuance Costs
	The Partnership capitalizes costs incurred in connection with the issuance of debt and the establishment of credit facilities and capital leasing arrangements. These costs are amortized as an adjustment to interest expense over the life of the borrowing or term of the credit facility using the effective interest method. Amortization expense of $6.1 million, $7.7 million and $8.1 million is included in interest expense for the years ended December 31, 2014, 2013, and 2012, respectively. As of December 31, 2014 and 2013, unamortized debt issuance costs of $24.6 million and $33.6 million, respectively, are included in other assets in the consolidated balance sheets.
	Sale-Leaseback Financing Arrangements
	The Partnership is party to two arrangements in which it sold assets to an affiliate and immediately leased those assets back from the affiliates. Because the Partnership had continued involvement in the assets sold, the proceeds received on the sale of the assets were recorded as long-term financing liabilities in our consolidated balance sheets. Under both of these arrangements, the Partnership pays a fixed minimum payment, as well as contingent payments for volumes in excess of the contractual minimum payments. Interest is accrued on the outstanding principal amounts of the financing arrangements using an implied interest rate, which was initially determined at inception of the lease and is adjusted for changes in expected amounts and timing of future payments based on the mine plans. Payments are first applied against accrued interest and any excess is applied against the outstanding principal. The Partnership accounts for such changes by adjusting in the current period, the life-to-date interest previously recorded on the sale-leaseback to reflect the new effective interest rate as if it was applied from the inception of the transaction (i.e., retroactively applied). If there is a material change to the mine plans, the impact of a change in the effective interest rate to the consolidated statements of operations could be significant.
	Asset Retirement Obligations
	The Partnership’s asset retirement obligations (“ARO”) consist primarily of spending estimates related to reclaiming surface land, refuse areas, slurry ponds and support facilities at the Partnership’s underground mines in accordance with federal and state reclamation laws as required by each mining permit. These obligations are typically incurred at the time development of a mine commences for underground mines or when construction begins for support facilities, refuse areas and slurry ponds. The Partnership estimates its ARO for final reclamation and mine closure based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and a market risk premium and then discounted at a credit-adjusted, risk-free rate. Upon initial recognition of a liability, a corresponding amount is capitalized as part of the carrying value of the related long-lived asset. Over time, the liability is accreted to its present value and the capitalized cost is amortized over the useful life of the related asset on a units-of-production basis. As changes in estimates occur (such as mine plan revisions, changes in estimated costs or changes in timing of the performance of reclamation activities), the revisions to the obligation and asset are recognized at the appropriate credit-adjusted, risk-free interest rate.
	Derivative Financial Instruments
	The Partnership utilizes derivative financial instruments principally to manage exposures to coal prices. The Partnership records the fair value of each instrument as either an asset or liability in the consolidated balance sheets and the change in fair value of each instrument is recorded in the consolidated statements of operations.
	Coal contracts provide for the physical purchase or sale of coal in quantities expected to be used or sold by the Partnership over a reasonable period in the normal course of business, and are not recognized on the consolidated balance sheets.
	Fair Value
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at a given measurement date. Valuation techniques used must maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value.
	The hierarchy, as defined below, gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs.
	Level 1 is defined as observable inputs, such as quoted prices in active markets for identical assets.
	Level 2 is defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3 is defined as unobservable inputs in which little or no market data exists, therefore, requiring an entity to develop its own assumptions.
	The carrying value of cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term nature of these instruments.
	Variable Interest Entities (VIEs)
	VIEs are primarily entities that lack sufficient equity to finance their activities without additional financial support from other parties or whose equity holders, as a group, lack one or more of the following characteristics: (a) direct or indirect ability to make decisions, (b) obligation to absorb expected losses or (c) right to receive expected residual returns. VIEs must be evaluated quantitatively and qualitatively to determine the primary beneficiary, which is the reporting entity that has (a) the power to direct activities of a VIE that most significantly impact the VIEs economic performance and (b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The primary beneficiary is required to consolidate the VIE for financial reporting purposes.
	To determine a VIE's primary beneficiary, the Partnership performs a qualitative assessment to determine which party, if any, has the power to direct activities of the VIE and the obligation to absorb losses and/or receive its benefits. This assessment involves identifying the activities that most significantly impact the VIE's economic performance and determine whether it, or another party, has the power to direct those activities. When evaluating whether the Partnership is the primary beneficiary of a VIE, the Partnership performs a qualitative analysis that considers the design of the VIE, the nature of the Partnership’s involvement and the variable interests held by other parties. If that evaluation is inconclusive as to which party absorbs a majority of the entity’s expected losses or residual returns, a quantitative analysis would be performed to determine the primary beneficiary. The income attributable to consolidated variable interest entities is recorded as net income attributable to noncontrolling interests in the consolidated statements of operations.
	Income Taxes
	We are not a taxable entity for federal or state income tax purposes; the tax effect of our activities accrues to the unitholders. While Section 7704(a) of the tax code generally provides that publicly traded partnerships will be treated as corporations for federal income tax purposes, if 90% or more of a partnership’s gross income for every taxable year it is publicly traded consists of “qualifying income,” the partnership may continue to be treated as a partnership for federal income tax purposes (the “Qualifying Income Exception”). Qualifying income includes income and gains derived from the mining, transportation and marketing of minerals and natural resources, such as coal. Other types of qualifying income include interest (other than from a financial business), dividends, gains from the sale of real property and gains from the sale or other disposition of capital assets held for the production of income that otherwise constitutes qualifying income.
	We currently meet the Qualifying Income Exception and expect to continue to qualify prospectively for this exception. As such, each of our unitholders will take into account their respective share of our items of income, gain, loss and deduction in computing their federal income tax liability as if the unitholder had earned such income directly, even if we make no cash distributions to the unitholder. Distributions we make to a unitholder generally will not give rise to income or gain taxable to such unitholder, unless the amount of cash distributed exceeds the unitholder’s adjusted tax basis. Net income for financial statement purposes may differ significantly from taxable income reportable to unitholders as a result of differences between the tax basis and financial reporting basis of assets and liabilities and the taxable income allocation requirements under our partnership agreement. Individual unitholders have different investment basis depending upon the timing and price of acquisition of their partnership units. Furthermore, each unitholder ’s tax accounting methods, which is partially dependent upon the unitholder’s tax position, differs from the accounting methods followed in our consolidated financial statements. Accordingly, the aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each unitholder’s tax attributes in our partnership is not available to us.
	Our tax counsel has provided an opinion that FELP will be treated as a partnership. However, as is customary, no ruling has been or will be requested from the Internal Revenue Service (“IRS”) regarding our classification as a partnership for federal income tax purposes.
	FELLC, its subsidiaries and controlled entities were established as limited liability companies, and thus for federal and, if applicable, state and local income tax purposes, are treated as pass-through entities. Therefore, no provision for income taxes was included in the consolidated financial statements.
	Supplemental Cash Flow Information
	The following is supplemental information to the statements of cash flows:
		For the Year Ended December 31,
		2014		2013		2012
		(In Thousands)
	Supplemental disclosure of cash flow information:
	Cash interest paid, net of amount capitalized	$	108,517	$	111,043	$	65,127
	Supplemental disclosure of noncash investing and financing activities:
	Noncash member distributions	$	12,187	$	61,990	$	—
	Accrued member distributions	$	—	$	—	$	25,000
	Financing of interest, debt issuance costs and equipment	$	—	$	—	$	14,829
	New Adopted Accounting Standards
	There were no new authoritative accounting pronouncements that had a significant impact on the Partnership’s consolidated financial statements or impacted comparability with prior periods presented.
	New Accounting Standards Issued and Not Yet Adopted
	In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 changes the requirements for reporting discontinued operations by updating the criteria for determining discontinued operations and modifies the disclosure requirements of both discontinued operations and certain other disposals not defined as discontinued operations. ASU 2014-08 is effective for annual and interim periods beginning after December 15, 2014 and we do not expect it will have a material effect on our consolidated financial statements.
In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, to clarify the principles used to recognize revenue. The guidance is effective for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted. We are in the process of evaluating the effects, if any, the adoption of this guidance will have on our consolidated financial statements.
In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management of the entity to evaluate whether there is substantial doubt about the entity’s ability to continue as a going concern. This ASU is effective for the annual reporting period ending after December 15, 2016, with early adoption permitted. This standard is not currently expected to have a material effect on the Partnership's financial statement disclosures, though the ultimate impact will be dependent on the Partnership's financial condition and expected operating outlook.

Initial_Public_Offering

Initial Public Offering	12 Months Ended
	Dec. 31, 2014
Initial Public Offering [Abstract]
Initial Public Offering	3. Initial Public Offering
	On June 18, 2014, the Partnership’s common units began trading on the New York Stock Exchange (“NYSE”) under the symbol “FELP.” Upon the closing of the initial public offering (“IPO”) on June 23, 2014, the following transactions occurred:
	—	Foresight Reserves and a member of management each contributed their membership interests in FELLC to the Partnership;
	—	The Partnership issued to Foresight Reserves and a member of management, on a pro rata basis, an aggregate of 44,613,895 common units and 64,738,895 subordinated units;
	—	The Partnership issued to our general partner, which was owned 99.333% by Foresight Reserves and 0.667% by a member of management, incentive distribution rights.  The incentive distribution rights entitle the holder to an increasing percentage, up to a maximum of 50%, of the cash the Partnership distributes in excess of $0.3881 per unit per quarter (see Note 17);
	—	The Partnership issued 17,500,000 units to the public at $20.00 per unit; and
	—	The $329.9 million of proceeds received from the sale of common units to the public, net of underwriters’ discount of $20.1 million, were used to repay $210.0 million of principal on the term loan and to pay a $115.0 million distribution to Foresight Reserves and a member of management, on a pro rata basis. Additionally, we incurred an additional $7.1 million in other offering costs during the year ended December 31, 2014 which were recorded against partners’ capital.
	In July 2014, the underwriters’ overallotment option expired, resulting in an additional 2,625,000 units being issued, on a pro rata basis, to Foresight Reserves and a member of management for no additional consideration. The initial common units held by the public, after the issuance of these overallotment units in July 2014, represented 13.5% of the outstanding limited partnership interest.

Coal_Derivative_Contracts

Coal Derivative Contracts	12 Months Ended
	Dec. 31, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Coal Derivative Contracts	4. Coal Derivative Contracts
	The Partnership has commodity price risk for its coal sales as a result of changes in the market value of its coal. To minimize this risk, we enter into long-term, fixed price coal supply sales agreements and coal derivative swap contracts.
	As of December 31, 2014 and 2013, we had outstanding coal derivative swap contracts to fix the selling price on 3.4 million tons and 2.0 million tons, respectively. Swaps are designed so that the Partnership receives or makes payments based on a differential between fixed and variable prices for coal. The coal derivative contracts are economic hedges to certain future unpriced (indexed) sales commitments and expected sales through 2017.  The coal derivative contracts are indexed to the Argus API 2 price index, the benchmark price for coal imported into northwest Europe. The coal derivative contracts are accounted for as freestanding derivatives and any gains or losses resulting from adjusting these contracts to fair value are recorded into earnings. We record the fair value of all positions with a given counterparty on a gross basis in the consolidated balance sheets (see Note 16).
	We have master netting agreements with all of our counterparties that allow for the settlement of contracts in an asset position with contracts in a liability position in the event of default. We manage counterparty risk through the utilization of investment grade commercial banks, diversification of counterparties and our counterparty netting arrangements.
	The following is a summary of the unrealized and realized gains recorded on coal derivatives for the years ended December 31, 2014, 2013 and 2012:
		For the Year Ended December 31,
		2014		2013			2012
		(In Thousands)
	Unrealized gain on coal derivatives	$	57,126	$	2,453		$	534
	Realized gain (loss) on coal derivatives		19,204		(61	)		—
	Gain on coal derivatives	$	76,330	$	2,392		$	534
	We received $7.3 million and $1.0 million in proceeds during the years ended December 31, 2014 and 2013, respectively, from derivatives that settled prior to an economically hedged sales contract. These settlements were recorded as an investing activity in the consolidated statements of cash flows.

Accounts_Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2014
Accounts Receivable Net [Abstract]
Accounts Receivable	5. Accounts Receivable
	Accounts receivable consists of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Trade accounts receivable	$	72,687	$	54,084
	Other receivables		8,076		4,903
	Total accounts receivable	$	80,763	$	58,987

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	6. Inventories
	Inventories consist of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Parts and supplies	$	32,137	$	30,155
	Raw coal		6,200		4,250
	Clean coal		54,065		36,885
	Total inventories	$	92,402	$	71,290

Property_Plant_Equipment_and_D

Property, Plant, Equipment and Development, Net	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Property, Plant, Equipment and Development, Net	7. Property, Plant, Equipment and Development, Net
	Property, plant, equipment and development, net consist of the following:
		December 31,			December 31,
		2014			2013
		(In Thousands)
	Land, land rights and mineral rights	$	107,348		$	114,058
	Machinery and equipment		1,074,272			984,920
	Machinery and equipment under capital leases		126,401			70,500
	Buildings and structures		230,070			218,037
	Development costs		695,386			619,117
	Other		9,212			8,564
	Property, plant, equipment and development		2,242,689			2,015,196
	Less: accumulated depreciation, depletion and amortization		(769,626	)		(601,122	)
	Property, plant, equipment and development, net	$	1,473,063		$	1,414,074

Accrued_Expenses_and_Other_Cur

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2014
Accrued Liabilities And Other Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	8. Accrued Expenses and Other Current Liabilities
	Accrued expenses and other current liabilities consist of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Employee compensation, benefits and payroll taxes	$	13,119	$	17,137
	Taxes other than income		5,494		4,270
	Asset retirement obligations		4,207		809
	Royalties (non-affiliate)		2,975		2,999
	Liquidated damages (non-affiliate)		7,315		7,448
	Other		4,492		4,852
	Total accrued expenses and other current liabilities	$	37,602	$	37,515

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt and Capital Lease Obligations	9. Long-Term Debt and Capital Lease Obligations
	Long-term debt and capital lease obligations consist of the following:
		December 31,				December 31,
		2014				2013
		(In Thousands)
	2021 Senior Notes	$	596,213			$	595,795
	Revolving Credit Facility		319,500				259,000
	Term Loan		235,822				444,602
	5.78% longwall financing arrangement		61,628				72,833
	5.555% longwall financing arrangement		61,875				72,187
	Capital lease obligations		85,633				43,180
	Interim longwall financing arrangement		—				31,616
	Total long-term debt and capital lease obligations		1,360,671				1,519,213
	Less: current portion		(44,143	)			(70,034	)
	Long-term debt and capital lease obligations	$	1,316,528			$	1,449,179
	2021 Senior Notes
	In August 2013, FELLC issued $600.0 million of 7.875% senior notes due August 15, 2021 (the “2021 Senior Notes”). The proceeds from the issuance were used to redeem $600.0 million of outstanding 9.625% senior notes due in 2017 (the “2017 Senior Notes”) through a tender offer. We recorded a $77.3 million loss on the early extinguishment of debt during the year ended December 31, 2013 for the $72.1 million in tender costs to redeem the 2017 Senior Notes and to write-off $5.2 million in unamortized debt issuance costs. The tender costs were recorded as an operating activity in the consolidated statement of cash flows. The 2021 Senior Notes are guaranteed on a senior unsecured basis by all of the domestic operating subsidiaries of Foresight Energy LP, other than Foresight Energy Finance Corporation, co-issuer of the notes. The interest on the 2021 Senior Notes is due semiannually on February 15 and August 15 of each year. The 2021 Senior Notes were issued at an initial discount of $4.3 million, which is being amortized using the effective interest method over the term of the notes.
	Prior to August 15, 2016, we may redeem some or all of the 2021 Senior Notes at a redemption price equal to the sum of the principal amount of the 2021 Senior Notes to be redeemed, plus accrued and unpaid interest, plus the applicable make-whole premium. After August 15, 2016, we may redeem all or a part of the 2021 Senior Notes at the redemption prices (expressed as a percentage of principal) set forth below plus accrued and unpaid interest, if redeemed during the 12-month period commencing on August 15 of the years indicated below:
	Year		Percentage
	2016		105.91%
	2017		103.94%
	2018		101.97%
	2019 and thereafter		100.00%
	Revolving Credit Facility
	In August 2013, FELLC executed the second amendment to its credit agreement (the “Credit Agreement”) to increase the borrowing capacity under its senior secured revolving credit facility (the “Revolving Credit Facility”) from $400.0 million to $500.0 million and extend the maturity date to August 23, 2018. The amendment resulted in the write-off of $0.4 million in unamortized debt issuance costs due to certain lenders changing their commitment level under the credit agreement. Borrowings under the Revolving Credit Facility bear interest at a rate equal to, at the Partnership’s option, (1) British Bankers’ Association (as published by Reuters) LIBOR plus an applicable margin ranging from 2.50% to 3.50% or (2) a base rate plus an applicable margin ranging from 1.50% to 2.50%, in each case, determined in accordance with the Partnership’s consolidated net leverage ratio. The Partnership is also required to pay a 0.5% commitment fee to the lenders under the Revolving Credit Facility for unutilized commitments. The weighted-average interest rate on borrowings under the Revolving Credit Facility as of December 31, 2014 and 2013 was 3.5%. At December 31, 2014, we had $6.5 million outstanding in letters of credit and $174.0 million of remaining capacity under the Revolving Credit Facility.
	Under the Credit Agreement, we are subject to customary debt covenants, including a consolidated interest coverage ratio and a consolidated senior secured leverage ratio.  We were in compliance with our financial debt covenants as of December 31, 2014.
	Term Loan
	In August 2013, the Credit Agreement was also amended for the issuance of a $450.0 million senior secured term B loan (the “Term Loan”). The Term Loan was issued at an original issuance discount of $4.5 million which will be amortized over the term of the loan. In June 2014, we used proceeds from the IPO to repay $210.0 million in principal outstanding under the Term Loan. This prepayment resulted in the write-off of $2.8 million in unamortized debt issuance costs and $1.9 million of unamortized debt discount. The prepayment of principal was applied to prospective scheduled quarterly principal payments as set forth in the Credit Agreement such that no further scheduled payments are due until the Term Loan matures on August 23, 2020. The Term Loan bears interest at LIBOR plus 4.5%, subject to a 1.0% LIBOR floor. As of December 31, 2014 and 2013, the interest rate on the Term Loan was 5.5%.
	Longwall Financing Arrangements and Capital Lease Obligations
	In January 2010, FELLC entered into a credit agreement with a financial institution to provide financing for longwall equipment and related parts and accessories. The financing arrangement is collateralized by the longwall mine equipment. Interest accrues on the note at a fixed rate per annum of 5.78% and is due semiannually in June and December until maturity. Principal is due in 17 equal semiannual payments through June 30, 2020. The outstanding balance as of December 31, 2014 was $61.6 million. The guaranty agreement between FELLC and the lender under this financing arrangement has financial covenants that are identical to those of the Credit Agreement.
	In May 2010, FELLC entered into a credit agreement with a financial institution to provide financing for longwall equipment and related parts and accessories. The financing arrangement is collateralized by the longwall mine equipment. Interest accrues on the note at a fixed rate per annum of 5.555% and is due semiannually in March and September until maturity. Principal is due in 17 equal semiannual payments through September 30, 2020. The outstanding balance as of December 31, 2014 was $61.9 million. The guaranty agreement between FELLC and the lender under this financing arrangement has financial covenants that are identical to those of the Credit Agreement.
	In March 2012, FELLC entered into a finance agreement with a financial institution to fund the manufacturing of longwall equipment. Upon taking possession of the longwall equipment during the third quarter of 2012, this interim longwall finance agreement was converted into six individual leases with maturities of four and five years beginning on September 1, 2012. These leases contain a bargain purchase option at the end of the lease term and are accounted for as capital lease obligations. These capital lease obligations bear interest ranging from 5.4% to 6.3%, and principal and interest payments are due monthly over the terms of the leases. As of December 31, 2014, $30.5 million was outstanding under these capital lease obligations.
	In November 2014, the Partnership entered into a sale-leaseback financing arrangement with a financial institution under which it sold a set of longwall shields and related equipment to a financial institution for $55.9 million and leased the shields back under three individual leases.  We account for these leases as capital lease obligations since ownership of the longwall shields and related equipment transfer back to us upon the completion of the leases.  These capital lease obligations bear interest at 5.762% and principal and interest payments are due monthly over the five-year terms of the leases.  Aggregate termination payments of $2.8 million are due at the end of the lease terms.   As of December 31, 2014, $55.1 million was outstanding under these capital lease obligations.
	In November 2013, FELLC entered into an interim longwall financing arrangement and master lease agreement with a lender to finance the installment payments required under a contract with a vendor for the purchase of a set of longwall shields and related parts and equipment. This interim longwall financing arrangement, as amended, allowed for borrowings up to the expected purchase price of $63.2 million. In May 2014, the interim longwall financing arrangement and master lease agreement were terminated with the repayment of the $61.3 million outstanding balance. Lender fees of $0.3 million were recorded to loss on early extinguishment of debt during for the early termination of the master lease agreement.
	Trade Accounts Receivable Securitization Program
	On January 13, 2015, Foresight Energy LP and certain of its wholly-owned subsidiaries, entered into a $70.0 million receivables securitization program (the “Program”).  Under this Program, our subsidiaries will sell their customer trade receivables (the “Receivables”), on a revolving basis, to Foresight Receivables LLC, a wholly-owned special purpose subsidiary of Foresight Energy LP (the “SPV”).  The SPV will then pledge its interests in the Receivables to the securitization program lenders, which will either make loans or issue letters of credit to, or on behalf of, the SPV.  The maximum amount of advances and letters of credit outstanding under the program may not exceed $70 million. The amount eligible for borrowing will be determined by the qualified receivable balances outstanding.  The Program has a three-year maturity and will expire on January 12, 2018.  The borrowings under the Program have two tranches of interest rates that approximate the one-month LIBOR rate plus 0.80%, and the Program also carries a commitment fee of 0.40% for unutilized commitments.
	We used the initial $57.2 million of proceeds under the Program primarily to reduce amounts outstanding under our Revolving Credit Facility.
	Maturity Tables
	The following summarizes the contractual principal maturities of long-term debt (excluding unamortized aggregate discounts of $5.7 million) and capital lease obligations as of December 31, 2014:
		Long-Term Debt				Capital Lease Obligations
		(In Thousands)
	2015	$	21,518			$	22,625
	2016		21,518				21,936
	2017		21,518				16,098
	2018		341,018				11,267
	2019		21,518				13,707
	Thereafter		853,663				—
	Total	$	1,280,753			$	85,633
	The above table represents defined contractual repayments and does not assume any early voluntary prepayment of principal.
	The aggregate amount of minimum lease payments (which includes principal and interest) for capital lease obligations is $96.4 million as of December 31, 2014. Minimum lease payments from 2015 through 2019 are as follows:
	(In Thousands)	2015			2016			2017		2018		2019
	Minimum lease payments	$	26,957		$	24,922		$	17,950	$	12,411	$	14,172

SaleLeaseback_Financing_Arrang

Sale-Leaseback Financing Arrangements	12 Months Ended
	Dec. 31, 2014
Leases Capital [Abstract]
Sale-Leaseback Financing Arrangements	10. Sale-Leaseback Financing Arrangements
	Macoupin Energy Sale-Leaseback Financing Arrangement
	In January 2009, Macoupin entered into a sales agreement with WPP, LLC (“WPP”) and HOD, LLC (“HOD”) (subsidiaries of Natural Resource Partners LP (“NRP”)) to sell certain mineral reserves and rail facility assets (the “Macoupin Sales Arrangement”). NRP is an affiliate of the Partnership (see Note 14). Macoupin received $143.5 million in cash in exchange for certain mineral reserve and transportation assets. Simultaneous with the closing, Macoupin entered into a lease with WPP for mining the mineral reserves (the “Mineral Reserves Lease”) and with HOD for the use of the rail loadout and rail loop (the “Macoupin Rail Loadout Lease” and the “Rail Loop Lease,” respectively). The Mineral Reserves Lease is a 20-year noncancelable lease that contains renewal elections for six additional five-year terms. The Macoupin Rail Loadout Lease and the Rail Loop Lease are 99 year noncancelable leases. Under the Mineral Reserves Lease, Macoupin makes monthly payments equal to the greater of $5.40 per ton or 8.00% of the sales price, plus $0.60 per ton for each ton of coal sold from the leased mineral reserves, subject to a minimum royalty of $4.0 million per quarter through December 31, 2028. After the initial 20-year term, the annual minimum royalty is $10,000 per year. The minimum royalty is recoupable on future tons mined. If during any quarter the tonnage royalty under the Mineral Reserves Lease and tonnage fees paid under the Macoupin Rail Loadout and Rail Loop Leases discussed below exceed $4.0 million, Macoupin may generally recoup any unrecouped quarterly payments made during the preceding 20 quarters on a first paid, first recouped basis. The Macoupin Rail Loadout Lease and Rail Loop Lease require an aggregate payment of $3.00 ($1.50 for the rail loop facility and $1.50 for the rail load-out facility) for each ton of coal loaded through the facility for the first 30 years, up to 3.4 million tons per year. After the initial 30-year term, Macoupin would pay an annual rental payment of $20,000 per year for usage of the rail loadout and rail loop. The Macoupin Sales Arrangement, Mineral Reserves Lease, Macoupin Rail Loadout Lease and Rail Loop Lease are collectively accounted for as a financing arrangement (the “Macoupin Sale-Leaseback”). This financing arrangement is recourse to Macoupin and not recourse to Foresight Energy LP or any of its other subsidiaries.
	At December 31, 2014 and 2013, the amount outstanding under the Macoupin Sale-Leaseback was $143.5 million. The effective interest rate on the financing obligation was 13.9% and 14.2% as of December 31, 2014 and 2013, respectively. Interest expense was $16.3 million, $19.6 million and $20.6 million for the years ended December 31, 2014, 2013 and 2012, respectively. As of December 31, 2014 and 2013, interest of $3.0 million and $6.8 million, respectively, was accrued in the consolidated balance sheets for the Macoupin Sale-Leaseback.
	Sugar Camp Energy Sale-Leaseback Financing Arrangement
	In March 2012, Sugar Camp entered into a sales agreement with HOD for which it received a total of $50.0 million in cash in exchange for certain rail loadout assets (“Sugar Camp Sales Agreement”). Simultaneous with the closing, Sugar Camp entered into a lease transaction with HOD for the use of the rail loadout (the “Sugar Camp Rail Loadout Lease”). The Sugar Camp Rail Loadout Lease is a 20-year noncancelable lease that contains renewal elections for 16 additional five-year terms. Under the Sugar Camp Rail Loadout Lease, Sugar Camp will pay a monthly royalty of $1.10 per ton for every ton of coal mined from specified reserves and loaded through the rail loadout. The royalty is subject to adjustment based on the time it takes for Sugar Camp to complete each longwall move. The royalty payments are subject to a minimum payment amount of $1.3 million per quarter for the first twenty years the lease is in effect. After the initial 20-year term, Sugar Camp would pay an annual rental payment of $10,000 per year. To the extent the minimum payment exceeds amounts owed based on actual coal loaded, the excess is recoupable within two years of payment.
	The Sugar Camp Sales Agreement and Sugar Camp Rail Loadout Lease are collectively accounted for as a financing arrangement (the “Sugar Camp Sale-Leaseback”). This financing arrangement is recourse to Sugar Camp and Foresight Energy LP has a limited declining commercial guaranty which began at $15 million and decreases with each minimum payment made by Sugar Camp. At December 31, 2014 and 2013, the amount outstanding under the Sugar Camp Sale-Leaseback was $50.0 million. The effective interest rate on the financing, which is derived from the timing and tons of coal to be mined as set forth in the current mine plan and the related cash payments, was 13.9% and 14.3% at December 31, 2014 and 2013, respectively. Interest expense recorded on the Sugar Camp Sale-Leaseback was $6.4 million, $7.2 million and $5.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. As of December 31, 2014 and 2013, interest of $2.5 million and $2.3 million, respectively, was accrued in the consolidated balance sheets for the Sugar Camp Sale-Leaseback.
	In August 2013, an agreement was reached between the Partnership, Foresight Reserves and HOD that allows for the existing Sugar Camp Rail Loadout Lease to be amended in the future to include coal produced from the second longwall at Sugar Camp on what is expected to be materially consistent terms as the original agreement discussed. Pursuant to such an amendment occurring, the consideration paid by HOD for including coal produced by the second longwall at Sugar Camp will be paid directly to Foresight Reserves.
	Maturity Tables
	The following summarizes the maturities of expected principal payments, based on current mine plans, on the Partnership’s sale-leaseback financing arrangements, and accrued interest at December 31, 2014:
		Sale-Leaseback Financing Arrangements			Accrued Interest
		(In Thousands)
	2015	$	—		$	5,582
	2016		600			—
	2017		1,603			—
	2018		2,761			—
	2019		3,144			—
	Thereafter		185,326			—
	Total	$	193,434		$	5,582
	The aggregate amounts of remaining minimum lease payments on the Partnership’s sale-leaseback financing arrangements are $310.3 million. Minimum payments from 2015 through 2019 are as follows:
	In Thousands	2015		2016			2017		2018		2019
	Minimum lease payments	$	21,000	$	21,000		$	21,000	$	21,000	$	21,000

Contractual_Arrangements_and_O

Contractual Arrangements and Operating Leases	12 Months Ended
	Dec. 31, 2014
Leases Operating [Abstract]
Contractual Arrangements and Operating Leases	11.  Contractual Arrangements and Operating Leases
	The Partnership leases certain surface rights, mineral reserves, mining, transportation and other equipment under various lease agreements with related entities under common control, other affiliated entities and independent third parties in the normal course of business.
	The mineral reserve leases can generally be renewed as long as the mineral reserves are being developed and mined until all economically recoverable reserves are depleted or until mining operations cease. The lease agreements typically require a production royalty at the greater amount of a base amount per ton or a percent of the gross selling price of the coal. Generally, the leases contain provisions that require the payment of minimum royalties regardless of the volume of coal produced or the level of mining activity. The minimum royalties are generally recoupable against production royalties over a contractually defined period of time (typically five to ten years). Some of these agreements also require overriding royalty and/or wheelage payments. Under the terms of certain mineral reserve leases, the Partnership is to use commercially reasonable efforts to acquire additional mineral reserves in certain properties as defined in the agreements and is responsible for the acquisition costs and the assets are to be titled to the lessor. Transportation throughput agreements generally require a per ton fee amount for coal transported and contain certain escalation clauses and/or renegotiation clauses. For certain transportation assets, the Partnership is responsible for operations, repairs, and maintenance and for keeping the transportation facilities in good working order. Surface rights, mining, and other equipment leases require monthly payments based upon the specified agreements. Certain of these leases provide options for the purchase of the property at various times during the life of the lease, generally at its then-fair market value. The Partnership also leases certain office space, rail cars and equipment under leases with varying expiration dates.
	The following presents future minimum payments, by year, required under contractual royalty and throughput arrangements with related entities and third parties as of December 31, 2014:
		Royalties – Third Party		Royalties – Related Party		Transportation Minimums – Third Party		Transportation Minimums – Related Party
		(In Thousands)
	2015	$	2,004	$	57,667	$	28,025	$	42,320
	2016		2,004		57,667		28,025		44,160
	2017		2,004		57,667		20,780		46,080
	2018		2,004		57,667		20,780		48,160
	2019		2,004		57,667		20,780		50,320
	Thereafter		11,189		315,001		44,280		107,440
	Total	$	21,209	$	603,336	$	162,670	$	338,480
	The following presents future minimum lease payments, by year, required under noncancelable operating leases with initial terms greater than one year, as of December 31, 2014:
		Operating Leases – Third Party		Operating Leases – Related Party
		(In Thousands)
	2015	$	3,352	$	105
	2016		2,227		105
	2017		1,428		105
	2018		680		105
	2019		—		100
	Thereafter		—		200
	Total	$	7,687	$	720
	Total rental expense from operating leases for the years ended December 31, 2014, 2013, and 2012 was $16.1 million, $17.0 million, and $17.2 million, respectively. Included in rental expense is $9.9 million, $9.9 million, and $11.5 million for the years ended December 31, 2014, 2013 and 2012, respectively, of contingent rental payments to Williamson Transport, a subsidiary of NRP, for the rail loadout facility at Williamson Energy. We pay contingent rental fees, net of a fixed per ton amount received for maintaining the facility, on each ton of coal passed through the rail loadout facility.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	12. Asset Retirement Obligations
	The change in the carrying amount of asset retirement obligations was as follows:
		For the Year Ended December 31,
		2014			2013			2012
		(In Thousands)
	Balance at beginning of period (including current portion)	$	21,225		$	19,449		$	19,967
	Accretion expense		1,621			1,527			1,552
	Adjustments for liabilities incurred or changes in estimates		13,747			625			(1,496	)
	Expenditures for reclamation activities		(1,013	)		(376	)		(574	)
	Balance at end of period (including current portion)		35,580			21,225			19,449
	Less: current portion of asset retirement obligations		(4,207	)		(809	)		(99	)
	Noncurrent portion of asset retirement obligations	$	31,373		$	20,416		$	19,350
	The credit-adjusted, risk-free interest rates used in determining the asset retirement obligations were 6.6%, 8.8% and 7.6% at December 31, 2014, 2013, and 2012, respectively.

Coal_Workers_Pneumoconiosis_an

Coal Workers Pneumoconiosis and Workers Compensation	12 Months Ended
	Dec. 31, 2014
Postemployment Benefits [Abstract]
Coal Workers' Pneumoconiosis and Workers' Compensation	13.  Coal Workers’ Pneumoconiosis and Workers’ Compensation
	Certain of our consolidated affiliates are responsible under Illinois statutes and the Federal Coal Mine Health and Safety Act of 1969, as amended, for medical and disability benefits to employees and their dependents resulting from occurrences of coal workers’ pneumoconiosis disease (“CWP”). In addition, state statutes dictate that we provide income replacement and medical treatment for work-related traumatic injury claims, including survivor benefits for employment related deaths. Effective July1, 2014, we terminated our guaranteed cost program in favor of a high deductible insurance program.
	Our liability for CWP benefits was estimated by an independent actuary based on assumptions regarding medical costs, allocated loss adjustment expense, claim development patterns and interest rates. For the year ended December 31, 2014, we recorded CWP expense of $1.5 million and have a CWP liability of $1.5 million recorded in other long-term liabilities in the consolidated balance sheet as of December 31, 2014.
	Our liability for workers compensation benefits was determined by a third-party administrator based on actual claims incurred and the expected development of those claims. For the year ended December 31, 2014, we recorded workers’ compensation expense of $1.4 million and have a workers’ compensation liability of $1.1 million recorded in accrued expenses and other current liabilities in the consolidated balance sheet.

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related-Party Transactions	14. Related-Party Transactions
	The chairman of our general partner’s board of directors and the controlling member of Foresight Reserves, Chris Cline, directly and indirectly beneficially owns a 31% and 4% interest in the general and limited partner interests of NRP, respectively. We routinely engage in transactions in the normal course of business with NRP and its subsidiaries and Foresight Reserves and its affiliates. These transactions include production royalties, transportation services, administrative arrangements, coal handling and storage services, supply agreements, service agreements, land leases and sale-leaseback financing arrangements (see Note 10, sale-leaseback financing arrangements are excluded from the discussion and tables below). We also acquire, from time to time, mining equipment from Foresight Reserves and affiliated entities.
	If a conflict or potential conflict of interest arises between our general partner or its affiliates, on the one hand, and us or our unitholders, on the other hand, the resolution of any such conflict or potential conflict should be addressed by the conflicts committee. The independent members of the board of directors of our general partner serve on our conflicts committee to review specific matters that the board believes may involve conflicts of interest and determines to submit to the conflicts committee for review. The conflicts committee determines if the resolution of the conflict of interest is adverse to the interest of the partnership. Any matters approved by the conflicts committee are conclusively deemed to be approved by us and all of our partners and not a breach by our general partner of any duties it may owe us or our unitholders.
	Limited Partnership Agreement
	The Partnership’s general partner manages the Partnership’s operations and activities as specified in the partnership agreement. The general partner of the Partnership is managed by its board of directors. Foresight Reserves has the right to select the directors of the general partner. The members of the board of directors of the general partner are not elected by the unitholders and are not subject to reelection by the unitholders. The officers of the general partner manage the day-to-day affairs of the Partnership’s business. The partnership agreement provides that the Partnership will reimburse its general partner for all direct and indirect expenses incurred or payments made by the general partner on behalf of the Partnership. No amounts were incurred by the general partner or reimbursed under the partnership agreement from the IPO date to December 31, 2014.
	Mineral Reserve Leases
	Our mines have a series of mineral reserve leases with Colt, LLC (“Colt”) and Ruger, LLC (“Ruger”), subsidiaries of Foresight Reserves.  Each of these leases have initial terms of 10 years with six renewal periods of five years each, at the election of the lessees, and  generally require the lessees to pay the greater of $3.40 per ton or 8.5% of the gross sales price, as defined in the respective agreements, of such coal. We also have overriding royalty agreements with Ruger pursuant to which we pay royalties equal to 8.0% of the gross selling prices, as defined in the agreements. Each of these mineral reserve leases generally require a minimum annual royalty payment, which is recoupable only against actual production royalties from future tons mined during the period of 10 years following the date on which any such royalty is paid.
	We also lease mineral reserves under lease agreements with subsidiaries of NRP, including WPP, HOD, and Independence Energy, LLC (“Independence”). The initial terms of these agreements vary, however, each carries an option by the lessee to extend the leases until all merchantable and mineable coal has been mined and removed. Royalty payments under these arrangements are generally determined based on the greater of a minimum per ton amount (ranging from $2.50 per ton to $5.40 per ton) or a percentage of the gross sales price (generally 8.0% - 9.0%), as defined in the respective agreements. We are also subject under certain of these mineral reserve agreements to overriding royalties and/or wheelage fees. Our mineral reserve leases with NRP subsidiaries also require minimum quarterly or annual royalties which are generally recoupable on future tons mined and sold during the preceding five-year period from the excess tonnage royalty payments on a first paid, first recouped basis.
	As of December 31, 2014, we have established a $34.7 million reserve against a contractual prepaid royalty between Hillsboro and WPP given that the recoupment of certain prior minimum royalty payments was improbable given the remaining recoupment period available and forecasted demand for Hillsboro coal based on current and forecasted near-term market conditions. We continually evaluate our ability to recoup prepaid royalty balances which includes, among other things, assessing mine production plans, sales commitments, current and forecasted future coal market conditions, and remaining years available for recoupment.
	Transloading Agreements
	In connection with the 2013 Reorganization (see Note 17), each of our mines entered into a transloading and storage agreement with Sitran, a barge transloading facility on the Ohio River owned by Foresight Reserves. These agreements provide for the unloading of coal from railcars into stockpiles at Sitran and for the loading of coal from stockpiles into barges. Under these agreements each mine pays Sitran a fee for each ton of coal offloaded, stored or transloaded at Sitran’s facility. The agreements carry no minimum volume requirements. Each agreement has an initial term of three years and automatically renew for successive one-year periods unless terminated by either party. On February 25, 2015, Foresight Reserves and a member of management contributed Sitran to the Partnership (see Note 17).
	In August 2011, an affiliated company owned by Foresight Reserves acquired the IC RailMarine Terminal in Convent, Louisiana. This terminal, commonly referred to as the Convent Marine Terminal (“CMT”), is owned by Raven Energy LLC, an entity controlled and beneficially owned by Christopher Cline. The terminal is designed to ship and receive commodities via rail, river barge and ocean vessel. We have a contract for throughput at the terminal that continues through December 31, 2021 under which we pay fees based on the tonnages of coal we move through the terminal, subject to minimum annual take-or-pay volume commitments.
	Other
	In August 2013, FELLC entered into an equipment repair and rebuild agreement with Seneca Rebuild LLC (“Seneca Rebuild”), an affiliated entity owned indirectly by Chris Cline. The agreement called for Seneca Rebuild to be the primary provider of repair and rebuild services for mining machinery and equipment for our mines. Effective April 1, 2014, FELLC reached an agreement to acquire Seneca Rebuild for $3.8 million, net of cash acquired. Because FELLC and Seneca Rebuild were under common control, the assets and liabilities of Seneca Rebuild were recorded by FELLC at carrying value on the acquisition date. Seneca Rebuild’s net assets on the acquisition date consisted principally of property, plant and equipment. The $0.3 million paid over the excess of the carrying value of the net assets of Seneca Rebuild on the acquisition date was recorded as a deemed distribution. Given the immateriality of this acquisition, the financial results of Seneca Rebuild are reflected prospectively in the consolidated financial statements of the Partnership.
	Williamson leases property from Williamson Transport, an affiliate of NRP, under two surface leases with initial terms through October 15, 2031 and an option to extend the leases in five-year increments until all the coal leased from an NRP affiliate is mined on Williamson’s premises. Williamson Transport has the option to put the land to Williamson for its fair market value as determined by an independent appraiser at any time during the lease term. Additionally, under a separate lease with an initial term through March 12, 2018, Williamson pays $5,000 per year for use of the premises and a fee, currently at $1.80 per ton, for each ton of coal produced at Williamson that is loaded through the Williamson rail loadout facility. Williamson Transport may elect to renew or extend the sublease for successive five-year periods. If Williamson Transport elects not to renew the sublease, Williamson has the option to buy the Williamson rail loadout facility for its fair market value as determined by an independent appraiser. Williamson receives a fee of $0.25 per ton from Williamson Transport for each ton of coal that is loaded through the Williamson rail loadout facility in exchange for operating the load out.
	We are party to two surface leases in relation to the coal preparation plant and rail loadout facility at Williamson with New River Royalty, a subsidiary of Foresight Reserves. The primary terms of the leases expire on October 15, 2021, but may be extended by New River Royalty for additional five-year terms under the same terms and conditions until all of the merchantable and mineable coal has been mined and removed from Williamson. Williamson is required to pay aggregate rent of $100,000 per year to New River Royalty under the leases. Additionally, New River Royalty may require Williamson to purchase any portion of either of the leased properties at any time while the leases are in effect for $3,000 an acre. Williamson Transport has the option to purchase any property optioned under the leases if Williamson does not perform its purchase obligation within fifteen days of receiving notice of its purchase obligation.
	We may arrange air travel on an individual flight basis with affiliated entities controlled by Chris Cline. These expenses are incurred hourly (at estimated cost), by flight, and are initially paid by the affiliated entities and then reimbursed by us. We also from time to time utilize other assets controlled by Chris Cline and reimburse the affiliated entities on a time-incurred basis.
	In January 2007, Chris Cline, Foresight Reserves, Adena Minerals LLC and their respective affiliates (collectively, “Adena Entities”) and NRP executed a restricted business contribution agreement. The restricted business contribution agreement obligates the Adena Entities and their affiliates to offer NRP any business owned, operated or invested in by the Adena Entities, subject to certain exceptions, that either (a) owns, leases or invests in hard minerals or (b) owns, operates, leases or invests in identified transportation infrastructure relating to certain future mine developments by the Adena Entities in Illinois. NRP’s acquisition of certain coal reserves and infrastructure assets related to our Macoupin, Hillsboro and Sugar Camp mining complexes, discussed above and in Note 10, were deals consummated under the restricted business contribution agreement with the Adena Entities. The Adena Entities are required to offer and could consummate additional deals under the restricted business contribution agreement in the future.
	During the years ended December 31, 2014 and 2013, we purchased $18.1 million and $14.7 million in mining supplies from an affiliated joint venture under a supply agreement entered into in May 2013 (see Note 15).
	We receive monthly fees from Foresight Reserves in exchange for performing bookkeeping and other administrative functions for certain of its subsidiaries.
	The following table presents the affiliate amounts included in our consolidated balance sheets:
	Affiliated Company		Balance Sheet Location		December 31,				December 31,
					2014				2013
					(In Thousands)
	Foresight Reserves and affiliated entities		Due from affiliates		$	387			$	368
	NRP and affiliated entities		Due from affiliates			187				—
	Total				$	574			$	368
	Foresight Reserves and affiliated entities		Due to affiliates		$	8,730			$	4,521
	NRP and affiliated entities		Due to affiliates			7,148				5,051
	Total				$	15,878			$	9,572
	Foresight Reserves and affiliated entities		Prepaid royalties		$	53,671			$	37,644
	NRP and affiliated entities(1)		Prepaid royalties			11,071				39,801
	Total				$	64,742			$	77,445
	(1) – Prepaid royalties with NRP and affiliated entities is presented net of a $34,700 reserve.
	A summary of expenses (income) incurred with affiliated entities is as follows for the years ended December 31, 2014, 2013 and 2012:
		For the Year Ended December 31,
		2014				2013				2012
		(In Thousands)
	Royalty expense – NRP and affiliated entities(1)	$	48,652			$	51,345			$	42,051
	Royalty expense – Foresight Reserves and affiliated entities(1)	$	11,282			$	8,294			$	8,790
	Loadout services – NRP and affiliated entities(1)	$	9,878			$	10,000			$	11,608
	Terminal fees – Foresight Reserves and affiliated entities(2)	$	52,781			$	30,217			$	26,275
	Management and transportation usage fees – Foresight	$	—			$	1,488			$	3,127
	Reserves and affiliated entities(3)
	Administrative fee income – Foresight	$	(256	)		$	(120	)		$	(30	)
	Reserves and affiliated entities(4)
	Principal location in the consolidated statements of operations:
	(1) – Cost of coal produced (excluding depreciation, depletion and amortization)
	(2) – Transportation
	(3) – Selling, general and administrative
	(4) – Other operating income, net
	The contractual commitment tables for operating leases, transportation throughput agreements, and royalty agreements with affiliated parties are disclosed in Note 11.

Variable_Interest_Entities_VIE

Variable Interest Entities (VIEs)	12 Months Ended
	Dec. 31, 2014
Variable Interest Entity Nonconsolidated Carrying Amount Assets And Liabilities [Abstract]
Variable Interest Entities (VIEs)	15. Variable Interest Entities (VIEs)
	The consolidated financial statements include VIEs for which the Partnership or its subsidiary is the primary beneficiary. Among those VIEs consolidated by the Partnership and its subsidiaries are Mach Mining, LLC; M-Class Mining, LLC; MaRyan Mining LLC; Patton Mining LLC; Viking Mining LLC, Coal Field Construction Company LLC; Coal Field Repair Services LLC and LD Labor Company LLC (prior to the 2013 Reorganization date discussed below) (collectively, the “Contractor VIEs”). Each of the Contractor VIEs holds a contract to provide one or more of the following services to a Partnership subsidiary: contract mining, processing and loading services, or construction and maintenance services. Each of the Contractor VIEs generally receives a nominal per ton fee ($0.01 to $0.02 per ton) above its cost of operations as compensation for services performed. All of these entities were determined not to have sufficient equity at risk and are therefore VIEs. The Partnership was determined to be the primary beneficiary of each of these entities given it controls these entities under a contractual cost-plus arrangement. During the years ended December 31, 2014, 2013 and 2012, in aggregate, the Contractor VIEs earned income of $0.4 million, $0.3 million and $0.2 million, respectively, under the contractual arrangements with the Partnership which was recorded as net income attributable to noncontrolling interests in the consolidated statements of operations.
	On August 23, 2013, FELLC effected a reorganization pursuant to which certain transportation assets were distributed to its members (see Note 17). Among the assets distributed were Adena Resources LLC (“Adena”), a subsidiary that provides water and other miscellaneous rights to the mines and Hillsboro’s coal loadout facility, including the land on which the facility is situated (collectively, the “Loadout”).
	Adena has various water rights contracts that are used to provide water to the Partnership’s mines. Concurrent with the distribution of Adena to FELLC members, we entered into a water resources agreement between the Partnership’s mines and Adena providing for water resources to be available at each of the mines. As compensation for furnishing water to the mines, we pay Adena the actual cost (including capital expenditures) incurred by Adena plus an annual fee of $10,000. Adena is determined not to have sufficient equity at risk and is therefore a VIE. The Partnership is determined to be the primary beneficiary of Adena given it controls this entity under a contractual cost-plus arrangement. During the years ended December 31, 2014 and 2013, Adena incurred a loss of $0.4 million and $0.2 million, respectively, which was recorded as net income attributable to noncontrolling interests in the consolidated statements of operations. On February 25, 2015, Foresight Reserves and a member of management contributed Adena to the Partnership (see Note 17).
	Subsequent to the 2013 Reorganization, Foresight Reserves placed the Loadout into a newly created subsidiary, Hillsboro Transport, LLC (“Hillsboro Transport”). A throughput agreement was entered into between Hillsboro and Hillsboro Transport for Hillsboro Transport to operate the Loadout. As compensation for operating and maintaining the Loadout, Hillsboro pays $0.99 per ton for every ton of coal loaded through the Loadout, subject to a minimum quarterly payment of $1.3 million, which began in the first quarter of 2014. Hillsboro Transport was determined not to have sufficient equity at risk as a result of the throughput agreement’s guaranteed minimum quarterly payment and is therefore a VIE. Hillsboro was determined to be the primary beneficiary of this entity as it implicitly controls Hillsboro Transport given the related-party relationship between Hillsboro and Hillsboro Transport and the fact that the sole assets held by Hillsboro Transport are unique to Hillsboro’s operations. During the years ended December 31, 2014 and 2013, Hillsboro Transport earned $3.8 million and $2.0 million, respectively, in net income under this arrangement, which is presented in net income attributable to noncontrolling interests in the consolidated statements of operations. On February 25, 2015, Foresight Reserves and a member of management contributed Hillsboro Transport to the Partnership (see Note 17).
	The liabilities recognized as a result of consolidating the VIEs do not necessarily represent additional claims on the general assets of the Partnership outside of the VIEs; rather, they represent claims against the specific assets of the consolidated VIEs. Conversely, assets recognized as a result of consolidating these VIEs do not necessarily represent additional assets that could be used to satisfy claims against the Partnership’s general assets. There are no restrictions on the VIE assets that are reported in the Partnership’s general assets. The total consolidated VIE assets and liabilities reflected in the Partnership’s consolidated balance sheets are as follows:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Assets:
	Current assets	$	4,939	$	4,386
	Long-term assets		1,554		2,141
	Total assets	$	6,493	$	6,527
	Liabilities:
	Current liabilities	$	10,145	$	5,310
	Long-term liabilities		1,131		157
	Total liabilities	$	11,276	$	5,467
	In May 2013, an affiliate owned by Chris Cline and a third-party supplier of mining supplies formed a joint venture whose purpose is the manufacture and sale of supplies primarily for use by the Partnership in the conduct of its mining operations. The agreement obligates the Partnership’s coal mines to purchase at least 90% of their aggregate annual requirements for certain mining supplies from the supplier parties, subject to exceptions as set forth in the agreement. The initial term of the amended agreement is five years and expires in April 2018. The supplies sold under this arrangement result in an agreed-upon fixed profit percentage for the joint venture. This joint venture was determined to be a VIE given that the equity holders do not have the obligation to absorb the expected losses or the right to receive the expected residual returns of the joint venture as a result of the Partnership effectively guaranteeing a fixed-profit percentage on the supplies it purchases from the joint venture. We are not the primary beneficiary of this joint venture and, therefore, do not consolidate the joint venture, given that the power over the joint venture is conveyed through the board of directors of the joint venture and no party controls the board of directors.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	16. Fair Value of Financial Instruments
	The tables below set forth, by level, the Partnership’s net financial assets and liabilities for which fair value is measured on a recurring basis:
		Fair Value at December 31, 2014
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	61,037		$	—	$	61,037		$	—
	Total	$	61,037		$	—	$	61,037		$	—
		Fair Value at December 31, 2013
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	2,020		$	—	$	2,020		$	—
	Liability Award		(11,700	)		—		—			(11,700	)
	Total	$	(9,680	)	$	—	$	2,020		$	(11,700	)
	The Partnership’s coal derivative contracts are valued based on direct broker quotes and corroborated with API 2 market pricing data. The liability award represents a phantom equity award (“Liability Award”) to a retired executive for which the value was determined based on the fair value, as defined in the agreement, of Foresight Reserves as of the employee’s retirement date and was adjusted for distributions made to Foresight Reserves’ members. This Liability Award fully vested in 2010 and was granted principally for services performed to develop the Partnership’s longwall mines. Prior to March 31, 2014, the Liability Award was Level 3 in the fair value hierarchy given Foresight Reserves was a private company; therefore, there was no liquid market to determine the fair value of Foresight Reserves’ equity. The fair value of the Liability Award was determined using a discounted cash flow model and corroborated with recent equity transactions at Foresight Reserves. Effective March 31, 2014, the Liability Award amount was negotiated between the Partnership and the employee to be $12.4 million; therefore, the value of this liability was contracted and therefore no longer a Level 3 liability. As of December 31, 2014, $0.4 million of the unpaid balance is recorded in accrued expenses and other current liabilities for required payments over the next year, and the remaining $3.8 million is recorded in other long-term liabilities, which will be paid out ratably through 2024. The note payable to the retired executive currently bears interest at 3.45%.
	The classification and amount of the Partnership’s financial instruments measured at fair value on a recurring basis, which are presented on a gross basis in the consolidated balance sheets as of December 31, 2014 and 2013, are as follows:
		Fair Value at December 31, 2014
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	36,080		$	24,957	$	—		$	—
	Total	$	36,080		$	24,957	$	—		$	—
		Fair Value at December 31, 2013
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	1,976		$	912	$	(531	)	$	(337	)
	Liability Award		—			—		(11,700	)		—
	Total	$	1,976		$	912	$	(12,231	)	$	(337	)
	The following is a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the years ended December 31, 2014 and 2013:
		Liability Award
		(In Thousands)
	Balance at January 1, 2014	$	11,700
	Recorded fair value losses (gains):
	Included in earnings		690
	Purchases, issuances and settlements		(12,390	)
	Balance at December 31, 2014	$	—
	Balance at January 1, 2013	$	—
	Recorded fair value losses (gains):
	Included in earnings		677
	Capitalized into development costs		(217	)
	Purchases, issuances and settlements		11,240
	Balance at December 31, 2013	$	11,700
	During the years ended December 31, 2014, 2013 and 2012, there were no assets or liabilities that were transferred between Level 1 and Level 2.
	Long-Term Debt
	The fair value of long-term debt as of December 31, 2014 and 2013 was $1,279.7 million and $1,509.2 million, respectively. The fair value of long-term debt was calculated based on the amount of future cash flows associated with each debt instrument discounted at the Partnership’s current estimated credit-adjusted borrowing rate for similar debt instruments with comparable terms. This is considered a Level 3 fair value measurement.

Partners_Capital

Partners' Capital	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Partners' Capital	17. Partners’ Capital
	Common and Subordinated Units
	All subordinated units are currently held by Foresight Reserves and a member of management. The principal difference between our common units and subordinated units is that subordinated unitholders are not entitled to receive a distribution of available cash until the holders of common units have received the minimum quarterly distribution (“MQD”).  The MQD is $0.3375 per unit for such quarter plus any cumulative arrearages of previously unpaid MQDs from previous quarters. Also, subordinated unitholders are not entitled to receive arrearages. The subordination period will end, and the subordinated units will convert to common units, on a one-for-one basis, on the first business day after the Partnership has paid the MQD for each of three consecutive, non-overlapping four-quarter periods ending on or after March 31, 2017 and there are no outstanding arrearages on the common units. Notwithstanding the foregoing, the subordination period will end on the first business day after the Partnership has paid an aggregate amount of at least $2.025 per unit (150.0% of the MQD on an annualized basis) on the outstanding common and subordinated units and the Partnership has paid the related distribution on the incentive distribution rights, for any four-quarter period ending on or after March 31, 2015 and there are no outstanding arrearages on the common units. Our partnership agreement provides that our general partner will make a determination as to whether a distribution will be made, but our partnership agreement does not require us to pay distributions at any time or at any amount. Our partnership agreement authorizes us to issue an unlimited number of additional partnership interests for the consideration and on the terms and conditions determined by our general partner without the approval of the unitholders.
	Incentive Distribution Rights
	Our general partner owns all of the incentive distribution rights (“IDRs”). IDRs represent the right to receive an increasing percentage of quarterly distributions of available cash from operating surplus after the MQD and the target distribution levels (described below) have been achieved. Our general partner may transfer these rights separately from its general partner interest, subject to restrictions in our partnership agreement. Our general partner, as the IDR holder, will have the right, subsequent to the subordination period and subject to distributions exceeding the MQD by at least 150% for four consecutive quarters, to reset the target distribution levels and receive common units.
	Allocation of Net Income (Loss)
	Our partnership agreement contains provisions for the allocation of net income and loss to the unitholders and the general partner. For purposes of maintaining partner capital accounts, the partnership agreement generally specifies that items of income and loss shall be allocated among the partners in accordance with their respective percentage interest.
	Percentage Allocation of Available Cash from Operating Surplus
	The following table illustrates the percentage allocation of available cash from operating surplus between the unitholders and our general partner (as the holder of our IDRs) based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of the IDR holder and the unitholders of any available cash from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution Per Common Unit”. The percentage interests shown for our unitholders and our general partner for the MQD are also applicable to quarterly distribution amounts that are less than the MQD.
	The percentage interests set forth below assumes there are no arrearages on common units.
		Total Quarterly Distribution	Marginal Percentage
		Per Common Unit	Interest in Distributions
			Unitholders			General Partner (IDRs)
	Minimum quarterly distribution	$0.34		100	%		—
	First target distribution	Above $0.3375 up to $0.3881		100	%		—
	Second target distribution	Above $0.3881 up to $0.4219		85	%		15	%
	Third target distribution	Above $0.4219 up to $0.5063		75	%		25	%
	Thereafter	Above $0.5063		50	%		50	%
	Our partnership agreement sets forth the calculation to be used to determine the amount and priority of cash distributions that the common and subordinated unitholders and general partner will receive.
	In August and November of 2014, we declared and paid quarterly cash distributions of $0.03 per unit (equal to the MQD, rounded-up, and prorated for the period from the closing date of the IPO to the end of the second quarter) and $0.35 per unit, respectively, to all unitholders on the respective record dates.
	On February 6, 2015, we declared a quarterly cash distribution of $0.36 per unit to all unitholders, which was paid on February 27, 2015, to all unitholders of record on February 16, 2015.
	Predecessor Members’ Deficit
	Simultaneously with the closing of the debt refinancing on August 23, 2013 (see Note 9), FELLC underwent a reorganization (the “2013 Reorganization”) pursuant to which it distributed to its members 100% of its ownership interest in Sitran, Adena and Hillsboro Transport. FELLC recorded a non-cash distribution totaling $62.0 million in August 2013 to reflect these distributions to its members. In May 2014, based upon the terms of the 2013 Reorganization, FELLC distributed to its members approximately 1,900 acres of surface land not needed for current or currently projected future operations and $0.1 million in cash. The carrying value of the distributed land was $12.2 million. Additionally, in connection with the acquisition of Seneca Rebuild on April 1, 2014, a deemed distribution in the amount of $0.3 million was recorded to reflect the excess of the purchase price paid by FELLC over the carrying value of the net assets acquired (see Note 14).
	On June 23, 2014, in connection with the IPO, Foresight Reserves and a member of management each contributed their membership interests in FELLC to the Partnership in exchange for common and subordinated units of FELP (see Note 3).  As a result, the members’ deficit balance of $104.9 million at the time of the transfer was allocated, pro rata based on units outstanding, to common and subordinated unitholder capital accounts.
	Noncontrolling Interests
	Noncontrolling interests’ equity and net income attributable to noncontrolling interests result from the consolidation of variable interest entities for which the Partnership has no equity interests (see Note 15).
	Contribution of Assets
	On February 25, 2015, Foresight Reserves and a member of management contributed 100% of the equity of Sitran, Adena and Hillsboro Transport to the Partnership. The entities were contributed by Foresight Reserves and a member of management for no consideration.  Sitran, Adena and Hillsboro Transport had an aggregate net book value of approximately $60 million at January 31, 2015.

EquityBased_Compensation

Equity-Based Compensation (LTIP Awards)	12 Months Ended
	Dec. 31, 2014
LTIP Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-Based Compensation	18. Equity-Based Compensation
	Long-Term Incentive Plan
	Upon the closing of our IPO, the Partnership adopted a Long-Term Incentive Plan ("LTIP") for employees, directors, officers and certain key third-parties (collectively, the "Participants").  The Plan allows for the issuance of equity-based compensation in the form of phantom units, unit awards, unit options, unit appreciation rights, restricted units, other unit-based awards, distribution equivalent rights, performance awards, and substitute awards to Participants.  The LTIP awards granted thus far are phantom units, which upon satisfaction of vesting requirements, entitle the LTIP participant to receive FELP common units. The Board of Directors of the Partnership authorized 7.0 million common units to be granted under the LTIP, with 6.2 million units available for grant as of December 31, 2014.  Annual grant levels and vesting requirements are recommended by the Partnership's chief executive officer, subject to the review and approval by the board of directors.
	Long-Term Incentive Compensation Awards
	In June 2014, upon the closing of the IPO, pre-existing cash-based compensation liability awards were converted to equity awards which are to be settled in FELP common units after meeting certain vesting requirements.  As a result, on June 23, 2014, $0.6 million was reclassified from accrued expenses and other current liabilities to partners' capital for the conversion of the pre-existing cash-based awards to 154,027 phantom units to be issued under the LTIP.   No additional compensation expense was recorded as a result of the modification of these awards. These modified awards are time-based unit awards and generally vest, subject to continued employment, ratably over three-year periods from the award date (with accelerated vesting in certain instances).  Compensation expense for these awards is recognized on a straight-line basis over the requisite service period, net of estimated forfeitures.  Upon vesting, the Partnership issues authorized and unissued shares of the Partnership's common units to the recipient.   In December 2014, vesting requirements had been satisfied on certain of the awards resulting in 45,736 unrestricted common units being issued (the remaining 27,926 units were settled in cash to satisfy the individual minimum tax obligations of the Participants).  As of December 31, 2014, none of the awards had been forfeited.
	LTIP Awards
	In June 2014, the Partnership also granted 595,075 phantom units to employees under the LTIP, of which 72,500 units vested immediately.  As a result of the immediate vesting, 46,681 unrestricted common units were issued (the remaining 25,819 units were settled in cash to satisfy the individual statutory minimum tax obligations of the Participants).  The remaining awards are considered time-based unit awards and generally cliff-vest, subject to continued employment, at the end of three years of service (with accelerated vesting under certain instances).  Compensation expense for these awards is recognized on a straight-line basis over the requisite service period, net of estimated forfeitures.  Upon vesting, the Partnership will issue authorized and unissued shares of the Partnership’s common units to the recipient.  As of December 31, 2014, 9,750 units had been forfeited.
	On February 5, 2015, the board of directors approved equity grants to the Partnership’s chief executive officer consisting of 215,954 common units and 215,796 subordinated units under the LTIP. The awards are fully-vested as of the grant date, but are subject to certain sale and transfer restrictions through December 31, 2019.
	Director Awards
	Also in 2014, the Partnership granted 7,919 phantom units to non-employee directors under the LTIP.  These awards are considered time-based unit awards and vest ratably over a three-year period (with accelerated vesting in certain instances).  Compensation expense for these awards is recognized on a straight-line basis over the requisite service period.  As of December 31, 2014, none of the director awards had vested or been forfeited.
	Summary
	For the year ended December 31, 2014, our equity-based compensation expense was $5.0 million, net of estimated forfeitures, of which $0.3 million was capitalized.  Approximately 63% of the Partnership's equity-based compensation is reported through selling, general and administrative expenses in the consolidated statement of operations with the remaining 37% recorded through cost of coal sales.  As of December 31, 2014, the total unrecognized compensation expense for phantom unit awards that are expected to vest was $9.0 million.  This expense is expected to be recognized over a weighted-average period of 2.3 years.  The intrinsic value of the non-vested LTIP awards was $10.1 million as of December 31, 2014.  All non-vested phantom units include tandem distribution incentive rights, which provide for the right to accrue quarterly cash distributions in an amount equal to the cash distributions the Partnership makes to unitholders during the vesting period and will be settled in cash upon vesting.  The Partnership has approximately $0.2 million accrued for this liability as of December 31, 2014.  Any distributions accrued to a Participants’ account will be forfeited if the related phantom award fails to vest according to the relevant vesting conditions.
	A summary of LTIP award activity for the year ended December 31, 2014 is as follows:
		Number of Units			Weighted Average Grant Date Fair Value per Unit
	Non-vested grants at January 1, 2014		-		$	-
	Granted		757,021		$	19.99
	Vested		(146,162	)	$	20
	Forfeited		(9,750	)	$	20
	Non-vested grants at December 31, 2014		601,109		$	19.99

Earnings_per_Limited_Partner_U

Earnings per Limited Partner Unit	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings per Limited Partner Unit	19. Earnings per Limited Partner Unit
	Limited partners’ interest in net income attributable to the Partnership and basic and diluted earnings per unit reflect net income attributable to the Partnership from the June 23, 2014 closing date of the IPO through December 31, 2014. We compute earnings per unit (“EPU”) using the two-class method for master limited partnerships as prescribed in Accounting Standards Codification (“ASC”) 260, Earnings Per Share. The two-class method requires that securities that meet the definition of a participating security be considered for inclusion in the computation of basic EPU. In addition to the common and subordinated units, we have also identified the general partner interest and IDRs as participating securities. Under the two-class method, EPU is calculated as if all of the earnings for the period were distributed under the terms of the partnership agreement, regardless of whether the general partner has discretion over the amount of distributions to be made in any particular period, whether those earnings would actually be distributed during a particular period from an economic or practical perspective, or whether the general partner has other legal or contractual limitations on its ability to pay distributions that would prevent it from distributing all of the earnings for a particular period.
	The Partnership’s net income is allocated to the limited partners, including the holders of the subordinated units, in accordance with their respective ownership percentages, after giving effect to any special income or expense allocations and incentive distributions paid to the general partner, if any. The partnership agreement contractually limits distributions to available cash as determined by our general partner; therefore, undistributed earnings of the Partnership are not allocated to the IDR holder. There were no allocations of earnings to participating securities during the periods presented below. Basic EPU is computed by dividing net earnings attributable to unitholders by the weighted-average number of units outstanding during each period. However, because our IPO was completed on June 23, 2014, the units outstanding from the IPO date are utilized for the period presented.  Basic common units outstanding includes the 2,625,000 overallotment units offered to the underwriters, which were issued to Foresight Reserves and a member of management in July 2014, as of the IPO date. Diluted EPU reflects the potential dilution of common equivalent units that could occur if equity participation units are converted into common units.
	The following table illustrates the Partnership’s calculation of net income per common and subordinated unit for the period indicated:
		Common Unitholders		Subordinated Unitholders		Total
	Year Ended December 31, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income subsequent to IPO available to limited partner units	$	35,154	$	35,038	$	70,192
	Denominator:
	Weighted-average units to calculate basic EPU		64,790		64,739		129,529
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,790		64,739		129,529
	Basic net income per unit	$	0.54	$	0.54	$	0.54
	Diluted net income per unit	$	0.54	$	0.54	$	0.54
	(1) -	Diluted EPU gives effect to all dilutive potential common units outstanding during the period using the treasury stock method. Diluted EPU excludes all dilutive potential units calculated under the treasury stock method if their effect is anti-dilutive. For the year ended December 31, 2014, approximately 0.6 million phantom units were anti-dilutive, and therefore excluded from the diluted EPU calculation.

Risk_Concentrations

Risk Concentrations	12 Months Ended
	Dec. 31, 2014
Risks And Uncertainties [Abstract]
Risk Concentrations	20. Risk Concentrations
	Sales and Credit Risk
	The Partnership determines creditworthiness for trade customers based on an evaluation of the customer’s financial condition. Credit losses have historically been minimal. The aggregate outstanding trade receivable balance as of December 31, 2014 from customers representing greater than 10% of our total sales was $20.4 million.
	For the years ended December 31, 2014, 2013 and 2012, the following customers exceeded 10% of total coal sales:
		For the Year Ended December 31,
		2014		2013	2012
		(Percentage of Total Coal Sales)
	Customer A		11%	(A)		14%
	Customer B		12%	(A)	(A)
	Customer C	(A)		(A)		10%
	(A) – Less than 10% of total coal sales for this period.
	During the years ended December 31, 2014, 2013 and 2012, export tons (inclusive of tons sold from mines under development) represented 30%, 33% and 44% of tons sold, respectively. Tons exported into Europe during the years ended December 31, 2014, 2013 and 2012 represented approximately 26%, 23% and 28%, respectively, of total tons sold during those years (inclusive of tons sold from mines under development). No other international geographic regions exceeded 10% of tons sold during the years ended December 31, 2014, 2013 and 2012.  Our domestic coal sales are principally to electric utility companies in the eastern United States with installed pollution control devices.
	Transportation
	The Partnership depends on rail, barge, and export terminal systems to deliver coal to its customers. Disruption of these services due to weather-related problems, mechanical difficulties, strikes, lockouts, bottlenecks, and other events could temporarily impair the Partnership’s ability to supply coal to its customers, resulting in decreased shipments. As such, the Partnership has sought to diversify transportation options and has entered into long-term contracts with transportation providers to ensure transportation is available to transport its coal.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Contingencies	21. Contingencies
	In January 2014, the Illinois Environmental Protection Agency (the “IEPA”) issued Sugar Camp a violation notice regarding construction of an underground injection well without issuance of an appropriate permit (“January Notice”). Sugar Camp is working with the IEPA to finalize its permit application, which has been in process since May 2013. The IEPA has determined not to enter into a compliance commitment agreement with respect to the January Notice and has provided notice to Sugar Camp that the January Notice will be referred to the Illinois Attorney General for enforcement.  While Sugar Camp believes this referral may result in the assessment of a penalty of an amount yet to be determined, there can be no assurances that an acceptable agreement will be reached. Failure to reach a satisfactory agreement with the Illinois Attorney General with respect to the January Notice could result in the assessment of fines or penalties or a suspension of injecting underground at the affected operations until a final resolution is obtained.
	Sugar Camp is working to implement a sustainable solution for the future disposal of water at the mine in compliance with its permits. Sugar Camp expects to incur capital expenditures of approximately $33.0 million, $32.7 million of which has been expended through December 31, 2014.
	In November 2012, six citizens filed requests for administrative review of Revision No. 1 to Permit No. 399 for the Hillsboro mine. Revision No. 1 allowed for conversion of the currently permitted coal refuse disposal facility from a non-impounding to an impounding structure. Shortly after the filing of Revision No. 1, one citizen withdrew his request. Following a hearing on both the Illinois Department of Natural Resources’ (IDNR) and Hillsboro’s motions to dismiss, the hearing officer dismissed the claims of two of the remaining five petitioners and also limited some of the issues remaining for administrative review. In June 2014, two of the remaining three petitioners voluntarily dismissed their requests. A hearing is scheduled for spring 2015 to address all legal issues raised by the remaining petitioner.
	FELLC acquired the Shay No. 1 Mine at Macoupin (“Shay Mine”) in 2009. Prior to this acquisition, in 2003, ExxonMobil Coal USA, Inc. (“Exxon”), the prior owner of the Shay Mine, enrolled the mine in the IEPA’s Site Remediation Program (“SRP”) to address some concerns regarding groundwater contamination from the refuse areas. In 2011, Macoupin proposed, and the IEPA accepted, a compliance commitment agreement (“CCA”) with remediation steps designed to respond to the groundwater contamination concerns. Further, in May 2013, Macoupin submitted a corrective action plan (“CAP”) with groundwater modeling to the IEPA to address the long-term compliance and corrective measures planned for the cleanup of groundwater contamination issues. In June 2013, the IEPA referred the CCA to the Illinois Attorney General’s Office for enforcement on the basis that the compliance period for the CCA extended for too long of a period for the IEPA to monitor. The CAP has been approved by the IEPA and Macoupin reached an agreement in principle with the Illinois Attorney General which, upon finalization of a consent decree, will result in the CAP being implemented.   As of December 31, 2014, the Partnership had accrued $6.9 million for this matter as an asset retirement obligation, as it relates to ongoing mining operations at Macoupin. However, there can be no assurance that the ultimate costs will not exceed this amount.
	In addition, in 2013, the IDNR renewed a permit for the Macoupin refuse disposal area. An environmental group has submitted a Request for Administrative Review of this permit renewal and the legal proceeding is ongoing. While the Partnership believes the IDNR decisions on the issuance of the permit for slurry disposal and renewal for existing refuse disposal area were proper, there can be no guarantee that the permit and the revisions to permits will not be vacated or substantially modified, which could result in additional costs or cessation of some or all operations at the mine.
	We are also party to various other litigation matters, in most cases involving ordinary and routine claims incidental to our business. We cannot reasonably estimate the ultimate legal and financial liability with respect to all pending litigation matters. However, we believe, based on our examination of such matters, that the ultimate liability will not have a material adverse effect on our financial position, results of operations or cash flows. As of December 31, 2014, we have $1.2 million accrued, in aggregate, for various litigation matters.
	Performance Bonds
	We had outstanding surety bonds with third parties of approximately $54.8 million as of December 31, 2014 to secure reclamation and other performance commitments. The Partnership is not required to post collateral for these bonds.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	22. Employee Benefit Plans
	The Partnership offers safe harbor 401(k) plans (the “Plans”) for all employees who are eligible to participate. Employees are immediately eligible to participate upon becoming a full-time employee with the Partnership and its subsidiaries and affiliates. The Plans allow for the deferral of all or part of a participant’s compensation, as defined by the Plans, up to the current limits provided by the Internal Revenue Service. The safe harbor matching feature calls for the Partnership to contribute 100% of the first 3% of compensation a participant contributes, and 50% of the next 2% of compensation contributed by the participant. Partnership contributions under the Plans for the years ended December 31, 2014, 2013, and 2012 were $3.1 million, $2.5 million, and $2.4 million, respectively.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Information	23.  Selected Quarterly Financial Information
	A summary of the unaudited quarterly results for the years ended December 31, 2014 and 2013 is presented below:
		For the Year Ended December 31, 2014
		1st Quarter		2nd Quarter			3rd Quarter			4th Quarter
		(In Thousands, Except per Unit Data)
	Coal sales	$	242,723	$	266,677		$	299,964		$	300,040
	Operating income	$	61,520	$	66,174		$	74,357		$	55,005
	Net income	$	31,916	$	30,845		$	46,155		$	30,131
	Net (loss) income attributable to limited partner units (1)	N/A		$	(4,231	)	$	45,366		$	29,057
	Basic and diluted (loss) income per limited partner unit (1)	N/A		$	(0.03	)	$	0.35		$	0.22
		For the Year Ended December 31, 2013
		1st Quarter		2nd Quarter			3rd Quarter			4th Quarter
		(In Thousands, Except per Unit Data)
	Coal sales	$	232,593	$	215,930		$	240,868		$	268,021
	Operating income	$	57,420	$	41,927		$	49,488		$	55,352
	Net income (loss)	$	29,220	$	14,167		$	(57,833	)	$	24,963
	Net income attributable to limited partner units (1)	N/A		N/A			N/A			N/A
	Basic and diluted earnings per limited partner unit (1)	N/A		N/A			N/A			N/A
	-1	Calculated based on net (loss) income attributable to limited partners and limited partner units outstanding, as applicable, subsequent to the IPO on June 23, 2014.
	In the second quarter of 2014, we recorded an early extinguishment of debt loss of $5.0 million due to the early repayment of $210.0 million of principal under our Term Loan (see Note 9).
	In the fourth quarter of 2014, we recorded a charge of $34.7 million to impair certain prepaid royalties with an affiliate (see Note 14).
	In the third quarter of 2013, we recorded a loss of $77.8 million for the early extinguishment of debt which includes $72.1 million in tender costs and fees to redeem the 2017 Senior Notes and the write-off of $5.7 million in unamortized deferred debt issuance costs and the net unamortized debt premium of the extinguished debt (see Note 9).
	In the fourth quarter of 2013, we reversed $4.3 million in discretionary bonuses, which had been accrued ratably during the first three quarters of 2013.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	24. Subsequent Events
	Subsequent events described in Notes 9, 17 and 18.

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation And Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Foresight Energy LP
	Schedule II —Valuation and Qualifying Accounts
	Description	Balance at Beginning of Period		Charged to Costs and Expenses		Charged to Other Accounts		Deductions		Other		Balance at End of Period
		(In Thousands)
	2014
	Reserves deducted from asset accounts:
	Prepaid royalty recoupment reserve	$	—	$	34,700	$	—	$	—	$	—	$	34,700
	Allowance for doubtful accounts		—		—		—		—		—		—
	2013
	Reserves deducted from asset accounts:
	Prepaid royalty recoupment reserve	$	—	$	—	$	—	$	—	$	—	$	—
	Allowance for doubtful accounts		—		—		—		—		—		—
	2012
	Reserves deducted from asset accounts:
	Prepaid royalty recoupment reserve	$	—	$	—	$	—	$	—	$	—	$	—
	Allowance for doubtful accounts		—		—		—		—		—		—

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and loss during the reporting period. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition
	Once mines are in production, coal sales include sales to customers of coal produced and, from time to time, the re-sale of coal purchased from third parties. The Partnership recognizes sales at the time legal title and risk of loss pass to the customer at contracted amounts that are fixed or determinable. For domestic coal sales, this generally occurs when coal is loaded onto railcars at the mine or onto barges at terminals. For coal sales to international markets, this generally occurs when coal is loaded onto an ocean vessel. Quality and weight adjustments are recorded as necessary based on contract specifications as a reduction or increase to coal sales and accounts receivable.
Transportation Expenses	Transportation Expenses
	Costs related to the handling and transporting of coal to the point of sale are included in coal inventory in the consolidated balance sheets. Upon the recognition of the sale, these costs are included in transportation expenses in the consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Partnership considers cash deposits with original maturities of less than three months to be cash and cash equivalents. Cash and cash equivalents are stated at cost, which approximates fair value.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts
	The Partnership evaluates the need for an allowance for uncollectible receivables based on a review of account balances that are likely to be uncollectible, as determined by such variables as customer creditworthiness, the age of the receivables and disputed amounts. Historically, credit losses have been insignificant. At December 31, 2014 and 2013, no allowance was recorded for uncollectible accounts receivable as all amounts were deemed collectible.
Inventories	Inventories
	Inventories are valued at the lower of average cost or market. Parts and supplies inventory consists of spare parts for equipment and supplies used in the mining process. Raw coal represents coal stockpiles that require processing through a preparation plant prior to shipment to a customer. Clean coal represents coal stockpiles that will be sold in their current condition. Coal inventory costs include labor, equipment costs, supplies, transportation costs incurred prior to the transfer of title to customers, depreciation, depletion, amortization and direct mine operating overhead.
Deferred Longwall Costs	Deferred Longwall Costs
	The Partnership defers the direct costs associated with longwall moves, including longwall set-up costs, supplies and refurbishment costs of longwall equipment. These deferred costs are expensed on a units-of-production basis into cost of coal produced (excluding depreciation, amortization and depreciation) over the panel benefited by these costs, which has historically approximated one year.
Prepaid Royalties	Prepaid Royalties
	Prepaid royalties consist of recoupable minimum royalty payments due under various lease agreements entered into by the Partnership. Prepaid royalties expected to be recouped within one year are classified as current assets in the Partnership’s consolidated balance sheets. The Partnership continually evaluates its ability to recoup prepaid royalty balances, which includes, among other factors, assessing mine production plans, sales commitments, future coal market conditions and remaining years available for recoupment. The contractual recoupment periods on the prepaid royalty balances generally range from five to ten years from the date the minimum royalty was paid.
Property, Plant, Equipment and Development, Net	Property, Plant, Equipment and Development, Net
	Property, plant and equipment are recorded at cost. Costs that extend the useful lives or increase the productivity of the assets are capitalized, while normal repairs and maintenance that do not extend the useful life or increase the productivity of the asset are expensed as incurred. Asset retirement obligations for the various assets have been recorded as components of the specific assets to which they relate. Interest costs applicable to major additions are capitalized during the construction period. Interest costs capitalized into property, plant, equipment and development, net for the years ended December 31, 2014, 2013, and 2012, were $5.2 million, $3.6 million, and $19.0 million, respectively. Property, plant and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Machinery and equipment under capital lease agreements are amortized using the straight-line method over the useful lives of the assets given that, in each case, ownership transfers at the end of the lease terms. The cost of acquiring land (subsidence) rights and mineral rights is amortized using the units-of-production method over the mineral reserves benefited by the costs. The estimated useful lives of machinery and equipment, buildings and structures and other categories are as follows:
	Machinery and equipment	3–20 years
	Buildings and structures	3–40 years
	Other	3–20 years
	Costs of developing new mines or significantly expanding the capacity of existing mines are capitalized and amortized using the units-of-production method over the mineral reserves benefited by the development. Costs related to locating coal deposits and evaluating the economic viability of such deposits are expensed as incurred. During the development phase, the Partnership establishes access to the mineral reserves and makes other preparations for commercial production. Development costs principally include clearing land, building roads, sinking shafts, driving slopes and developing refuse areas, ventilation and transportation passageways at the mines. Development costs also include the build-out of the Partnership’s transportation infrastructure. Costs incurred during the development phase are capitalized and proceeds from the incidental sale of coal during development are recorded as a reduction of the related mine development costs. For reporting in the statements of cash flows, cash expended in the investment in mining rights, equipment and development during the development phase is reported net of capitalized coal sales. Mines in development included the first and second longwalls at Sugar Camp through March 1, 2012 and June 1, 2014, respectively, and the first longwall at Hillsboro through September 1, 2012.
Impairment of Depreciable Assets	Impairment of Depreciable Assets
	The Partnership records impairment losses on depreciable assets used in operations when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than their carrying amounts. Impairment losses are measured by comparing the estimated fair value of the impaired asset to its carrying amount. There were no impairment losses recorded during the years ended December 31, 2014, 2013 or 2012.
Debt Issuance Costs	Debt Issuance Costs
	The Partnership capitalizes costs incurred in connection with the issuance of debt and the establishment of credit facilities and capital leasing arrangements. These costs are amortized as an adjustment to interest expense over the life of the borrowing or term of the credit facility using the effective interest method. Amortization expense of $6.1 million, $7.7 million and $8.1 million is included in interest expense for the years ended December 31, 2014, 2013, and 2012, respectively. As of December 31, 2014 and 2013, unamortized debt issuance costs of $24.6 million and $33.6 million, respectively, are included in other assets in the consolidated balance sheets.
Sale-Leaseback Financing Arrangements	Sale-Leaseback Financing Arrangements
	The Partnership is party to two arrangements in which it sold assets to an affiliate and immediately leased those assets back from the affiliates. Because the Partnership had continued involvement in the assets sold, the proceeds received on the sale of the assets were recorded as long-term financing liabilities in our consolidated balance sheets. Under both of these arrangements, the Partnership pays a fixed minimum payment, as well as contingent payments for volumes in excess of the contractual minimum payments. Interest is accrued on the outstanding principal amounts of the financing arrangements using an implied interest rate, which was initially determined at inception of the lease and is adjusted for changes in expected amounts and timing of future payments based on the mine plans. Payments are first applied against accrued interest and any excess is applied against the outstanding principal. The Partnership accounts for such changes by adjusting in the current period, the life-to-date interest previously recorded on the sale-leaseback to reflect the new effective interest rate as if it was applied from the inception of the transaction (i.e., retroactively applied). If there is a material change to the mine plans, the impact of a change in the effective interest rate to the consolidated statements of operations could be significant.
Asset Retirement Obligations	Asset Retirement Obligations
	The Partnership’s asset retirement obligations (“ARO”) consist primarily of spending estimates related to reclaiming surface land, refuse areas, slurry ponds and support facilities at the Partnership’s underground mines in accordance with federal and state reclamation laws as required by each mining permit. These obligations are typically incurred at the time development of a mine commences for underground mines or when construction begins for support facilities, refuse areas and slurry ponds. The Partnership estimates its ARO for final reclamation and mine closure based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and a market risk premium and then discounted at a credit-adjusted, risk-free rate. Upon initial recognition of a liability, a corresponding amount is capitalized as part of the carrying value of the related long-lived asset. Over time, the liability is accreted to its present value and the capitalized cost is amortized over the useful life of the related asset on a units-of-production basis. As changes in estimates occur (such as mine plan revisions, changes in estimated costs or changes in timing of the performance of reclamation activities), the revisions to the obligation and asset are recognized at the appropriate credit-adjusted, risk-free interest rate.
Derivative Financial Instruments	Derivative Financial Instruments
	The Partnership utilizes derivative financial instruments principally to manage exposures to coal prices. The Partnership records the fair value of each instrument as either an asset or liability in the consolidated balance sheets and the change in fair value of each instrument is recorded in the consolidated statements of operations.
	Coal contracts provide for the physical purchase or sale of coal in quantities expected to be used or sold by the Partnership over a reasonable period in the normal course of business, and are not recognized on the consolidated balance sheets.
Fair Value	Fair Value
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at a given measurement date. Valuation techniques used must maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value.
	The hierarchy, as defined below, gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs.
	Level 1 is defined as observable inputs, such as quoted prices in active markets for identical assets.
	Level 2 is defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3 is defined as unobservable inputs in which little or no market data exists, therefore, requiring an entity to develop its own assumptions.
	The carrying value of cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term nature of these instruments.
Variable Interest Entities (VIEs)	Variable Interest Entities (VIEs)
	VIEs are primarily entities that lack sufficient equity to finance their activities without additional financial support from other parties or whose equity holders, as a group, lack one or more of the following characteristics: (a) direct or indirect ability to make decisions, (b) obligation to absorb expected losses or (c) right to receive expected residual returns. VIEs must be evaluated quantitatively and qualitatively to determine the primary beneficiary, which is the reporting entity that has (a) the power to direct activities of a VIE that most significantly impact the VIEs economic performance and (b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The primary beneficiary is required to consolidate the VIE for financial reporting purposes.
	To determine a VIE's primary beneficiary, the Partnership performs a qualitative assessment to determine which party, if any, has the power to direct activities of the VIE and the obligation to absorb losses and/or receive its benefits. This assessment involves identifying the activities that most significantly impact the VIE's economic performance and determine whether it, or another party, has the power to direct those activities. When evaluating whether the Partnership is the primary beneficiary of a VIE, the Partnership performs a qualitative analysis that considers the design of the VIE, the nature of the Partnership’s involvement and the variable interests held by other parties. If that evaluation is inconclusive as to which party absorbs a majority of the entity’s expected losses or residual returns, a quantitative analysis would be performed to determine the primary beneficiary. The income attributable to consolidated variable interest entities is recorded as net income attributable to noncontrolling interests in the consolidated statements of operations.
Income Taxes	Income Taxes
	We are not a taxable entity for federal or state income tax purposes; the tax effect of our activities accrues to the unitholders. While Section 7704(a) of the tax code generally provides that publicly traded partnerships will be treated as corporations for federal income tax purposes, if 90% or more of a partnership’s gross income for every taxable year it is publicly traded consists of “qualifying income,” the partnership may continue to be treated as a partnership for federal income tax purposes (the “Qualifying Income Exception”). Qualifying income includes income and gains derived from the mining, transportation and marketing of minerals and natural resources, such as coal. Other types of qualifying income include interest (other than from a financial business), dividends, gains from the sale of real property and gains from the sale or other disposition of capital assets held for the production of income that otherwise constitutes qualifying income.
	We currently meet the Qualifying Income Exception and expect to continue to qualify prospectively for this exception. As such, each of our unitholders will take into account their respective share of our items of income, gain, loss and deduction in computing their federal income tax liability as if the unitholder had earned such income directly, even if we make no cash distributions to the unitholder. Distributions we make to a unitholder generally will not give rise to income or gain taxable to such unitholder, unless the amount of cash distributed exceeds the unitholder’s adjusted tax basis. Net income for financial statement purposes may differ significantly from taxable income reportable to unitholders as a result of differences between the tax basis and financial reporting basis of assets and liabilities and the taxable income allocation requirements under our partnership agreement. Individual unitholders have different investment basis depending upon the timing and price of acquisition of their partnership units. Furthermore, each unitholder ’s tax accounting methods, which is partially dependent upon the unitholder’s tax position, differs from the accounting methods followed in our consolidated financial statements. Accordingly, the aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each unitholder’s tax attributes in our partnership is not available to us.
	Our tax counsel has provided an opinion that FELP will be treated as a partnership. However, as is customary, no ruling has been or will be requested from the Internal Revenue Service (“IRS”) regarding our classification as a partnership for federal income tax purposes.
	FELLC, its subsidiaries and controlled entities were established as limited liability companies, and thus for federal and, if applicable, state and local income tax purposes, are treated as pass-through entities. Therefore, no provision for income taxes was included in the consolidated financial statements.
Supplemental Cash Flow Information	Supplemental Cash Flow Information
	The following is supplemental information to the statements of cash flows:
		For the Year Ended December 31,
		2014		2013		2012
		(In Thousands)
	Supplemental disclosure of cash flow information:
	Cash interest paid, net of amount capitalized	$	108,517	$	111,043	$	65,127
	Supplemental disclosure of noncash investing and financing activities:
	Noncash member distributions	$	12,187	$	61,990	$	—
	Accrued member distributions	$	—	$	—	$	25,000
	Financing of interest, debt issuance costs and equipment	$	—	$	—	$	14,829
New Adopted Accounting Standards	New Adopted Accounting Standards
	There were no new authoritative accounting pronouncements that had a significant impact on the Partnership’s consolidated financial statements or impacted comparability with prior periods presented.
New Accounting Standards Issued and Not Yet Adopted	New Accounting Standards Issued and Not Yet Adopted
	In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 changes the requirements for reporting discontinued operations by updating the criteria for determining discontinued operations and modifies the disclosure requirements of both discontinued operations and certain other disposals not defined as discontinued operations. ASU 2014-08 is effective for annual and interim periods beginning after December 15, 2014 and we do not expect it will have a material effect on our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, to clarify the principles used to recognize revenue. The guidance is effective for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted. We are in the process of evaluating the effects, if any, the adoption of this guidance will have on our consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management of the entity to evaluate whether there is substantial doubt about the entity’s ability to continue as a going concern. This ASU is effective for the annual reporting period ending after December 15, 2016, with early adoption permitted. This standard is not currently expected to have a material effect on the Partnership's financial statement disclosures, though the ultimate impact will be dependent on the Partnership's financial condition and expected operating outlook.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Estimated Useful Lives of Property Plant and Equipment	The estimated useful lives of machinery and equipment, buildings and structures and other categories are as follows:
	Machinery and equipment	3–20 years
	Buildings and structures	3–40 years
	Other	3–20 years
Supplemental Cash Flow Information	The following is supplemental information to the statements of cash flows:
		For the Year Ended December 31,
		2014		2013		2012
		(In Thousands)
	Supplemental disclosure of cash flow information:
	Cash interest paid, net of amount capitalized	$	108,517	$	111,043	$	65,127
	Supplemental disclosure of noncash investing and financing activities:
	Noncash member distributions	$	12,187	$	61,990	$	—
	Accrued member distributions	$	—	$	—	$	25,000
	Financing of interest, debt issuance costs and equipment	$	—	$	—	$	14,829

Coal_Derivative_Contracts_Tabl

Coal Derivative Contracts (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of (Gain)/Loss on Coal Derivatives	The following is a summary of the unrealized and realized gains recorded on coal derivatives for the years ended December 31, 2014, 2013 and 2012:
		For the Year Ended December 31,
		2014		2013			2012
		(In Thousands)
	Unrealized gain on coal derivatives	$	57,126	$	2,453		$	534
	Realized gain (loss) on coal derivatives		19,204		(61	)		—
	Gain on coal derivatives	$	76,330	$	2,392		$	534

Accounts_Receivable_Tables

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Receivable Net [Abstract]
Schedule of Accounts Receivable	Accounts receivable consists of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Trade accounts receivable	$	72,687	$	54,084
	Other receivables		8,076		4,903
	Total accounts receivable	$	80,763	$	58,987

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consist of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Parts and supplies	$	32,137	$	30,155
	Raw coal		6,200		4,250
	Clean coal		54,065		36,885
	Total inventories	$	92,402	$	71,290

Property_Plant_Equipment_and_D1

Property, Plant, Equipment and Development, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Schedule of Property Plant And Equipment Net Carrying Value	Property, plant, equipment and development, net consist of the following:
		December 31,			December 31,
		2014			2013
		(In Thousands)
	Land, land rights and mineral rights	$	107,348		$	114,058
	Machinery and equipment		1,074,272			984,920
	Machinery and equipment under capital leases		126,401			70,500
	Buildings and structures		230,070			218,037
	Development costs		695,386			619,117
	Other		9,212			8,564
	Property, plant, equipment and development		2,242,689			2,015,196
	Less: accumulated depreciation, depletion and amortization		(769,626	)		(601,122	)
	Property, plant, equipment and development, net	$	1,473,063		$	1,414,074

Accrued_Expenses_and_Other_Cur1

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Accrued Liabilities And Other Liabilities [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Employee compensation, benefits and payroll taxes	$	13,119	$	17,137
	Taxes other than income		5,494		4,270
	Asset retirement obligations		4,207		809
	Royalties (non-affiliate)		2,975		2,999
	Liquidated damages (non-affiliate)		7,315		7,448
	Other		4,492		4,852
	Total accrued expenses and other current liabilities	$	37,602	$	37,515

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of Long-Term Debt and Capital Lease Obligations	Long-term debt and capital lease obligations consist of the following:
		December 31,				December 31,
		2014				2013
		(In Thousands)
	2021 Senior Notes	$	596,213			$	595,795
	Revolving Credit Facility		319,500				259,000
	Term Loan		235,822				444,602
	5.78% longwall financing arrangement		61,628				72,833
	5.555% longwall financing arrangement		61,875				72,187
	Capital lease obligations		85,633				43,180
	Interim longwall financing arrangement		—				31,616
	Total long-term debt and capital lease obligations		1,360,671				1,519,213
	Less: current portion		(44,143	)			(70,034	)
	Long-term debt and capital lease obligations	$	1,316,528			$	1,449,179
Schedule of Senior Notes at the Redemption Prices	Prior to August 15, 2016, we may redeem some or all of the 2021 Senior Notes at a redemption price equal to the sum of the principal amount of the 2021 Senior Notes to be redeemed, plus accrued and unpaid interest, plus the applicable make-whole premium. After August 15, 2016, we may redeem all or a part of the 2021 Senior Notes at the redemption prices (expressed as a percentage of principal) set forth below plus accrued and unpaid interest, if redeemed during the 12-month period commencing on August 15 of the years indicated below:
	Year		Percentage
	2016		105.91%
	2017		103.94%
	2018		101.97%
	2019 and thereafter		100.00%
Schedule of Contractual Maturities of Long Term Debt Principal and Capital Lease Obligations	The following summarizes the contractual principal maturities of long-term debt (excluding unamortized aggregate discounts of $5.7 million) and capital lease obligations as of December 31, 2014:
		Long-Term Debt				Capital Lease Obligations
		(In Thousands)
	2015	$	21,518			$	22,625
	2016		21,518				21,936
	2017		21,518				16,098
	2018		341,018				11,267
	2019		21,518				13,707
	Thereafter		853,663				—
	Total	$	1,280,753			$	85,633
Schedule of Minimum Lease Payments for Capital Lease Obligations	The aggregate amount of minimum lease payments (which includes principal and interest) for capital lease obligations is $96.4 million as of December 31, 2014. Minimum lease payments from 2015 through 2019 are as follows:
	(In Thousands)	2015			2016			2017		2018		2019
	Minimum lease payments	$	26,957		$	24,922		$	17,950	$	12,411	$	14,172

SaleLeaseback_Financing_Arrang1

Sale-Leaseback Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2014
Leases Capital [Abstract]
Schedule of Maturities Expected Principal Payments	The following summarizes the maturities of expected principal payments, based on current mine plans, on the Partnership’s sale-leaseback financing arrangements, and accrued interest at December 31, 2014:
		Sale-Leaseback Financing Arrangements			Accrued Interest
		(In Thousands)
	2015	$	—		$	5,582
	2016		600			—
	2017		1,603			—
	2018		2,761			—
	2019		3,144			—
	Thereafter		185,326			—
	Total	$	193,434		$	5,582
Schedule of Minimum Lease Payments	Minimum payments from 2015 through 2019 are as follows:
	In Thousands	2015		2016			2017		2018		2019
	Minimum lease payments	$	21,000	$	21,000		$	21,000	$	21,000	$	21,000

Contractual_Arrangements_and_O1

Contractual Arrangements and Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Contractual Royalty and Throughput Arrangements
Operating Leased Assets [Line Items]
Summary of Future Lease Minimum Payments	The following presents future minimum payments, by year, required under contractual royalty and throughput arrangements with related entities and third parties as of December 31, 2014:
		Royalties – Third Party		Royalties – Related Party		Transportation Minimums – Third Party		Transportation Minimums – Related Party
		(In Thousands)
	2015	$	2,004	$	57,667	$	28,025	$	42,320
	2016		2,004		57,667		28,025		44,160
	2017		2,004		57,667		20,780		46,080
	2018		2,004		57,667		20,780		48,160
	2019		2,004		57,667		20,780		50,320
	Thereafter		11,189		315,001		44,280		107,440
	Total	$	21,209	$	603,336	$	162,670	$	338,480
Noncancelable Operating Leases
Operating Leased Assets [Line Items]
Summary of Future Lease Minimum Payments	The following presents future minimum lease payments, by year, required under noncancelable operating leases with initial terms greater than one year, as of December 31, 2014:
		Operating Leases – Third Party		Operating Leases – Related Party
		(In Thousands)
	2015	$	3,352	$	105
	2016		2,227		105
	2017		1,428		105
	2018		680		105
	2019		—		100
	Thereafter		—		200
	Total	$	7,687	$	720

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Changes in Carrying Amount of Asset Retirement Obligations	The change in the carrying amount of asset retirement obligations was as follows:
		For the Year Ended December 31,
		2014			2013			2012
		(In Thousands)
	Balance at beginning of period (including current portion)	$	21,225		$	19,449		$	19,967
	Accretion expense		1,621			1,527			1,552
	Adjustments for liabilities incurred or changes in estimates		13,747			625			(1,496	)
	Expenditures for reclamation activities		(1,013	)		(376	)		(574	)
	Balance at end of period (including current portion)		35,580			21,225			19,449
	Less: current portion of asset retirement obligations		(4,207	)		(809	)		(99	)
	Noncurrent portion of asset retirement obligations	$	31,373		$	20,416		$	19,350

RelatedParty_Transactions_Tabl

Related-Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Summary of Affiliate Amounts Included in Condensed Consolidated Balance Sheets	The following table presents the affiliate amounts included in our consolidated balance sheets:
	Affiliated Company		Balance Sheet Location		December 31,				December 31,
					2014				2013
					(In Thousands)
	Foresight Reserves and affiliated entities		Due from affiliates		$	387			$	368
	NRP and affiliated entities		Due from affiliates			187				—
	Total				$	574			$	368
	Foresight Reserves and affiliated entities		Due to affiliates		$	8,730			$	4,521
	NRP and affiliated entities		Due to affiliates			7,148				5,051
	Total				$	15,878			$	9,572
	Foresight Reserves and affiliated entities		Prepaid royalties		$	53,671			$	37,644
	NRP and affiliated entities(1)		Prepaid royalties			11,071				39,801
	Total				$	64,742			$	77,445
	(1) – Prepaid royalties with NRP and affiliated entities is presented net of a $34,700 reserve.
Summary of Expenses (Income) Incurred With Affiliated Entities
	A summary of expenses (income) incurred with affiliated entities is as follows for the years ended December 31, 2014, 2013 and 2012:
		For the Year Ended December 31,
		2014				2013				2012
		(In Thousands)
	Royalty expense – NRP and affiliated entities(1)	$	48,652			$	51,345			$	42,051
	Royalty expense – Foresight Reserves and affiliated entities(1)	$	11,282			$	8,294			$	8,790
	Loadout services – NRP and affiliated entities(1)	$	9,878			$	10,000			$	11,608
	Terminal fees – Foresight Reserves and affiliated entities(2)	$	52,781			$	30,217			$	26,275
	Management and transportation usage fees – Foresight	$	—			$	1,488			$	3,127
	Reserves and affiliated entities(3)
	Administrative fee income – Foresight	$	(256	)		$	(120	)		$	(30	)
	Reserves and affiliated entities(4)
	Principal location in the consolidated statements of operations:
	(1) – Cost of coal produced (excluding depreciation, depletion and amortization)
	(2) – Transportation
	(3) – Selling, general and administrative
	(4) – Other operating income, net

Variable_Interest_Entities_VIE1

Variable Interest Entities (VIEs) (Tables)	12 Months Ended
	Dec. 31, 2014
Variable Interest Entity Nonconsolidated Carrying Amount Assets And Liabilities [Abstract]
Summary of Consolidated VIE Assets and Liabilities	The liabilities recognized as a result of consolidating the VIEs do not necessarily represent additional claims on the general assets of the Partnership outside of the VIEs; rather, they represent claims against the specific assets of the consolidated VIEs. Conversely, assets recognized as a result of consolidating these VIEs do not necessarily represent additional assets that could be used to satisfy claims against the Partnership’s general assets. There are no restrictions on the VIE assets that are reported in the Partnership’s general assets. The total consolidated VIE assets and liabilities reflected in the Partnership’s consolidated balance sheets are as follows:
		December 31,		December 31,
		2014		2013
		(In Thousands)
	Assets:
	Current assets	$	4,939	$	4,386
	Long-term assets		1,554		2,141
	Total assets	$	6,493	$	6,527
	Liabilities:
	Current liabilities	$	10,145	$	5,310
	Long-term liabilities		1,131		157
	Total liabilities	$	11,276	$	5,467

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Net Financial Assets and Liabilities Measured on Recurring Basis	The tables below set forth, by level, the Partnership’s net financial assets and liabilities for which fair value is measured on a recurring basis:
		Fair Value at December 31, 2014
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	61,037		$	—	$	61,037		$	—
	Total	$	61,037		$	—	$	61,037		$	—
		Fair Value at December 31, 2013
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	2,020		$	—	$	2,020		$	—
	Liability Award		(11,700	)		—		—			(11,700	)
	Total	$	(9,680	)	$	—	$	2,020		$	(11,700	)
Fair Value of Gross Financial Assets and Liabilities Measured on a Recurring Basis	The classification and amount of the Partnership’s financial instruments measured at fair value on a recurring basis, which are presented on a gross basis in the consolidated balance sheets as of December 31, 2014 and 2013, are as follows:
		Fair Value at December 31, 2014
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	36,080		$	24,957	$	—		$	—
	Total	$	36,080		$	24,957	$	—		$	—
		Fair Value at December 31, 2013
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	1,976		$	912	$	(531	)	$	(337	)
	Liability Award		—			—		(11,700	)		—
	Total	$	1,976		$	912	$	(12,231	)	$	(337	)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Table Text Block	The following is a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the years ended December 31, 2014 and 2013:
		Liability Award
		(In Thousands)
	Balance at January 1, 2014	$	11,700
	Recorded fair value losses (gains):
	Included in earnings		690
	Purchases, issuances and settlements		(12,390	)
	Balance at December 31, 2014	$	—
	Balance at January 1, 2013	$	—
	Recorded fair value losses (gains):
	Included in earnings		677
	Capitalized into development costs		(217	)
	Purchases, issuances and settlements		11,240
	Balance at December 31, 2013	$	11,700

Partners_Capital_Tables

Partners' Capital (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Schedule of Percentage Allocations of Available Cash from Operating Surplus	The following table illustrates the percentage allocation of available cash from operating surplus between the unitholders and our general partner (as the holder of our IDRs) based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of the IDR holder and the unitholders of any available cash from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution Per Common Unit”. The percentage interests shown for our unitholders and our general partner for the MQD are also applicable to quarterly distribution amounts that are less than the MQD.
	The percentage interests set forth below assumes there are no arrearages on common units.
		Total Quarterly Distribution	Marginal Percentage
		Per Common Unit	Interest in Distributions
			Unitholders			General Partner (IDRs)
	Minimum quarterly distribution	$0.34		100	%		—
	First target distribution	Above $0.3375 up to $0.3881		100	%		—
	Second target distribution	Above $0.3881 up to $0.4219		85	%		15	%
	Third target distribution	Above $0.4219 up to $0.5063		75	%		25	%
	Thereafter	Above $0.5063		50	%		50	%

EquityBased_Compensation_Table

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Non-vested LTIP Award Activity	A summary of LTIP award activity for the year ended December 31, 2014 is as follows:
		Number of Units			Weighted Average Grant Date Fair Value per Unit
	Non-vested grants at January 1, 2014		-		$	-
	Granted		757,021		$	19.99
	Vested		(146,162	)	$	20
	Forfeited		(9,750	)	$	20
	Non-vested grants at December 31, 2014		601,109		$	19.99

Earnings_per_Limited_Partner_U1

Earnings per Limited Partner Unit (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit	The following table illustrates the Partnership’s calculation of net income per common and subordinated unit for the period indicated:
		Common Unitholders		Subordinated Unitholders		Total
	Year Ended December 31, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income subsequent to IPO available to limited partner units	$	35,154	$	35,038	$	70,192
	Denominator:
	Weighted-average units to calculate basic EPU		64,790		64,739		129,529
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,790		64,739		129,529
	Basic net income per unit	$	0.54	$	0.54	$	0.54
	Diluted net income per unit	$	0.54	$	0.54	$	0.54
	(1) -	Diluted EPU gives effect to all dilutive potential common units outstanding during the period using the treasury stock method. Diluted EPU excludes all dilutive potential units calculated under the treasury stock method if their effect is anti-dilutive. For the year ended December 31, 2014, approximately 0.6 million phantom units were anti-dilutive, and therefore excluded from the diluted EPU calculation.

Risk_Concentrations_Tables

Risk Concentrations (Tables)	12 Months Ended
	Dec. 31, 2014
Risks And Uncertainties [Abstract]
Schedules of Risk Concentrations	For the years ended December 31, 2014, 2013 and 2012, the following customers exceeded 10% of total coal sales:
		For the Year Ended December 31,
		2014		2013	2012
		(Percentage of Total Coal Sales)
	Customer A		11%	(A)		14%
	Customer B		12%	(A)	(A)
	Customer C	(A)		(A)		10%
	(A) – Less than 10% of total coal sales for this period.

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Information	A summary of the unaudited quarterly results for the years ended December 31, 2014 and 2013 is presented below:
		For the Year Ended December 31, 2014
		1st Quarter		2nd Quarter			3rd Quarter			4th Quarter
		(In Thousands, Except per Unit Data)
	Coal sales	$	242,723	$	266,677		$	299,964		$	300,040
	Operating income	$	61,520	$	66,174		$	74,357		$	55,005
	Net income	$	31,916	$	30,845		$	46,155		$	30,131
	Net (loss) income attributable to limited partner units (1)	N/A		$	(4,231	)	$	45,366		$	29,057
	Basic and diluted (loss) income per limited partner unit (1)	N/A		$	(0.03	)	$	0.35		$	0.22
		For the Year Ended December 31, 2013
		1st Quarter		2nd Quarter			3rd Quarter			4th Quarter
		(In Thousands, Except per Unit Data)
	Coal sales	$	232,593	$	215,930		$	240,868		$	268,021
	Operating income	$	57,420	$	41,927		$	49,488		$	55,352
	Net income (loss)	$	29,220	$	14,167		$	(57,833	)	$	24,963
	Net income attributable to limited partner units (1)	N/A		N/A			N/A			N/A
	Basic and diluted earnings per limited partner unit (1)	N/A		N/A			N/A			N/A
	-1	Calculated based on net (loss) income attributable to limited partners and limited partner units outstanding, as applicable, subsequent to the IPO on June 23, 2014.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation - Additional Information (Details) (Foresight Energy LLC)	12 Months Ended
	Dec. 31, 2014
Foresight Reserves, LP
Schedule Of Organization And Basis Of Presentation [Line Items]
Ownership percentage prior to 6/23/2014	99.33%
Member of Management
Schedule Of Organization And Basis Of Presentation [Line Items]
Ownership percentage prior to 6/23/2014	0.67%

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Allowance recorded for uncollectible accounts receivable	$0	$0
Prepaid royalties, description	Prepaid royalties consist of recoupable minimum royalty payments due under various lease agreements entered into by the Partnership. Prepaid royalties expected to be recouped within one year are classified as current assets in the Partnershipbs consolidated balance sheets.
Interest costs capitalized in to property, plant, equipment and development, net	5,200,000	3,600,000	19,000,000
Impairment losses recorded	0	0	0
Amortization expense included in interest expense	6,100,000	7,700,000	8,100,000
Unamortized debt issuance cost	24,600,000	33,600,000
Provision for income taxes	$0	$0	$0
New adopted accounting standards, description	There were no new authoritative accounting pronouncements that had a significant impact on the Partnershipbs consolidated financial statements or impacted comparability with prior periods presented
Maximum
Summary Of Significant Accounting Policies [Line Items]
Prepaid royalties, contractual recoupment period	10 years
Maximum | Cash and Cash Equivalents
Summary Of Significant Accounting Policies [Line Items]
Cash deposits with original maturities	3 months
Minimum
Summary Of Significant Accounting Policies [Line Items]
Prepaid royalties, contractual recoupment period	5 years

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Estimated Useful Lives of Property Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2014
Machinery and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Machinery and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	20 years
Building and Structures | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Building and Structures | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	40 years
Other | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Other | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, estimated useful lives	20 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Aug. 23, 2013	31-May-14	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental disclosure of cash flow information:
Cash interest paid, net of amount capitalized			$108,517	$111,043	$65,127
Supplemental disclosure of noncash investing and financing activities:
Noncash member distributions	62,000	12,200	12,187	61,990
Accrued member distributions					25,000
Financing of interest, debt issuance costs and equipment					$14,829

Initial_Public_Offering_Additi

Initial Public Offering - Additional Information (Details) (USD $)	0 Months Ended	12 Months Ended	1 Months Ended
	Jun. 23, 2014	Dec. 31, 2014	Jul. 31, 2014
Initial Public Offering [Line Items]
Maximum IDR holder marginal percentage interest in distributions	50.00%
IDR quarterly distribution per unit distribution threshold	$0.39
Partnership units issued to public	17,500,000
Partnership units issue price per unit	$20
Proceeds from issuance of common units (net of underwriters' discount)	$329,900,000	$329,875,000
Underwriters discount	20,100,000
Proceeds from sale of common units used to pay reserve and members	115,000,000
Additional offering costs, partners capital		7,100,000
Over allotment units issued			2,625,000
Common Units
Initial Public Offering [Line Items]
Number of common units issued to Foresight Reserves and a member of management	44,613,895
Subordinated Units
Initial Public Offering [Line Items]
Number of common units issued to Foresight Reserves and a member of management	64,738,895
Term Loan
Initial Public Offering [Line Items]
Proceeds from sale of common units used to repay term loan	$210,000,000
Shares Held by Public
Initial Public Offering [Line Items]
Partnership interest owned			13.50%
Foresight Energy GP LLC | Foresight Reserves, LP
Initial Public Offering [Line Items]
Partnership interest owned	99.33%
Foresight Energy GP LLC | Foresight Reserves Management
Initial Public Offering [Line Items]
Partnership interest owned	0.67%

Coal_Derivative_Contracts_Addi

Coal Derivative Contracts - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	T	T
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Outstanding coal derivative contracts	3,400,000	2,000,000
Proceeds from settlement of derivatives	$7.30	$1

Coal_Derivative_Contracts_Summ

Coal Derivative Contracts - Summary of (Gain)/Loss on Coal Derivatives (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments Gain Loss [Line Items]
Unrealized gain on coal derivatives	$57,126	$2,453	$534
Gain on coal derivatives	76,330	2,392	534
Coal Derivative Contracts
Derivative Instruments Gain Loss [Line Items]
Unrealized gain on coal derivatives	57,126	2,453	534
Realized gain (loss) on coal derivatives	19,204	-61
Gain on coal derivatives	$76,330	$2,392	$534

Accounts_Receivable_Schedule_o

Accounts Receivable - Schedule of Accounts Receivable (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Receivable Net [Abstract]
Trade accounts receivable	$72,687	$54,084
Other receivables	8,076	4,903
Total accounts receivable	$80,763	$58,987

Inventories_Schedule_of_Invent

Inventories - Schedule of Inventories (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory [Line Items]
Parts and supplies	$32,137	$30,155
Inventories	92,402	71,290
Raw coal
Inventory [Line Items]
Coal	6,200	4,250
Clean coal
Inventory [Line Items]
Coal	$54,065	$36,885

Property_Plant_Equipment_and_D2

Property, Plant, Equipment and Development, Net (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property Plant And Equipment [Abstract]
Land, land rights and mineral rights	$107,348	$114,058
Machinery and equipment	1,074,272	984,920
Machinery and equipment under capital leases	126,401	70,500
Buildings and structures	230,070	218,037
Development costs	695,386	619,117
Other	9,212	8,564
Property, plant, equipment and development	2,242,689	2,015,196
Less: accumulated depreciation, depletion and amortization	-769,626	-601,122
Property, plant, equipment and development, net	$1,473,063	$1,414,074

Accrued_Expenses_and_Other_Cur2

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accrued Liabilities And Other Liabilities [Abstract]
Employee compensation, benefits and payroll taxes	$13,119	$17,137
Taxes other than income	5,494	4,270
Asset retirement obligations	4,207	809	99
Royalties (non-affiliate)	2,975	2,999
Liquidated damages (non-affiliate)	7,315	7,448
Other	4,492	4,852
Total accrued expenses and other current liabilities	$37,602	$37,515

LongTerm_Debt_and_Capital_Leas2

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Capital lease obligations	$85,633	$43,180
Total long-term debt and capital lease obligations	1,360,671	1,519,213
Less: current portion	-44,143	-70,034
Long-term debt and capital lease obligations	1,316,528	1,449,179
2021 Senior Notes
Debt Instrument [Line Items]
Long-term debt	596,213	595,795
Term Loan
Debt Instrument [Line Items]
Long-term debt	235,822	444,602
5.78% longwall financing arrangement
Debt Instrument [Line Items]
Long-term debt	61,628	72,833
5.555% longwall financing arrangement
Debt Instrument [Line Items]
Long-term debt	61,875	72,187
Interim longwall financing arrangement
Debt Instrument [Line Items]
Long-term debt		31,616
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$319,500	$259,000

LongTerm_Debt_and_Capital_Leas3

Long-Term Debt and Capital Lease Obligations (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2010	31-May-10
2021 Senior Notes
Debt Instrument [Line Items]
Debt instrument maturity year	2021	2021
Debt instrument interest percentage	7.88%
5.78% longwall financing arrangement
Debt Instrument [Line Items]
Debt instrument interest percentage	5.78%	5.78%	5.78%
5.555% longwall financing arrangement
Debt Instrument [Line Items]
Debt instrument interest percentage	5.56%	5.56%		5.56%

LongTerm_Debt_and_Capital_Leas4

Long-Term Debt and Capital Lease Obligations - Additional Information (Details) (USD $)

12 Months Ended

0 Months Ended

1 Months Ended

3 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Aug. 23, 2013

Aug. 31, 2013

Sep. 30, 2013

Jun. 30, 2014

Jan. 31, 2010

31-May-10

31-May-14

Jan. 13, 2015

Nov. 30, 2014

Nov. 30, 2013

Payments

Payments

Tranche

Debt Instrument [Line Items]

Loss on early extinguishment of debt

$4,681,000

$5,625,000

Unamortized debt discount cost

5,700,000

Capital lease obligations

85,633,000

43,180,000

Amount of fees recorded in loss on early extinguishment of debt

-4,979,000

-77,773,000

Minimum lease payments, total

96,400,000

Revolving Credit Facility, Before amendment

Debt Instrument [Line Items]

Maximum borrowings capacity under credit facility

400,000,000

Revolving Credit Facility

Debt Instrument [Line Items]

Unamortized debt issuance cost written-off

400,000

Maximum borrowings capacity under credit facility

500,000,000

Credit agreement maturity Period

23-Aug-18

Commitment fee

0.50%

Weighted average interest rate

3.50%

3.50%

Outstanding letters of credit

6,500,000

Remaining borrowing capacity under revolving credit facility

174,000,000

Long-term debt

319,500,000

259,000,000

LIBOR | Revolving Credit Facility | Minimum

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

2.50%

LIBOR | Revolving Credit Facility | Maximum

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

3.50%

Base Rate | Revolving Credit Facility | Minimum

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

1.50%

Base Rate | Revolving Credit Facility | Maximum

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

2.50%

2017 Senior Notes

Debt Instrument [Line Items]

Debt instrument interest percentage

9.63%

Payment to redeem debt

600,000,000

Debt instrument maturity year

2017

Loss on early extinguishment of debt

77,300,000

Early repayment of debt, tender cost

72,100,000

72,100,000

Unamortized debt issuance cost written-off

5,200,000

5,700,000

Amount of fees recorded in loss on early extinguishment of debt

77,800,000

2021 Senior Notes

Debt Instrument [Line Items]

Maturity date of borrowings

15-Aug-21

Debt Instrument, face amount

600,000,000

Debt instrument interest percentage

7.88%

Debt instrument maturity year

2021

2021

Senior notes, interest payment term

The interest on the 2021 Senior Notes is due semiannually on February 15 and August 15 of each year.

Unamortized debt discount cost

4,300,000

Debt redemption, description

Prior to August 15, 2016, we may redeem some or all of the 2021 Senior Notes at a redemption price equal to the sum of the principal amount of the 2021 Senior Notes to be redeemed, plus accrued and unpaid interest, plus the applicable make whole premium.

Long-term debt

596,213,000

595,795,000

Term Loan

Debt Instrument [Line Items]

Maturity date of borrowings

23-Aug-20

Debt Instrument, face amount

450,000,000

Debt instrument interest percentage

5.50%

5.50%

Unamortized debt issuance cost written-off

2,800,000

Unamortized debt discount cost

4,500,000

Repayment of long-term debt

210,000,000

Unamortized debt discount balance

1,900,000

Debt instrument, LIBOR floor rate, Minimum

1.00%

Long-term debt

235,822,000

444,602,000

Term Loan | LIBOR

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

4.50%

5.78% longwall financing arrangement

Debt Instrument [Line Items]

Maturity date of borrowings

30-Jun-20

Debt instrument interest percentage

5.78%

5.78%

5.78%

Number of equal semi annual payments

17

Long-term debt

61,628,000

72,833,000

5.555% longwall financing arrangement

Debt Instrument [Line Items]

Maturity date of borrowings

30-Sep-20

Debt instrument interest percentage

5.56%

5.56%

5.56%

Number of equal semi annual payments

17

Long-term debt

61,875,000

72,187,000

5.4% to 6.3% Capital Lease Obligations

Debt Instrument [Line Items]

Capital lease obligations

30,500,000

Commencement date

This interim longwall finance agreement was converted into six individual leases with maturities of four and five years beginning on September 1, 2012

5.4% to 6.3% Capital Lease Obligations | Minimum

Debt Instrument [Line Items]

Capital lease obligations bear interest rate

5.40%

5.4% to 6.3% Capital Lease Obligations | Maximum

Debt Instrument [Line Items]

Capital lease obligations bear interest rate

6.30%

5.762% Capital Lease Obligations

Debt Instrument [Line Items]

Capital lease obligations bear interest rate

5.76%

Capital lease obligations

55,100,000

55,900,000

Termination fees due end of the lease terms

2,800,000

Interim longwall financing arrangement

Debt Instrument [Line Items]

Maximum borrowings capacity under credit facility

63,200,000

Repayment of long-term debt

61,300,000

Long-term debt

31,616,000

Amount of fees recorded in loss on early extinguishment of debt

300,000

Trade Accounts Receivable Securitization Program | Subsequent Event

Debt Instrument [Line Items]

Maturity date of borrowings

12-Jan-18

Maximum borrowings capacity under credit facility

70,000,000

Commitment fee

0.40%

Securitization program receivables

70,000,000

No of tranches

2

Trade Accounts Receivable Securitization Program | Revolving Credit Facility | Subsequent Event

Debt Instrument [Line Items]

Securitization program outstanding

$57,200,000

Trade Accounts Receivable Securitization Program | LIBOR | Subsequent Event

Debt Instrument [Line Items]

Interest rate on borrowings under credit facility

0.80%

LongTerm_Debt_and_Capital_Leas5

Long-Term Debt and Capital Lease Obligations - Summary of Senior Notes at the Redemption Prices Percentage (Details) (2021 Senior Notes)	12 Months Ended
	Dec. 31, 2014
2016
Debt Instrument Redemption [Line Items]
Debt instrument redemption price percentage	105.91%
2017
Debt Instrument Redemption [Line Items]
Debt instrument redemption price percentage	103.94%
2018
Debt Instrument Redemption [Line Items]
Debt instrument redemption price percentage	101.97%
2019 and thereafter
Debt Instrument Redemption [Line Items]
Debt instrument redemption price percentage	100.00%

LongTerm_Debt_and_Capital_Leas6

Long-Term Debt and Capital Lease Obligations - Summary of Contractual Maturities of Long Term Debt Principal and Capital Lease Obligations (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Long-Term Debt
Debt Instrument [Line Items]
2015	$21,518
2016	21,518
2017	21,518
2018	341,018
2019	21,518
Thereafter	853,663
Total	1,280,753
Capital Lease Obligations
Debt Instrument [Line Items]
2015	22,625
2016	21,936
2017	16,098
2018	11,267
2019	13,707
Total	$85,633

LongTerm_Debt_and_Capital_Leas7

Long-Term Debt and Capital Lease Obligations - Summary of Minimum Lease Payments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Capital Leases Future Minimum Payments Due [Abstract]
2015	$26,957
2016	24,922
2017	17,950
2018	12,411
2019	$14,172

SaleLeaseback_Financing_Arrang2

Sale-Leaseback Financing Arrangements - Additional Information (Details) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2009	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Sale Leaseback Transaction [Line Items]
Sale-leaseback financing arrangements		$193,434,000	$193,434,000
Sale-lease back transaction, accrued interest expense		25,136,000	27,645,000
Aggregate amounts of remaining minimum lease payments		310,300,000
Macoupin
Sale Leaseback Transaction [Line Items]
Sale-leaseback transaction, description		In January 2009, Macoupin entered into a sales agreement with WPP, LLC (bWPPb) and HOD, LLC (bHODb) (subsidiaries of Natural Resource Partners LP (bNRPb)) to sell certain mineral reserves and rail facility assets (the bMacoupin Sales Arrangementb). NRP is an affiliate of the Partnership (see Note 14). Macoupin received $143.5 million in cash in exchange for certain mineral reserve and transportation assets
Proceeds from sale-leaseback financing arrangement	143,500,000
Term of noncancelable lease		20 years
Lease renewal terms		5 years
Payments to noncancelable lease		5.4
Payment of lease on sales price rate		8.00%
Additional payments noncancelable lease		0.6
Sale leaseback transaction, quarterly royalty payments		4,000,000
Sale leaseback transaction, annual minimum royalty payments		10,000
Initial lease terms, in years		20 years
Sale-leaseback financing arrangements		143,500,000	143,500,000
Sale-leaseback transaction, imputed interest rate		13.90%	14.20%
Sale-lease back transaction, interest expense		16,300,000	19,600,000	20,600,000
Sale-lease back transaction, accrued interest expense		3,000,000	6,800,000
Sugar Camp
Sale Leaseback Transaction [Line Items]
Sale-leaseback transaction, description		In March 2012, Sugar Camp entered into a sales agreement with HOD for which it received a total of $50.0 million in cash in exchange for certain rail loadout assets (bSugar Camp Sales Agreementb).
Proceeds from sale-leaseback financing arrangement		50,000,000
Term of noncancelable lease		20 years
Lease renewal terms		5 years
Payments to noncancelable lease		1.1
Sale leaseback transaction, quarterly royalty payments		1,300,000
Sale leaseback transaction, annual minimum royalty payments		10,000
Initial lease terms, in years		20 years
Sale-leaseback financing arrangements		50,000,000	50,000,000
Sale-leaseback transaction, imputed interest rate		13.90%	14.30%
Sale-lease back transaction, interest expense		6,400,000	7,200,000	5,400,000
Sale-lease back transaction, accrued interest expense		2,500,000	2,300,000
lessee to recoup excess royalty payments		2 years
Limited declining commercial guaranty		15,000,000
Macoupin Rail Loadout Lease and Rail Loop
Sale Leaseback Transaction [Line Items]
Term of noncancelable lease		99 years
Initial lease terms, in years		30 years
Lease transactions aggregate payments		3
Volume of coal loaded		3,400,000
Sale leaseback transaction, annual rental payments		20,000
Royalty and fees paid		$4,000,000
Macoupin Rail Loop
Sale Leaseback Transaction [Line Items]
Lease transactions aggregate payments		1.5
Macoupin Rail Load-out
Sale Leaseback Transaction [Line Items]
Lease transactions aggregate payments		1.5

SaleLeaseback_Financing_Arrang3

Sale-Leaseback Financing Arrangements - Summary of Maturities Expected Principal Payments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Sale-Leaseback Financing Arrangements
2016	$600
2017	1,603
2018	2,761
2019	3,144
Thereafter	185,326
Total	193,434
Accrued Interest
Accrued Interest, 2015	5,582
Accrued Interest, Total	$5,582

SaleLeaseback_Financing_Arrang4

Sale-Leaseback Financing Arrangements - Schedule of Minimum Lease Payments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases Capital [Abstract]
2015	$21,000
2016	21,000
2017	21,000
2018	21,000
2019	$21,000

Contractual_Arrangements_and_O2

Contractual Arrangements and Operating Leases - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Total rental expenses from operating leases	$16,100,000	$17,000,000	$17,200,000
Contingent rental payments	$9,900,000	$9,900,000	$11,500,000
Minimum
Operating Leased Assets [Line Items]
Minimum royalties recoupable time period against production royalties	5 years
Maximum
Operating Leased Assets [Line Items]
Minimum royalties recoupable time period against production royalties	10 years

Contractual_Arrangements_and_O3

Contractual Arrangements and Operating Leases - Summary of Future Minimum Payments With Relate to Contractual Royalty and Throughput Arrangements (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Royalties | Third Party
Operating Leased Assets [Line Items]
2015	$2,004
2016	2,004
2017	2,004
2018	2,004
2019	2,004
Thereafter	11,189
Total	21,209
Royalties | Related Party
Operating Leased Assets [Line Items]
2015	57,667
2016	57,667
2017	57,667
2018	57,667
2019	57,667
Thereafter	315,001
Total	603,336
Transportation Minimums | Third Party
Operating Leased Assets [Line Items]
2015	28,025
2016	28,025
2017	20,780
2018	20,780
2019	20,780
Thereafter	44,280
Total	162,670
Transportation Minimums | Related Party
Operating Leased Assets [Line Items]
2015	42,320
2016	44,160
2017	46,080
2018	48,160
2019	50,320
Thereafter	107,440
Total	$338,480

Contractual_Arrangements_and_O4

Contractual Arrangements and Operating Leases - Summary of Future Minimum Lease Payments Under Noncancelable Operating Leases (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating Leases - Third Party
Operating Leased Assets [Line Items]
2015	$3,352
2016	2,227
2017	1,428
2018	680
Total	7,687
Operating Leases - Related Party
Operating Leased Assets [Line Items]
2015	105
2016	105
2017	105
2018	105
2019	100
Thereafter	200
Total	$720

Asset_Retirement_Obligations_C

Asset Retirement Obligations - Changes in Carrying Amount of Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation Disclosure [Abstract]
Beginning balance	$21,225	$19,449	$19,967
Accretion expense	1,621	1,527	1,552
Adjustments for liabilities incurred or changes in estimates	13,747	625	-1,496
Expenditures for reclamation activities	-1,013	-376	-574
Ending balance	35,580	21,225	19,449
Less: current portion of asset retirement obligations	-4,207	-809	-99
Noncurrent portion of asset retirement obligations	$31,373	$20,416	$19,350

Asset_Retirement_Obligations_A

Asset Retirement Obligations - Additional Information (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligation risk free interest rate	6.60%	8.80%	7.60%

Coal_Workers_Pneumoconiosis_an1

Coal Workers Pneumoconiosis and Workers Compensation - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Coal Workersb Pneumoconiosis
Defined Benefit Plan Disclosure [Line Items]
CWP and workers' compensation expense	$1.50
CWP liability	1.5
Workers Compensation
Defined Benefit Plan Disclosure [Line Items]
CWP and workers' compensation expense	1.4
CWP liability	$1.10

RelatedParty_Transactions_Addi

Related-Party Transactions - Additional Information (Details) (USD $)	0 Months Ended	12 Months Ended
	Apr. 02, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Prepaid royalty reserve		$34,700,000
Amount paid excess of carrying value of net assets acquired	300,000
Rental fee		16,100,000	17,000,000	17,200,000
Purchase Obligation Period Beyond Obligation		15 days
Purchase of mining supplies from affiliates		18,100,000	14,700,000
New River Royalty, LLC
Related Party Transaction [Line Items]
Operating lease number of leases		2
Lease expiration date		15-Oct-21
Lease renewal terms		5 years
Rental fee		100,000
Purchase of leased properties		3,000
Description of Lessee Leasing Arrangements		Williamson Transport has the option to purchase any property optioned under the leases if Williamson does not perform its purchase obligation within fifteen days of receiving notice of its purchase obligation.
General Partner
Related Party Transaction [Line Items]
Percentage of beneficial interested owned by Cline and affiliates		31.00%
Limited Partners
Related Party Transaction [Line Items]
Percentage of beneficial interested owned by Cline and affiliates		4.00%
Colt LLC
Related Party Transaction [Line Items]
Lease term		10 years
Number of renewals		6
Lessor renewal term		5 years
Lease payment per ton		3.4
Percentage of gross price		8.50%
Ruger LLC
Related Party Transaction [Line Items]
Lease term		10 years
Number of renewals		6
Lessor renewal term		5 years
Lease payment per ton		3.4
Percentage of gross price		8.50%
Ruger LLC | Royalties
Related Party Transaction [Line Items]
Percentage of gross price		8.00%
NRP and Affiliated Entities
Related Party Transaction [Line Items]
Operating lease number of leases		2
Lease expiration date		15-Oct-31
Lease renewal terms		5 years
NRP and Affiliated Entities | Minimum
Related Party Transaction [Line Items]
Lease payment per ton		2.5
Percentage of gross price		8.00%
NRP and Affiliated Entities | Maximum
Related Party Transaction [Line Items]
Lease payment per ton		5.4
Percentage of gross price		9.00%
Seneca Rebuild LLC
Related Party Transaction [Line Items]
Net of cash acquired	3,800,000
Amount paid excess of carrying value of net assets acquired	300,000
Williamson Rail Loadout Facility
Related Party Transaction [Line Items]
Lease payment per ton		1.8
Lease expiration date		12-Mar-18
Lease renewal terms		5 years
Rental fee		$5,000
Williamson Transport
Related Party Transaction [Line Items]
Lease payment per ton		0.25

RelatedParty_Transactions_Summ

Related-Party Transactions - Summary of Affiliate Amounts Included in Condensed Consolidated Balance Sheets (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Related Party Transaction [Line Items]
Due from affiliates	$574		$368
Due to affiliates	15,878		9,572
Prepaid royalties	8,380		6,330
Affiliates
Related Party Transaction [Line Items]
Due from affiliates	574		368
Due to affiliates	15,878		9,572
Prepaid royalties	64,742		77,445
Foresight Reserves and Affiliated Entities | Affiliates
Related Party Transaction [Line Items]
Due from affiliates	387		368
Due to affiliates	8,730		4,521
Prepaid royalties	53,671		37,644
NRP and Affiliated Entities | Affiliates
Related Party Transaction [Line Items]
Due from affiliates	187
Due to affiliates	7,148		5,051
Prepaid royalties	$11,071	[1]	$39,801	[1]
[1]	Prepaid royalties with NRP and affiliated entities is presented net of a $34,700 reserve.

RelatedParty_Transactions_Summ1

Related-Party Transactions - Summary of Affiliate Amounts Included in Condensed Consolidated Balance Sheets (Parenthetical) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Related Party Transactions [Abstract]
Prepaid royalty reserve	$34.70

RelatedParty_Transactions_Summ2

Related-Party Transactions - Summary of Expenses (Income) Incurred With Affiliated Entities (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
NRP and Affiliated Entities
Related Party Transaction [Line Items]
Royalty expense	$48,652	[1]	$51,345	[1]	$42,051	[1]
Loadout services	9,878	[1]	10,000	[1]	11,608	[1]
Foresight Reserves and Affiliated Entities
Related Party Transaction [Line Items]
Royalty expense	11,282	[1]	8,294	[1]	8,790	[1]
Terminal fees	52,781	[2]	30,217	[2]	26,275	[2]
Management and transportation usage fees			1,488	[3]	3,127	[3]
Administrative fee income	($256)	[4]	($120)	[4]	($30)	[4]
[1]	Cost of coal produced (excluding depreciation, depletion and amortization)
[2]	Transportation
[3]	Selling, general and administrative
[4]	Other operating income

Variable_Interest_Entities_VIE2

Variable Interest Entities (VIEs) - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Net income attributable to noncontrolling interests	$3,847,000	$2,236,000	($160,000)
Contractor VIEs
Variable Interest Entity [Line Items]
Net income attributable to noncontrolling interests	400,000	300,000	200,000
Minimum fee received per ton of coal mined or processed	0.01
Maximum fee paid per ton of coal mined or processed	0.02
Variable Interest Entity, Primary Beneficiary | Hillsboro Transport
Variable Interest Entity [Line Items]
Net income attributable to noncontrolling interests	3,800,000	2,000,000
Compensation for operating and maintaining loadout	0.99
Minimum quarterly payment	1,300,000
Variable Interest Entity, Primary Beneficiary | Adena Resources L L C
Variable Interest Entity [Line Items]
Net income attributable to noncontrolling interests	-400,000	-200,000
Compensation for furnishing water	$10,000
VIEs which the Partnership is not the Primary Beneficiary
Variable Interest Entity [Line Items]
Percentage of annual mining supply requirements purchased	90.00%
Initial term of agreement as amended	5 years
Amended agreement term expiration date	2018-04

Variable_Interest_Entities_VIE3

Variable Interest Entities (VIEs) - Summary of Consolidated VIE Assets and Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets
Current assets	$275,265	$186,096
Total assets	1,865,222	1,710,171
Liabilities:
Current liabilities	182,696	194,921
Total liabilities	1,729,539	1,858,287
Variable Interest Entity, Primary Beneficiary
Assets
Current assets	4,939	4,386
Long-term assets	1,554	2,141
Total assets	6,493	6,527
Liabilities:
Current liabilities	10,145	5,310
Long-term liabilities	1,131	157
Total liabilities	$11,276	$5,467

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Fair Value of Net Financial Assets and Liabilities (Details) (Fair Value, Measurements, Recurring, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	$61,037	($9,680)
Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability Award		-11,700
Fair Value, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	61,037	2,020
Fair Value, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total		-11,700
Fair Value, Level 3 | Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability Award		-11,700
Coal Derivative Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Coal derivative contracts	61,037	2,020
Coal Derivative Contracts | Fair Value, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Coal derivative contracts	$61,037	$2,020

Fair_Value_Measures_and_Disclo

Fair Value Measures and Disclosures - Additional Information (Details) (USD $)	0 Months Ended
	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets or liabilities transferred between level 1 and level 2		$0	$0	$0
Fair value of Long-Term Debt (Level III)		1,279,700,000	1,509,200,000
Accrued Expenses and Other Current Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other notes payable		400,000
Other Noncurrent Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other notes payable		3,800,000
Phantom Share Units (PSUs)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability award that was contracted and removed from Level III measurement	$12,400,000
Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate on other notes payable		3.45%

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Fair Value of Gross Financial Assets and Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Current b Coal Derivative Assets	$36,080	$1,976
Long-Term b Coal Derivative Assets	24,957	912
Other Long-Term Liabilities	-5,508	-337
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Current b Coal Derivative Assets	36,080	1,976
Long-Term b Coal Derivative Assets	24,957	912
Accrued Expenses		-12,231
Other Long-Term Liabilities		-337
Fair Value, Measurements, Recurring | Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Accrued Expenses		-11,700
Fair Value, Measurements, Recurring | Coal Derivative Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Current b Coal Derivative Assets	36,080	1,976
Long-Term b Coal Derivative Assets	24,957	912
Accrued Expenses		-531
Other Long-Term Liabilities		($337)

Fair_Value_Measures_and_Disclo1

Fair Value Measures and Disclosures - Fair Value Measurement of Reconciliation of Beginning and Ending Balances for Assets and Liabilities (Details) (Fair Value, Measurements, Recurring, Liability Award, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Measurements, Recurring | Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability balance, beginning	$11,700	$0
Recorded fair value losses (gains):
Included in earnings	690	677
Capitalized into development costs		-217
Purchases, issuances and settlements	-12,390	11,240
Liability balance, ending	$0	$11,700

Partners_Capital_Additional_In

Partners' Capital - Additional Information (Details) (USD $)	0 Months Ended			1 Months Ended			12 Months Ended		0 Months Ended
	Jun. 23, 2014	Apr. 02, 2014	Aug. 23, 2013	Nov. 30, 2014	Aug. 31, 2014	31-May-14	Dec. 31, 2014	Dec. 31, 2013	Feb. 06, 2015	Feb. 25, 2015
						acre
Capital Unit [Line Items]
Minimum quarterly distribution per unit							$0.34
Conversion of common units, description							Subordinated units will convert to common units, on a one-for-one basis, on the first business day after the Partnership has paid the MQD for each of three consecutive, non-overlapping four-quarter periods ending on or after March 31, 2017 and there are no outstanding arrearages on the common units. Notwithstanding the foregoing, the subordination period will end on the first business day after the Partnership has paid an aggregate amount of at least $2.025 per unit (150.0% of the MQD on an annualized basis) on the outstanding common and subordinated units and the Partnership has paid the related distribution on the incentive distribution rights, for any four-quarter period ending on or after March 31, 2015 and there are no outstanding arrearages on the common units.
Percentage paid of MQD required for conversion of subordinated units to common units							150.00%
Aggregate per unit annual distribution amount, for conversion of subordinated units to common units							$2.02
Cash distribution paid				$0.35	$0.03
Cash distribution declared							$0.38
Cash distribution declaration date							6-Feb-15
Cash distribution record date							16-Feb-15
Percentage of ownership interests distributed			100.00%
Noncash member distributions			$62,000,000			$12,200,000	$12,187,000	$61,990,000
Surface land distributed to members						1,900
Distribution paid in cash						100,000
Deemed distribution		300,000
Members deficit balance allocated, pro rata base	104,900,000
Noncontrolling interest in variable interest entity							0	10,120,000
Subsequent Event
Capital Unit [Line Items]
Cash distribution declared									$0.36
Percentage of ownership interests distributed										100.00%
Book Value Of Contributed Assets										$60,000,000

Partners_Capital_Schedule_of_P

Partners' Capital - Schedule of Percentage Allocations of Available Cash from Operating Surplus (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Minimum Quarterly Distribution
Distribution Made To Limited Partner [Line Items]
Total Quarterly Distribution Per Common Unit, maximum	$0.34
Percentage Distributed To Unitholders	100.00%
First Target Distribution
Distribution Made To Limited Partner [Line Items]
Total Quarterly Distribution Per Common Unit, minimum	$0.34
Total Quarterly Distribution Per Common Unit, maximum	$0.39
Percentage Distributed To Unitholders	100.00%
Second Target Distribution
Distribution Made To Limited Partner [Line Items]
Total Quarterly Distribution Per Common Unit, minimum	$0.39
Total Quarterly Distribution Per Common Unit, maximum	$0.42
Percentage Distributed To Unitholders	85.00%
Percentage Distributed to General Partner (IDRs)	15.00%
Third Target Distribution
Distribution Made To Limited Partner [Line Items]
Total Quarterly Distribution Per Common Unit, minimum	$0.42
Total Quarterly Distribution Per Common Unit, maximum	$0.51
Percentage Distributed To Unitholders	75.00%
Percentage Distributed to General Partner (IDRs)	25.00%
Thereafter
Distribution Made To Limited Partner [Line Items]
Total Quarterly Distribution Per Common Unit, maximum	$0.51
Percentage Distributed To Unitholders	50.00%
Percentage Distributed to General Partner (IDRs)	50.00%

EquityBased_Compensation_Addit

Equity-Based Compensation - Additional Information (Details) (USD $)	12 Months Ended	1 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Feb. 05, 2015	Dec. 31, 2014	Jun. 23, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	$5,000,000
Shared-based compensation capitalized	300,000			300,000
Unrecognized share based compensation expense	9,000,000			9,000,000
Weighted average period for recognition of expense	2 years 3 months 18 days
Intrinsic value of non-vested grants	10,100,000			10,100,000
Limited partners cash distributions payable	200,000			200,000
Selling, General and Administrative Expenses
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Partnership's equity-based compensation	63.00%			63.00%
Cost of Coal Sales
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Partnership's equity-based compensation	37.00%			37.00%
Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation award, vesting period	3 years
Awards forfeited	0
LTIP Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate number of common units authorized	7,000,000			7,000,000
Number of units granted	6,200,000			6,200,000
Number of Units, Granted	757,021
Equity-based compensation award, vesting period		3 years
Unrestricted common share issued		46,681
Units settled in cash to settle minimum tax obligations		25,819
Issuance of vested LTIP awards	146,162
Awards forfeited	9,750
LTIP Awards | Common Units | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted			215,954
LTIP Awards | Subordinated Units | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted			215,796
LTIP Awards | Phantom Share Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted		595,075
Issuance of vested LTIP awards		72,500
LTIP Awards | Phantom Share Units (PSUs) | Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted	7,919
LTIC Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation award, vesting period	3 years
Unrestricted common share issued				45,736
Units settled in cash to settle minimum tax obligations				27,926
Awards forfeited	0
LTIC Awards | Award Modification
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accrued expenses and other current liabilities to partners capital					600,000
Compensation expense	$0
LTIC Awards | Phantom Share Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted					154,027

EquityBased_Compensation_Summa

Equity-Based Compensation - Summary of Non-vested LTIP Award Activity (Details) (LTIP Awards, USD $)	12 Months Ended
	Dec. 31, 2014
LTIP Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted	757,021
Number of Units, Vested	-146,162
Number of Units, Forfeited	-9,750
Non-vested grants, Ending	601,109
Weighted Average Grant Date Fair Value per Unit, Granted	$19.99
Weighted Average Grant Date Fair Value per Unit, Vested	$20
Weighted Average Grant Date Fair Value per Unit, Forfeited	$20
Non-vested grants, Ending	$19.99

Earnings_per_Limited_Partner_U2

Earnings per Limited Partner Unit (Details) (Underwriters overallotment)	Jul. 18, 2014
Underwriters overallotment
Incentive Distribution Made To Managing Member Or General Partner [Line Items]
Shares, Issued	2,625,000

Earnings_per_Limited_Partner_U3

Earnings per Limited Partner Unit - Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Distribution Made To Limited Partner [Line Items]
Net income subsequent to IPO available to limited partner units	$70,192
Weighted-average units to calculate basic EPU	129,529
Weighted-average units to calculate diluted EPU	129,529
Basic net income per unit	$0.54
Diluted net income per unit	$0.54
Common Unitholders
Distribution Made To Limited Partner [Line Items]
Net income subsequent to IPO available to limited partner units	35,154
Weighted-average units to calculate basic EPU	64,790
Weighted-average units to calculate diluted EPU	64,790
Basic net income per unit	$0.54
Diluted net income per unit	$0.54
Subordinated Units
Distribution Made To Limited Partner [Line Items]
Net income subsequent to IPO available to limited partner units	$35,038
Weighted-average units to calculate basic EPU	64,739
Weighted-average units to calculate diluted EPU	64,739
Basic net income per unit	$0.54
Diluted net income per unit	$0.54

Earnings_per_Limited_Partner_U4

Earnings per Limited Partner Unit - Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit (Parenthetical) (Details) (Phantom Share Units (PSUs))	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Phantom Share Units (PSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	0.6

Risk_Concentrations_Additional

Risk Concentrations - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Aggregate outstanding trade receivable balance	20.4
Sales Revenue, Net | Geographic Concentration Risk | All Countries
Concentration Risk [Line Items]
Export sales as a percentage of total sales	30.00%	33.00%	44.00%
Sales Revenue, Net | Geographic Concentration Risk | Europe
Concentration Risk [Line Items]
Export sales as a percentage of total sales	26.00%	23.00%	28.00%

Schedules_of_Risk_Concentratio

Schedules of Risk Concentrations (Details) (Sales Revenue, Net, Customer Concentration Risk)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012
Customer A
Concentration Risk [Line Items]
Percentage of total coal sales	11.00%	14.00%
Customer B
Concentration Risk [Line Items]
Percentage of total coal sales	12.00%
Customer C
Concentration Risk [Line Items]
Percentage of total coal sales		10.00%

Schedules_of_Risk_Concentratio1

Schedules of Risk Concentrations (Details) (Parenthetical) (Maximum)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Maximum
Concentration Risk [Line Items]
Percentage of total coal sales	10.00%	10.00%	10.00%

Contingencies_Additional_Infor

Contingencies - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Contingencies [Line Items]
Asset retirement obligations	$35,580,000	$21,225,000	$19,449,000	$19,967,000
Accrued litigation expense	1,200,000
Surety Bond
Loss Contingencies [Line Items]
Outstanding performance bonds	54,800,000
Shay Mine
Loss Contingencies [Line Items]
Asset retirement obligations	6,900,000
Sugar Camp
Loss Contingencies [Line Items]
Expected Capital expenditures under Sugar Camp compliance commitment agreement	33,000,000
Actual spent on capital expenditures to comply with the Sugar Camp compliance commitment agreement	$32,700,000

Employee_Benefit_Plans_Additio

Employee Benefit Plans - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$3.10	$2.50	$2.40
Award Modification
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	100.00%
Defined contribution plan, maximum annual contributions per employee, percent	3.00%
3-5% of compensation
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	50.00%
Defined contribution plan, maximum annual contributions per employee, percent	2.00%

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (Details) (USD $)	3 Months Ended											12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Coal sales	$300,040		$299,964		$266,677		$242,723	$268,021	$240,868	$215,930	$232,593	$1,109,404	$957,412	$845,886
Operating income	55,005		74,357		66,174		61,520	55,352	49,488	41,927	57,420	257,056	204,187	208,251
Net income	30,131		46,155		30,845		31,916	24,963	-57,833	14,167	29,220	139,047	10,517	125,671
Net (loss) income attributable to limited partner units	$29,057	[1]	$45,366	[1]	($4,231)	[1]						$135,200	$8,281	$125,831
Basic and diluted (loss) income per limited partner unit	$0.22	[1]	$0.35	[1]	($0.03)	[1]
[1]	Calculated based on net (loss) income attributable to limited partners and limited partner units outstanding, as applicable, subsequent to the IPO on June 23, 2014.

Selected_Quarterly_Financial_I3

Selected Quarterly Financial Information (Parenthetical) (Details) (USD $)	12 Months Ended		3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2014	Sep. 30, 2013
Quarterly Financial Information Disclosure [Line Items]
Prepaid royalty reserve	$34,700,000
Amount of fees recorded in loss on early extinguishment of debt	-4,979,000	-77,773,000
Reversed discretionary bonuses		4,300,000
Term Loan
Quarterly Financial Information Disclosure [Line Items]
Amount of fees recorded in loss on early extinguishment of debt			5,000,000
Repayment of long-term debt			210,000,000
2017 Senior Notes
Quarterly Financial Information Disclosure [Line Items]
Amount of fees recorded in loss on early extinguishment of debt				77,800,000
Early repayment of debt, tender cost		72,100,000		72,100,000
Unamortized debt issuance costs and net debt premiums written-off		$5,200,000		$5,700,000

Valuation_and_Qualifying_Accou1

Valuation and Qualifying Accounts (Details) (Prepaid Royalty Recoupment Reserve, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Prepaid Royalty Recoupment Reserve
Valuation And Qualifying Accounts Disclosure [Line Items]
Charged to Costs and Expenses	$34,700
Balance at End of Period	$34,700